Hypoxia familiarization training has been an integral part of naval

Transcription

Feasibility Report:
Using the Reduced Oxygen Breathing Device
In the Naval Aviation Survival Training Program
Prepared by Naval Operational Medicine Institute
Task Force 21-04
Submitted 31 August 2004
TF 21-04: ROBD Feasibility Report
Task Force Members
Naval Survival Training Institute Personnel:
LT Anthony Artino, MSC, USNR
Director, Human Performance & Training Technology, Code 022
Task Force Lead
LCDR Adam Michels, MSC, USN
Director, Administration, Code 021
LCDR Mike Prevost, MSC, USN
Director, Safety & Standardization, Code 025
LCDR Dan Patterson, MSC, USN
Director, Operations, Code 023
Mr. Brian Swan
Instructional Designer, Safety & Standardization, Code 025
HM1 Timothy Sudduth, USN
Aerospace Physiology Technician, Human Performance & Training Technology, Code 022
Naval Air Systems Command Personnel:
CDR Rick Mason, MSC, USN
Deputy Director, Aviation, NAVAIR Orlando, Training Systems Division
LCDR Joe Essex, MSC, USN
Assistant Program Manager for Training Systems, PMA-205
Naval Aerospace Medical Research Laboratory Personnel:
CAPT Charles Vacchiano, NC, USN
Director, Biomedical Sciences
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Executive Summary
Hypoxia familiarization training has been an integral part of naval aviation survival training for more
than 50 years. Traditionally, Navy and Marine Corps pilots, flight officers, and enlisted aircrew learn
to recognize the symptoms of hypoxia and treat themselves accordingly while being exposed to
hypobaric conditions in a low pressure chamber (LPC). Recently, a new training device has been
developed that induces hypoxia using mixed gas. This new device, dubbed the reduced oxygen
breathing device (ROBD), simulates the diminished oxygen present at altitude by diluting the inspired
oxygen with nitrogen under sea level conditions. The purpose of this report is to examine the
feasibility of implementing ROBD training in lieu of traditional LPC training.
The ROBD has the potential to be a valuable training tool for teaching aviators to recognize and
recover from hypoxia – a life-threatening, in-flight emergency. Using this device, there is little doubt
that the Naval Aviation Survival Training Program (NASTP) can provide safe and realistic training – to
at least a portion of the Navy and Marine Corps aviation population – that will save lives. Additionally,
the device may be more cost effective than the LPC, particularly when training small groups of
students. That being said, the ROBD does have some inherent limitations that make it an
inappropriate choice for all aviation survival training.
Educationally, there are a number of essential indoctrination training objectives that cannot be
supported using the ROBD. These include oxygen regulator familiarization and problems associated
with changes in barometric pressure (e.g., trapped gas issues). Additionally, due to their
inexperience with flight procedures, ROBD training provides no benefit in authenticity to indoctrination
students. For these two reasons, ROBD training is considered inappropriate for indoctrination
trainees. If this conclusion is accepted as valid, then it follows that as all Aviation Survival Training
Centers (ASTCs) conduct at least some amount of indoctrination training, removal of LPCs from all
training sites is not feasible – unless the fleet is willing to accept the cost of having to send
indoctrination students TAD to receive training at a few designated ASTCs.
Logistically, ROBD training is very man-hour intensive, particularly when compared to LPCs that are
filled to capacity. Additionally, ROBD training takes longer to complete and therefore requires
changes in the daily training schedule. Although most ASTCs could realistically manage the
schedule modifications required to make ROBD training work efficiently in the context of their normal
training day, ROBD training may not be manageable for units that train large numbers of students.
Based on these considerations, it is clear that completely replacing all eight LPCs with ROBDs is not
feasible and would not be in the best interest of fleet operational readiness. However, ROBD training
does offer significant advantages for certain aircrew populations and should be seriously considered
as a valuable training tool for incorporation into portions of the NASTP.
After a thorough analysis of ROBD and traditional LPC training, the following recommendations are
made for implementing ROBD training into the NASTP: (1) Procure a limited number of ROBDs and
begin implementing ROBD training for refresher tactical jet aircrew as soon as aircraft-specific flight
scenarios are completed; (2) Begin developing non-pilot ROBD flight scenarios for refresher tactical
jet flight officers; (3) Do NOT replace traditional LPC training with ROBD training for indoctrination
students; (4) Complete a more detailed analysis of refresher students who do not fly in tactical jet
aircraft to determine specific training recommendations; (5) Begin test and evaluation to determine
feasibility of integrating ROBD into fleet simulators / weapons systems trainers; (6) Once refresher
training has been well established at select ASTCs, complete a full-scale Training Effectiveness
Evaluation to evaluate the relative effectiveness of ROBD and LPC for training refresher students in
hypoxia recognition and recovery; (7) Once refresher training has been well established at select
ASTCs, review curriculum distribution at each ASTC to determine feasibility of standing down
individual LPCs at units that train very few indoctrination students.
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Contents
Task Force Members
Executive Summary
Report Purpose
ROBD Overview
Device Operation
Hypoxia Research Conclusions
Current ROBD Employment
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ii
1
1
1
1
1
Educational Analysis
Historical Perspective
Analysis of Learning Objectives
Authenticity of Training
Educational Conclusions/Recommendations
2
2
2
2
3
Cost Analysis
Manpower and Lifecycle Costs
Cost Savings Using ROBD Exclusively
Realizing Actual Cost Savings
Additional Costs
Fiscal Conclusions
3
3
4
5
5
5
Logistics Analysis
Handling High Student Loads
LPC Functions Other Than Training
Logistical Conclusions
5
5
6
6
Conclusions
Recommendations
References
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7
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Appendix A: NASTP SOP Chapter 20: ROBD Operations
Appendix B: ROBD Development Article
Appendix C: Current ROBD Pilot Study Description
Appendix D: ROBD Pilot Study Results
Appendix E: Educational Analysis and Tables of Objectives
Appendix F: Cost Analysis and NASTP Training Tables
Appendix G: Military Man-hours Article
Appendix H: ROBD Procurement and Implementation Plan
A-1
B-1
C-1
D-1
E-1
F-1
G-1
H-1
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Report Purpose
The purpose of this report is to examine the feasibility of implementing reduced oxygen breathing
device (ROBD) training in lieu of traditional low pressure chamber (LPC) training. This report is
comprised of five sections: (1) a brief overview of the ROBD, including its operation, capabilities, and
current employment; (2) an educational analysis comparing the relative capabilities of the LPC and
ROBD to meet current Naval Aviation Survival Training Program (NASTP) learning objectives; (3) a
cost analysis comparing fiscal and manpower requirements for each training option; (4) an analysis
comparing the logistics required to use the ROBD as an exclusive replacement for the LPC to the
procedures currently in place for operating the LPC; and (5) conclusions and recommendations for
using the ROBD for hypoxia training.
ROBD Overview
Device Operation
The ROBD is a portable device that simulates, at sea level conditions, the rarified atmosphere
present at altitude by adding additional nitrogen to ambient air, thus reducing the partial pressure of
inspired oxygen. The device, which delivers the oxygen/nitrogen gas mixture through a standard
aviator’s oxygen mask, is capable of simulating altitudes from 0 to 43,000 feet. Unlike the LPC, which
seats up to 24 students, the ROBD is designed to train one student at a time. In its current
configuration, the device requires two personnel to operate: one person to control the ascent and
descent of the device and one person to instruct and monitor the student. However, if several
devices are being used in the same location, a qualified instructor can perform instructor duties for up
to four ROBDs, for a minimum staffing requirement of five personnel for four devices (see Appendix A
for a complete description of ROBD standard operating procedures). In contrast to the LPC, the
ROBD is not capable of simulating changes in barometric pressure. Thus, the ROBD cannot be used
to train students to recognize and recover from problems associated with trapped gas in the sinuses,
middle ears, and gastrointestinal tract. Likewise, because the ROBD does not simulate changes in
barometric pressure, the device poses no risk of decompression sickness (DCS). For a more
detailed description of the ROBD, including a history of its design and development, see Appendix B.
Hypoxia Research Conclusions
Initial research with the ROBD focused on demonstrating that the device could induce a controlled
state of hypoxia at sea level in human subjects. This sea level hypoxia paradigm was tested in a
group of flight surgeons and found to reliably reproduce the cognitive and physiologic effects
associated with hypoxia (Sausen, Bower, Stiney, Feigl, Wartman, & Clark, 2003).
After establishing the capability of the ROBD to induce hypoxia, the question of whether or not the
hypoxia experience produced by diluting the inspired oxygen concentration at sea level was the
equivalent of that produced by exposure to simulated altitude in a LPC was addressed. A study by
the Naval Aerospace Medical Research Laboratory was conducted to compare the cognitive,
physiologic, and subjective effects of sea level (ROBD) and reduced barometric pressure (LPC)
induced hypoxia. In brief, the researchers determined that there was no significant difference in any
of the responses to hypoxia produced by the two devices, and they concluded that the objective and
subjective effects of decreasing tissue oxygenation are the same regardless of whether this decrease
is produced at sea level with the ROBD or at reduced barometric pressure with the LPC (Vacchiano,
Vagedes, & Gonzalez, 2004).
Current ROBD Employment
In February of 2004 the Naval Survival Training Institute (NSTI) began a small-scale pilot study using
the ROBD in lieu of the LPC to train refresher students. Although still ongoing, to date NSTI has
trained 34 students using the ROBD in combination with a computer-based flight simulator. During
1
this training, students experience hypoxia while completing a simulated instrument approach and do
so in the context of their flying duties (i.e., while talking to air traffic control, making level speed
changes, and changing aircraft heading). For a complete description of this training and pictures of
the device configuration, see Appendix C.
Following ROBD training, all students complete a 20-question evaluation which asks them to rate the
quality of the training. Thus far, student feedback has been very positive. Of the 34 students trained
with the ROBD, 33 were able to recognize their hypoxia symptoms and recover the aircraft, and all 34
agreed that the ROBD is a valuable training tool for teaching hypoxia recognition and recovery. For a
complete presentation of these results, see Appendix D.
Educational Analysis
Appendix E contains a complete and thorough discussion of all relevant educational issues. An
abridged version of that discussion is provided below. Appendix E also contains tables for each
curriculum and identifies which objectives are and are not supported by LPC and ROBD training.
Low pressure chambers have been a part of Naval Aviation training since World War II. The effects
of altitude-induced hypoxia are well documented; there is little doubt that personally experiencing the
symptoms of acute hypoxia is an important – vital – training requirement for both indoctrination
students and experienced aircrew. Additionally, LPCs provide training in how the gasses trapped
inside of the body react to the pressure changes experienced during changes in altitude (specifically,
the effects on the middle ear, sinuses, and gastrointestinal tract).
Although the training validity of experiencing hypoxia has rarely been called into question, the highly
artificial environment of 18 individuals sitting in an LPC becoming hypoxic all together while
performing non flight-related tasks such as playing “patty-cake” or doing simple math problems has
been frequently cited as an area of training that could be improved. A concept termed “simulator
physiology” or “SimPhys” was initiated that would move the hypoxia portion of the training to a flight
simulator. The ROBD was conceived as a means to that end. To clearly state an important point: the
ROBD was conceived and designed, from the outset, as a device to be used by refresher tactical jet
aircrew, as part of SimPhys training, and not as a stand-alone substitute for LPC training.
Analysis of Learning Objectives
Currently, the LPC is indicated for 11 NASTP curricula and provides training in three broad areas: (1)
oxygen equipment familiarization, (2) trapped gas expansion/contraction effects and procedures, and
(3) hypoxia exposure/procedures. After reviewing each learning objective for each of the courses
(see Appendix E), it was determined that the objectives relating to helmets, masks, and hypoxia
exposure are supported by the ROBD, whereas objectives relating to regulators and trapped gas
issues are not supported.
While the relative supportability of training objectives is fairly clear-cut, assessing the authenticity of
training is a much more subjective consideration. Within this discussion, there are two major issues:
(1) becoming hypoxic while wearing an oxygen mask, and (2) performing “authentic” flight-related
tasks while becoming/experiencing hypoxia. It is believed that the authenticity of training for refresher
tactical jet students should be considered to be quite high; probably higher than that received in
traditional LPC training. Due to their inexperience in flight procedures, ROBD training will provide no
benefit in authenticity to indoctrination students, and if those students will eventually be flying
pressurized aircraft that do not require constant oxygen mask use, the ROBD may actually provide a
significantly reduced authenticity in training. For other communities, there is the combination of the
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requirement for unusual scenarios to “justify” becoming hypoxic while wearing a mask and currently
unidentified/undeveloped simulator-related tasks to be developed that must be considered.
Educational Conclusions/Recommendations
Based on the above discussions (and the complete analysis presented in Appendix E), the following
educationally-focused conclusions and recommendations are made for the implementation of the
ROBD:
1. Authenticity of ROBD training appears to be high for refresher tactical jet aircrew (R1/RP1).
Implement ROBD training for refresher tactical jet aircrew as soon as aircraft-specific flight
scenarios are completed.
2. ROBD training is not appropriate for indoctrination students (N1/NP1, N2/NP5, USN/USAF Joint
Indoctrination, N3/NP3, N4/NP4, N2/NP7, N2/NP8, and NP6). Do NOT replace traditional LPC
training with ROBD training for indoctrination students.
3. Refresher students who do not fly in tactical jet aircraft (R2/RP2 and R4/RP4) may or may not
receive more effective or authentic training using the ROBD. Complete a more detailed analysis
of this audience to determine specific training recommendations.
Cost Analysis
Manpower and Life Cycle Costs
Table F-1 in Appendix F provides a detailed, line-by-line accounting of all costs associated with LPC
and ROBD training. The student numbers provided are based on training data from FY02 (see
Appendix F-2). Because one ROBD is required to train one student, an estimate had to be made for
the number of ROBDs required at each Aviation Survival Training Center (ASTC) to adequately
handle individual unit training loads. Using ASTC averages for the number of students trained per
LPC fight, as well as the number of students trained per month, ROBD device requirements were
estimated for each ASTC. These device requirements do not take into account logistical limitations
(i.e., personnel and time requirements). These issues are discussed in the next section.
An overview of LPC and ROBD operating costs, organized by ASTC, is provided in Table 1.
Table 1
Overview of LPC and ROBD Operating Costs
LPC
Cost of LPC Compared to
Cost of ROBD
(LPC ÷ ROBD)
130,367
1.6
ROBD
Pensacola
$
202,773
$
Cherry Point
$
67,428
$
11,579
5.8
Patuxent River
$
72,270
$
29,501
2.4
Jacksonville
$
89,489
$
42,808
2.1
Norfolk
$
97,998
$
57,376
1.7
Miramar
$
104,971
$
66,052
1.6
Lemoore
$
72,984
$
18,565
3.9
Whidbey Island
$
71,896
$
27,457
2.6
Total Annual Costs
$
779,808
$
383,706
2.0
3
As Table 1 indicates, the total annual cost of operating eight LPCs is two times more expensive than
the cost of operating 30 ROBDs. However, when compared to ROBD training, the cost effectiveness
of LPC training is highly dependent on student load at a particular ASTC. For example, the cost of
running one LPC at Pensacola, which trains an average of 337 students per month in their LPC, is
60% more expensive than the cost of operating eight ROBDs at the same unit. In contrast, the cost
of running one LPC at Cherry Point, which trains an average of 22 students per month in their LPC, is
5.8 times more expensive than the cost of operating two ROBDs at the same unit. Therefore, it can
be said that the cost effectiveness of LPC training is highly dependent on student load, with the cost
effectiveness approaching that of ROBD training only when student load is high. This phenomenon is
the result of manning requirements (particularly inside observer requirements) and high maintenance
overhead associated with LPC training.
Cost Savings Using ROBD Exclusively
Table 2 shows the initial investment needed to purchase 30 ROBDs. This estimate is based on the
equipment required to operate the device in accordance with the current ROBD training paradigm
(see Appendix C). It includes not only the equipment required to run the ROBD (e.g., gas mixer and
regulators) but also the computer equipment necessary to run the flight simulation (e.g., desktop
computer, display, software, and aircraft controls).
Table 2
Initial ROBD Investment Costs
Component
Cost
Units
Total
ROBD Gas Mixer
$ 22,594
30 $
677,820
Gas Regulators
$
722
30 $
21,660
ROBD Case
$
643
30 $
19,290
High Pressure Hoses
$
192
30 $
5,760
Computer
$ 1,637
30 $
49,110
Display
$
900
30 $
27,000
Software
$
30
30 $
900
Comms Suite
$
763
30 $
22,890
Aircraft Controls
$ 2,923
30 $
87,690
Total
$ 30,404
30 $
912,120
Table 3 shows the potential cumulative net savings associated with replacing NSTI’s eight LPCs with
30 ROBDs. This table takes into account annual cost savings linked to using ROBD exclusively, as
well as initial and ongoing ROBD system costs.
Table 3
Cumulative Total Net Savings Using ROBD Exclusively
FY05
1.
FY06
FY07
FY08
FY09
LPC Total Annual Operating Costs
$
779,808
$
803,202
$
827,298
$
852,117
$
877,681
ROBD Total Annual Operating Costs
Annual Gross Savings
$
383,706
$
395,217
$
407,074
$
419,286
$
431,865
$
396,102
$
407,985
$
420,224
$
432,831
$
445,816
Annual Cumulative Savings
$
396,102
$
804,087
$ 1,224,311
$ 1,657,142
$ 2,102,958
2.
$
912,120
$
962,120
$ 1,012,120
$ 1,062,120
$ 1,112,120
$
$
1.
Cumulative ROBD System Costs
Cumulative Total Net Savings
1.
2.
($516,018)
($158,033) $
212,191
595,022
Annual operating costs are adjusted for inflation (3%).
System costs include initial cost of purchasing 30 ROBDs, plus $50,000 worth of annual upgrades.
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990,838
Realizing Actual Cost Savings
Although there is an apparent cost savings associated with replacing the LPCs with ROBDs, only a
portion of this savings would be realized. For example, the savings linked with not having to pay
hazardous duty incentive pay (HDIP) program-wide is $225,000. This represents a real savings.
