Issue 6, 12/2006 ReDo

Communiqué
Issue # 6 Volume # 1
“Tail wheel
aircraft are
not inherently
directionally
unstable on
the ground
because they
are tail draggers.”
These words from Murry I. Rozansky
became the topic for our design group
meeting. Mr., Rozansky enlightened us with
his analysis on aircraft landing gear design
and other subjects. He also provided the
attached write up and photos of his
discussion, which everyone should find
thoroughly informative. His paper will explain
his COSCO Design Study
(with advance aeroshopcart
technology) and how he
sees aircraft landing gear
design.
Murry acknowledged that
while he was in the process
of studying roadable aircraft
he needed to look closer at
aircraft landing gear design.
Since three wheel vehicles
are judged as a motorcycle.
A roadable type aircraft would be easier to
carry out under present vehicle regulations
as a motorcycle. An example he gave was
the Bede car or autocycle which had 4
wheels but only three could touch at anyone
time. SEE Bede Write Up. John brought
up the Dymaxion Car three wheel car which
seemed to function with rear steering. See
Dymaxion Write Up.
The meeting turned into a very interesting
exchange of ideas. Many of the members
expressing views in a round table type
atmosphere. The mixture of ideas developed
into a very informative and worthwhile
discussion.
The group debated the challenges of
building a roadable car and who would buy
something which did not fulfill either situation
fully. The history of flying cars has been a
complicated one. As airplanes, they can be
heavy and as a car they lack daily comfort
and handling features. Not a full aircraft or a
full car, compromised for either role. You
start with many technical challenges in
roadable aircraft design and with major
concession in the design from the beginning.
John Lyon stated that a group of his friends
tried to figure out one day which would be
better to own. Would you buy the roadable
part of the flying car and rent the aircraft part
or vise versa. They came to the conclusion
that they should own the aircraft unit and
rent the ground unit when they arrived.
John and friends figured that Hertz and Avis
rental car agencies had solved this problem
without having too own two
units. But, others knew you
couldn’t always get a car.
Murry, Barnaby and John
discussed the merits of the
Zuck
PlaneMoblie
as
a
roadable concept and its
landing gear.
This was an
aircraft designed in 1947 as a
two place road able airplane;
40hp Continental A-40; span:
31'6" length: 15'6" load: 375# v:
90/80/40 range: 285. [NX30031]. Floating, or
pivotal, wing, free to change its angle of
attack according to the vagaries of the air
currents. There were no rudders or elevators
in the tail, instead the wings had "ailerators,"
a combination of ailerons and elevators.
Looking somewhat like an Aeronca C-3
gone haywire, it reportedly suffered a severe
ground loop during a test flight. The
Whitaker-Zuck Planemobile was 19 feet
long, with 32.5 feet of folding wings. It
solved the problem of what to do with the
wings by simply folding them across its
back, to be carried like a hermit crab carries
his shell.
Zuck had problems with this aircraft handling
correctly on the ground during takeoff.
Barnaby informed us that it was a two
control aircraft without a moveable rudder.
Its main problem was as you
went down the runway and
speed up; it had no
moveable
rudder
or
differential
braking
or
steering as the tail came up
so around the aircraft went
into a ground loop.
Zuck did write a book called
A Plane in Every Garage.
Barnaby’s review of this
book was most amusing. He
reviewed it as a cross
between 1950’s techno and
cold
war
paranoia.
Individuals would work where the bomb
would drop. But, fly home or live in a
survivable area from the fallout. It seems
Zuck also figured out that the steering had to
be in the front two wheels and stated so in
his book.
Murry went back to his main concept; it’s
about how you do the steering that matters.
It was also his opinion that the flight
hardware had to go with road configuration
on any roadable aircraft design to be
commercial viable. He also likes the idea of
an Auto Gyro roadable because it does not
impose a large penalty on the road because
the flight blades can be stored like skis on a
roof. But, the gyro has a limit to efficiency
over a fix wing which he believes would hurt
sells.
Bob Young acknowledged that the type of
landing gear on an aircraft / vehicle should
be dictated by the mission of the vehicle.
For an off road aircraft he would want a tail
dragger. Having dealt with tri-wheel vehicles
at Honda with the steering wheel in front has
shown them to be very unstable. When he
flew in Alaska in the 1950’s he saw many
Cessna 182’s upside on their backs.
Cessna had to lower the gear and make it
wider to solve some of these problems.
Bobs main theme was it does not matter
what type of landing gear configuration you
have. Once you learn to fly it correctly it
makes no difference. It’s like a musical
instrument you have to learn to play it.
Murry declared that some where harder to
learn then others. They then discussed four
wheel vehicles and four wheel steering with
both concluding that they had not been
successful on many vehicles.
The tri-gear was not always safer then a tail
dragger. Bob thought that a successful
handling ground vehicle like a three wheel
Morgan design might show promise for a
road able design.
Someone stated that a similar type
motorcycle / auto could be built from plans.
An example would be The Tri-Magnum three
wheeler DIY project designed by Robert Q.
Riley. The drive train is a high-CC
motorcycle rear end mated to a simple steel
frame which in turn mates to a VW beetle
front suspension. A simple body of wood,
urethane
foam,
and
fiberglass
is
constructed. The vehicle's plans are the best
sellers at Robert Q. Riley's site. The plans
debuted in the February 1983 issue of
Mechanix Illustrated magazine but are now
available for purchase from the designer’s
website. Some states recognize the TriMagnum as a motorcycle, some as a car,
and others as a Specially Constructed
Vehicle. To comply with state laws some
people have added a single motorcycle
head light in addition to the two regular car
headlights.
http://www.rqriley.com/tri-mag.html
http://www.rqriley.com/doran.html
http://www.rqriley.com/xr3.htm
http://www.rqriley.com
Murry was then asked why he thought that
the Molt Taylor Aero Car was not a winning
design as a roadable aircraft. He saw the
AeroCar as a small car which had to tow
large light surface areas down the highway.
This combination could be very hard to
control at highway speeds and windy
weather. Since one of the Molt’s selling
points was that you would land the aircraft if
weather was really bad. You would continue
your trip on the road as you drove through
the weather front. Most likely there would
be some major winds you would have to tow
the light wings and tail around.
The idea of combining Molt Taylor’s MiniImp and General Motors Lean Machine as a
roadable design was also brought up. The
Mini-Imp has folding wings and similar
technology as the aerocar for the propeller
drive system. Make the tail cone removable
with the removable wings. What you have is
a three wheel vehicle that looks similar to
GM Lean Machine Motorcycle. Could you
tow the light wings and tail areas with a light
weight motorcycle? See Lean Machine
attachment.
How did this all end, very simply with Murry
demonstrating his aeroshopcart (shopping
As the group
cart to the uninformed).
pushed the aeroshopcart backwards and
forward in the hanger, Murry’s theory came
to life as it rolled forward and ground looped.
Another very informative meeting. If that
wasn’t enough we had the Luscombe
company representatives stop for a talk.
Foundation is now a subsidiary of the
company and called “Team Luscombe". Key
personnel will continue to work for Team
Luscombe and will continue to be based at
Chandler, Arizona.
Why would anyone even attempt to build a
75 year old design again? Well, it turns out
there are many reasons. John was able to
research some AOPA and GAMA data. This
data composed of pilot surveys showed that
77% of the pilots where into flying for
adventure and fun. Pilots had the same
attitude as rock climbers, sail boater, etc
towards fun and adventure.
Luscombe Silvaire Aircraft Company
We had John Dearden stop by for informal
talk about the company’s plans. They
seemed very upbeat and optimistic about
becoming an aircraft manufacturer. The
Luscombe seems to have arrived just in time
for the new LSA arena. The Dearden’s think
that the Luscombe, first built in the 1930s, is
the right airplane at the right time.
Then there was the explosion of the kit
plane market. Basically going from about
500 kits to over 10,000 sold. This market
gave people the fun type of aircraft that they
wanted.
There were also a lot of people who would
like to build a kitplane. Many did not trust
their abilities. Some did not want to face
problems with family structure that may
come from a kitplane.
They then went looking for what was out
there which could fill this need for a fun
aircraft. Looking to get a Type Certificate or
manufacturing rights. They had a list of
aircraft like the Taylocraft, Swift, Ercoupe,
Luscombe and a few others. The Luscombe
came out on top.