However, because much of the cost associated with LPC maintenance is government service (GS)
labor, and much of that labor would need to stay in place to maintain other training devices, this
savings may not be fully realized (particularly at units with only one GS employee). For the three
ASTCs that use a commercial contract for operating their LPCs, the cost savings related to not having
to operate the LPC would in fact lower the overall commercial contract cost, and therefore would
represent a real cost savings. Ultimately, because much of the costs connected with both LPC and
ROBD operations are labor costs, the real savings can only be determined once decisions concerning
both government and military manning at each ASTC have been made.
Additional Costs
Every year the Navy incurs an additional cost from injuries sustained during LPC training. For
example, in FY02 there were 193 LPC reactions. These reactions included 10 DCS incidents, 123
ear blocks, 33 sinus blocks, eight tooth problems, and 19 reactions classified as “other.” Because the
severity of these injuries varies widely from injury to injury, it is difficult to estimate an average trainee
incapacitation time. In fact, in some cases there may have been no incapacitation time at all (e.g.,
minor tympanic membrane irritation that can result from an ear block on descent). Likewise, because
NSTI trains a variety of personnel, from young enlisted aircrew candidates to senior flag officers, it is
difficult to estimate the average paygrade of injured students. For these reasons, it is virtually
impossible to calculate an annual cost associated with these injuries. However, LPC injury costs are
real and should be considered when making cost-benefit decisions.
Fiscal Conclusions
Based on the cost analysis presented above, the following fiscal conclusions are made:
1. On paper, ROBD training appears to be more cost effective than LPC training. However, the cost
effectiveness of LPC training approaches that of ROBD training when student load is high.
2. Over five years, there is an apparent cost savings of $990,838 associated with replacing LPCs
with ROBDs. However, only a portion of this savings would be realized since much of the cost is
connected to labor which would need to remain in place.
3. There are additional costs incurred each year from injuries sustained during LPC training.
Although difficult to quantify, these costs should be considered by decision makers.
Logistics Analysis
Handling High Student Loads
A review of table F-1 in Appendix F reveals that although ROBD training may be more cost effective
when compared to LPC training, it is actually more man-hour intensive to operate. According to the
table, it takes approximately 40% more military man-hours to operate 30 ROBDs than to train the
same number of students in eight LPCs. It should be noted that this difference occurs when
comparing the ROBD to training done with partially full LPCs. If all LPCs were filled to capacity, the
man-hours required to train a student in the LPC would drop dramatically and the man-hour disparity
between ROBD and LPC would increase. This affect can be demonstrated by comparing an ASTC
that traditionally trains large numbers of students in their LPC (e.g., ASTC Pensacola) to an ASTC
that trains very few (e.g., ASTC Lemoore). The military man-hours required to run eight ROBDs at
Pensacola is approximately 50% greater than the military man-hours required to train the same
number of students in one LPC. One the other hand, the military man-hours required to run four
5
ROBDs at Lemoore is only 14% greater than the military man-hours required to train the same
number of students in one LPC.
ROBD training is not only more man-hour intensive, it also takes longer to complete, particularly when
training a large class of students. For example, it takes approximately one hour to train 24 students
in one LPC that is filled to capacity. With four ROBDs running at the same time, this same number of
students would take approximately three hours to train. Thus, the primary logistical limitations of
ROBD training are: (1) it is more man-hour intensive than LPC training, and (2) it is difficult to train
large numbers of students in a short amount of time.
For most ASTCs, this man-hour and total time difference between ROBD and LPC training can be
overcome with some minor changes to the daily schedule. For example, instead of training 20
refresher students at ASTC Miramar in the LPC at one time and in one hour, this same group of
students could be split into five groups of four and trained using the ROBD in a “rotating stations” setup. That is, while four students receive their half hour ROBD training module, the other four groups
receive four other half hour course modules (e.g., parachute descent procedures, ejection seats,
parachute landing falls, aviation life support equipment, and personal protective equipment). At the
end of the half hour, the groups rotate through to the next station. In all, this entire block of training
would take approximately 2.5 hours to complete. This block of time is realistic for an afternoon
training session, especially when one considers that an hour or more of time would be saved
elsewhere in the training day by not having to operate the LPC. Logistically, the most difficult part of
this type of scenario is ASTC manning, especially if other training is occurring at the same time (e.g.,
ASTC Miramar traditionally conducts aviation physiology training concurrently with water survival
training, which, by itself, is very man-hour intensive).
As the number of students grows beyond 20, the logistics of ROBD training become difficult, if not
impossible to manage. For example, ASTC Pensacola routinely trains 40 or more Aviation Preflight
Indoctrination (API) students in a given physiology class that is limited, by Naval Aviation Schools
Command, to two days in length. Using the LPC, this group of students is easily handled in a few
hours by splitting the class in two and operating two flights in one day. With eight ROBDs running,
this same group of students would also take about three hours to train, but the logistics would be next
to impossible to manage. Unlike many of the modules in the refresher curriculum that run
approximately one half hour, most of the modules in the indoctrination curriculum are an hour or more
in length. Therefore, the “rotating stations” scenario described above would not be effective.
Additionally, running eight ROBDs at the same time would require, at a minimum, 10 personnel and,
at a maximum, 16 personnel (see the discussion section of Appendix G for a detailed description of
ROBD manning considerations). Add to this the additional four instructors needed to teach the other
stations modules, as well as the additional instructors required to teach concurrent classes (ASTC
Pensacola normally teaches an API and aircrew class simultaneously) and you quickly begin to
exceed the manning currently in place at ASTC Pensacola.
LPC Functions Other Than Training
The LPC is used for functions other than training, including medical evaluation, aviation life support
systems test and evaluation, mishap reenactment, and research (e.g., photorefractive keratotomy).
Of these four functions, medical evaluation flights (type VI flight profiles) are the most common. In
FY02 NSTI ran 30 medical evaluation flights for 33 individuals. These flights are special hypobaric
chamber profiles that are requested by flight surgeons and other medical personnel to medically
evaluate an individual’s adaptability and physical qualification to begin flight training or continue on
flight status. The majority of these medical evaluation flights are requested to evaluate an individual’s
ability to tolerate changes in barometric pressure (e.g., ability to clear one’s ears and/or sinuses).
Because the ROBD is not capable of simulating changes in barometric pressure, it cannot be used for
this purpose. Therefore, if all LPCs were replaced with ROBDs, this capability would be lost.
Logistical Conclusions
Based on the logistics analysis presented above, the following conclusions are made:
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1. ROBD training is very man-hour intensive, particularly when compared to LPCs that are filled to
capacity.
2. ROBD training takes longer to complete and therefore requires changes in the daily training
schedule. The logistics required to make ROBD training work efficiently within the context of a
normal training day are realistically manageable for class sizes of 20 or less but become difficult,
if not impossible, for very large classes (40+).
3. LPCs are used for medical evaluations that normally test an individual’s ability to tolerate changes
in barometric pressure. The ROBD cannot be used for this purpose.
Conclusions
The ROBD has the potential to be a valuable training tool for teaching aviators to recognize and
recover from hypoxia – a life-threatening, in-flight emergency. Using this device, there is little doubt
that the NASTP can provide safe and realistic training – to at least a portion of the Navy and Marine
Corps aviation population – that will save lives. Additionally, the device may be more cost effective
than the LPC, particularly when training small groups of students. That being said, the ROBD does
have some inherent limitations that make it an inappropriate choice for all aviation survival training.
Educationally, there are a number of essential indoctrination training objectives that cannot be
supported using the ROBD. These include oxygen regulator familiarization and problems associated
with changes in barometric pressure (e.g., trapped gas issues). Additionally, due to their
inexperience with flight procedures, ROBD training provides no benefit in authenticity to indoctrination
students. For these two reasons, ROBD training is considered inappropriate for indoctrination
trainees. If this conclusion is accepted as valid, then it follows that as all ASTCs conduct at least
some amount of indoctrination training, removal of LPCs from all training sites is not feasible (see
Table F-3 in Appendix F for training numbers at each ASTC by curricula) – unless the fleet is willing
to accept the cost of having to send indoctrination students TAD to receive training at a few
designated ASTCs.
Logistically, most ASTCs could realistically manage the schedule modifications required to make
ROBD training work efficiently in the context of their normal training day. However, for units that train
very large classes, ROBD training may be impossible to manage without having to lengthen the
training day and/or increase military manpower.
Based on these considerations and the discussions provided in the previous sections of this report, it
is clear that completely replacing all eight LPCs with ROBDs is not feasible and would not be in the
best interest of fleet operational readiness. However, ROBD training does offer significant
advantages for certain aircrew populations and should be seriously considered as a valuable training
tool for incorporation into portions of the NASTP.
Recommendations
After a thorough analysis of ROBD and traditional LPC training, the following recommendations are
made for implementing ROBD training into the NASTP:
1. Procure a limited number of ROBDs and begin implementing ROBD training for refresher tactical
jet aircrew (R1/RP1) as soon as aircraft-specific flight scenarios are completed. The ROBD
equals or exceeds the LPC in meeting objective requirements, and appears to provide a much
greater level of authenticity of training. Emphasis should be placed on eventually completely
replacing traditional LPC training with ROBD for this refresher community. In FY04 NAVAIR
7
PMA-205 allocated $400,000 to procure a limited number of ROBDs for integration into the
NASTP at select ASTCs.
2. Begin developing non-pilot ROBD flight scenarios for refresher tactical jet flight officers. Non-pilot
flight scenarios have already been discussed and will undergo further development once ROBDs
have been procured. These types of scenarios are best developed with fleet input at ASTCs that
service large numbers of refresher tactical jet aircrew.
3. Do NOT replace traditional LPC training with ROBD training for indoctrination students (N1/NP1,
N2/NP5, USN/USAF Joint Indoctrination, N3/NP3, N4/NP4, N2/NP7, N2/NP8, and NP6). The
lack of training in trapped gas issues that would result from eliminating the LPC from
indoctrination courses is considered unacceptable. The ROBD could be used as a classroom
demonstration to illustrate hypoxia onset rates at higher altitudes than experienced in the LPC.
This position has been independently reached by the USAF, who are also in the process of
integrating ROBDs into aviation physiology training for refresher students only. As both the
USN/USAF Joint Indoctrination and the NP6 have joint training implications, these are considered
especially poor candidates for replacement.
4. Complete a more detailed analysis of refresher students who do not fly in tactical jet aircraft
(R2/RP2 and R4/RP4) to determine specific training recommendations. Students in this broad
category will have to be assessed on a more case-by-case basis. As has been demonstrated in
NSTI’s ROBD pilot study, the device is probably more effective and authentic for T-34 instructor
pilots, but could the same be said for a C-130 loadmaster? Closer analysis of specific duties of
individual crew positions on individual aircraft (an analysis that is far beyond the scope of this
discussion) needs to be conducted to determine specific recommendations.
5. Concurrent with ROBD use for tactical jet aircrew at the ASTCs, begin test and evaluation to
determine feasibility of integrating ROBD into fleet simulators / weapons systems trainers. The
ultimate in training realism is the integration of ROBD with fleet simulators (aka, SimPhys). There
are, however, integration issues that must be resolved (i.e., hardware, software, plumbing, and
communications issues), as well as realistic training scenarios that must be developed prior to
use in the fleet. NAVAIR PMA-205 has already begun this process and is currently developing a
simulator integration assessment plan.
6. Once refresher training has been well established at select ASTCs, complete a Training
Effectiveness Evaluation (TEE) to evaluate the relative effectiveness of ROBD and LPC for
training refresher students in hypoxia recognition and recovery. To date, the effectiveness of
ROBD training has undergone a limited assessment with a limited student population. Once
ROBD training has been fully established at select ASTCs, a full-scale TEE should be completed
to compare the educational effectiveness of ROBD versus LPC training. Only then can program
managers make informed decisions about the future direction of hypoxia training.
7. Once refresher training has been well established at select ASTCs, review curriculum distribution
at each ASTC to determine feasibility of standing down individual LPCs at units that train very few
indoctrination students. If a determination is made that ROBD training is in fact more effective for
refresher students, consideration should be given to the possibility of standing down individual
LPCs at ASTCs that train very few indoctrination students. If this option is deemed feasible, a
trade-off will have to be made between the money saved by not having to operate inefficient
LPCs and the additional TAD costs incurred by students who are forced to travel to a few
designated ASTCs.
8
References
Sausen, KP, Bower, EA, Stiney, ME, Feigl, C, Wartman, R, Clark, JB. A closed-loop reduced oxygen
breathing device for inducing hypoxia in humans. Aviat Space Environ Med 2003; 74:1190-1197.
Vacchiano, CA, Vagedes, K, Gonzalez, D. Comparison of the physiological, cognitive and subjective
effects of sea level and altitude-induced hypoxia. Presented at the 2004 Annual Meeting of the
Aerospace Medical Association; May 2004.
9
Appendix A
CHAPTER 20
REDUCED OXYGEN BREATHING DEVICE (ROBD) OPERATIONS
2001.
GENERAL
1.
Function. The Reduced Oxygen Breathing Device (ROBD) provides familiarization training on
emergency procedures necessary as a result of a loss of cabin pressurization, malfunctioning oxygen
equipment and other emergencies that result in the need for supplemental or emergency oxygen. The device
also demonstrates the effects of reduced oxygen levels on the body at a given altitude. The ROBD can be
used as a stand-alone training tool or may be used in conjunction with a flight simulator to train aircraft
specific emergency procedures. In conjunction with a simulator, it can be used to recreate specific mishap
scenarios or near mishap scenarios to provide more realistic training.
2.
Description. The ROBD produces normobaric hypoxia by delivering precise percentages of oxygen
and nitrogen from attached pressurized cylinders or from an oxygen/nitrogen extraction system. It delivers a
precisely controlled gas mixture to an aviator’s oxygen mask to accurately simulate the equivalent oxygen
concentration at altitudes from sea level to over 35,000 feet. The operator, through a computer console,
varies the percentage of oxygen being supplied to the student, thereby controlling simulated ascent rates,
descent rates, and desired altitudes.
2002.
PERSONNEL
1. Minimum Personnel Requirements. A minimum of two personnel are required to operate the device
and perform training. One shall be a designated Aerospace Physiologist and the other an Aerospace
Physiology Technician who is JQR qualified. At least one shall be OOD qualified. One Aerospace
Physiologist may supervise up to four ROBDs as long as all positions are staffed by JQR qualified personnel.
a.
Device Positions/Stations for Staff Personnel. The following required device
positions/stations shall be filled during device operations:
(1)
Officer of the Day (OOD)
(2)
ROBD Instructor
(3)
ROBD Operator
b.
The duties of the OOD and the ROBD Instructor or Operator may be performed by one
individual if that individual is qualified for both positions.
2. Qualifications. All personnel filling the required device positions/stations shall be fully JQR qualified.
Refer to Chapter 5, paragraph 505 of this SOP for qualification guidelines. If personnel under training are
assigned duties for an ROBD position, they shall be under the supervision of a JQR qualifier.
3. Responsibilities. This section covers the duties and responsibilities of the Officer of the Day, ROBD
Instructor, and ROBD Operator.
a.
Officer of the Day (OOD). The OOD is responsible for all phases of ROBD training and shall:
(1)
Be onboard the ROBD training site during ROBD operations.
(2) In the event of an injury, ensure the appropriate information is recorded on a SF 600.
Once the final disposition of the case has been made, complete the appropriate injury reporting procedures
A-1
Appendix A
per this SOP.
b.
ROBD Instructor. The ROBD Instructor shall normally be a designated Aerospace
Physiologist. However, a fully JQR qualified Aerospace Physiology Technician (E-5 or above) may perform
the duties as an ROBD Instructor as long as the OOD and an Aerospace Physiologist is present in the ROBD
training facility.
(1)
The ROBD Instructor is responsible for the safety of the student participating in ROBD
training.
(2) The ROBD Instructor is in charge of the ROBD training being conducted regardless of
the rate/rank of the ROBD Operator. All suggestions given to the Instructor shall be given due consideration
(e.g. treatment suggestions, correcting student problems, etc.).
(3)
The ROBD instructor may be relieved only by the DH or the OOD.
(4)
Prior to beginning a flight, the ROBD Instructor shall:
(a) Ensure that emergency medical personnel are readily available and that the
Medical Treatment Facility (MTF) has been notified.
(b) Ensure that all device positions/stations are staffed by JQR qualified personnel
(personnel under training must be individually observed).
(c)
Ensure that students are medically screened and have a current Aeromedical
(d)
Brief the student on the ROBD flight.
Clearance Notice.
(e) Ensure medical treatment area is ready for training IAW NASTP SOP Appendix E,
paragraph 1 and 4.
(5) During the ROBD flight, the ROBD Instructor is responsible for the conduct of the
ROBD operator (i.e., ascend, descend or select 100% oxygen as appropriate for the training scenario or
emergency). Furthermore, the Instructor is responsible for injured persons until they are disconnected from
the ROBD and turned over to emergency medical personnel.
(6)
Following the ROBD flight, the ROBD Instructor shall:
(a)
Inform the OOD of any emergency as soon as time permits.
(b)
Conduct a debrief of the ROBD flight with the student.
(c)
Ensure that proper training documentation is completed.
(d)
Ensure that training documentation is forwarded to the host ASTC.
(e)
Sign the completed flight log.
c.
ROBD Operator. The ROBD Operator is responsible for operating the ROBD in accordance
with the ROBD Instructor’s instructions and shall:
(1)
Prior to beginning a flight, the ROBD Operator shall:
(a)
Fit the student with an oxygen mask.
A-2
Appendix A
(b)
Perform all preflight checks of the ROBD, helmet, and oxygen mask.
(c)
Notify the duty Medical Officer.
(d)
Conduct student medical screening and ensure that the Aeromedical Clearance
Notice is current.
(2)
During the ROBD flight, the ROBD Operator shall:
(a)
Ascend and descend the ROBD in accordance with the ROBD Instructor’s
(b)
Monitor the student’s blood oxygen saturation.
instructions.
(3)
2003.
1.
Following the ROBD flight, the ROBD Operator shall:
(a)
Ensure that the oxygen mask is cleaned.
(b)
Secure the ROBD and perform post flight procedures.
OPERATING PROCEDURES
ROBD General Safety and Operating Procedures
a.
A Medical Officer shall be notified and shall be available by telephone or electronic pager
during all ROBD training. If unable to directly contact the duty Medical Officer, the local Medical Treatment
Facility (MTF) Emergency Room/Acute Care Clinic shall be advised and directed to inform the duty Medical
Officer of the ROBD operation (record the name of the POC at the MTF in the Flight Log).
b.
The following restrictions apply to personnel participating in ROBD training:
(1)
Terminal altitude shall not exceed 37,000 feet.
(2)
Blood oxygen saturation levels shall never fall below 50%.
(3)
No more than five exposures to simulated altitudes over 15,000 feet per individual in a
24-hour period.
(4) The flight shall be terminated if the student loses consciousness or becomes
incoherent and incapable of performing emergency procedures. Subsequent flights may be performed, but
only after the student has recovered fully (i.e., absence of symptoms and blood oxygen saturation greater
than 95%).
(5)
When ROBD training is provided outside of the ASTC environment, emergency
medical response must be within a four minute response time. Additionally, 100% oxygen shall be available
on site and the medical treatment area shall be IAW the NASTP SOP Appendix E, Paragraphs 1 and 4.
2. ROBD Flight Profiles. Flight profiles can be made to suit the needs of training and shall be
approved by the NASTP Model Manager.
2004. EMERGENCY PROCEDURES
A-3
Appendix A
1. DOR and TTO Requests. A student may request DOR or a TTO at any point during the ROBD
training evolution. Prior to ROBD operations (as part of the pre-brief), a review of the DOR and TTO policy
shall be conducted. Once ROBD operations begin, the ROBD Instructor is tasked with appropriately
assessing and handling these requests using the guidance provided below.
a.
DOR Request: Each request must be assessed and handled appropriately based on both
altitude of the ROBD at the time of request and the urgency of the situation. If a student elects to remove
himself or herself from a ROBD training evolution either verbally or by actions, the following shall be
accomplished:
(1) The ROBD Operator shall immediately stop the ascent/descent of the ROBD and the
ROBD Instructor shall attempt to verbally confirm the student’s desire to be removed from the training
evolution. If a verbal confirmation is not obtained, but the student’s actions indicate a desire to be removed
(for other than medical reasons), the ROBD Instructor shall initially handle the situation as a TTO/potential
DOR.
(2) Once determined that a TTO/potential DOR is occurring, the ROBD Instructor shall
then order the ROBD Operator to perform a 100% oxygen infusion.
b.
TTO request: Each request must be assessed and handled appropriately based on both
altitude of the ROBD at the time of the request and the urgency of the situation. A TTO can be requested
verbally, or by using the “level off” hand signal, or by giving the TTO hand signal. Once a TTO request has
been initiated, the following shall be accomplished:
(1) The ROBD Operator shall immediately stop the ascent/descent rate of the ROBD and
the ROBD Instructor shall attempt to verbally confirm the individual’s TTO desire and nature of the concern.
(2) The ROBD Instructor shall address the concern and implement appropriate procedures
as outlined in this chapter.
(3) If the TTO addresses a legitimate safety concern, the ROBD Instructor (in consultation
with the OOD) shall terminate ROBD training until the safety issue is properly resolved.
2.
Procedures for ROBD Reactions. Different types of reactions may occur during ROBD operations.
Staff personnel (especially the ROBD Instructor and Operator), shall be aware of the procedures to be
followed when an ROBD reaction occurs.
a.
In the event an individual experiences a reaction to the ROBD flight, follow the appropriate
procedure listed below. Additionally, the following must be accomplished:
(1)
Refer the individual to the medical treatment facility, providing documentation on a SF
(2)
Refer to Chapter 4 of this SOP for injury reporting procedures and responsibilities.
600.
b.
shall be used.
Cardiopulmonary Arrest. Standard American Heart Association/Red Cross CPR protocols
c.
Loss of Consciousness. Any loss of consciousness, except for brief periods associated with
the hypoxia demonstration, is considered an extreme medical emergency and should be treated as such by
expediting transportation to an emergency medical treatment facility. Vital signs must be checked constantly,
and CPR initiated if warranted.
d.
Hyperventilation. Hyperventilation can result from apprehension, positive pressure breathing
A-4
Appendix A
and/or hypoxia. Suspected hyperventilation should be treated as follows:
(1)
Encourage the student to slow down their breathing rate (using the “pause breathing
method”).
(2) If consciousness is lost, place the student on the floor in a horizontal position (if
practical) and follow loss of consciousness procedures per this SOP.
e.
ROBD Power Loss
(1)
Remove student’s oxygen mask.
(2)
When power is restored, perform preflight checks prior to resuming the ROBD flight.
f.
Other Medical Emergencies. There is always the possibility for medical
conditions/emergencies not specifically discussed above to occur. The judgment of the ROBD Instructor
must be used in determining the appropriate course of action, given the urgency of the situation. Generally
speaking, if symptoms could be the result of several different conditions, treatment for the “worst case
scenario” should be initiated.
2005.
SITE SPECIFIC ROBD PROCEDURES
This section shall be filled in by the ASTC as appropriate, with DET OIC approval, and reviewed by the
NASTP MM during the annual Training Readiness Assessment. The information/policies in this section
should address site-specific situations and shall not contradict policies of this SOP, the NASTP MM, or higher
authority.
A-5
Appendix B
History, Operation & Scientific Evolution of
the Reduced Oxygen Breathing Device
By
CAPT Chuck Vacchiano
Head, Biomedical Sciences Department
Naval Aerospace Medical Research Laboratory
The value of hypoxia familiarization training has been demonstrated repeatedly in the operational
aviation community. Many lives and countless dollars have been saved as a result of early identification
of the symptoms of hypoxia. The ability of Navy and Marine Corps pilots, flight officers and aircrew to
recognize and respond to this critical in-flight emergency is the direct result of the training provided by
Aerospace Physiologists and Aerospace Physiology Technicians for over 50 years. To date, initial and
refresher hypoxia training has taken place in an altitude chamber whose size and operating requirements
limit the training options available during the hypoxic period. In addition, while the statistical probability of
suffering a significant permanent injury during or following exposure to altitude is low, the possibility does
exist. The “hypoxia threat” and the issues noted above have been detailed in a previous article authored
by HM1 Stephanie O’Brien and LT Anthony Artino.
The idea that hypoxia training could be performed by diluting the inspired concentration of oxygen at
sea level is not new and indeed has been around for at least several decades. Studies designed to
evaluate various physiologic effects of hypoxia, and the description of devices and systems to induce
such, show up sporadically in the aerospace and general scientific literature. The author’s first exposure
to this issue occurred in 1997 following a chance phone conversation with then LCDR Ryan Eichner
(CAPT Ryan Eichner, Retired). CAPT Eichner was attached to the “green side” aviation community at the
time and was inquiring about the ability of engineer’s at the Naval Medical Research Institute (NMRI; now
Naval Medical Research Command) to construct a device that could deliver a hypoxic gas mixture via a
standard aviator’s mask while flying a simulator. A plan was developed for a device that would dilute
inspired oxygen with nitrogen using mass flow controller (MFC) technology. However, the cost of the
development, construction, and testing of the device was greater than the funds available from the Marine
Corps and therefore the device was never built. As fate would have it, a device specifically intended for
use as an aviation hypoxia familiarization training tool was under development at the Naval Aerospace
Medical Research Laboratory (NAMRL) in Pensacola, Florida.
The prototype Reduced Oxygen Breathing
Device (ROBD) was conceived by research
Photo 1
scientists and constructed by engineers and
technicians at NAMRL in 1999 (Photo 1). Early
development and experimentation with the
device was carried out by CDR Eric Bower,
Chief Michael Stiney, LT Ken Sausen, Mr. Rick
Wartman and Mr. Efrain Molina. The first ROBD
incorporated a “closed-loop” design which
required a carbon dioxide scrubber and a bulky
silicone mask with inhalation and exhalation
hoses much like those used for measuring
metabolic rates. The ability of this system to in
fact produce hypoxia was demonstrated in a
group of flight surgeons as detailed below. This
cumbersome system was abandoned in favor of
an “open-loop / non-rebreathing” design with a single hose and use of a standard aviators mask. The
non-rebreathing prototype ROBD consists of a gas mixing container constructed of Schedule 40 polyvinyl
chloride pipe in a loop configuration. A quick-disconnect fitting is mounted on one end of the loop, such
B-1
Appendix B
that a standard aviator’s oxygen mask can be connected exactly as it would be connected in an aircraft.
The other end of the loop is open to the atmosphere via a one-way value. An oxygen sensor is
positioned in the mixing loop in close proximity to the quick disconnect fitting and just downstream from a
mixing fan. The oxygen concentration in the loop, which is displayed in percent (%) and can be
monitored by the operator, is converted from an analog to a digital signal and sent continuously to the
computer controller. A computer program developed at NAMRL using LabView™ software continuously
monitors the concentration of oxygen in the loop just downstream from the mixing fan. At the start of
inspiration, room air is drawn into the loop through the one-way value. The measured percentage of
oxygen in the loop is compared to a target level of oxygen. If the loop oxygen concentration exceeds the
target value, the software controller actuates a solenoid valve connected to a cylinder of nitrogen gas.
When the two values match, the solenoid valve is turned off. Conversely, if the concentration of oxygen
in the mixing loop is below that of the target value, a solenoid valve connected to an oxygen cylinder is
actuated, until again those values are matched. The operator sets the target values by inputting an
ascent rate and ceiling altitude into the computer program. The operator computer interface consists of a
single screen with labeled boxes for entering the desired ascent rate and ceiling altitude and a graphic
that uses line plots to show the desired and actual ascent (in feet per minute) and stability of the final
altitude achieved. In addition, subject oxygen saturation (SaO2) is monitored using a pulse oximeter and
displayed on the computer screen.
Several safety features are built into the ROBD. The first level of safety is the trainee himself. If the
trainee becomes uncomfortable for any reason, the mask can simply be removed and room air will be
immediately inspired. The second level of safety is the observer / operator. If the observer / operator
determines that the subject is in distress, it is possible to manually activate the oxygen solenoid from the
control panel, thereby enabling the observer to flood the circuit with oxygen. Of note, no capability to
manually activate the nitrogen solenoid is present, minimizing the chance for an accidental or inadvertent
release of nitrogen into the loop. Finally, software controls are also incorporated that reduce the chance
for inadvertent hypoxia. The software has programmed limiters that prohibit the oxygen concentration in
the mixing loop from falling below 6% (approximate altitude of 30,000 ft.). If the level of oxygen in the
loop falls below this level, the software disables the solenoids, enabling room air to enter the mask
undiluted by nitrogen. An audible alarm is also incorporated to notify the operator should the inspired
oxygen concentration fall below preset levels. The prototype ROBD weighs approximately 65 lbs. and
requires a 120 volt / 60 Hz electrical source, an external computer and pulse oximeter, and a medical
grade oxygen and nitrogen supply. The oxygen sensor is a consumable element of the system which
requires periodic replacement as a function of time and total oxygen concentration exposure.
Initial research with the ROBD focused on simply demonstrating that the device could produce a
controlled state of hypoxia at sea level in human subjects. This “proof of concept” work examined the
ability of the ROBD to induce the expected changes in blood pressure, pulse, cardiac output, oxygen
saturation and psychomotor performance at simulated altitudes of 10,000, 15,000 and 18,000 feet in the
laboratory setting. This sea level hypoxia paradigm was tested in a group of flight surgeons and found to
reliably reproduce the cognitive and physiologic effects associated with hypoxia. After establishing the
ability of the ROBD to induce hypoxia the question of whether or not the hypoxia experience produced by
diluting the inspired oxygen concentration at sea level was the equivalent of that produced by exposure to
altitude in a hypobaric chamber was addressed. This issue was of great importance to the Aviation
Physiology community and their potential endorsement of the ROBD as a training tool. The seminal
research to address this question was initiated in the fall of 2001 at NAMRL by the author, HM2 David
Gonzalez and Ms. Kristina Vagedes. The study, funded by the Office of Naval Research, was designed
to compare the cognitive, physiologic and subjective effects of sea level and altitude induced hypoxia. An
obvious requirement for this work was access to an altitude chamber and trainee subjects. The project
was embraced by members of the AP community and the entire staff attached to the Aviation Survival
Training Center (ASTC) at NAS Pensacola (NOMI, Det Central) from 2001 to 2002. Personnel
instrumental in making the chamber accessible to the research team were CAPT Donnie Plombon, CDR
Jeff Andrews, Mr. Bill Bower, and LT Brian Bohrer who managed the day to day access to trainees and
chamber runs. Subjects included 70 volunteers from the aircrew training program who were scheduled
for hypoxia familiarization training (Type II flight; 4 min at 25,000 feet). Subjects were enrolled in the study
B-2
Appendix B
on Tuesday mornings prior to the ASTC staff safety briefs. The subjects were instrumented and baseline
physiologic and cognitive performance data were collected. Physiologic data collection included heart
rate and rhythm using signal averaged ECG technology, oxygen saturation via pulse oximetry and a
direct measure of cerebral neural function
using a clinical tool known as the Bispectral
Photo 2
Index (BIS). Cognitive performance was
measured using a portion of the Space
Cognitive Assessment Test (SCAT) battery.
A 4 minute customized version of the
Continuous Performance Test (CPT) portion
of the SCAT battery was graciously provided
by one of the developers, CDR Dan Reeves.
Data was again collected during the 4
minute hypoxia exposure period and 15
minutes following exit from the chamber
(recovery period). On Friday of the week in
which chamber training occurred, subjects
reported to NAMRL and were exposed to 4
minutes of sea level hypoxia via the ROBD
with pre- and post-breathing of 100%
oxygen to duplicate the chamber scenario
(Photo 2). The variables noted above were again measured at baseline, during and after the hypoxia
exposure. In addition, data regarding subjective symptoms of hypoxia were collected following both
exposure conditions. The primary weakness of the study was the inability to randomize subjects to the
initial hypoxia exposure condition (chamber versus ROBD). This was due to a logistical issue limiting
access to the student pool prior to reporting to the ASTC and resulted in a small but distinguishable
training affect in the cognitive performance data set. Both chamber and ROBD generated hypoxia
resulted in the expected decrements in oxygen saturation and cognitive performance and increase in
heart rate compared to baseline. Intensity and type of subjective symptoms reported were also similar
between the two exposure conditions. In brief, we were unable to discern a difference in the cognitive,
physiologic and subjective response to hypoxia produced at simulated altitude as compared to sea level
reduced oxygen breathing. We concluded that the objective and subjective effects of decreasing tissue
oxygenation are the same regardless of whether this decrease is produced at sea level or at altitude.
Percent Oxygen
Of interest was the early observation that subjects exposed to the ROBD had lower oxygen
saturations and they self-terminated the exposure earlier than when exposed to hypoxia in the altitude
chamber. This prompted a series of 10
Photo
measurements of the oxygen partial
Fig
ure 11
Figure
1
pressure (referenced in % O2) in the
Comparison of Chamber, ROBD and Calculated Oxygen
ROBD breathing loop and in the chamber
Concentration During Simulated
Ascent to, and Level Flight at 25,000 Feet
at specific simulated altitudes. The results
of those measurements are seen in figure
30.0
Chamber
1 where average ROBD and chamber
27.5
Calculated
oxygen percentage are plotted against the
ROBD
25.0
calculated sea level oxygen equivalent
22.5
percentage at various altitudes.
This
20.0
graphic demonstrates the fidelity of the
17.5
ROBD as well at the result of both inside
15.0
12.5
observers and trainees prebreathing
10.0
100% oxygen and exhaling into the
7.5
chamber environment (note the elevated
5.0
oxygen percentage above that of room air
Ground 5000 10000 15000 20000 25000
at the start of chamber ascent). The
graphic shows the first 4 minute chamber
Simulated Altitude
hypoxia exposure period (low side
Sea Level Equiv.
O2 Concentration
= 18,000 ft.
Start Hypoxia
B-3
Sea Level Equiv.
O2 Concentration
= 22,000 ft.
4 minutes
End Hypoxia
Appendix B
exposure). The chamber sea level oxygen equivalent percentage continued to decline the during the
“high side” exposure and achieved the sea level equivalent of 25,000 feet at the end of that 4 minute
period (not shown).
Having demonstrated the feasibility of using sea level induced hypoxia as a training tool, the next step
was to move the device from a relatively crude single prototype constructed at NAMRL to a commercially
produced and available product. This initiative resulted in a Cooperative Research and Development
Agreement (CRADA) and licensing agreement with a local commercial aerospace company. At the same
time United States and foreign patents were filed for the ROBD. This first attempt at product
development resulted in the breathing loop technology developed at NAMRL repackaged in a somewhat
more durable and commercially desirable form (Photo 3). A laptop or desktop computer was still required
for operation and an extraneous pulse oximeter for
safety. While this product is currently in use at
Photo 3
NAMRL as a research tool and has recently been
sold commercially on a limited scale, it was not
considered to be sufficiently reliable, durable or “user
friendly” for general use in the fleet. However,
further experience with the device guided the
development of an in depth statement of work (SOW)
with respect to the requirements of a commercially
produced operationally deployable apparatus. The
SOW led to an additional private industry CRADA
and licensing agreement and a major paradigm shift
in the gas mixing technology. The mixing loop, in
which room air is diluted by solenoid controlled
injection of nitrogen gas, was eliminated in favor of
mass flow controller technology.
Mass flow
controllers are specific for a particular gas and
deliver a precise controllable quantity of that gas based on the density and temperature of the gas. The
newest iteration of the ROBD contains mass flow controllers for air and nitrogen. The quantity of gas
exiting the mass flow controllers is so precisely controlled that generation of sea level oxygen equivalent
altitudes by mixing of air and nitrogen can be accomplished without the large reservoir necessary to
dampen changes in oxygen concentration produced by solenoid injection of nitrogen into a breathing
loop. This technology permits extremely rapid changes in altitude (1 second) and is extremely precise
(literally no variation from selected altitude). In addition, the gas mixing apparatus, dubbed the ROBD2,
contains an embedded computer controller and pulse oximeter and is mounted in a shock absorbing
“harding” case. The prototype ROBD2 (Photo 4, Patent Pending) was recently tested and evaluated at
NAMRL, revisions to the SOW were provided
to the manufacturer and the commercial
Photo 4
version is expected to be available for
purchase by the end of the current fiscal year.