LUSCOMBE aircraft are to go back into
production at FlaBob. The company will
initially move into Hangar One at Flabob,
where it plans to produce a Light Sport
Aircraft (LSA) version of the plane.
They will try to produce two versions of the
famous Luscombe 8. They are a Light Sport
version powered by a Continental O-200,
followed by a type certified model with a
more powerful Lycoming O-320 engine.
Initially, they plan to offer the aircraft in taildragger configuration and in time will offer
an alternative tricycle gear model. As many
know, the Luscombe 8A, 8B (possibly other
models, though the 8E and 8F are not
eligible) models of the popular Luscombe
Silveraire are already approved as Light
Sport Planes.
They had been tied down in litigation with
the Don Luscombe Aviation History
Foundation. They now hold the complete
factory hardware and intellectual property,
including the Type Certificate. The
They got a good exclusive license, but the
license was not honored and litigation had to
take place which prevented any aircraft from
being built. They are now prepared to build
the new LSA at FlaBob for the many fun and
adventurous souls. If the new Luscombe
can be built for a profit at their price point. It
will be one good bargain for an all new metal
aircraft.
The picture Show
At this meeting we viewed another video program
by brilliant German aeronautical engineer Dr.
Alexander Lippisch. The film centered on early
aviation design before and after the Wright
Brothers.
I can not write a better article then what
the Wright Brothers themselves placed
on paper so the following is their view of
the early years.
The Wright Brothers Aëroplane
by Orville and Wilbur Wright
Century Magazine, September 1908
THE article which follows is the first popular
account of their experiments prepared by
the inventors. Their accounts heretofore
have been brief statements of bare
accomplishments, without explanation of the
manner in which results were attained. The
article will be found of special interest, in
view of the fact that they have contracted to
deliver to the United States Government a
complete machine, the trials of which are
expected to take place about the time of the
appearance of this number of THE
CENTURY. -THE EDITOR [OF THE
CENTURY].
THOUGH THE SUBJECT of aërial
navigation is generally considered new, it
has occupied the minds of men more or less
from the earliest ages. Our personal interest
in it dates from our childhood days. Late in
the autumn of 1878, our father came into the
house one evening with some object partly
concealed in his hands, and before we could
see what it was, he tossed it into the air.
Instead of falling to the floor, as we
expected, it flew across the room till it struck
the ceiling, where it fluttered awhile, and
finally sank to the floor. It was a little toy,
known to scientists as a "hélicoptère," but
which we, with sublime disregard for
science, at once dubbed a "bat." It was a
light frame of cork and bamboo, covered
with paper, which formed two screws, driven
in opposite directions by rubber bands under
torsion. A toy so delicate lasted only a short
time in the hands of small boys, but its
memory was abiding.
Several years later we began building these
hélicoptères for ourselves, making each one
larger than that preceding. But, to our
astonishment, we found that the larger the
"bat," the less it flew. We did not know that a
machine having only twice the linear
dimensions of another would require eight
times the power. We finally became
discouraged, and returned to kite-flying, a
sport to which we had devoted so much
attention that we were regarded as experts.
But as we became older, we had to give up
this fascinating sport as unbecoming to boys
of our ages.
It was not till the news of the sad death of
Lilienthal reached America in the summer of
1896 that we again gave more than passing
attention to the subject of flying. We then
studied with great interest Chanute's
"Progress in Flying Machines," Langley's
"Experiments
in
Aërodynamics,"
the
"Aëronautical Annuals" of 1895, 1896, and
1897, and several pamphlets published by
the Smithsonian Institution, especially
articles by Lilienthal and extracts from
Mouillard's "Empire of the Air." The larger
works gave us a good understanding of the
nature of the flying problem, and the
difficulties in past attempts to solve it, while
Mouillard
and
Lilienthal,
the
great
missionaries of the flying cause, infected us
with their own unquenchable enthusiasm,
and transformed idle curiosity into the active
zeal of workers.
In the field of aviation there were two
schools. The first, represented by such men
as Professor Langley and Sir Hiram Maxim,
gave chief attention to power flight; the
second, represented by Lilienthal, Mouillard,
and Chanute, to soaring flight. Our
sympathies were with the latter school,
partly from impatience at the wasteful
extravagance of mounting delicate and
costly machinery on wings which no one
knew how to manage, and partly, no doubt,
from
the
extraordinary
charm
and
enthusiasm with which the apostles of
soaring flight set forth the beauties of sailing
through the air on fixed wings, deriving the
motive power from the wind itself.
The balancing of a flyer may seem, at first
thought, to be a very simple matter, yet
almost every experimenter had found in this
the one point which he could not
satisfactorily
master.
Many
different
methods were tried. Some experimenters
placed the center of gravity far below the
wings, in the belief that the weight would
naturally seek to remain at the lowest point.
It was true, that, like the pendulum, it tended
to seek the lowest point; but also, like the
pendulum, it tended to oscillate in a manner
destructive of all stability. A more
satisfactory system, especially for lateral
balance, was that of arranging the wings in
the shape of a broad V, to form a dihedral
angle, with the center low and the wingtips
elevated. In theory this was an automatic
system, but in practice it had two serious
defects: first, it tended to keep the machine
oscillating; and, second, its usefulness was
restricted to calm air.
In a slightly modified form the same system
was applied to the fore-and-aft balance. The
main aëroplane was set at a positive angle,
and a horizontal tail at a negative angle,
while the center of gravity was placed far
forward. As in the case of lateral control,
there was a tendency to constant
undulation, and the very forces which
caused a restoration of balance in calms,
caused a disturbance of the balance in
winds. Notwithstanding the known limitations
of this principle, it had been embodied in
almost every prominent flying-machine
which had been built.
After considering the practical effect of the
dihedral principle, we reached the
conclusion that a flyer founded upon it might
be of interest from a scientific point of view,
but could be of no value in a practical way.
We therefore resolved to try a fundamentally
different principle. We would arrange the
machine so that it would not tend to right
itself. We would make it as inert as possible
to the effects of change of direction or
speed, and thus reduce the effects of windgusts to a minimum. We would do this in the
fore-and-aft
stability
by
giving
the
aëroplanes a peculiar shape; and in the
lateral balance, by arching the surfaces from
tip to tip, just the reverse of what our
predecessors had done. Then by some
suitable contrivance, actuated by the
operator, forces should be brought into play
to regulate the balance.
Lilienthal and Chanute had guided and
balanced their machines by shifting the
weight of the operator's body. But this
method seemed to us incapable of
expansion to meet large conditions, because
the weight to be moved and the distance of
possible motion were limited, while the
disturbing forces steadily increased, both
with wing area and with wind velocity. In
order to meet the needs of large machines,
we wished to employ some system whereby
the operator could vary at will the inclination
of different parts of the wings, and thus
obtain from the wind forces to restore the
balance which the wind itself had disturbed.
This could easily be done by using wings
capable of being warped, and by
supplementary adjustable surfaces in the
shape of rudders. As the forces obtainable
for control would necessarily increase in the
same ratio as the disturbing forces, the
method seemed capable of expansion to an
almost unlimited extent. A happy device was
discovered whereby the apparently rigid
system of superposed surfaces, invented by
Wenham, and improved by Stringfellow and
Chanute, could be warped in a most
unexpected way, so that the aëroplanes
could be presented on the right and left
sides at different angles to the wind. This,
with an adjustable, horizontal front rudder,
formed the main feature of our first glider.
The period from 1885 to 1900 was one of
unexampled activity in aëronautics, and for a
time there was high hope that the age of
flying was at hand. But Maxim, after
spending $100,000, abandoned the work;
the Ader machine, built at the expense of
the French Government, was a failure;
Lilienthal and Pilcher were killed in
experiments; and Chanute and many others,
from one cause or another, had relaxed their
efforts, though it subsequently became
known that Professor Langley was still
secretly at work on a machine for the United
States Government. The public, discouraged
by the failures and tragedies just witnessed,
considered flight beyond the reach of man,
and classed its adherents with the inventors
of perpetual motion.
We began our active experiments at the
close of this period, in October, 1900, at
Kitty Hawk, North Carolina. Our machine
was designed to be flown as a kite, with a
man on board, in winds of from fifteen to
twenty miles an hour. But, upon trial, it was
found that much stronger winds were
required to lift it. Suitable winds not being
plentiful, we found it necessary, in order to
test the new balancing system, to fly the
machine as a kite without a man on board,
operating the levers through cords from the
ground. This did not give the practice
anticipated, but it inspired confidence in the
new system of balance.
In the summer of 1901 we became
personally acquainted with Mr. Chanute.
When he learned that we were interested in
flying as a sport, and not with any
expectation of recovering the money we
were expending on it, he gave us much
encouragement. At our invitation, he spent
several weeks with us at our camp at Kill
Devil Hill, four miles south of Kitty Hawk,
during our experiments of that and the two
succeeding years. He also witnessed one
flight of the power machine near Dayton,
Ohio, in October, 1904.
The machine of 1901 was built with the
shape of surface used by Lilienthal, curved
from front to rear like the segment of a
parabola, with a curvature 1/12 the depth of
its cord; but to make doubly sure that it
would have sufficient lifting capacity when
flown as a kite in fifteen- or twenty-mile
winds, we increased the area from 165
square feet, used in 1900, to 308 square
feet -- a size much larger than Lilienthal,
Pilcher, or Chanute had deemed safe. Upon
trial, however, the lifting capacity again fell
very far short of calculation, so that the idea
of securing practice while flying as a kite,
had to be abandoned. Mr. Chanute, who
witnessed the experiments, told us that the
trouble was not due to poor construction of
the machine. We saw only one other
explanation -- that the tables of airpressures in general use were incorrect.
We then turned to gliding -- coasting down
hill on the air -- as the only method of getting
the desired practice in balancing a machine.
After a few minutes' practice we were able
to make glides of over 300 feet, and in a few
days were safely operating in twenty-sevenmile winds[1]. In these experiments we met
with several unexpected phenomena. We
found that, contrary to the teachings of the
books, the center of pressure on a curved
surface traveled backward when the surface
was inclined, at small angles, more and
more edgewise to the wind. We also
discovered that in free flight, when the wing
on one side of the machine was presented
to the wind at a greater angle than the one
on the other side, the wing with the greater
angle descended, and the machine turned in
a direction just the reverse of what we were
led to expect when flying the machine as a
kite. The larger angle gave more resistance
to forward motion, and reduced the speed of
the wing on that side. The decrease in
speed more than counterbalanced the effect
of the larger angle. The addition of a fixed
vertical vane in the rear increased the
trouble, and made the machine absolutely
dangerous. It was some time before a
remedy was discovered. This consisted of
movable rudders working in conjunction with
the twisting of the wings. The details of this
arrangement are given in our patent
specifications, published several years ago.
The experiments of 1901 were far from
encouraging. Although Mr. Chanute assured
us that, both in control and in weight carried
per horse-power, the results obtained were
better than those of any of our
predecessors, yet we saw that the
calculations upon which all flying-machines
had been based were unreliable, and that all
were simply groping in the dark. Having set
out with absolute faith in the existing
scientific data, we were driven to doubt one
thing after another, till finally, after two years
of experiment, we cast it all aside, and
decided to rely entirely upon our own
investigations. Truth and error were
everywhere so intimately mixed as to be
undistinguishable. Nevertheless, the time
expended in preliminary study of books was
not misspent, for they gave us a good
general understanding of the subject, and
enabled us at the outset to avoid effort in
many directions in which results would have
been hopeless.
The standard for measurements of windpressures is the force produced by a current
of air of one mile per hour velocity striking
square against a plane of one square-foot
area. The practical difficulties of obtaining an
exact measurement of this force have been
great. The measurements by different
recognized authorities vary fifty per cent.
When this simplest of measurements
presents so great difficulties, what shall be
said of the troubles encountered by those
who attempt to find the pressure at each
angle as the plane is inclined more and
more edgewise to the wind? In the
eighteenth century the French Academy
prepared tables giving such information, and
at a later date the Aëronautical Society of
Great Britain made similar experiments.
Many
persons
likewise
published
measurements and formulas; but the results
were so discordant that Professor Langley
undertook a new series of measurements,
the results of which form the basis of his
celebrated
work,
"Experiments
in
Aerodynamics." Yet a critical examination of
the data upon which he based his
conclusions as to the pressures at small
angles shows results so various as to make
many of his conclusions little better than
guess-work.
To work intelligently, one needs to know the
effects of a multitude of variations that could
be incorporated in the surfaces of flyingmachines. The pressures on squares are
different from those on rectangles, circles,
triangles, or ellipses; arched surfaces differ
from planes, and vary among themselves
according to the depth of curvature; true
arcs differ from parabolas, and the latter
differ among themselves; thick surfaces
differ from thin, and surfaces thicker in one
place than another vary in pressure when
the positions of maximum thickness are
different; some surfaces are most efficient at
one angle, others at other angles. The
shape of the edge also makes a difference,
so that thousands of combinations are
possible in so simple a thing as a wing.
We had taken up aëronautics merely as a
sport. We reluctantly entered upon the
scientific side of it. But we soon found the
work so fascinating that we were drawn into
it deeper and deeper. Two testing-machines
were built, which we believed would avoid
the errors to which the measurements of
others had been subject. After making
preliminary measurements on a great
number of different-shaped surfaces, to
secure a general understanding of the
subject,
we
began
systematic
measurements of standard surfaces, so
varied in design as to bring out the
underlying causes of differences noted in
their pressures. Measurements were
tabulated on nearly fifty of these at all angles
from zero to 45 degrees, at intervals of 2 1/2
degrees. Measurements were also secured
showing the effects on each other when
surfaces are superposed, or when they
follow one another.
Some strange results were obtained. One
surface, with a heavy roll at the front edge,
showed the same lift for all angles from 71/2
to 45 degrees. A square plane, contrary to
the measurements of all our predecessors,
gave a greater pressure at 30 degrees than
at 45 degrees. This seemed so anomalous
that we were almost ready to doubt our own
measurements, when a simple test was
suggested. A weather-vane, with two planes
attached to the pointer at an angle of 80
degrees with each other, was made.
According to our tables, such a vane would
be in unstable equilibrium when pointing
directly into the wind; for if by chance the
wind should happen to strike one plane at
39 degrees and the other at 41 degrees, the
plane with the smaller angle would have the
greater pressure, and the pointer would be
turned still farther out of the course of the
wind until the two vanes again secured
equal pressures, which would be at
approximately 30 and 50 degrees. But the
vane performed in this very manner. Further
corroboration of the tables was obtained in
experiments with a new glider at Kill Devil
Hill the next season. In September and
October, 1902, nearly one thousand gliding
flights were made, several of which covered
distances of over 600 feet. Some, made
against a wind of thirty-six miles an hour,
gave proof of the effectiveness of the
devices for control. With this machine, in the
autumn of 1903, we made a number of
flights in which we remained in the air for
over a minute, often soaring for a
considerable time in one spot, without any
descent at all. Little wonder that our
unscientific assistant should think the only
thing needed to keep it indefinitely in the air
would be a coat of feathers to make it light!
With accurate data for making calculations,
and a system of balance effective in winds
as well as in calms, we were now in a
position, we thought, to build a successful
power-flyer. The first designs provided for a
total weight of 600 pounds, including the
operator and an eight horsepower motor.
But, upon completion, the motor gave more
power than had been estimated, and this
allowed 150 pounds to be added for
strengthening the wings and other parts.
Our tables made the designing of the wings
an easy matter; and as screw propellers are
simply wings traveling in a spiral course, we
anticipated no trouble from this source. We
had thought of getting the theory of the
screw-propeller from the marine engineers,
and then, by applying our tables of airpressures to their formulas of designing airpropellers suitable for our purpose. But so
far as we could learn, the marine engineers
possessed only empirical formulas, and the
exact action of the screw-propeller, after a
century of use, was still very obscure. As we
were not in a position to undertake a long
series of practical experiments to discover a
propeller suitable for our machine, it seemed
necessary to obtain such a thorough
understanding of the theory of its reactions
as would enable us to design them from
calculation alone. What at first seemed a
simple problem became more complex the
longer we studied it. With the machine
moving forward, the air flying backward, the
propellers turning sidewise, and nothing
standing still, it seemed impossible to find a
starting-point from which to trace the various
simultaneous reactions. Contemplation of it
was confusing. After long arguments, we
often found ourselves in the ludicrous
position of each having been converted to
the other's side, with no more agreement
than when the discussion began.