Unique features of the ROBD2 include onboard computer control, 20 programmable
“flight” profiles with manual override or manual
control, production of sea level oxygen
equivalents up to 43,000 feet MSL, the ability
to perform standard hypoxia familiarization
training (25,000 feet) with a positive pressure
breathing experience (up to 20 inches of
water) and the ability to interface with a
simulator and provide graded positive
pressure to the breathing mask above 30,000
feet. A hybrid gas extraction system is currently being developed to produce medical grade air and
nitrogen from room air using molecular sieve technology (Photo 5). The ROBD2 will be capable of using
compressed gas cylinders or the gas extraction system (when available) for operation.
B-4
Appendix B
The ROBD is currently being used in multiple research projects at NAMRL and has widespread interest
from diverse organizations including the Air Force, private industry, universities, the Federal Aviation
Administration, and the general medical community. In February of 2004, the Naval Survival Training
Institute deployed an ROBD pilot curriculum and trained its first aviator using the ROBD in lieu of the
altitude chamber. For questions about the device or current research initiatives please contact CAPT
Chuck Vacchiano at 850-452-3287, ext. 1153 or LCDR Merrill Rice at 850-452-3287, ext. 1168.
Photo 5
B-5
Appendix C
Slide 1
Navy Hypoxia Training
using the
Reduced Oxygen
Breathing Device (ROBD)
LT Anthony Artino
Director, Human Performance & Training Technology
Naval Survival Training Institute
This short brief provides an overview of current reduced oxygen breathing device (ROBD)
hypoxia training.
To date, 34 refresher pilots have been trained using the ROBD in lieu of the low pressure
chamber (LPC).
C-1
Appendix C
Slide 2
Overview
• Why use the ROBD?
• Authorization to use the device
• Current ROBD pilot curriculum
– Setup
– Training scenario
This brief includes:
-
A quick review of why the ROBD might be a useful training tool within the Naval Aviation
Survival Training Program (NASTP);
-
A discussion of the authorization to use the ROBD in NASTP training;
-
A review of the current ROBD setup and training scenario.
C-2
Appendix C
Slide 3
Why use the ROBD?
Safer & More
Reliable
•
Reliably produced hypoxia with very few health risks;
specifically, no chance for DCS or barotrauma;
•
More accurately simulate hypoxic conditions at altitude;
Improved
Instructional Realism
Advantages of ROBD over Low Pressure Chamber
for Refresher Students
•
Induce hypoxia in students while wearing an oxygen mask
and while performing actual in-flight duties;
•
Operate the device anywhere, including inside a fleet
simulator/weapons system trainer;
•
Ultimately, integrate hypoxia with performance of in-flight
emergency procedures to counter the threat.
The ROBD might be more appropriate training for REFRESHER students (i.e. experienced
aviators who have been through the LPC at least once before).
NASTP decompression sickness incidence rates for Type II Flights:
Students -
0.229%
Inside Observers -
0.328%
The risk is low, but it is still a real risk (especially if you are one of the people to get bent).
In the past two years, Naval Aviation has seen a rash of hypoxia incidents in aviators wearing
oxygen masks. These incidents have occurred primarily in the F/A-18 community in aircraft using
onboard oxygen generating systems (OBOGS). The old concern about “we don’t want to get
people hypoxic while wearing a mask because that’s negative training” may no longer be valid
(particularly in the jet community).
Operating the device IN a simulator is one of the big ticket items that could bring us closer to the
“train like you fight” paradigm. Operating the device in a simulator also allows us to add
something new to our hypoxia training – it gives aviators the opportunity to get hypoxic and then
practice their actual aircraft-specific emergency procedures to counter the threat.
C-3
Appendix C
Slide 4
A Training Continuum
ROBD & Laptop
ROBD & Fleet
Simulator
Low Pressure
Chamber
High
Low
Improving Instructional Realism
ROBD & PC-Based
Flight Simulator
Current and future hypoxia training can be thought of as falling along a continuum of instructional
realism. To the left is where we are today with our LPC training (with realism being somewhat
low). Next to it is where we are today with ROBD training and a laptop simulator (with realism
being somewhat higher). Further to the right is where we might be able to go within our ASTCs,
using a PC-based flight simulator (with realism getting even better). Finally, all the way to the
right is where we would ultimately like to go – using ROBD inside a fleet simulator.
C-4
Appendix C
Slide 5
Authorization to use ROBD
in lieu of the Low Pressure Chamber
This is Appendix E of OPNAVINST 37107T, which is our requirements document. Chapter 8
specifically discusses the NASTP, and Appendix E describes the various program modules.
Module C is LPC training and there is a line in that description which says “ROBD training, when
available, can be substituted for the LPC flight.” This one line allowed us to begin using the
ROBD in NASTP training.
C-5
Appendix C
Slide 6
Authorization to use ROBD
in lieu of the Low Pressure Chamber
• Naval Aviation Survival Training Program
(NASTP) Standard Operating Procedures (SOP)
– SOP Chapter 20: ROBD Operations
• Minimum personnel requirements - Officer of the Day, ROBD
Instructor, ROBD Operator
• Limits on terminal altitude, minimum O2 sat, and maximum
exposures in a 24 hour period
• NASTP Job Qualification Requirements (JQR)
– Tasks you must complete and knowledge/skills you
must have before being qualified to operate the ROBD
Before we could train our first student, we needed an SOP chapter and a Job Qualification
Requirements (JQR) document.
C-6
Appendix C
Slide 7
ROBD Setup
NASTP Pilot Curriculum
This photo shows the current configuration of our ROBD training.
Specific pieces of equipment and personnel include: the ROBD mixer (black box), small oxygen
and nitrogen tanks (green bag), ROBD Operator (right side of photo), ROBD Instructor (center of
photo), trainee (left side of photo), and communications system, which provides two-way
communications between all personnel.
C-7
Appendix C
Slide 8
ROBD Setup
Other pieces of equipment include: the ROBD controller (small laptop, left side of photo), pulse
oximeter (small yellow device, center of photo), and flight simulator laptop (right side of photo).
The ROBD Operator is on the left side of this photo, and the ROBD Instructor is in the center.
C-8
Appendix C
Slide 9
ROBD Setup
This photo shows the trainee flying the laptop flight simulation. He is wearing a helmet and
standard aviator’s oxygen mask (MBU-12, though MBU-24 can also be used). He is controlling
the aircraft with a basic flight simulator stick, which is in his lap.
C-9
Appendix C
Slide 10
ROBD Setup
The ROBD Instructor is also a safety observer. In this case, the Instructor is standing beside the
student to ensure he does not loose consciousness following a bout of severe hypoxia (see pulse
oximeter reading of 64% oxygen-hemoglobin saturation and a heart rate of 93 beats per minute).
C-10
Appendix C
Slide 11
ROBD Training Scenario
• Using Microsoft® Flight Simulator 2002 with
NETC’s Microsim plug-in
– Configured to look and fly like a T-34C
• One exposure to a simulated altitude of
25,000 feet
– ROBD ascent - 10,000 feet/min
The flight simulation uses Microsoft Flight Simulator 2002 with a T-34C “plug-in.” This plug-in
was developed by the Naval Education and Training Command’s (NETC) Microsim program.
NETC is currently doing a study to determine the effectiveness of using the Microsim program in
primary flight training.
The Microsim instruments work just like they would in the aircraft. Even the VFR landmarks are
fairly accurate.
In this scenario, we ascend the ROBD to 25,000 feet to match a standard Type II LPC flight
profile. The ascent rate was a bit arbitrary. We could have ascended faster, to simulate a more
rapid onset oxygen systems failure, but we decided to use 10,000 feet per minute.
C-11
Appendix C
Slide 12
Flight Profile
• Simulated cross-country in T-34C
• ILS approach into Mchord AFB, Washington
• Starting Point:
– Altitude - FL 250
• T-34C service ceiling is 25,000 feet
• Oxygen mask required above 10,000 feet
– Initial gas mixture - room air through ROBD
• Talking with Seattle Center and Seattle Approach
– Given heading, altitude, and radio frequency changes
• While pilot is distracted with flying duties and comms,
ROBD is brought to 25,000 feet
• Prior to scenario, we brief the pilots to…
– Verbalize their hypoxia symptoms and talk us through their actions
in the aircraft
– If symptoms persist, request an emergency descent
The mission and all of these procedures are briefed to the aviators PRIOR TO the scenario. We
also give them the approach plate and discuss it. The mission is an ILS approach into Mchord Air
Force Base. We used Mchord because we wanted to setup a high altitude approach so we could
get the students up near 25,000 feet. The service ceiling of the T-34C is 25,000, and it is very
seldom that they would actually fly at these altitudes. However, in order to make our scenario
believable (and allow us to subject them to 25,000 feet of altitude), we had to push the envelop a
bit here.
The communications with air traffic control help the aviator “get his head in the game.” We give
each aviator a knee-board and most of our subjects take things very seriously, even writing down
radio frequencies, winds, and runway information.
The pilot is asked to verbalize symptoms and walk us through his procedures in the aircraft,
which normally include checking his oxygen equipment, hoses, etc, and making sure his regulator
is on and working. We normally do a “challenge-response” type of exercise where the pilot will
verbalize what it is that he is checking and we will respond with the status of that component. For
example, he might say “I’m checking my oxygen hose” and we might say “okay, your hose is
connected,” or he might say “I’m checking my regulator” and we might say “okay, your flow
indicator is no longer blinking black-to-white, white-to-black” (which indicates a failure of the
oxygen system).
Eventually, if symptoms persist, the pilot requests an emergency descent to below 10,000 feet
and the simulation is ended.
C-12
Appendix D
Reduced Oxygen Breathing Device Pilot Study
Study Results
Study Demographics:
Students trained as of 02 Aug 04 – 34
Average total flight hours – 2895 hours
Average number of LPC exposures – 3.23
Service:
25
24
20
15
10
2
2
6
5
0
USN
USMC
USAF
CIV
Primary Aircraft:
16
5
D-1
1
3
T-1
1
C-130
F/A-18
1
T-2
T-45
3
CV-22
4
T-6
16
14
12
10
8
6
4
2
0
T-34
1.
re
co
er
ve
m
in
ry
at
ed
tra
Pu
in
ls
in
e
g
ox
lo
w
er
Pi
lo
lim
tu
it
nr
es
po
ns
Sy
iv
st
e
em
Pr
ob
le
m
Pi
lo
tt
ni
ti a
te
d
2.
Pi
lo
ti
Appendix D
Evaluation ended by:
35
30
33
25
20
15
10
5
0
D-2
0
1
0
0
Appendix D
3.
Have you ever experienced hypoxia in an aircraft? If yes, please explain
similarities/differences between your experience in the aircraft and this ROBD training
event.
30
28
25
20
15
10
5
0
6
Yes
No
Comments:
Yes:
“Anxiety, increased breathing intake was similar.”
"Mostly the same."
"Exactly the same, amazing."
"Very similar with the light headed euphoric feeling. I didn't get the tingling fingers with the
ROBD."
"Rapid onset in aircraft at 41K, visual disturbances, hands shaking, blue nail beds. Slow onset
with ROBD, no visual manifestation or blueness at all."
"At 10K MSL, yawned, performed occasional deep breaths - no tingling, no "hot flashes" etc."
D-3
Appendix D
4.
Did you have safety concerns about the ROBD (today) / LPC (last time)?
35
30
25
20
15
10
5
0
32
27
2
yes
6
no
ROBD (today)
yes
no
LPC (last time)
Comments:
ROBD Yes:
"Due to the number of people to complete training."
LPC Yes:
"Always worried about blowing out a sinus or ear that might down me."
"DCS, blah, blah."
D-4
Appendix D
5a.
During ROBD hypoxia training, were you able to recognize your hypoxia symptoms?
35
30
25
20
15
10
5
0
32
1
yes
1
yes/no
no
Comments:
Yes:
"Initially, dizziness was my most prominent symptom. Then hot flashes and darkened vision. I
also had to think about slowing down my breathing rate."
"I started to feel light headed and abnormal. I knew this was not right. I reported it and took
action. Then it got to tingling in fingers and onset of euphoria."
"Tingling in fingers and numbing of cheeks."
"I started to feel anxious and was trying to pull in more oxygen during each breath."
"Taking deep breaths, shakiness in hands, difficulty concentrating."
"Headache, eye pain."
"Wooziness, slightly dizzy."
"Lack of thinking clarity; lack of attention to detail."
"Tingling in the scalp, increased breathing"
"Started getting hot flashes, fuzzy vision, and tingling."
"You really never knew when to expect."
"I felt the familiar light headedness and effort to concentrate."
"Became harder to concentrate, harder to execute simple tasks."
"Felt short of breath, difficulty concentrating."
"Light headed."
"Numbness in the lips."
D-5
Appendix D
"Yes, fingers, shortness of breath, difficulty to read back of instructions."
"The first sign was my breathing rate. Then blue nails and twitching hands."
"Loss of visual acuity, flush skin, tingling extremities."
"Tingling sensation in hands, slight dizziness."
"Initially I felt tingling and was told that had not been a change. Then later when I felt tingling I did
not account it as due to hypoxia."
“Oxygen deprivation, deep breaths, tingling.”
"Yes, tingling and air starvation."
"Light headed, confused too many numbers."
"Visual color loss."
"Tingling extremities and oxygen hunger."
"Tingling, air hunger, slight confusion."
"Each low pressure chamber ride in my career, I experienced the same indications of hypoxia
that I did today."
"Hot, gasping for air."
"Hot, deep breathing."
"Different from chamber. Chamber has always been visual acuity and obvious loss of color
vision. Here I experienced labored breathing and general uncomfortablness."
Yes/No:
"Thought, but not sure."
No:
"Didn't really have any visual."
D-6
Appendix D
5b.
During ROBD hypoxia training, did the instrument approach distract you from immediately
recognizing your hypoxia symptoms?
25
23
20
15
10
9
2
5
0
yes
no
maybe
Comments:
Yes:
"Somewhat, and probably definitely if I didn't know it was coming."
"Trying to figure out why the specific heading was given."
"A bit due to tasking, but I'd had it before, so it was easier to recognize."
"Concentrating on something other than just waiting for symptoms."
"I was trying to complete the task at hand and was slow to admit that I was hypoxic."
"Yes in that I didn't recognize that my nails were blue or my hands twitched or my decreased
concentration. However, my breathing seemed a quick recognition."
"Concentration, compartmentalization."
No:
“It was obvious."
"Basically due to the fact that the approach was just a simple arc intercept. Talking to center and
repeating read back instructions wasn't a big distracter."
"Poor air work alerted me to symptoms."
"Didn't get that far."
"I didn't really reference the approach plate."
"Picked up on it a little faster as I tried to fly a normal approach vice pattycake in the chamber."
"Recognized difficulty concentrating."
D-7
Appendix D
"However the simulator is difficult to fly and my difficulty with it may have masked my hypoxia."
"Good scenario."
"Never got to the approach."
"Fairly proficient at instrument approach procedures, what screwed me up were understanding
comms."
"Experience might be a significant advantage."
Maybe:
"Maybe."
D-8
Appendix D
5c.
During ROBD hypoxia training, did flying distract you from immediately recognizing your
hypoxia symptoms?
20
19
15
15
10
5
0
yes
no
Comments:
Yes:
"Flying the T-34 cockpit I was scanning instruments everywhere."
"Yes, lots of attention spent trying to keep it straight and level."
"Just trying to fly took more effort that recognizing what seemed to almost be subconscious."
"I was distracted with my cockpit scan and a bit slower to notice onset despite obvious
expectations (physiological training)."
"Same time, great training."
"Same answers as above."
"Same as above."
"Same."
No:
"No, but it made it very realistic."
"Poor air work alerted me to symptoms."
"Actively flying and communicating made it easier to recognize loss of cognitive skills."
"Recognized difficulty concentrating/remembering."
"More realistic than patty-cake."
"Expecting symptoms."
"Allowed me to see that I wasn't flying normally radios, etc."
"Again, experience."
D-9
Appendix D
6.
The onset of hypoxia during ROBD training was ______ as the onset during low pressure
chamber training.
20
19
15
10
9
6
5
0
more insidious less insidious
the same
Comments:
Less Insidious:
"Task loading makes a big difference."
The Same:
"To a bit more."
Compared to current hypoxia training in a low pressure chamber; was ROBD hypoxia
training in a simulated environment…
35
30
25
20
15
10
5
0
32
sa
m
e
th
e
ab
ou
t
re
al
is
tic
le
ss
tic
0
re
al
is
e
m
or
7.
D-10
2
Appendix D
8.
Considering the current low pressure chamber refresher training; should ROBD training
be conducted…
25
20
21
15
13
10
0
5
th
e
LP
C
LP
C
LP
C
th
e
w
ta
ll;
co
nt
in
ue
In
st
e
ad
ith
of
to
di
tio
n
N
ot
a
In
ad
on
ly
0
Comments:
In additional to the LPC:
"Great training in a realistic environment."
"Use the chamber for initial training."
"Though low pressure could be significantly reduced, like initial and once every 10 years."
Instead of the LPC:
"I like if for refreshers, but the chamber is nice to see how silly you get when you have no flying
experience."
"Add with simulator training."
D-11
Appendix D
9.
How frequently should ROBD training be conducted?
12
11
10
8
7
6
8
7
4
2
0
1
0
se
m
ne
ve
r
i- a
nn
ua
l ly
an
nu
al
ly
ev
er
y
2y
rs
ev
er
y
3y
rs
ev
er
y
4y
rs
ev
er
y
5
yr
s
0
Comments:
"This depends: If ROBD will be kept "painless," CBT followed by short ROBD then...more often -1 or 2 years. If kept with "full-up" training, then 4 years."
Annually:
"With NATOPS check in simulator."
Every 2 years:
"If can be more mobile to go to units."
Every 3 years:
"Before each flying tour."
Every 4 years:
"Platform dependent.”
D-12
Appendix D
Please identify the symptoms of hypoxia you experienced during ROBD training.
70%
65%
60%
56%
50%
44%
40%
35%
29%
30%
15%
9%
stress
headache
euphoria
cold flash
3%
apprehension
nausea
dizziness
tingling
difficulty concentrating
blurred vision
lack of coordination
lights dimming
3%
6%
fatigue
9%
10%
0%
18%
15%
tunnel vision
20%
18%
18%
hot flash
10.
Comments:
"Previously, in the low pressure chamber, the most prominent symptom I experienced was
nausea. I also felt dizzy the longer my mask was off. Today's experience was different like I
described earlier."