It was not till several months had passed,
and every phase of the problem had been
thrashed over and over, that the various
reactions began to untangle themselves.
When once a clear understanding had been
obtained, there was no difficulty in designing
suitable propellers, with proper diameter,
pitch, and area of blade, to meet the
requirements of the flyer. High efficiency in a
screw-propeller is not dependent upon any
particular or peculiar shape, and there is no
such thing as a "best" screw. A propeller
giving a high dynamic efficiency when used
upon one machine, may be almost worthless
when used upon another. The propeller
should in every case be designed to meet
the particular conditions of the machine to
which it is to be applied. Our first propellers,
built entirely from calculation, gave in useful
work 66 per cent. of the power expended.
This was about one third more than had
been secured by Maxim or Langley.
The first flights with the power-machine were
made on the 17th of December, 1903. Only
five persons besides ourselves were
present. These were Messrs. John T.
Daniels, W. S. Dough, and A. D. Etheridge
of the Kill Devil Life Saving Station; Mr. W.
C. Brinkley of Manteo, and Mr. John Ward of
Naghead. Although a general invitation had
been extended to the people living within
five or six miles, not many were willing to
face the rigors of a cold December wind in
order to see, as they no doubt thought,
another flying-machine not fly. The first flight
lasted only twelve seconds, a flight very
modest compared with that of birds, but it
was, nevertheless, the first in the history of
the world in which a machine carrying a man
had raised itself by its own power into the air
in free flight, had sailed forward on a level
course without reduction of speed, and had
finally landed without being wrecked. The
second and third flights were a little longer,
and the fourth lasted fifty-nine seconds,
covering a distance of 852 feet over the
ground against a twenty-mile wind.
After the last flight, the machine was carried
back to camp and set down in what was
thought to be a safe place. But a few
minutes later, while we were engaged in
conversation about the flights, a sudden
gust of wind struck the machine, and started
to turn it over. All made a rush to stop it, but
we were too late. Mr. Daniels, a giant in
stature and strength, was lifted off his feet,
and falling inside, between the surfaces,
was shaken about like a rattle in a box as
the machine rolled over and over. He finally
fell out upon the sand with nothing worse
than painful bruises, but the damage to the
machine caused a discontinuance of
experiments.
In the spring of 1904, through the kindness
of Mr. Torrence Huffman of Dayton, Ohio,
we were permitted to erect a shed, and to
continue experiments, on what is known as
the Huffman Prairie, at Simms Station, eight
miles east of Dayton. The new machine was
heavier and stronger, but similar to the one
flown at Kill Devil Hill. When it was ready for
its first trial, every newspaper in Dayton was
notified, and about a dozen representatives
of the press were present. Our only request
was that no pictures be taken, and that the
reports be unsensational, so as not to attract
crowds to our experiment grounds. There
were probably fifty persons altogether on the
ground. When preparations had been
completed, a wind of only three or four miles
was blowing, -- insufficient for starting on so
short a track, -- but since many had come a
long way to see the machine in action, an
attempt was made. To add to the other
difficulty, the engine refused to work
properly. The machine, after running the
length of the track, slid off the end without
rising into the air at all. Several of the
newspaper men returned the next day, but
were again disappointed. The engine
performed badly, and after a glide of only
sixty feet, the machine came to the ground.
Further trial was postponed till the motor
could be put in better running condition. The
reporters had now, no doubt, lost confidence
in the machine, though their reports, in
kindness, concealed it. Later, when they
heard that we were making flights of several
minutes' duration, knowing that longer flights
had been made with air-ships, and not
knowing any essential difference between
airships and flying machines, they were but
little interested.
We had not been flying long in 1904 before
we found that the problem of equilibrium had
not as yet been entirely solved. Sometimes,
in making a circle, the machine would turn
over sidewise despite anything the operator
could do, although, under the same
conditions in ordinary straight flight, it could
have been righted in an instant. In one flight,
in 1905, while circling around a honey
locust-tree at a height of about fifty feet, the
machine suddenly began to turn up on one
wing, and took a course toward the tree. The
operator, not relishing the idea of landing in
a thorn- tree, attempted to reach the ground.
The left wing, however, struck the tree at a
height of ten or twelve feet from the ground,
and carried away several branches; but the
flight, which had already covered a distance
of six miles, was continued to the startingpoint.
The causes of these troubles -- too technical
for explanation here -- were not entirely
overcome till the end of September, 1905.
The flights then rapidly increased in length,
till experiments were discontinued after the
5th of October, on account of the number of
people attracted to the field. Although made
on a ground open on every side, and
bordered on two sides by much traveled
thoroughfares, with electric cars passing
every hour, and seen by all the people living
in the neighborhood for miles around, and
by several hundred others, yet these flights
have been made by some newspapers the
subject of a great "mystery."
A practical flyer having been finally realized,
we spent the years 1906 and 1907 in
constructing new machines and in business
negotiations. It was not till May of this year
that experiments (discontinued in October,
1905) were resumed at Kill Devil Hill, North
Carolina. The recent flights were made to
test the ability of our machine to meet the
requirements of a contract with the United
States Government to furnish a flyer capable
of carrying two men and sufficient fuel
supplies for a flight of 125 miles, with a
speed of forty miles an hour. The machine
used in these tests was the same one with
which the flights were made at Simms
Station in 1905, though several changes had
been made to meet present requirements.
The operator assumed a sitting position,
instead of lying prone, as in 1905, and a
seat was added for a passenger. A larger
motor was installed, and radiators and
gasolene reservoirs of larger capacity
replaced those previously used. No attempt
was made to make high or long flights.
In order to show the general reader the way
in which the machine operates, let us fancy
ourselves ready for the start. The machine is
placed upon a single rail track facing the
wind, and is securely fastened with a cable.
The engine is put in motion, and the
propellers in the rear whir.
You take your seat at the center of the
machine beside the operator. He slips the
cable, and you shoot forward. An assistant
who has been holding the machine in
balance on the rail, starts forward with you,
but before you have gone fifty feet the speed
is too great for him, and he lets go. Before
reaching the end of the track the operator
moves the front rudder, and the machine lifts
from the rail like a kite supported by the
pressure of the air underneath it. The
ground under you is at first a perfect blur,
but as you rise the objects become clearer.
At a height of one hundred feet you feel
hardly any motion at all, except for the wind
which strikes your face. If you did not take
the precaution to fasten your hat before
starting, you have probably lost it by this
time. The operator moves a lever: the right
wing rises, and the machine swings about to
the left. You make a very short turn, yet you
do not feel the sensation of being thrown
from your seat, so often experienced in
automobile and railway travel. You find
yourself facing toward the point from which
you started. The objects on the ground now
seem to be moving at much higher speed,
though you perceive no change in the
pressure of the wind on your face. You know
then that you are traveling with the wind.
When you near the starting point, the
operator stops the motor while still high in
the air. The machine coasts down at an
oblique angle to the ground, and after sliding
fifty or a hundred feet comes to rest.
Although the machine often lands when
traveling at a speed of a mile a minute, you
feel no shock whatever, and cannot, in fact,
tell the exact moment at which it first
touched the ground. The motor close beside
you kept up an almost deafening roar during
the whole flight, yet in your excitement, you
did not notice it till it stopped. Our
experiments have been conducted entirely
at our own expense. In the beginning we
had no thought of recovering what we were
expending, which was not great, and was
limited to what we could afford for
recreation. Later, when a successful flight
had been made with a motor, we gave up
the business in which we were engaged, to
devote our entire time and capital to the
development of a machine for practical
uses. As soon as our condition is such that
constant attention to business is not
required, we expect to prepare for
publication the results of our laboratory
experiments, which alone made an early
solution of the flying problem possible.
The gliding flights were all made against
the wind. The difficulty in high winds is in
maintaining balance, not in traveling
against the wind.
Next Issue
Barnaby Wainfan
Speaks On Drag Reduction
Don Crawford
Demonstrates
His table Top Wind Tunnel
Bass Ackwards
By Murry I. Rozansky
I've been putting off writing this article
because of the same fears that Galileo
must have felt before publishing his
book showing all the planets, including
the Earth, revolving around the Sun.