"The symptoms were less obvious than in the chamber. Using the ROBD I was saturated with
flying tasks unlike playing patty cake watching other folks get silly. All of a sudden I realized
things were abnormal and funny. I felt light headed and then tingling in my finger tips. I initiated
my actions and on my emergency descent I got euphoric and a feeling of not caring. I got all of
these in the chamber as you tend to go farther in the chamber. There is no harm in screwing up
patty-cake, but in the Microsim you want to keep the plane right side up."
"Symptoms were not as quick during onset as with the chamber. The flying duties helped with
realization of the symptoms."
"I definitely had trouble keeping up with information passed during radio calls (headings, altitudes,
altimeter setting). An active controller is a key part of the stimulation."
"Much better because of the "aircraft" simulation."
"Heavy breathing. Cannot remember the previous times."
"Held mic button after completing transmission, became difficult to see "exact" heading on HIS, in
fingertips, started to get worse."
D-13
Appendix D
"Overall the ROBD was much better, very accurate symptoms."
"Started to feel light headed and euphoric. I noticed flying becoming more of a task. It was pretty
realistic. The only other thing I didn't experience that I experienced in the jet (S-3 @ 26K feet)
was tingling fingers."
"Same symptoms but onset was faster. Slow onset in the chamber resulted in slower recognition
for me personally."
"I saw more extreme symptoms in the LPC trainer - visual disturbances, muscle tremors, blue
tissues, inability to concentrate or reason. ROBD training showed symptoms on a much smaller
scale."
"Experienced light headedness. ROBD with mircrosim made recognizing impact of hypoxia on
flying more apparent."
"Tingling and numbness in the lips/ fingertips were the same as before. Lack of coordination was
more evident due to the approach sequence, difficulties breathing when the hypoxia set in."
"More pronounced."
"The ROBD was better than the chamber because concentrating on the simulator brought out the
insidious aspects of hypoxia better than the chamber."
"All very similar, however, much more realistic and similar to actual flight."
"Chamber: Tingling, cyanosis, fixation. ROBD: Color loss."
"Vision became labored."
"All symptoms I am used to for hypoxia were exactly the same during the ROBD run. The
difference was that I felt the sensations come on stronger and quicker. In addition, this time I had
a hard time concentrating on comms."
"More comfortable than low pressure chamber."
"During chamber flights, I usually experience tingling along with blurred vision and hot flashes.
The ROBD sessions were mostly hot flashes and concentrating and deep breathing."
"Both here and the chamber. Usually in the chamber I'd get loss of color vision. ROBD never
had any loss of color or acuity. Labored breathing, never had this in the chamber."
D-14
Appendix D
11.
Is the ROBD a valuable training tool for teaching pilots to recognize and recover from
hypoxia?
40
30
34
20
0
10
0
Yes
No
Comments:
"And they need to tell you in their cockpit what they would be doing (EP/NATOPS-wise)."
"Absolutely!"
12.
Today’s training objective was – To recognize the symptoms of and treat for hypoxic
hypoxia at a simulated altitude of 25,000 ft. Did ROBD hypoxia training adequately meet
this objective?
40
30
34
20
0
10
0
13.
Yes
No
Do you consider yourself adequately trained to cope with the emergencies associated with
hypoxia?
40
30
34
20
0
10
0
Yes
No
D-15
Appendix D
14.
Would ROBD hypoxia training be more effective/realistic if it were conducted inside your
aircraft’s simulator?
30
25
28
20
15
4
10
2
5
0
yes
no
Other
Comments:
Yes:
"Definitely!"
"Of course it would, but this is great training!"
"Highly recommended."
"But not necessarily required."
"Without a doubt."
"Absolutely, this would be a perfect scenario. The type specific EP could be run at the same
time."
"However, I would think medical personnel need to be involved."
"Definitely."
Other:
"I think any simulator that allows a task is acceptable."
"It would enhance training in the T-34, however, it wouldn't in the E-6"
D-16
Appendix D
15.
Today you were subjected to one hypoxic exposure. Would a second (or third) exposure
to hypoxia improve the training?
16
16
15.5
15
14.5
14
14
13.5
13
yes
no
Comments:
Yes:
"One evolution got the point across; however, it might be beneficial to do one slow onset scenario
and one rapid decompression scenario."
"Maybe a second exposure would have been good. Perhaps changing the time and strength of
hypoxia onset could be used."
"Again, not necessarily required as this exposure met training objectives."
"I recovered immediately when symptoms first occurred, letting the simulation go further might be
beneficial."
"If the first exposure was quickly concluded with safe recover, second exposure could be used to
push the limits." Maybe it was a bad day and you were behind recognizing symptoms? Or
maybe it takes a long time to descend and recover."
"Maybe mix up a rapid decompression type scenario with a slower onset scenario."
"I think the ROBD training is good, but in addition to the LP trainer, which allows the individual to
explore symptoms fully."
"Additional flights with a debrief on how hypoxia effected performance would be useful."
"Rapid onset VS slow onset profiles."
"Recognized sooner"
"Maybe could see additional symptoms."
"Combine with simulator which you’re familiar with would add to the experience. Combine with a
regular simulator event."
"Doing the run a second time in rapid sequence would more effectively incorporate a sense of
“muscle memory" to recognize symptoms"
D-17
Appendix D
No:
"Well, if you go again to take it farther - go deeper into hypoxia - you might get negative training
thinking…"I can go this far.""
"I think that once you see how your own body responds to hypoxia, then refresher training every
four years would suffice."
"Once is effective."
"You know the feeling, you aren’t going to forget in 2 minutes"
"I am familiar with the sensations and symptoms, no need for a second ride for refresher, possibly
two for initial training would be beneficial."
"One is all you need if student realizes and understands their hypoxia symptoms and how they
handle them."
"Not during the same visit."
"Got the point, well."
"As long as you could treat yourself."
Did not mark yes or no:
"Repetitiveness always helps to solidify hypoxic exposure."
"Perhaps, if symptoms were any different on subsequent sessions."
"I would need more experience with this device to better appreciate and recognize."
D-18
Appendix D
16.
Are there any other changes you would recommend to improve ROBD hypoxia training?
"Coordinate with simulators."
"Make sure students are not allowed to watch each other."
"Flight Docs who could simulate this training in the actual training simulators."
"No."
"Dim the lights and make the pilot read a color map to demonstrate effects of hypoxia on vision."
"Insert into existing simulators."
"If incorporated with simulators and given in conjunction with other objectives."
"Let the scenario go until you can recognize that you are no longer hypoxic."
"Increase aircraft simulator fidelity and distract aircrews to the point that they are not expecting/
anticipating hypoxia."
"More units."
"No, other than possibly a real simulator."
"Get in the simulators at least annually."
"Set up a system that could accommodate more people at once."
"Bigger screen for the flight instruments."
"Have the pilot fly an S1 or S3 Instrument pattern."
"Run with specific aircraft model as a simulator event."
"Easily identified. In a timely manner. Case-by-case"
"No. The training was great the way it was"
"No."
"No."
"No."
"More often, more experience."
D-19
Appendix D
17.
Overall, how would you rate your ROBD hypoxia training?
20
19
15
12
10
is
fa
ct
or
y
to
ry
sa
t
tis
fa
c
un
sa
0
3
ex
ce
lle
ou
nt
ts
ta
nd
in
g
0
0
go
od
5
Comments:
Excellent:
"At this experimental stage."
"With higher aircraft fidelity (outstanding)."
D-20
Appendix D
18.
Which hypoxia training program do you consider more effective: the low pressure
chamber version or the ROBD version you have just completed?
30
28
25
20
15
10
2
5
0
LPC
3
1
ROBD
Both
Other
Comments:
LPC:
"More time spent in a hypoxic condition-better exploration of all symptoms, onset and recovery."
"LPC is good to identify other physiological effects such as trapped gasses, valsalva, and
hypoxia. The two should be used together."
ROBD:
"Certainly more realistic - bottom line."
"Once you know how to fly - it is more realistic and allows you to take corrective actions and see
what it feels like while you are really concentrating and trying to fly."
"The ROBD provides the distractions that would be present during actual flying conditions."
"More realistic than patty-cake."
"I didn't know when it was going to happen."
"More realistic training that can be used to augment simulator training."
"I didn't really get hypoxic in the chamber - plus, it's good to see hypoxia effects while "flying.""
"A much more realistic environment."
"Faster and more realistic; can be completed if med down due to sinus/ear problems."
"Not knowing when the deprivation occurred."
D-21
Appendix D
"Just seemed more realistic."
"What better way to train aircrews to recognize and react to hypoxia in the cockpit than to be…in
the cockpit. Aircrews can also learn how exactly (flying, instrument scan, read approach plates)
they will be affected in the cockpit."
"Unknown, realistic, valuable and realistic skills you are trying to accomplish."
"Much less risk and provides recognition."
"More realistically demonstrates hypoxia to aircrew without the possible sinus block or DCS
problems."
"Unable to blend in group, a lot more individual training. Better environment and tasking with the
flight profile."
"Almost real world."
"ROBD prevents group think and allows the individual to see how hypoxia effects them. I would
not recommend identical training for initial quals. In that case I would talk the subject through the
change in oxygen so they know what they are feeling. All refresher training should be ROBD, as
it is much more realistic."
"Real world application - very insidious."
"More realistic."
"You feel the effects of hypoxia quickly."
"A lot more realistic."
"Much quicker onset of hypoxia and the associated symptoms."
"Having to fly and simulated ATC forced me to divide my attention."
"Realism of flying while hypoxia sets in."
Both:
"Both are useful; LPC for valsalva, trapped gasses exposure. ROBD for hypoxia exposure."
Other (did not mark yes or no):
"Put into realistic environment with simulator as an aid to identify symptoms."
"They were different. I'd need more exposures to decide."
"I feel overall, for my experience, they are equal."
D-22
Appendix D
19.
Please provide any additional comments/suggestions with respect to ROBD hypoxia
training:
"Have individuals bring their own helmets."
"Should be used as a refresher trainer."
"This training could be very realistic in a simulator where the flight was 30 minutes and you (as
the pilot) were unsure when the hypoxia was going to take place."
"Great program! Better to see how hypoxia can affect our flight duties with less side effects and
possible repercussions."
"More applicable to fleet aircrew than to students. Recommend sending this trainer to fleet
squadrons so aircrew in the tactical community are exposed to hypoxia and its dangers."
"I liked the ROBD, however, the display on the computer was too small; recommend projection on
the wall or larger monitor."
"Great Training - especially for those with an experience level to have a base knowledge to reflect
off of. For new students the instrument portion may be overwhelming by itself."
"I recognized that I was willing to let my hypoxia symptoms develop while in the "cockpit" flying
verses in the chamber. I found myself "recovering" much earlier in ROBD (trouble seeing HSI
headings) than in the chamber. I probably reacted as I would in the aircraft, only waiting for a few
of my symptoms prior to recovering. In the chamber I got pretty hypoxic."
"None to add, its good training with the flying simulator for tasking. Demonstrates how hard it can
be and importance of early recognition and corrective action."
"Could easily be incorporated in semi annual EP simulator for training command pilots."
"Great for safe hypoxia training, integrate with simulators, design system to get more people
through in timely fashion instead of one at a time."
"Good system! Sounds like you have plans to take it to the next level of training by taking it to the
specific airframe."
"Run two simulations, one with oxygen and one without. Don't tell refresher which simulator
event hypoxia will occur."
"Outstanding concept to the hypoxia symptoms with the flight simulator."
"Great job, this will be essential to saving more than a few lives. Important because it concerns
hypoxia with the aircraft (simulator) experience."
"Overall good training. If symptoms were not recognized on the initial run then possibly a second
run could be added."
"I would do a combo of LPC with ROBD. Do the LPC every 4 years with the ROBD every 2 years
for refresher training."
"Great time. I hope to do it again in the future."
"I would be willing to do this a few more times to increase my experience."
D-23
Appendix E
Should Low Pressure Chambers (LPCs) be Replaced with Reduced Oxygen Breathing Devices
(ROBDs) Systematically Throughout the Naval Aviation Survival Training Program?
-- An Educational Analysis -Brian D. Swan, Instructional Designer, Naval Survival Training Institute
ABSTRACT
Low Pressure Chambers (LPCs) have been a part of Naval Aviation training since World War II. The effects of
altitude-induced hypoxia are well documented; there is little doubt that personally experiencing the symptoms of
acute hypoxia is an important – vital – training requirement for both indoctrination students and experienced
aircrew. Additionally, LPCs provide training in how the gasses trapped inside of the body react to the pressure
changes experienced during changes in altitude (specifically, the effects on the middle ear, sinuses, and
gastrointestinal tract). Although the training validity of experiencing hypoxia has rarely been called into question,
the highly artificial environment of 18 individuals sitting in an LPC becoming hypoxic all together while performing
non flight-related tasks such as playing “patty-cake” or doing simple math problems has been frequently cited as an
area of training that could be improved. A concept termed “SimPhys” was initiated that would move the hypoxia
portion of the training to a flight simulator. The ROBD was conceived as a means to that end. To clearly state an
important point: the ROBD was conceived and designed, from the out start, as a device to be used by refresher
tactical jet aircrew, as part of simulator-based aviation physiology training, and not as a stand-alone substitute for
LPC training. Currently, the LPC is indicated for 11 NASTP curricula and provides training in three broad areas: (1)
oxygen equipment familiarization, (2) trapped gas expansion/contraction effects and procedures, and (3) hypoxia
exposure/procedures. After reviewing each learning objective for each of the courses, it was determined that the
objectives relating to helmets, masks, and hypoxia exposure are supported by the ROBD, whereas objectives
relating to regulators and trapped gas issues are not supported. While the relative supportability of training
objectives is relatively clear-cut, assessing the authenticity of training is a much more subjective consideration.
Within this discussion, there are two major issues: (1) becoming hypoxic while wearing an oxygen mask and (2)
performing “authentic” flight-related tasks while becoming/experiencing hypoxia. It is believed that the authenticity
of training for refresher tactical jet students should be considered to be quite high; probably higher than that
received in traditional LPC training. Due to their inexperience in flight procedures, ROBD training will provide no
benefit in authenticity to indoctrination students, and if those students will eventually be flying pressurized aircraft
that do not require constant oxygen mask use, the ROBD may actually provide a significantly reduced authenticity
in training. For other communities, there is the combination of the requirement for unusual scenarios to “justify”
becoming hypoxic while wearing a mask and currently unidentified/undeveloped simulator-related tasks to be
created that must be considered. Based on the educational discussions presented above, the following
recommendations are made for the implementation of the ROBD: 1. Implement ROBD training for refresher tactical
jet aircrew (R1/RP1) as soon as aircraft-specific flight scenarios are completed. 2. Do NOT replace traditional LPC
training with ROBD training for indoctrination students (N1/NP1, N2/NP5, USN/USAF Joint Indoctrination, N3/NP3,
N4/NP4, N2/NP7, N2/NP8, and NP6). 3. Refresher students who do not fly in tactical jet aircraft (R2/RP2 and
R4/RP4) may or may not receive more effective or authentic training using the ROBD.
Low Pressure Chambers (also known as hypobaric chambers and altitude chambers, referred to herewith
as LPCs) have been a part of Naval Aviation training since World War II. The effects of altitude-induced
hypoxia are well documented in both the scientific literature and in aviation safety literature; there is little
doubt in the collective minds of either the aerospace physiology community or the aviation safety
community that personally experiencing the symptoms of acute hypoxia is an important – vital – training
requirement for both indoctrination students and experienced aircrew. In addition to hypoxia exposure,
the LPCs provided another extremely important type of training: how the gasses trapped inside of the
body react to the pressure changes experienced during changes in altitude (specifically, the effects on the
middle ear, sinuses, and gastrointestinal tract). This is directly reflected in requirement for this type of
exposure/training in the Chief of Naval Operations Instruction (OPNAVINST) 3710.7; the “General
NATOPS Manual”, Appendix 2, Figure E-2. The Naval Bureau of Medicine and Surgery (BUMED), the
assigned Training Agent for this type of training, has used OPNAVINST 3710.7 as its requirements
document in the design and development of courses that are, collectively, the Naval Aviation Survival
Training Program (NASTP).
Although the training validity of the actual experience of hypoxia has rarely, if ever, been called into
question, the highly artificial environment of 18 individuals sitting in an LPC becoming hypoxic all together
while performing non flight-related tasks such as playing “patty-cake” or doing simple math problems has,
E-1
Appendix E
for at least the past 20 years (the extent of the author’s personal knowledge), been frequently cited as an
area of training that could be improved.
In parallel to this, in the early 1990s, an effort led by several Aeromedical Safety Officers (AMSOs)
attached to Marine Aircraft Groups proposed the idea of trying to conduct portions of the Aviation
Physiology Training Program in conjunction with actual simulator events; introducing physiological
elements into an actual simulated flight environment. This was specifically targeted at the experienced
crew members (refresher students) who were well versed in their aircraft duties, who could better encode
the physiological lessons into their established schemas and behavior patterns. Initially the rotary wing
community was approached with this concept, and a series of evaluations in the mid-1990s proved that
this type of training (referred to unofficially as “SimPhys” Training) was both feasible to conduct and was
highly rated by the students who participated. Manpower and training logistics issues prevented this trial
from expanding into a complete alternate training plan.
Even from the start, the “inventors” of SimPhys realized that in order to be able to use this type of training
with the tactical jet communities, there would have to be some method of being able to induce hypoxia at
ground level, while in a simulator. Thus was the concept of mixed gas-induced hypoxia born. The
physical device that would provide the mixed gas to the student has since been labeled the Reduced
Oxygen Breathing Device (ROBD).
To reinforce an important point: the ROBD was conceived and designed, from the outset, as a device to
be used for refresher tactical jet aircrew, as part of simulator-based aviation physiology training, and not
as a stand-alone substitute for LPC training. Integral to this was the assumption that experienced
refresher students are very familiar with the effects of pressure changes on trapped gases, and did not
require specific refresher training on these topics (rotary wing refresher students have not – at least in the
past 20 years - received recurrent LPC training).