The orthodox view at this time was the
Earth was the Center of the Universe.
Hopefully, my fellow aviation enthusiasts
will be more open-minded than the
Church was then, to my challenge of
aviation orthodoxy. Here goes.
Tail wheel aircraft are not inherently
directionally unstable on the ground
because they are tail draggers.
What about ground loops? What about
what we learned in ground school?
What tail draggers feel like when they
touch down with some side motion? I
can feel my reader's blood pressure
going up. "Burn him at the stake!" "He is
trying to make monkeys out of us!" I too,
believed the conventional view for a
long time but had some nagging doubts.
Let me go through some of the steps
that have lead me to this startling
conclusion.
I started flying in gliders. Of course, with
a crosswind, we were encouraged to
keep the up wind wing low to kill the
side ways motion and the nose pointed
down the runway inline with the direction
of motion. With a single main wheel
close to the C.G. and landing on grass a
little sideways motion at touch down
was a non-event. When I decided to get
my power ticket I bypassed many closer
flight schools in order to learn to fly in J3 Cubs. I never lost a Cub on landing
despite the occasional tail wheel falling
off. I did ground loop a Cessna 180
once while fumbling trying to get my feet
on the brake pedals. Just taxiing a tail
dragger you can feel that it does not
want to go straight.
What we have been taught is the most
important fact. A tail dragger's main
wheels are in front of its center of gravity
(CG). The mass and inertia of the
aircraft act through the CG. The tires will
resist the sideways motion. That will turn
the aircraft's nose opposite from the
direction of the side motion increasing
In the Conventional Tail-Dragger the side
force produced by a fixed tail wheel is not
enough to counter the side forces ahead
of the C.G. produced by the main wheels
when they are at an angle to the direction
of travel. This is the classic ground loop.
The fixed main wheels of the Conventional
Tricycle Gear are behind the C.G. and the
side force they produce turns the aircraft
into the direction of travel unlike the main
gear of the Conventional Tail-Dragger. The
castering nose wheel does not fight the
main gears' stabilizing effect, if your feet
are not in the wrong position.
the slip angle and therefore the side
force the tires are producing. All this
side force is produced in front of the CG,
which Newton has told us wants to go
straight ahead. The airplane responds
by rotating around the vertical axis. It is
a runaway situation. If not stopped early
with the rudder, tail wheel and /or
brakes, each bit of rotation increases
the tire side forces in front of the CG
causing more rotation, producing a
classic ground loop. It is like a spin out
in a tail-heavy car like the old VW bug.
But airplanes are not tail heavy. A doubt
and a clue.
I have been interested in and have
researched roadable aircraft and three
wheel road vehicles for quite some time.
It is educational to see how the various
designers
handle
the
differing
requirements of aircraft landing gear
and road wheel systems. Almost all
roadable aircraft use some form of road
vehicle wheel system as their landing
gear. Another clue came out of looking
at the two types of three wheel road
vehicles; the trike with one wheel in front
and the more car like configuration with
two front and a single rear wheel.
Three-wheelers get very little attention,
being lost in between motorcycles and
automobiles even though they were the
first self propelled road vehicles. There
is a Government funded safety study
from the 1970's and mention in two
automotive design books that I have, of
the advantages and disadvantages of
the two major three wheel vehicle types.
(One would never design a sidecar from
scratch. They are an add on to an
existing motorcycle.) The conclusions
were that the two front wheel
configuration is much safer than the one
with a single front wheel. For rollover
stability the CG needs to be at the mid
point or closer, to the end with the two
wheels. Having two wheels and the CG
toward the front gives the road vehicle a
stable understeering characteristic when
pushed to the cornering limits. The
single front wheel vehicles would oversteer and spinout like our old VW bug,
when pushed to the limit. Putting very
large tires on the back raised the limits
but did not prevent the terminal oversteer of the single front wheelers. The
two front wheel configuration, with its
maximum width and CG forward, also
lends itself to a more streamlined and
aerodynamically stable shape.
"What does that have to do with
airplanes?” You might ask. It is a clue.
When an airplane is on the ground, it is
a ground vehicle with pneumatic tires, a
CG location, steering and brakes like a
In my proposed Tail-Dragger with Castering
Main Gear the fixed tail wheel has a stabilizing
effect, being behind the C.G. just as the main
gear on the Conventional Tricycle Gear does.
The castering main wheels ahead of the C.G.
like the castering nose wheel do not
destabilize the aircraft It does not matter how
many wheels are at which end of the airplane.
For a stable aircraft the wheel(s) behind the
C.G. need to be fixed and the wheel(s) in front
of the C.G. need to be free to caster.
road vehicle. When I looked at the
wheel, cg and force diagrams in the
report and books on three wheelers I
was struck by how similar they were to
the diagrams in books on aircraft
landing gear design. Why are the results
so different? Why, in a road vehicle is
the two wheels in front configuration, a
tail dragger if you will, the safest and
most stable and in the aircraft, the
notorious, pilot humbling, ground
looping tail-dragger? When you see it,
you may smack yourself in the forehead
as I did.
In doing research for article I checked
other design and flying tail-dragger
books in my library including the classic
(1944), "Stick and Rudder" by Wolfgang
Lanngewiesche. It should still be
required reading by all pilots. When I
was learning to fly at Sky Manor Airport
(Pittstown, NJ) in the early 19707s, one
afternoon I found myself standing next
to the famous author watching some of
the other students practicing take offs
and landings in the Cubs. He asked me,
"How come you guys make such good
landings?" I replied as a matter of factly
as I could, "Wolfgang, we read your
book." There are hints that support my
theory in his book as in others but not
one that I have found has put it all
together. '"The Complete Taildragger
Pilot" by Harvey Plourde was quite
useful as it has a complete detailed
chapter just on the crosswind gear and
its piloting techniques.
If you haven't seen it yet, the crosswind
landing gear is another clue. Around
WW II attempts were made to try and
tame the tail-dragger and forms of the
so-called
crosswind
gear
were
developed. It was recognized by their
designers that the side force produced
by the main wheels ahead of the CG
was causing the initiation of the ground
loop. A mechanism was developed to
allow the main wheels to caster if there
was any significant side force on them.
Tires produce side force when they
operate at a slip angle. When they are
free to caster and are more or less
vertical, they can produce no side force
and therefore, no ground loops. The
crosswind gear effectively tamed
Cessna 190/195s and other tail
draggers. They could touch in a crab
and it was automatic, unlike the B-47
and B-52 where the pilot sets the
landing gear crab angle. The springloaded detents would pop out and let
the main wheels caster. No side force.
No ground loop!
There were same operational problems,
which is why you will rarely encounter
crosswind gear today. They were an
add on (like the motorcycle sidecar) to
existing tail wheel airplanes that
retained their steerable tail wheels and
could pop out of their detents at
unwanted times. Have you ever pushed
a cart with all castering wheels? It does
not know which way to go. There is no
side force to keep you from going off the
side of a sloped taxiway or to get you
around a turn taken a little to fast once
the detent spring's setting is overcome.
They could also shimmy if they were not
maintained properly. One type of
crosswind gear has a taxi lock, but it is
one more thing that could be forgotten
and trigger an accident Have you got it
yet?
I’ll give you one more clue. Some of the
best ground handling tail-draggers have
lockable tail wheels.
This is it. It may get me hanged, tarred
and feathered or burned at, the stake,
but I believe it is the real truth about tail
draggers.
Tail wheel aircraft are directionally
unstable on the ground because we
have been trying to steer the wrong
end!
I'll give you a bit of time to get over your
shock. It really is that simple. Before
you come after me with your torches,
ask yourself, how many wheeled
vehicles do you know of with rear wheel
steering? Fork lifts, some earthmovers;
low speed vehicles that need maximum
maneuverability. The only road vehicle I
have encountered that had rear wheel
steering
was
Buckmaster
Fuller
Dymaxion
three-wheeler,
which
apparently worked pretty well. I have not
found enough details on its steering
system to know how it was made to
work as well as it did. One of our
Government safety departments built
what was supposed to be a safer
motorcycle. It had a fixed, driven front
wheel and rear wheel steering like the
Dymaxion. It was really safe. As soon as
the rider started moving it would fall right
over, never going fast enough to hurt
him.
Do a safer experiment. Find an empty
parking lot and put your car in reverse.
Crank in some steering and hold the
steering wheel in a fixed position. If you
do not hold the fixed position the caster
of the front wheels in reverse will try to
pull the wheels to the stop and that will
cover up the effect you are looking for.
With the steering deflected and fixed, in
reverse the turn will tighten up. The turn
does not tighten up when you are going
forward. Are you convinced? You see,
having a fixed wheel or wheels behind
the CG is like having a vertical stabilizer
on the tail of an airplane. It makes the
vehicle want to go straight. It is a
stabilizer. The conventional tail wheel
with little weight on it, limp springs for
steering, swivel detents for tight turns
and ground handling do little to help the
pilot when he needs it most. The key
feature necessary for directionally
stability of two, three and four wheel
the tail dragger is to get rid of its bounce
and balloon tendency when dropped in.
The Fixed Nose Wheel with Castering
Main Gear configuration is even more
unstable than the Conventional TailDragger because the destabilizing fixed
nose wheel has a long lever arm in front of
the C.G. It is included to reinforce the
point that it is not the number of wheels in
front or behind the C.G. but which wheels
are fixed and which can caster that
determines whether a landing gear is
directionally stabile or not.
vehicles is castering wheel(s) in front of
the CG and fixed wheel(s) behind.
What does this discovery mean for
aviation? Is the Airbus 380 going to be
converted to a tail dragger to save the
weight of the nose gear? I think not,
although it is fun to think about. With tail
doors, it could speed up unloading. The
fact is, tricycle landing gear work pretty
well. Taxiing an aircraft is not supposed
to be a road race so terminal oversteer
should not be a problem.
Is there a place then, in general aviation
for the logical development of the
crosswind, tail dragger landing gear; the
castering, steerable main wheels, fixed
tail wheel configuration? Maybe for
bush planes and sport aircraft where
weight and drag savings and being rid of
the vulnerable nose gear would be
advantages. It would not be without cost
as robust steering pivots and steering
mechanisms would be needed One
would land in a crab like in an Ercoupe
and the fixed tail wheel will get you
tracking straight down the runway. One
thing our improved gear will not do for
Nothing is perfect and there are ways to
get rid of the bounce. A flatter than
normal taildragger ground altitude with
an energy absorbing main gear might
work. A normal spring gear gets what
little dampening it has from the
sideways scrubbing of the tires as the
wheels go up and down. Because of the
caster effect on our new configuration
the wheels going in opposite directions
would put large, possibly asymmetric
loads into the steering linkages. That
could cause mechanical breakages or
excessive weight. Worst, it could
prevent the wheels from castering freely
so the ground loop might return. With
castering main wheels it would be best if
the wheel suspension travel is more or
less vertical. The ground steering
control should be separate from the
rudder pedals so the main wheels are
free to caster on touch down without the
pilot's feet getting in the way.
What kind of main gear could we use?
The trailing link main gear like the
Ercoupe and Mooney works well and
could be made to be castering and
steerable like the nose gear on some De
Havilland aircraft. The oleo strut is a
natural as it is already used on the nose
of many aircraft Even the spring gear
can work if there is compliance between
the wheels. The springing in the linkage
between the wheels would cause some
slop in the steering though. Other than
some early design ideas for the main
gear pivots and steering mechanisms,
that's about as far as I've gotten with
this idea. With some clever design,
development and testing a tail-dragger
gear even an insurance company could
love is possible.
Well, dear reader, am I damned to hell,
"Bass Akwards”?
The
Experiment
This is a simple experiment you can do
at your local shopping center parking lot.
Find a lot with few cars. A slight down
hill slope is helpful, as you will not have
to push too hard to keep the cart going.
Pick a cart with good wheels and
casters that turn freely. Try it first with
the casters in front. Give it a good
straight push down hill. It should track
like an arrow down hill like in our
pictures on the left. It is worth having a
helper to catch the cart before it crashes
into any cars. Now turn the cart around
with the fixed wheels forward and the
casters in the rear. It may take a few
tries to get a straight launch. It may go
straight for a while but like in our photos
on the right, something will get the front
wheels out of line and start them going
sideways. The casters in the back can
do nothing to stop the increasing turn
rate. It is a classic ground loop. Some
times, if the slope is steep enough to
keep the cart going it will make a 180
and go the rest of the way down the hill
as God intended, with casters forward
and fixed wheels in back.
Murry I. Rozansky
James R. "Jim" Bede is a
controversial aircraft designer, who is often
credited with the creation of the modern
kitplane market. Few people are aware of
the fact that Jim Bede designed a vehicle
around a motorcycle engine called the
"LiteStar."
Various people have different ideas of how
many of these were sold, and of its history.
Apparently they were sold as the "Pulse"
and 400 of them were made, after which
production stopped because of DOT
restrictions on special VIN numbers.
After Bede Aviation collapsed, Bede took on
a number of engineering projects under
Bede Design. One of the first was a project
with his cousin to produce a car.
Simply called the Bede Car, the design used
an 80 hp motorcycle engine driving ducted
fan for power. Built primarily from fiberglass
on aluminum, the car was to have weighed
just less than 1,000 lb, less than half that of
a normal four seater built of steel. The
advantage to the design was a claimed 120
mpg fuel economy, although in retrospect
this seems ridiculously optimistic.
Bede Industries, his cousin's company,
intended to introduce the car starting in
1982, but the prototype unit proved the
concept infeasible. The engine had very low
power at low speeds, so low that it could not
even roll up an inclined driveway for parking
without "gunning" it. There was some talk of
adding electric motors for low speed
operation and reversing, but it is not clear if
these were fitted. The fate of the prototype is
unknown.
Another automobile project followed, this
time a smaller motorcycle-like vehicle. The
prototype was based on a production
motorcycle, but "stretched" and surrounded
with a fiberglass shell that looked somewhat
like the BD-5. During its long gestation
period it was known as the Autocycle or BD200, and later as the LiteStar and Pulse.
About 360 of these were produced and sold.
The following contains extracts of the
petition from Jim Bede to the National
Highway Transportation Safety
Administration.
BEDE DESIGN INC.
901 E. ORCHARD ST.
MUNDELEIN, IL 60060
(812) 949-0554
September 29, 1982
Mr. Frank QA. Berndt
Chief Counsel....National Highway
Transportation Safety Administration
400 7th Street, S.W.
Washington D.C. 20590
Dear Mr. Berndt,
We have developed a very efficient, highmileage modification of a motorcycle. Not
only have we significantly reduced the
aerodynamic drag, which accounts for the
one hundred mile per gallon plus mileage
that we have been able to obtain from this
vehicle, but we have also substantially
enhanced the safety characteristics of a
standard motorcycle.
Therefore, we would like your advice and
guidance as to the best way for this vehicle,
and those converting their motorcycles, to
maintain their motorcycle classifications. I
am enclosing several photographs of the
vehicle that illustrate the "three-wheel in
contact with the ground" as well as an
information booklet that discusses additional
technical features of this design.
Very truly yours,
BEDE DESIGN INCORPORATED
Signed; James R. Bede, President.
With note:
"Last fall we drove our prototype vehicle
from Cleveland to Washington D.C. and had
the opportunity to have Mr. Karl Clark of
H.H.T.S.A. along with others form the
agency view our vehicle.
Initialed, J.R.Bede
571.3 as a motorcycle. The license plate
area is designed for a motorcycle plate and
is placed directly under the rear taillight.
RESPONSE dated OCT 22, 1982
U.S. Department of Transportation National
Highway Traffic Safety Administration
Dear Mr. Bede:
This is in reply to your letter of September
29, 1982, asking for an interpretation that
your modified motorcycle is a "motorcycle"
under the Federal motor Vehicle safety
standards.....
This configuration appears to meet the
definition of "motorcycle" contained in 49
CFR 571.3(b) as a machine "designed to
travel on not more than three wheels in
contact with the ground." Although the
vehicle rests on four wheels, it travels on
only two or three depending upon whether it
is proceeding in a straight direction or in a
turn.
We appreciate your interest in motorcycle
safety.