When the working prototype of the ROBD became available, as much as everyone involved in the
process wanted to see it implemented in simulators, the logistics of modifying simulators and scheduling
simulator time was determined to be initially prohibitive, and rather than not using the new technology at
all, an interim plan was designed using the Microsoft Flight Simulator and MicroSim military scenarios as
a “stand-in” for an actual flight simulator. This still allowed experienced, refresher students the ability to
perform tasks that were more realistic than in classic LPC training, without incurring the logistic
roadblocks of full-scale simulator implementation. As a pilot program was required to evaluate the
subjective effectiveness and acceptability of the training, a student population readily available in the
Pensacola area was selected: refresher T-34 instructor pilots. This population was selected based on the
facts that the aircrew were all refreshers, flew with a traditional helmet and mask assembly, regularly wore
oxygen masks when flying above 10,000 feet, and applicable simulation scenarios were readily available.
In short, for the purposes of this study, there were no practical differences between refresher T-34
instructor pilots and the original tactical jet aircrew for whom the ROBD was conceived. This pilot study,
with an experimental population of 34, serves as the basis for all discussion of ROBD implementation
data.
Training Requirements and Learning Objectives
Currently, the LPC is indicated for 11 NASTP curricula (somewhat abbreviated titles have been used to
make this list less cumbersome):
N1/NP1 – Officer Aircrew Indoctrination Training
USN/USAF Joint Aviation Physiology Training
N2/NP5 – Enlisted Aircrew Indoctrination Training
R1/RP1 – Refresher Ejection Seat Aircrew Training
R2/RP2 – Refresher Fixed-Wing, Non-Ejection Seat Aircrew Training
R4/RP4 – Refresher Fixed-Wing, Non-Parachute-Equipped, Aircrew Training
E-2
Appendix E
N3/NP3 – Selected Passenger Training (used for indoctrination and refresher training)
N4/NP4 – Project Specialist Training (used for indoctrination and refresher training)
N2/NP7 – Midshipman Training
N2/NP8 – VIP and other Passenger Training
NP6 – Aviation Physiology for High Altitude Parachutists (Special Operations)
These, and the 11 other curricula for which NSTI is responsible have been authored and revised, by
many individuals with differing philosophies in curriculum design and management over the course of 20plus years, and as a result of this, there is a considerable lack of consistency in the style, formatting,
numbering, (and in several occasions even the existence of) specified training requirements and learning
objectives. This is compounded by an equally diverse population of Program Managers at BUMED and
Program Sponsors at OPNAV; everyone has had their “three years to make a difference”. Unfortunately
this has resulted in more false starts and incomplete products than any sense of continuous growth and
development. Internal analysis of this situation has led NSTI to the conclusion that a complete
educational review of all training requirements and objectives for all curricula must be conducted. At the
time of this writing, that re-engineering is approximately seventy five percent complete. This digression
has been included to explain why, in a number of occasions, “proposed” objectives are discussed in this
study; in many cases objectives were completely missing (but implied) or written in an educationally
unsound way. The objectives as presented in this paper were always the intent of the curriculum as
currently written, but if the actual curricula documents are cross-checked, differences will be found. The
process of formally implementing these changes is ongoing.
To determine if a new technology is educationally suitable for implementation in a standing curriculum,
the learning objectives must be reviewed to see if the new technology is capable of meeting all of them. If
it is, then the technology can be considered an educationally sound replacement. If it does not meet all of
the objectives, then three options are available: (1) reject the new technology, (2) modify the technology
so that it does meet all of the objectives, or (3) re-evaluate the training requirements and learning
objectives in light of the new technology and alter them if it is believed that the new technology, in the
long run, provides better training. An objective-by-objective analysis was conducted for all 11 courses in
which the LPC is an indicated training device to determine if the ROBD was able to support current
requirements. The detailed results of this analysis are included as attachments to this paper. The
following discussion summarizes those findings.
The LPC provides training in three broad areas: (1) oxygen equipment familiarization, (2) trapped gas
expansion/contraction effects and treatment procedures, and (3) hypoxia exposure/treatment procedures.
Each of these areas will be discussed individually.
Oxygen equipment familiarization
The objectives that fall under this category are partially supported by the ROBD. The device
configuration allows for any combination of helmet, headset and mask currently used in the Fleet, so
objectives relating to the use of these items can be considered to be fully supported. The ROBD does not
use a conventional regulator associated with Fleet aircraft (in fact, there is no external oxygen regulator at
all), so objectives relating to regulator use are not considered to be supported.
Trapped gas expansion/contraction effects and treatment procedures
Trapped gas effects are the direct result of changes in ambient pressure. As ROBD training is performed
at a constant atmospheric pressure, none of these effects will be experienced, and therefore there will be
no authentic environment in which to practice them. Objectives that fall under this category are not
considered to be supported.
Hypoxia exposure and treatment procedures
This is the specific function for which the ROBD was originally designed, and in this function it excels.
Due to its design, extremely accurate oxygen partial pressures are delivered – more accurate and
repeatable than is capable in LPC training. The ROBD also provides the ability to experience the effects
E-3
Appendix E
of hypoxia at much higher altitudes than is currently considered acceptable, given the potential risks of
decompression sickness. All objectives that fall under this category are considered fully supported.
In summary, objectives relating to helmets, masks, and hypoxia exposure are supported, whereas
objectives relating to regulators and trapped gas issues are not supported.
Whereas the relative supportability of training objectives is relatively clear-cut, assessing the authenticity
of training is a much more subjective consideration. Within this discussion, there are two major issues:
(1) becoming hypoxic while wearing an oxygen mask and (2) performing “authentic” flight-related tasks
while becoming/experiencing hypoxia.
Becoming hypoxic while wearing an oxygen mask.
This issue has probably raised more questions and concerns in the Naval Aerospace Physiology
community than any other. For as long as hypoxia recognition/treatment has been taught, the first step in
the corrective procedure has been “Go to 100% oxygen”; the assumption being that the aircrew has
become hypoxic because they were not wearing an oxygen mask and either flew an unpressurized
aircraft to an unsafe altitude, or were flying in a pressurized aircraft that lost its pressurization due to
some systems or structural failure. Historically, at one time, this was a valid assumption in virtually all
airframes. Currently, due to aircraft systems modifications and changes to operating procedures this is
not necessarily a correct assumption.
Per OPNAVINST 3710.7 all tactical jet aircrew are required to wear oxygen masks “from take-off to
landing”, therefore, if they were going to experience hypoxia at all, it would have to be while wearing an
oxygen mask (understanding that aircrew do, at times, remove their oxygen masks to ingest food and
water on long flights). Does mask-on hypoxia ever happen? Yes, it does. A recent review of Naval
Safety Center aircraft hazard and mishap reports from 1980 to 2002 revealed that a large percentage of
tactical jet hypoxia incidents were categorized as “mask-on” hypoxia. In fact, of the nine incidents that
occurred from 1991 to 2002, in aircraft flying with on-board oxygen generating systems (OBOGS), all
occurred in aircrew who were wearing oxygen masks at the time of the incident. (Ostrander & Johanson,
2004) These data are similar to a recent study by the Royal Australian Air Force which found that 63% of
all hypoxia incidents over an 11 year period were the result of regulator failure, connection failure, mask
leak, or other mask problem (Cable, 2003). Both the U.S. and Australian reports made specific
recommendations to include “mask-on” hypoxia training in all refresher hypoxia training. Given this data,
the type of training provided by the ROBD is not only “as authentic” as LPC training for tactical jet aircrew,
it is in fact “more authentic”.
A similar argument could be made for virtually all unpressurized aircraft, as OPNAVINST 3710.7 requires
all crew to be using 100% (implied delivered through a mask) when flying above 10,000 feet. This being
the case, they, too, should only experience hypoxia if there is a failure in their oxygen system, and as
above, would actually receive a “more authentic” learning experience using the ROBD. The T-34
instructor pilots that participated in the pilot study are a specific example of this better-served population.
The community in which the authenticity of ROBD training can – and should – be realistically questioned
is that of the pressurized, non-ejection seat aircraft. Crew in this type of aircraft typically fly without
wearing oxygen masks; they are only required when there is a loss of cabin pressurization or
smoke/fumes in the aircraft. The educational emphasis in this training has migrated from a rapid-onset,
acute hypoxia exposure to a gradual-onset, insidious hypoxia exposure. Given the great flexibility of the
ROBD in providing custom “flight profiles”, physiologically this phenomenon could be easily reproduced.
However, the primary training goal is for these students to recognize hypoxia symptoms when they
appear (gradually, and somewhat unexpectedly), and then take corrective action (putting on their masks)
to remedy the hypoxia. This specific stimulus-response set cannot be replicated by the ROBD. Looking
to the scenarios discussed above, could there be a scenario in which cabin pressure is lost, the crew put
on their masks, and discover a failed oxygen system as well? Yes, there could (structural damage to the
aircraft could cause both to happen), but it would be a much less likely scenario, and this author cannot
E-4
Appendix E
cite an example of this having occurred. In short, for this community, although the physiological hypoxic
experience can be authentically reproduced, the mechanism by which it is induced is marginally authentic
and would be using a highly unlikely combination of events to “justify” a training scenario.
Performing “authentic” flight-related tasks while becoming/experiencing hypoxia
Referring back to the historical perspective with which this paper began, providing more authentic flightrelated tasks (SimPhys) was the original motivation for developing the ROBD concept from the very
beginning. If deployed in an actual aircraft flight simulator, there can be no question that the ROBD will
provide the most authentic flight-related training possible, short of experiencing hypoxia during an actual
flight. (NOTE: Discussing the relative qualities of the aircraft flight simulator and the PC-based flight
simulation program exceeds the scope of this paper. The terms “simulation” or “simulator” are used
hereafter to refer to either configuration.)
Inherent in this is the very basic assumption that the student knows how to fly the simulator and
participate in interactive flight operations (e.g. controlling the aircraft, knowing systems and procedures,
communicating with air traffic controllers, being able to follow flight rules and regulations, etc.) If the
student has not already been trained in how to perform these flight-related tasks prior to ROBD training,
the very gain in authenticity that served as the educational justification for the development of the ROBD
is lost. In practical terms, this translates into the ROBD being an authentic training experience for
refresher students – more authentic than LPC training – but providing no “value added” authenticity for
indoctrination students (who would have to perform some non flight-related tasks while becoming
hypoxic).
Another concern is for students who do not actually control an aircraft (weapons systems officers,
navigators, crew chiefs, flight engineers, etc). The current scenarios are specifically designed for pilots,
flying the simulator. Although there is no reason to believe that effective scenarios could not be
developed for at least some other crew positions, at the time of this writing no work has been
accomplished in this direction, therefore no assessments of authenticity can be made.
In summary, the authenticity of training for refresher tactical jet students should be considered to be quite
high; probably higher than that received in traditional LPC training. Due to their inexperience in flight
procedures, ROBD training will provide no benefit in authenticity to indoctrination students, and if those
students will eventually be flying pressurized aircraft that do not require constant oxygen mask use, the
ROBD may actually provide a significantly reduced authenticity in training. For other communities, there
is the combination of the requirement for unusual scenarios to “justify” becoming hypoxic while wearing a
mask and currently unidentified/undeveloped simulator-related tasks to be developed that must be
considered.
Recommendations and Conclusions
Based on the discussions presented above, the following recommendations are made for the
implementation of the ROBD:
1. Implement ROBD training for refresher tactical jet aircrew (R1/RP1) training as soon as
aircraft-specific flight scenarios are completed. The ROBD equals or exceeds the LPC in meeting
objective requirements, and provides a much greater level of authenticity of training. Emphasis should be
placed on eventually completely replacing traditional LPC training with ROBD for this community.
2. Do NOT replace traditional LPC training with ROBD training for indoctrination students
(N1/NP1, N2/NP5, USN/USAF Joint Indoctrination, N3/NP3, N4/NP4, N2/NP7, N2/NP8, and NP6). The
lack of training in trapped gas issues that would result from eliminating the LPC from indoctrination
courses is considered unacceptable. The ROBD could be used as a classroom demonstration to illustrate
hypoxia onset rates at higher altitudes than experienced in the LPC. This position has been
independently reached by the USAF, who are also in the process of integrating ROBDs into aviation
physiology training for refresher students only. As both the USN/USAF Joint Indoctrination and the NP6
have joint training implications, these are considered especially poor candidates for replacement.
E-5
Appendix E
3. Refresher students who do not fly in tactical jet aircraft (R2/RP2 and R4/RP4) may or may not
receive more effective or authentic training using the ROBD. Students in this broad category will have to
be assessed on a more case-by-case basis. As has been demonstrated, the ROBD is probably more
effective and authentic for T-34 instructor pilots, but could the same be said for a C-130 loadmaster?
Closer analysis of specific duties of individual crew positions on individual aircraft (an analysis that is far
beyond the scope of this discussion) would have to be conducted before specific recommendations could
be made. Based on twenty years of anecdotal information and experience, the author believes that fewer
crew members in this category would truly benefit more from ROBD training than from traditional LPC
training.
E-6
Appendix E
References
Cable, GG. In-flight hypoxia incidents in military aircraft: causes and implications for training. Aviat Space
Environ Med 2003; 74:169–72.
Ostrander, G, Johanson, D. Naval Safety Center data review. Currently unpublished report; 2004.
E-7
Appendix E
N1/NP1 – Indoctrination Survival Training for Officer Aircrew Students
N5/NP2 – Indoctrination Training for Enlisted Aircrew Students (This curriculum scheduled for
elimination)
Objective
Objective Text
2.2
Experience the
effects of pressure
changes associated
with altitude
exposure, the
symptoms of
hypoxia, and the
function of oxygen
masks and
regulators.
Perform oxygen
mask and regulator
preflight and hookup.
2.2.5
Low Pressure
Chamber Support
Fully Supported.
ROBD Support
Partially Supported. Hypoxia exposure
symptoms are supported. Effects of pressure
changes is not supported. Function of oxygen
equipment is partially supported.
Fully Supported.
Partially Supported. The ROBD, as currently
configured, does not use a traditional aircraft
regulator, therefore regulator familiarization is
not practiced.
2.2.6
Perform techniques
for pressure
equalization in the
ears, sinuses, and
intestines.
Fully Supported.
Not Supported. As the ROBD does not
involve any ambient atmospheric pressure
changes, symptoms of trapped gas expansion
are not experienced, and therefore
meaningful application of corrective
procedures is not possible.
2.2.7
Experience the
symptoms of acute
hypoxia at a
simulated altitude of
25,000 ft.
Fully Supported.
Fully Supported. According to NAMRL
research, the ROBD provides what might be
considered to be “more authentic” symptoms,
as the exact partial pressures of the breathing
gasses are more accurately controlled.
2.2.8
Perform the
procedures to treat
for acute hypoxia.
Fully Supported.
Partially Supported. The “standard”
procedure for suspected hypoxia includes
putting on the oxygen mask. This reinforces
that if hypoxic, under situations in which all
equipment is properly functioning, breathing
oxygen will almost immediately remedy the
situation. The single greatest “problem” with
ROBD training is that the student is becoming
hypoxic while wearing an oxygen mask. The
specific scenario currently in use in trial
ROBD training is one in which the student is
flying at 25,000 ft and experiences an
equipment malfunction, resulting in hypoxia.
While considered “more realistic” for
experienced refresher students, for
indoctrination students, this may result in a
negative transfer of information and create a
loss of confidence in aviation life support
equipment. Concepts of checking to make
sure that the oxygen mask is correctly
E-8
Appendix E
connected and to initiate descent are
supported.
Additional Educational Issues
As currently employed, the ROBD uses a PC-based flight simulation program configured to closely
approximate the flight characteristics of a student’s “Fleet aircraft” (as the trial population is defined as “T34 Instructor Pilots”, scenarios using T-34 simulation are being used). Assumed in this simulation is the
student’s ability to perform basic flight maneuvers, ability to read and follow approach plates, and ability to
communicate with and follow the directions of Air Traffic Controllers. It cannot be assumed that
indoctrination students would have any of these abilities, therefore a considerably different set of
scenarios would have to be created, probably not involving actual flying skills. The belief that the benefits
of a more realistic flight environment outweigh the potential negative transfer discussed above, for
refresher students, served as the basis for the original educational justification of ROBD training. From
the purely educational perspective, the “value added” from ROBD training is completely lost if the flight
simulation aspects are removed, and what is left is the loss of experiencing the effects of reduced
pressure on the body (i.e. trapped gas expansion/contraction), and possible negative information transfer
during an indoctrination instructional event. The ROBD could be an effective classroom demonstration
tool to illustrate reduced Times of Useful Consciousness at altitudes higher than 25,000 feet.
Joint Specialized Undergraduate Flying Training – Aerospace Physiology - Lesson JP(0)115
Goal
Goal Text
Low Pressure
Chamber Support
Fully Supported.
1
Identify the proper
techniques for
pressure
breathing.
2
Conduct pre-flight
and in-flight checks
of oxygen
equipment.
Fully Supported.
Partially Supported. The ROBD, as currently
regulator, therefore regulator checks cannot be
performed.
3
Conduct the
procedures to treat
hypoxia.
Fully Supported.
Partially Supported. According to NAMRL
research, the ROBD provides what might be
considered to be “more authentic” symptoms, as
the exact partial pressures of the breathing
gasses are more accurately controlled. The
“standard” procedure for suspected hypoxia
includes putting on the oxygen mask. This
reinforces that if hypoxic, under situations in
which all equipment is properly functioning,
breathing oxygen will almost immediately remedy
the situation. The single greatest “problem” with
specific scenario currently in use in trial ROBD
training is one in which the student is flying at
25,000 ft and experiences an equipment
malfunction, resulting in hypoxia. While
considered “more realistic” for experienced
refresher students, for indoctrination students, this
E-9
ROBD Support
Not Currently Supported. “Identify” implies a
cognitive goal, which is independent of training
device, however, close liaison with the USAF
indicates a VERY high emphasis is placed on
performing PPB techniques. The current ROBD
does not have this capability; the “new” version is
supposed to have a PPB capability.
Appendix E
may result in a negative transfer of information
and create a loss of confidence in aviation life
support equipment. Concepts of checking to
make sure that the oxygen mask is correctly
connected and to initiate descent are supported.
4
Conduct
procedures to
perform trapped
gas procedures in
flight.
Fully Supported.
Not Supported. As the ROBD does not involve
any ambient atmospheric pressure changes,
symptoms of trapped gas expansion are not
experienced, and therefore meaningful application
of corrective procedures is not possible.