Sincerely,
Frank Berndt, Chief Counsel
After the BD-200 prototype was hand built
by Jim Bede, there were a couple more
autocycles built before a steady production
was started. For lack of a better term, we
call these Pre-production units. And some of
these were later titled and sold. So this adds
to the confusion when discussing serial
numbers.
Molds were made from the BD-200 for the
Scranton, Iowa built Litestars. When
production was moved to Owosso,
Michigan, another plaster-type model was
made from the BD-200, so that new molds
could be made in Owosso.
All Litestar and Pulse vehicles used similar
frame and body panels. The differences are
the engines used, headlight treatments,
winglets, vents and available options during
the production run between 1982 and 1990.
The PULSE was designed to comply with
USA Federal Regulations Title 49, Part
This is a pictures of the LiteStar #1
prototype as it sat in a St. Louis warehouse
before it was sold to a Hollywood actor. It
has already been restored and is actually
running again! The pictures make it look
"good," but in fact it was in sad shape inside
and needed a tremendous amount of work.
As you can see it has 4 wheels only three
contact the ground at any one time.
The Dymaxion Car - Fuller designed and built
prototypes of what he hoped would be a safer,
aerodynamic Dymaxion Car ("Dymaxion" is
contracted from DYnamic MAXimum tensION).
Dymaxion is a brand name that Fuller gave to
several of his inventions, to emphasize that he
considered them part of a more far-reaching
project to improve humanity's living conditions.
The Dymaxion car was a concept car from 1933,
designed by American inventor and architect
Buckminster Fuller. The car had a fuel efficiency
of 30 miles per US gallon (7.8 L/100 km), which
was unheard of in the United States at the time.
It could transport eleven passengers at speeds
of up to 120 miles per hour (193 km/h). The
patented 1937, Dymaxion car was intended to
later fly, when suitable alloys and engines
became available.
Fuller was seeking a scientifically determined
streamlined body in the Dymaxion Car. The
main feature is that it has three wheels - the rear
wheel is for steering, and the rigid front axle is
driven by a motor in the rear. This scheme was
problematic, first, because of the adverse
distribution of weight, and second because of
the direct transfer of physical laws of fluid
dynamics to a vehicle that is limited to streets, a
type of motion in which no drift can be tolerated
and reliable traction is the first requirement of
safety. Three of these cars were built, all of them
different and none were considered a
"prototype" in the usual industrial way of
thinking.
The car was a three wheeler, steered by a single
rear wheel, and could do a U-turn in its own
length. However, the rear-wheel steering made
the car somewhat counterintuitive to operate,
especially in crosswind situations. The body was
teardrop-shaped, and naturally aerodynamically
efficient. The car was twice as long as a
conventional automobile, at 20 feet (6 metres)
long. Drive power was provided by a rearmounted Ford V8 engine, which produced 85
bhp through the front wheels. The front axle was
also a Ford component, being the rear axle of a
contemporary Ford roadster turned upsidedown.
An accident at the 1933 Chicago world's fair
badly damaged the first prototype, killing the
driver, and seriously injuring the two
passengers. The Dymaxion had rolled over, and
although the driver was wearing a seatbelt, the
prototype's canvas roof had not offered sufficient
crash protection. The cause of the accident was
not determined, although Buckminster Fuller
reported that the accident was due to the actions
of another vehicle that had been closely
following the Dymaxion. [1] The crash prompted
investors to abandon the project, blaming the
accident on deficiencies in the vehicle's steering.
To Fuller, a three-wheeler wasn't radical, it was
simply logical. He didn't care about marketing
statistis, buyer profiles, or luxury styling cues.
This highly streamlined car used a Ford V-8
engine at the rear to drive the two front wheels.
The single rear wheel steered like the rudder of
a ship. Since the rear wheel could pivot 90
degrees, the car could easily turn on its own
axis, giveing the driver the sensation of meeting
himself coming.
We shouldn’t be building airplanes
with tail-dragging landing gear?
by Ray L. Leadabrand
This article was given to me over a year ago but it fits
this newsletter. I have not been able to locate Mr.
Leadabrand, so if anyone knows about him let me know
It is the purpose of this short paper to
recommend that those planning to build airplane
kits, should seriously consider using tricycle
landing gear configurations rather than building
their airplanes with conventional (tail dragger)
type landing gear? It is hoped this paper will be
successful in furthering my recommendation that
tricycle landing gear configurations are much
better than the conventional or tail dragger type
landing gear configurations, particularly from an
operational safety standpoint.
Over the years, there have been two kinds of
landing gear systems used for land based
airplanes. One of these landing gear
configurations
is
what
is
called
the
“conventional” gear (or tail- dragging landing
gear). This “conventional” landing gear has the
aircraft’s two main wheels located forward of the
aircraft’s center of gravity (cg) with a tail skid or
tail wheel at the aft end of the airplane under the
tail structure.
The other landing gear configuration is called
the “tricycle” landing gear. The tricycle landing
gear has the aircraft’s main landing gear located
somewhat aft of the aircraft’s cg and has a
single forward landing gear near the nose of the
airplane.
The tricycle landing gear was actually used on
the early Wright airplanes when the Wright
Brothers switched from landing skids to wheels
and placed one of the wheels up at the front of
the plane. Fred Weick, the designer of the
Ercoupe airplane applied the tricycle landing
gear to his early prototype Ercoupe type
airplanes in the 1930’s. He not only obtained a
patent for this type of landing gear configuration,
but he also received a prestigious award during
WWII for the improved safety of this type of
landing gear.
Most of the early airplanes, being built before
WWII, used the “conventional” (tail dragger) type
landing gear configuration. However, the
Ercoupe airplane designed by Fred Weick, with
the first models built somewhat prior to WWII,
was one of the first General Aviation (GA)
airplanes that used the tricycle landing gear
configuration. As more and more types of
military airplanes were built during WWII, there
was a gradual shift away from the conventional
landing gear to the tricycle landing gear
configuration (The B-25, B-26, B-24, B-29, C-54,
P-38, P-39, etc. were some of the WWII military
airplanes that used the Fred Weick tricycle
landing gear configuration). However, it is
interesting to note that most of the carrier based
fighter aircraft built during WWII used the tail
dragger or conventional landing gear! Although,
today, virtually all of the airplanes operating on
military aircraft carriers have tricycle landing
gear.
Following WWII, most of the GA airplanes
produced did not use the (Ercoupe) tricycle
landing gear configuration, but instead used the
tail-dragger or what was then known as the
“conventional” configuration. A couple of post
WWII exceptions were the Beech Bonanza, and
the Navion--both of which from their initial
beginnings, used the tricycle landing gear.
The way that each of these two landing gear
configurations perform are quite different. The
fact that the cg for the conventional (or taildragger) landing gear was aft of the main
landing gear wheels tended to cause pilots to
frequently ground loop the airplane when they
were trying to hold it straight down a runway
during a landing, especially when cross winds
were present.
The cg for the tricycle landing gear was in front
of the main landing gear wheels and this caused
landings to have a much greater potential for
helping the airplane continue down the runway
as desired by the pilot.
The difference between these two landing gear
configurations is examined in considerable detail
in the classic how to fly book, “Stick and Rudder”
written by Wolfgang Langewiesche (I have a
1944 version of the book, which actually may be
a first edition--although the book may have first
been published before WWII?). This excellent
book was certainly widely used during the many
pilot training activities that the military had going
during WWII--as well as by the civilian world
after WWII.
Today, there seems to still be strong beliefs by a
host of pilots that the “conventional” landing gear
configuration (tail dragger) is the best. That is,
those pilots who have mastered this landing
gear configuration are considered by some of
the ”older” pilots (that first learned to fly with tail
dragger airplanes) to be “true expert pilots”.
Therefore, for those pilots who now “only fly the
tricycle landing gear configured airplanes” seem
to be considered by these “old timers” to be
much less expert than those flying tail dragging
landing gear. Some of us believe that this is
mostly an ego issue. The origin of the ego was
proliferated by the fact that most of the airplanes
that pilots learned to fly just after WWII had tail
dragger or “conventional” landing gear. I have
heard many times the comment from other wise
respectable and competent pilots the following:
“pilots that can handle tail- draggers are much
better pilots than those who use tricycle landing
gear”!