5
Identify the proper
use of emergency
oxygen systems
and portable
oxygen equipment.
Identify visual
problems resulting
from decreased
oxygen during
night flying
conditions.
Fully Supported.
Not Supported. The ROBD does not involve any
direct student interaction with regulators, either
aircraft-mounted or portable.
Fully supported.
Fully Supported. Although currently conducted
ROBD scenarios do not specifically address this
issue (other than how it is implied during hypoxic
exposure), a night vision demo could easily be
accomplished while the student is under hypoxic
conditions.
Conduct the
procedures to
prevent hypoxia,
trapped gas, and
evolved gas
disorders after a
rapid
decompression.
Identify the
physical signs of a
rapid
decompression.
Identify the
physiological
effects of a rapid
decompression.
Fully Supported.
Not Supported. The realistic application of this
objective is to teach the student to put the oxygen
mask on as quickly as possible following an RD.
Although the hypoxic conditions associated with
RDs can be simulated (i.e. very rapid reduction in
pO2 in the inspired breathing gas), this can only
be accomplished while already wearing the mask.
Fully Supported.
Not Supported. As there is no change to the
ambient pressure, there are no physical changes
presented for identification.
Fully Supported.
Partially Supported. None of the trapped gas
effects will be experienced. Although
experiencing hypoxia following an RD is not
currently conducted as part of either LPC or
ROBD training, this could be introduced using an
ROBD without adding additional risk of
decompression sickness.
6
7
8
9
E-10
Appendix E
R1/RP1 – Refresher Survival Training for Aircrew flying in Ejection Seat Equipped Aircraft (Course
currently under review/revision)
Objective
Objective Text
2.2
Describe the
components and
operating
parameters of an
oxygen system
and experience
the effects of
exposure to
simulated
altitudes in
excess of 10,000
ft.
Preflight an
oxygen
regulator.
2.2.5
2.2.6
2.2.7
Preflight an
oxygen mask.
Recognize the
symptoms of
and treat for
hypoxic hypoxia
at a simulated
altitude of
25,000 ft.
Low Pressure
Chamber Support
Fully Supported.
ROBD Support
Partially Supported. Hypoxia exposure
symptoms are supported. Function of oxygen
equipment is partially supported.
Fully Supported.
Not Supported. The ROBD, as currently
regulator, therefore regulator familiarization is
not practiced. As aircrew in this community fly
primarily with the miniature regulator which has
few, if any, aircrew preflight inspection items to
be performed, this objective has been
recommended for removal from the curriculum.
If this objective is removed, ROBD training
would fully support the terminal objective of this
lesson topic.
Fully Supported.
Fully Supported.
Fully Supported.
Fully Supported. According to NAMRL research,
the ROBD provides what might be considered to
be “more authentic” symptoms, as the exact
partial pressures of the breathing gasses are
more accurately controlled. The “standard”
procedure for suspected hypoxia includes
putting on the oxygen mask. This reinforces that
if hypoxic, under situations in which all
equipment is properly functioning, breathing
oxygen will almost immediately remedy the
situation. The single greatest “problem” with
specific scenario currently in use in trial ROBD
training is one in which the student is flying at
25,000 ft and experiences an equipment
malfunction, resulting in hypoxia. Following the
trends in recent HAZREPs, and the NATOPS
requirement for tactical jet aircrew to be using
oxygen at all times, in the tactical jet community,
E-11
Appendix E
there is a much greater incidence of hypoxia
occurring due to this scenario than from loss of
cabin pressure while not wearing an oxygen
mask. As a point of instructional design, when
revised, this enabling objective will be separated
into two objectives; one for recognition and one
for treatment.
In reality, this community/curriculum is the one for which ROBD training was originally
conceived/designed, and is the only community in which there are not instructional “trade-offs” being
made or “forced” training scenarios being employed. Regardless of any other areas of potential
applicability, this curriculum can only benefit from the institution of ROBD training. Although at this time
specific RIO/WSO scenarios have not been developed, the software/hardware tools are available to
create these. The ultimate vision of NSTI is that ROBD training will be moved from the “schoolhouse”
environment of the Survival Training Centers and will be conducted in actual Fleet flight/weapons
systems simulators.
R2/RP2 – Refresher Survival Training for Aircrew flying in Fixed Wing, Non-Ejection Seat,
Parachute-Equipped Aircraft (Course currently under review/revision)
Objective
Objective Text
2.2
Describe the
components and
operating
parameters of an
oxygen system
and experience
the effects of
exposure to
simulated
altitudes in
excess of 10,000
ft.
Preflight an
oxygen
regulator.
2.2.5
2.2.6
2.2.7
Preflight an
oxygen mask.
Recognize the
symptoms of
and treat for
hypoxic hypoxia
at a simulated
altitude of
25,000 ft.
Low Pressure
Chamber Support
Fully Supported.
ROBD Support
Partially Supported. Hypoxia exposure symptoms
are supported. Function of oxygen equipment is
partially supported.
Fully Supported.
regulator, therefore regulator familiarization. is not
practiced.
Fully Supported.
Fully Supported.
Fully Supported.
procedure for suspected hypoxia includes putting
on the oxygen mask. This reinforces that if
hypoxic, under situations in which all equipment is
properly functioning, breathing oxygen will almost
immediately remedy the situation. The single
greatest “problem” with ROBD training is that the
student is becoming hypoxic while wearing an
oxygen mask. The specific scenario currently in
E-12
Appendix E
use in trial ROBD training is one in which the
student is flying at 25,000 ft and experiences an
equipment malfunction, resulting in hypoxia. This
scenario, however, for aircrew (other than T-34
pilots) who will be receiving this curriculum is
somewhat inappropriate. Current LPC profiles
simulate a gradual, unannounced reduction in
cabin pressure which will eventually be
recognized by students, who will then perform
corrective procedures (put on their masks). The
ROBD can only simulate an oxygen equipment
failure, therefore the scenario would have to be
constructed so that the crew was told that the
cabin pressurization system had failed, so they
were flying while wearing masks. During this
time, the oxygen system also fails, resulting in
hypoxia. As a point of instructional design, when
for treatment.
At this time, there is no indication of whether ROBD training will be inherently more “authentic” than LPC
training for this curriculum or simply be a different artificiality. Nor is there at this time a methodology for
presenting authentic task situations for non-pilots/navigators (e.g. crew chiefs, flight engineers, sonar
operators, etc.).
R4/RP4 – Refresher Survival Training for Aircrew flying in Fixed Wing, Non-Ejection Seat, NonParachute-Equipped Aircraft (Course currently under review/revision)
Objective
Objective Text
2.2
Describe the
components and
operating
parameters of an
oxygen system
and experience
the effects of
exposure to
simulated
altitudes in
excess of 10,000
ft.
Preflight an
oxygen
regulator.
2.2.5
2.2.6
2.2.7
Preflight an
oxygen mask.
Recognize the
symptoms of
and treat for
hypoxic hypoxia
Low Pressure
Chamber Support
Fully Supported.
ROBD Support
Partially Supported. Hypoxia exposure symptoms
are supported. Function of oxygen equipment is
partially supported.
Fully Supported.
regulator, therefore regulator familiarization is not
practiced.
Fully Supported.
Fully Supported.
Fully Supported.
E-13
Appendix E
at a simulated
altitude of
25,000 ft.
procedure for suspected hypoxia includes putting
on the oxygen mask. This reinforces that if
hypoxic, under situations in which all equipment is
properly functioning, breathing oxygen will almost
equipment malfunction, resulting in hypoxia. This
scenario, however, for aircrew (other than T-34
pilots) who will be receiving this curriculum is
somewhat inappropriate. Current LPC profiles
simulate a gradual, unannounced reduction in
cabin pressure which will eventually be
recognized by students, who will then perform
corrective procedures (put on their masks). The
ROBD can only simulate an oxygen equipment
failure, therefore the scenario would have to be
constructed so that the crew was told that the
cabin pressurization system had failed, so they
were flying while wearing masks. During this
time, the oxygen system also fails, resulting in
hypoxia. As a point of instructional design, when
for treatment.
At this time, there is no indication of whether ROBD training will be inherently more “authentic” than LPC
training for this curriculum or simply be a different artificiality. Nor is there at this time a methodology for
presenting authentic task situations for non-pilots/navigators (e.g. crew chiefs, flight engineers, flight
attendants, etc.).
N3/NP3 – NASTP Training for Selected Passengers (Proposed objectives for revision)
Objective
Objective Text
2.2.1
Preflight a flight
helmet and an
MBU-series
oxygen mask,
smoke mask, or
quick-don
oxygen mask, as
appropriate to
aircraft type.
2.2.2
Perform required
preflight
procedures
when flying with
a panel-mounted
Low Pressure
Chamber Support
Fully Supported.
Fully Supported.
ROBD Support
Fully Supported. The ROBD is capable of
supporting any current oxygen mask assembly.
Not Supported. The ROBD does not use a
traditional regulator, therefore this cannot be
accomplished.
E-14
Appendix E
regulator.
2.2.3
Experience the
effects of
trapped gas
expansion on
the ears,
sinuses, and
gastro-intestinal
tract.
Fully Supported.
Not Supported. As there is no ambient pressure
change during ROBD training, there is no ability to
meet this training objective.
2.2.4
Perform
procedures to
relieve trapped
gas imbalances
(dysbarism)
during ascent to
and descent
from a simulated
altitude of 8,000
feet.
Fully Supported.
change during ROBD training, there is no ability to
meet this training objective.
2.2.5
Experience the
effects of
hypoxia at a
simulated
altitude of
25,000 feet.
Perform
procedures to
self-treat for
suspected
hypoxia.
Fully Supported.
more accurately controlled.
Fully Supported.
Partially Supported. The “standard” procedure for
suspected hypoxia includes putting on the oxygen
mask. This reinforces that if hypoxic, under
situations in which all equipment is properly
functioning, breathing oxygen will almost
equipment malfunction, resulting in hypoxia.
While considered “more realistic” for experienced
refresher students, for indoctrination students, this
may result in a negative transfer of information
and create a loss of confidence in aviation life
support equipment. Concepts of checking to
make sure that the oxygen mask is correctly
connected and to initiate descent are supported.
2.2.6
E-15
Appendix E
N4/NP4 – NASTP Training for Project Specialists
Objective
Objective Text
Low Pressure
Chamber Support
Fully Supported.
ROBD Support
2.2.1
Preflight a flight
helmet and an
MBU-series
oxygen mask,
smoke mask, or
quick-don oxygen
mask, as
appropriate to
aircraft type.
2.2.2
Perform required
preflight
procedures when
flying with a
panel-mounted
regulator.
Fully Supported.
Not Supported. The ROBD does not use a
traditional regulator, therefore this cannot be
accomplished.
2.2.3
Experience the
effects of trapped
gas expansion on
the ears, sinuses,
and gastrointestinal tract.
Fully Supported.
change during ROBD training, there is no ability
to meet this training objective.
2.2.4
Perform
procedures to
relieve trapped
gas imbalances
(dysbarism)
during ascent to
and descent from
a simulated
altitude of 8,000
feet.
Fully Supported.
Not Supported. As there is not ambient
pressure change during ROBD training, there is
no ability to meet this training objective.
Fully Supported. The ROBD is capable of
supporting any current oxygen mask assembly.
The primary purpose for including LPC training in the N4/NP4 curriculum was to give students a chance
to experience the effects of pressure changes on the body and to become more familiar/comfortable with
the oxygen equipment.
E-16
Appendix E
N2/NP7 – NASTP Training for Midshipmen
N2/NP8 – NASTP Training for VIPs (This courses scheduled to be combined with N2/NP7 to form a
single course)
NP6 – Special Operations Forces Aviation Physiology Training (Under revision; analysis reflects
currently published objectives)
Objective
Objective Text
2.10
Perform the
donning and
doffing of oxygen
equipment in a
Low Pressure
Chamber
2.11
Perform
procedures for
trapped gas
resolution during
Low Pressure
Chamber training
evolution.
Low Pressure
Chamber Support
Fully Supported.
Fully Supported.
ROBD Support
Partially Supported. Obviously, the condition “in
a Low Pressure Altitude Chamber” is not
supported, although the actual task “donning
and doffing of oxygen equipment” can be
accomplished using the ROBD. This was a
poorly written objective, as the instructional
intent was for oxygen equipment familiarization –
to include the regulator (not to mention that the
actual donning and doffing are both done
outside of the LPC). The task of the objective,
as written, is fully supported, however as the
ROBD does not use a traditional regulator, the
instructional intent of the objective is not fully
supported.
change during ROBD training, there is no ability
to meet this training objective.
The primary purpose for including LPC training in the abbreviated N2/NP7 and N2/NP8 curricula was to
give students a chance to experience the effects of pressure changes on the body and to become more
familiar/comfortable with the oxygen equipment. In the case of the Midshipmen course, the LPC is also
considered to be a “cool ride”, as the entire course is viewed more as an entertaining recruiting tool to stir
up enthusiasm for aviation than as a training course. The NP6 course was designed to meet a joint
requirement for high altitude parachutists in the Special Operations branches of the services. Although
strangely missing from the published objectives, the content of the curriculum clearly indicates the
requirement for conducting panel-mounted regulator pre-flight checks and experiencing hypoxia at 35,000
ft. The ROBD is capable of meeting the hypoxia requirements, but does not meet the regulator check
requirements. At this time, there is no indication that the Army or Air Force would accept ROBD training
in place of LPC training for these personnel.
E-17
Table F-1: LPC and ROBD Operating Costs
Pensacola
ASTC
Device
LPC
1.
Number of
Devices
Cherry Point
ROBD
1
2.
Number of
Students Per Year
LPC
8
Patuxent River
ROBD
1
LPC
2
Jacksonville
ROBD
1
LPC
2
Norfolk
ROBD
1
LPC
4
Miramar
ROBD
1
LPC
4
Lemoore
ROBD
1
LPC
4
Whidbey Island
ROBD
1
LPC
3
Total
ROBD
1
LPC
3
ASTC
ROBD
Device
8
30
1.
Number of
Devices
4,049
4,049
266
266
844
844
1,247
1,247
1,753
1,753
2,053
2,053
450
450
752
752
11,414
11,414
2.
Number of
Students Per Year
2.
Number of
Flights Per Year
214
4,049
53
266
97
844
75
1,247
135
1,753
116
2,053
62
450
87
752
839
11,414
2.
Number of
Flights Per Year
2.
Average Number
of Students
Trained Per Month
337
337
22
22
70
70
104
104
146
146
171
171
38
38
63
63
119
951
2.
Average Number
of Students
Trained Per Month
2.
Average Number
of Flights Per
Month
18
337
4
22
8
70
6
104
11
146
10
171
5
38
7
63
9
951
2.
Average Number
of Flights Per
Month
2.
Average Number
of Students Per
Flight
19
1
5
1
9
1
17
1
13
1
18
1
7
1
9
1
12
1
2.
Average Number
of Students Per
Flight
186
274
20
19
47
61
52
85
87
119
86
139
28
32
42
53
550
781
2,232
3,286
241
231
568
735
628
1,014
1,049
1,423
1,036
1,667
333
380
507
630
6,594
9,366
78,723
$ 115,887
8,147
$ 20,045
$ 25,923
$ 22,157
$ 35,764
36,995
$ 50,205
58,805
$ 11,759
$ 13,404
$ 17,871
22,220
232,584
330,356
30
0
0
9
0
16
0
17
0
0
14
0
10
3.
Monthly Military
Man-Hours
Annual Military
Man-Hours
4.
Annual Military
Labor Costs
5.
$
HDIP Billets
Annual HDIP
Costs
$
54,000
$
8,489
$
11
$
-
6.
Annual Gas
Costs
$
1,020
$
7.
Service Contract
Costs
$
13,460
$
8.
Commercial
Contract Costs
$
TOTAL ANNUAL
COSTS
$ 202,773
Cost of LPC
Compared to
Cost of ROBD
(LPC ÷ ROBD)
70,050
$ 19,800
$
-
$ 16,200
$
-
67
$
3,365
$
$ 39,139
$ 130,367
$ 67,428
1.6
$
-
213
$
3,365
$
$ 36,025
$ 11,579
5.8
$ 72,270
$ 28,800
$
-
314
$
6,730
$
$ 38,532
$ 29,501
2.4
$ 89,489
$ 42,808
2.1
$
$
30,600
$
30,403
$
97,998
$
36,546
$
18
$
$
-
442
$
6,730
$
$
$ 57,376
32,400
$
-
517
$
6,730
$
36,025
$ 104,971
1.7
$ 25,200
$
1.6
66,052
$ 72,984
0
$
2,875
6.
Annual Gas
Costs
5,048
$
50,475
5,048
$
$ 36,025
3.9
$ 225,000
27,457
$ 779,808
7.
Service Contract
Costs
8.
Commercial
Contract Costs
$ 322,224
2.6
HDIP Billets
189
$
$
5.
Annual HDIP
Costs
113
$ 71,896
0
4.
Annual Military
Labor Costs
-
-
$ 18,565
125
Annual Military
Man-Hours
$
$
$ 36,025
$ 18,000
$
3.
Monthly Military
Man-Hours
$ 383,706
2.0
TOTAL ANNUAL
COSTS
Cost of LPC
Compared to
Cost of ROBD
(LPC ÷ ROBD)
Notes:
1. Number of ROBDs is based on historical ASTC LPC student load data. Pensacola requires eight ROBDs because it often runs two LPC flights in one day.
2. Student load data for the LPC is based on NASTP FY02 annual report (Appendix F-2).
3. See Appendix G-1 for military man-hour calculations.
4. Labor costs are based on the composite standard pay rates published by the DoD Comptroller’s Office for 2004. Pay rate ($35.27/hour) is a weighted averaged based on normal LPC manning.
5. Hazardous Duty Incentive Pay (HDIP) billets are based on current billet authorization.
6. ROBD annual gas costs are estimated based on local gas prices and the amount of gas used during a standard 20 minute ROBD flight to 25,000 feet. Actual operating costs may vary.
7. Service contract costs are estimates given by the commercial company currently producing the ROBD. Cost is $1682.50 per device and includes annual maintenance, consumables, and calibration.
8. Commercial contract costs for Cherry Point, Jacksonville, and Norfolk are actual current costs. All other sites do no use a commercial contract. However, it was determined that the commercial contract cost is an accurate estimate for all sites, and an average cost of
$36,025 was used for four of the five remaining sites. Because Pensacola does twice as much training as the next largest site, its commercial cost was doubled ($72,050). The commercial contract cost includes all non-military labor, device maintenance, and gas costs.
F-1
Table F-2: NASTP Low Pressure Chamber Training Data
FY02
Section: XI
Pensacola
NASTP Accumalitive HDIP Information
Authorized HDIP
Quotas
Actual/Filled HDIP
Billets
Officer
Officer
Enlisted
Number Of
Exposures
Enlisted
Number of LPC
Flights
Number of
Students
Number of
Number of Flights Average Number
Students per LPC per Quarter per
of Flights per
Flight
IO
Month per IO
1st Qtr
8
22
9
22
173
53
972
18.34
5.58
1.86
2nd Qtr
8
22
9
23
161
53
903
17.04
5.03
1.68
3rd Qtr
8
22
8
24
176
55
1050
19.09
5.50
1.83
4th Qtr
AVERAGE
8
22
7
22
140
53
1124
21.21
4.83
1.61
8
22
8.25
22.75
162.5
53.5
1012.25
18.92
5.23
1.74
Cherry Pt
1st Qtr
2
9
2
12
48
16
111
6.94
3.43
1.14
2nd Qtr
2
9
2
12
40
14
114
8.14
2.86
0.95
3rd Qtr
2
9
1
8
25
9
16
1.78
2.78
0.93
4th Qtr
2
9
2
9
35
14
25
1.79
3.18
1.06
2
9
1.75
10.25
37
13.25
66.5
4.66
3.06
1.02
1st Qtr
2
7
2
4
26
15
57
3.80
4.33
1.44
2nd Qtr
2
7
2
4
31
17
116
6.82
5.17
1.72
3rd Qtr
2
7
2
5
84
43
549
12.77
12.00
4.00
AVERAGE
Pax River
4th Qtr
AVERAGE
2
7
2
6
36
22
122
5.55
4.50
1.50
2
7
2
4.75
44.25
24.25
211
7.23
6.50
2.17
Whidbey Is
1st Qtr
2
8
2
6
32
15
131
8.73
4.00
1.33
2nd Qtr
2
8
3
6
55
22
225
10.23
6.11
2.04
3rd Qtr
2
8
2
8
53
28
190
6.79
5.30
1.77
4th Qtr
2
8
2
7
47
22
206
9.36
5.22
1.74
2
8
2.25
6.75
46.75
21.75
188
8.78
5.16
1.72
AVERAGE
Lemoore
1st Qtr
3
11
3
8
40
12
75
6.25
3.64
1.21
2nd Qtr
3
11
4
8
44
17
97
5.71
3.67
1.22
3rd Qtr
3
11
3
7
42
16
161
10.06
4.20
1.40
4th Qtr
3
11
3
9
42
17
117
6.88
3.50
1.17
3
11
3.25
8
42
15.5
112.5
7.23
3.75
1.25
AVERAGE
Miramar
1st Qtr
3
15
3
15
63
21
216
10.29
3.50
1.17
2nd Qtr
3
15
2
13
57
22
249
11.32
3.80
1.27
3rd Qtr
3
15
3
15
105
26
874
33.62
5.83
1.94
4th Qtr
3
15
3
12
142
47
714
15.19
9.47
3.16
3
15
2.75
13.75
91.75
29
513.25
17.60
5.65
1.88
AVERAGE
Norfolk
1st Qtr
3
12
3
12
59
21
299
14.24
3.93
1.31
2nd Qtr
3
12
3
11
75
30
302
10.07
5.36
1.79
3rd Qtr
3
12
3
10
175
60
812
13.53
13.46
4.49
4th Qtr
3
12
3
10
70
24
340
14.17
5.38
1.79
4
13
3
10.75
94.75
33.75
438.25
13.00
7.03
2.34
AVERAGE
Jax
1st Qtr
3
13
4
14
57
17
217
12.76
3.17
1.06
2nd Qtr
3
13
3
13
56
13
197
15.15
3.50
1.17
3rd Qtr
3
13
4
13
74
19
443
23.32
4.35
1.45
4th Qtr
3
13
4
10
87
26
390
15.00
6.21
2.07
3
13
3.75
12.5
68.5
18.75
311.75
16.56
4.31
1.44
AVERAGE
F-2
Table F-3: NASTP Physiology and Water Survival Training Totals
FY02
Section IX:
ASTC's
NASTP Physiology And Water Survival Totals By Curriculum
N1
NP1
N5
NP2
N2
NP7
N2
NP8
N3
NP3
N4
NP4
NP5
NP6
N6
N7
N8
N9
N10
N11
N12
N13
N14
RP1
R1
RP2
R2
RP3
R3
RP4
R4
Misc
Trng
Total
Cherry Point
132
24
2
29
1
32
3
146
84
152
0
3
4
1315
18
55
135
200
24
12
2371
Jacksonville
80
139
5
16
6
0
5
345
139
305
0
12
15
0
0
242
791
308
149
8
2565
Lemoore
46
45
67
36
12
46
1
130
49
169
5
8
11
0
0
232
85
46
6
11
1426
Miramar
311
1046
77
72
41
155
18
421
302
328
11
30
107
1071
0
509
406
1164
103
0
6172
Norfolk
65
584
183
47
4
0
0
317
37
326
0
4
0
134
70
472
815
530
102
0
3690
Patuxent River
32
502
30
48
174
0
13
0
146
0
0
13
15
0
0
96
166
88
62
0
1385
1933
32
5
16
20
0
675
1185
23
722
0
1903
631
0
0
230
476
196
86
0
10969
0
69
4
19
10
0
2
7
3
0
0
0
0
0
0
377
403
11
32
0
937
Pensacola
2836
Whidbey
421
NSTI HQ
Total
2836
2599
2441
373
283
268
421
233
717
2551
783
F-3
2002
16
1973
783
2520
88
2213
3277
2543
564
158
158
189
29673
Appendix G
Military Man-hours Required to Conduct Low Pressure Chamber and Reduced Oxygen
Breathing Device Training: A Formulaic Approach Based on Student Training Load
Brian D. Swan, Instructional Designer, Naval Survival Training Institute
Introduction and Background
The process of migrating some or all of the hypoxia familiarization training for Navy and Marine
Aircrew from Low Pressure Chamber (LPC)-based training to Reduced Oxygen Breathing Device
(ROBD)-based training has many educational, fiscal, and manpower issues that must be
considered. The purpose of this brief paper is to specifically address a method of estimating the
military manpower required to perform the two modalities of training as, primarily, a function of
student load. Other variables such as number of classes offered per month, average number of
students per class, and number of ROBDs available at an ASTC are also taken into account.
Swan (1987, 1988) published a series of formulas designed to estimate the total man-hours
required to conduct aviation physiology and water survival training, using formulaic budgeting
techniques that were being used by various government agencies, most specifically departments
of higher education. Counting man-hours instead of straight dollars, he developed a series of
formulas that described all aspects of classroom and dynamic training, as a function of the
variables listed above. Although many aspects of this original work would have to be revisited in
light of intervening curriculum changes, the basic operation of the LPC has not changed in ways
that would affect these formulas; therefore, the formulas for the LPC remain valuable tools in
estimating man-hours required. For the purposes of the present discussion, only military manhours are of interest, so the focus will be primarily on operations and not on the device
maintenance functions typically performed by contractor or Government Service personnel.
Five specific elements were factored into each of the original training device equations: (1)
Scheduled Device Maintenance Hours (SMH), (2) Unscheduled Device Maintenance Hours
(UMH), (3) Training Equipment Maintenance Hours (TEMH), (4) Fixed Student Contact Hours
(FSCH), and (5) Variable Student Contact Hours (VSCH). The goal was to express all of these
elements in terms of the total number of students per month (x), the number of classes per month
(m), and the average number of students per class (c).
The basic formula, in its qualitative representation would be:
SMH + UMH + TEMH + FSCH + VSCH
(1)
or, as adapted for the purposes of determining military-only man-hours:
TEMH + FSCH + VSCH
(2)
Low Pressure Chamber Man-hour Formula Derivation
Scheduled Maintenance Hours (SMHs)
This factor is performed by civilian personnel and has been eliminated from the original estimate
model.
Unscheduled Maintenance Hours (UMHs)
This factor is performed by civilian personnel and has been eliminated from the original estimate
model.
Training Equipment Maintenance Hours (TEMHs)
G-1
Appendix G
TEMHs reflect the amount of time required to maintain the helmets and masks used in LPC
training evolutions. This includes the build-up, troubleshooting, repairs, and post-flight cleaning
conducted by staff parachute riggers and corpsmen. A basic assumption is made that
maintenance varies directly with student load. Measured historical data (from ASTC Miramar)
indicated that the average amount of time spent on these functions is 25 hours/month. Matching
student training load for the same time period, it was found that an average of 120 students per
month were trained in the LPC. Therefore, the TEMHs, as a function of student load, is
expressed as:
25 hrs/month / 120 studs/month = .208 hrs/student = .208x
(3)
Fixed Student Contact Hours (FSCHs)
FSCHs are those hours that are fixed for each LPC flight, independent of the number of students
involved in the flight.
Fixed Military Personnel for Pre-Ox
Fixed Military Personnel for LPC Flight
1
Chief Observer
1
1
1
Chief Observer
Lock Standby
Recorder
1
Total
3
Total
Time element = .5 hours
Contact Time per event
1 person x .5 hours = .5 man-hours
3 people x .5 hours = 1.5 man-hours
Combining the two:
.5 + 1.5 = 2 hours/class
Or, in terms of m, equation (4) gives the algebraic expression for FSCH:
2m
(4)
Variable Student Contact Hours (VSCHs)
The VSCH value reflects the number of Inside Instructor/Observer (IO) man-hours as a direct
mathematical function of the number of students per event (c). As each IO expends one hour per
flight (30 minutes pre-ox and 30 minutes flight time), the VSCH value equals the number of IOs.
To determine the IO hours per student, the average number of students per flight is divided by the
required number of IOs for that average. This quotient is represented as I and is given in the table
below as a function of c, for the range c= 1 through 22:
I/O Contact Hour Factor Table (Variable “I”)
Calculated Students
per flight
I/O Contact
Factor
1
2
2
1
G-2
Appendix G
3
4
5
6
7
8
9,13,14,19
10,11,20,21,22
15,16
12,17,18
0.68
0.5
0.4
0.34
0.3
0.26
0.24
0.2
0.21
0.18
NOTE: If calculated values for c are being used, the number should be rounded to the nearest
whole-number value.
Given that “I” represents the IO requirements per student, it follows that the VSCHs can be
expressed in terms of I and x as is illustrated in equation (5)
Ix
(5)
When equations (3), (4), and (5) are substituted into equation (2), equation (6), the total military
man-hours for Low Pressure Chamber operations is achieved:
.208x + 2m + Ix
(6)
Reduced Oxygen Breathing Device Man-hour Formula Derivation
Based on a similar philosophy, man-hour requirements for ROBD training can also be calculated
as a function of student load and number of ROBDs available at an ASTC.
For basic, single-device operation, two people are required; an operator and an instructor/safety
observer. As it requires approximately 30 minutes per student, the simplest formula for ROBD
training can be expressed as:
(2)(.5x) = 1x
(7)
As a “worst case” figure, this will estimate to total man-hours required to operate the ROBD. The
Naval Aviation Survival Training Program Standard Operating Procedures (NASTP SOP),
however, makes the provision that up to 4 ROBDs may be operated under one instructor/safety
observer (e.g. if an ASTC has 4 ROBDs, it would require a total of 5 personnel; 4 operators and 1
instructor/safety observer, vice 8 personnel). In this case, operator personnel and
instructor/safety observer personnel must be calculated separately and added together.
The operator hours are determined using the same logic as used above (1 person, for 30
minutes, per student), expressed algebraically as:
(1)(.5x) = .5x
(8)
The number of instructors/safety observers is best expressed, for a population, as a function of
students trained and number of ROBDs present at an ASTC. If an ASTC has only one ROBD,
then students will be trained sequentially, and the end result will be the same as the “worst case”
scenario discussed above. For example, given a class of 12 students, each student would
receive 30 minutes of training presented by one operator and one instructor/safety observer,
requiring the instructor/safety observer to be present for all 12 cycles – 6 hours of total time to
train and observer time. Conversely, if an ASTC has four ROBDs, then students can be trained
G-3
Appendix G
four at a time, reducing the total time to train and observer time down to 90 minutes.
Algebraically, the instructor/safety observer time requirements can be expresses as:
.5x / r
(9)
where r is the number of ROBDs located at an ASTC. The “best case” scenario may then be
completely described by adding the operator time (8) and the instructor/safety observer time (9):
.5x + .5x / r
(10)
For a given number of students, and a given number or ROBDs, the results of equations (7) and
(10) provide a range estimate for time to train using the ROBD.
To find a “single” point number to use for statistical comparison between the two training
methods, use a simple algebraic average of best and worst case figures. Expressed as a single,
combined formula as:
[x + (.5x / r)] / 2
(11)
Discussion
Low Pressure Chamber training has been a standby of the NASTP for over 40 years. During the
course of those 40 years there have been some procedural differences – primarily in the terminal
altitudes used to train – however the manning and basic procedures have remained largely
unaltered. Over the past 20 years, there have been virtually no changes. The formulas
presented in this paper are merely a numeric description of the status quo, and were represented as a basis for comparison with the newly derived ROBD man-hour formulas.
With the ROBD formulas the question arises of why should the “worst case” even be considered.
In the reality of training at an ASTC, the ROBD is considerably different than any other training
currently conducted, and requires different skill sets than have ever been expected of NASTP
instructors in the past or present, most notably, the ability to carry out authentic aircraft/air traffic
control communications procedures. Historically, most of the training devices and scenarios used
are “scripted”; instructors need to be able to present information in a pre-arranged, linear fashion
with pre-established decision making points. The type of communications required to maximize
the effectiveness of ROBD training will be largely unscripted; instructors and/or operators will be
required to respond to unscripted responses on the part of students in a way that very closely
mirrors the way in which an actual air traffic controller would respond (an exact parallel to aircraft
simulator instructors). There will be a period of time when there will be few instructors/operators
capable of conducting this training; the number should grow with time, assuming that ASTC
instructor training programs are in place and are being effectively monitored. In reference to the
formulas, this would indicate that during early stages of implementation, the number provided by
the worst case formula will probably be the most accurate, while with time, the best case formula
may become more accurate.
Conclusions
The purpose of this paper was not to provide recommendations as to which training method was
either more or less efficient with regards to man-hours required to provide hypoxia training to
students, but rather to provide a tool set that managers can use to see what the relative effects of
class size, total students trained and device availability are when comparing the two. Final
decisions will have to take all of these factors, as well as instructor training, ASTC logistics, and
instructional validity of the ROBD into account.
G-4
Appendix G
References
Swan, B.D. (1987). Equations for determination of man-hours required to provide NAPTP and
NAWSTP Training. Navy Physiology. 4th Quarter 1987. p. 17-22.
Swan, B.D. (1988). Manpower Formulas Revisited. Navy Physiology. 2nd/3rd Quarters 1988.
p. 1-7.
G-5
Appendix H
ROBD Procurement and Implementation Plan
LT Anthony Artino,
Director, Human Performance & Training Technology,
ROBD Hypoxia Training System Costs
Naval Air Systems Command, Program Management Activity 205 (PMA-205) provides fiscal
support for procurement, operations and maintenance of training devices used in support of the
Naval Aviation Survival Training Program (NASTP). To date, PMA-205 has provided $400,000 to
procure initial device and support equipment required to establish an initial ROBD training
capability within the NASTP.
Table H-1 shows the initial investment needed to purchase 13 ROBD Hypoxia Training Systems.
This estimate is an update of Table 2 and is based on the equipment required to operate the
device in accordance with the current ROBD training paradigm (see Appendix C). The costs
include not only the equipment required to run the ROBD (e.g., gas mixer and regulators) but also
the computer equipment necessary to run the flight simulation (e.g., desktop computer, display,
software, and aircraft controls). As noted in Table H-1, six of the 13 ROBD gas mixers will be
purchased at a one-time, discounted price.
Table H-1
Initial ROBD Hypoxia Training System Costs
Component
Cost
Units
Total
1.
ROBD Gas Mixer
$ 25,493
7 $ 178,451
2.
ROBD Gas Mixer (discounted price)
$ 18,500
6 $ 111,000
Gas Regulators
$
760
13 $
9,880
ROBD Case
$
677
13 $
8,801
High Pressure Hoses
$
203
13 $
2,639
Oxygen Extension Hoses
$
30
13 $
390
Computer
$ 1,750
13 $ 22,750
Display
$
600
13 $
7,800
Software
$
30
13 $
390
Communications Suite
$
858
13 $ 11,154
Aircraft Controls
$ 3,470
13 $ 45,110
Total
13 $ 398,365
1.
Approximate single system cost at standard price = $33,871
2.
Approximate single system cost at discounted price = $26,878
H-1
Appendix H
ROBD Implementation Plan
The initial purchase of 13 ROBD Hypoxia Training Systems will be distributed to four Aviation
Survival Training Centers (ASTCs) in order to establish an initial ROBD training capability within
the NASTP during FY-05. Table H-2 outlines system distribution at these four ASTCs.
Table H-2
Initial ROBD Training Capability Distribution Plan
Aviation Survival Training Center
Units
Primary Aircraft
ASTC Pensacola
1
T-6, T-2, & T-45
ASTC Miramar
4
F/A-18
ASTC Lemoore
4
F/A-18
ASTC Norfolk
4
F/A-18 & F-14
Total
13
T-6, T-2, T-45, F/A-18, & F-14
Future Considerations
At present, ROBD procurement is priority #4 on the Trainer Management Team (TMT) #21
Priority List. However, there are currently no other funds specifically earmarked for ROBD
procurement beyond FY-04. That being said, PMA-205 is activity looking to obtain additional
APN-7 funding for future ROBD procurement. Using today’s estimates, the NASTP would need
to purchase 17 additional ROBD Hypoxia Training Systems to achieve full ROBD training
capability.
H-2

Hypoxia familiarization training has been an integral part of naval

Transcription

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