Let’s examine what happens when each of
these types of landing gear configurations are
used by pilots to make landings. In order that
each configuration can be appropriately
described, I have chosen to use two types of
airplanes that I have personally flown to use in
this discussion. The airplane having the
“conventional” or tail dragger landing gear will be
the Cessna 140. The airplane having the tricycle
landing gear will be the Ercoupe—the Ercoupe
will be one which does not have separate rudder
pedal controls. Both are moderate performers
with their 85 hp engines.
Let’s first briefly mention how these two kinds of
airplanes manage their take-offs—as the takeoff phase of flight also uses the landing gear but
is somewhat less stressful than landings,
especially during cross winds.
The Cessna 140 take-off starts its initial ground
role with the airplane in a climbing
configuration—that is it is setting on its main
gear and its tail wheel is also on the ground.
Thus the angle of attack of the wing is such that
it generates lift as the plane starts to move down
the runway. As power is applied and the airplane
starts its ground role for take off, the pilot is soon
able to raise the tail wheel, due to air flow over
the elevator, so that the airplane is in an almost
level flight configuration with the wing generating
only a modest degree of lift needed for a regular
departure. As the airplane gets nearer its takeoff speed, the pilot raises the nose, slightly, such
that the wings produce more lift and this soon
causes the airplane to leave the ground as its
speed increases. In its take-off run, the airplane
is kept going straight down the runway and the
fact that the cg of the airplane is between the
main gear and the tail wheel is not a significant
factor in keeping the airplane going straight
down the runway. Of course if the pilot desires
to have the airplane do a so-called “soft field”
take-off, the pilot does not raise the tail wheel
but keeps the nose well elevated so that the
wing generates an increasing lift component as
the plane accelerates. This soft field take-off
process also keeps the propeller from picking up
runway debris or gravel causing nicks in the
propeller blades.
The Ercoupe take-off, with its tricycle landing
gear, starts its initial ground role with the
airplane in an almost level attitude—as it sets on
the ground. Its nose is somewhat lower than
would be used in level flight which causes the
wing to produce a downward force (negative lift)
on the landing gear, that tends to keep the nose
gear firmly established on the runway. Keeping
the Ercoupe going straight down the runway is
accomplished by keeping the nose wheel
oriented down the runway by using pilot controls
to steer the nose wheel--the negative lift on the
wing keeps that nose wheel firmly on the
ground.
When take-off speed is achieved, the Ercoupe
nose must be abruptly lifted by the control
wheel, which in turn causes the wing to generate
positive lift. Thus, the airplane leaves the ground
lacking any tendency to swerve on the runway. It
would seem that if this nose lifting action is not
accomplished then the airplane may not fly, but
continues its ground role.
Next, lets look at the landing configuration for
these two types of airplanes which is a bit more
complex and supports the major claim of this
paper.
For the Cessna 140, the airplane is brought
down in altitude and speed such that it is in a
nose high attitude that resembles the attitude it
would have if all the landing gear (mains and tail
wheel) is on the ground. Because the cg of the
Cessna 140 is aft of the main landing gear, any
slight turning of the airplane as it touches the
runway is accentuated by the fact that the aft cg
location wants to make the airplane swerve off
the center-line of the runway. This swerve
tendency produces excessive turning forces
which can ultimately cause the classical (and
highly undesired) ground loop.
Of course in a cross wind, the location of the cg
greatly increases the swerving tendency and
makes ground loops a greater hazard for the
pilot to contend with. As a result, many of the
“old-timer” pilots that are most familiar to the tail
dragger landing gear believe that a pilot that can
land a tail dragger during a cross wind is a much
more proficient pilot than one that only has
tricycle landing gear experience—no doubt this
is the source of the tail-dragger “ego” concept
described above?
For landing the Ercoupe, the airplane is brought
down in altitude and speed such that it is also in
a slightly nose high altitude like the tail dragger
airplane. If there is a cross wind, the airplane is
crabbed (wings level—as with no separate
rudder control the airplane cannot be slipped)
such that the airplane is proceeding directly
down the runway, even though its nose is
pointing at an angle that causes it to somewhat
face into the cross wind direction. The airplane
is slowed appropriately to landing speed and the
main gear is allowed to come in contact with the
runway. As soon as this happens, the pilot
immediately lowers the nose of the Ercoupe with
the controls so that the nose wheel is on the
ground and is being firmly held there because
the wing is at a somewhat negative lift angle of
attack. As soon as the nose wheel is firmly on
the ground the pilot lets the control wheel rotate
freely allowing the nose wheel to caster, which
causes the airplane to line up with the center
line of the runway. This lining up takes place as
soon as the nose wheel is free to caster and
does not require special pilot actions—in fact
such a cross wind landing in an Ercoupe type
airplane does not require any special pilot
actions or unusual or difficult to learn skills. Also
the Ercoupe landing, even in a substantial crosswind, does not have a tendency to swerve or
cause a ground loop.
Because this kind of crabbed landing is quite
effective in handling cross winds, it means that
the airplane does not have to slip or put a wing
down to keep the path of the plane going down
the runway--of course an Ercoupe with its
coupled ailerons and rudders, with no separate
rudder control (no rudder pedals), is not able to
slip.
Because some of the large airline aircraft (747
for example) would drag its outboard engine if it
had to accommodate a cross wind by slipping
and/or lowering a wing to keep the airplane
going down the runway, this Ercoupe cross wind
landing technique was introduced to the airline
747 pilots as the 747 came on line for the
airlines. I was exposed to a rumor that one of
the airlines (American Airlines?) even procured
several Ercoupes to use to teach their new 747
pilots being trained this crabbing, cross wind,
landing maneuver. I have confirmed this rumor a
bit by private discussions with 747 pilots that
they indeed use the crabbed Ercoupe approach
during heavy cross winds.
When I was first learning to fly, (50 years ago) I
found that doing cross wind landings in a
Cessna 140 was not a simple process to learn.
Clearly, the fact that the Cessna 140 cg is aft of
the main landing gear makes the Cessna 140 a
relatively unstable aircraft during landings,
especially when cross winds are present. On the
other hand, landing an Ercoupe in a cross wind
(an Ercoupe that even has no separate rudder
pedals) is very simple and fool proof for even the
learning pilot. The location of the cg on the
Ercoupe being forward of the main landing gear
(between the main gear and the nose gear)
makes it a very stable airplane that makes it
willing to proceed appropriately down the
runway with no swerves or ground loop
tendencies.
Too often, pilots feel they have their tail dragger
landing skills all nailed down and tend to relax
during
cross
wind
landings.
However,
sometimes that is where the landing troubles for
conventional tail
dragger
landing
gear
commences. Deliberately, or even accidentally
because of pilot skill deficiencies, letting the
aircraft swerve during roll out brings in
centrifugal forces that can quickly become out of
control resulting in ground loops and perhaps
busted wings.
None of these swerving or ground loop problems
can occur with a tricycle landing gear airplane! It
is really amazing that even the very light
Ercoupe demonstrates a landing stability in
cross-wind situations that puts the tail dragger
airplane to shame!
The reader of this discussion is encouraged to
read (once again—and maybe even two more
times) Langewiesche’s Stick and Rudder book
that really compares the behaviors of the tricycle
landing gear configuration to the conventional
(tail dragger) landing gear configuration.
One of the conclusion stated in Langwieche’s
book is:
“the best reason why the traditional landing gear
is still widely used is not connected with landing
at all. The nose-high landing gear gives the best
possible performance on takeoff—especially if
the field is rough or soft. However, it is a poor
landing gear, but an excellent take-off gear”.
Add to this conclusion the ego pressure that
says that pilots who fly tail draggers are better
pilots than those who fly tricycle landing gear
and perhaps one can still see why so many new
home built airplanes are made with tail dragger
or conventional landing gear configurations..
I have concluded that the behavior of the simple
Ercoupe with its tricycle landing gear is so
superior to many general aviation airplanes with
conventional landing gear, that I have concluded
the growing number of home built airplanes
should not be made with tail dragger type
landing gear (except perhaps for some rough
back-country
uses).
Perhaps
the
kit
manufacturing activities should support this
conclusion and encourage their customers to
build their kits with tricycle landing gear?
It is hoped that the conclusions in this paper
indicating that the tricycle landing gear is a
considerable improvement on the conventional
tail dragger landing gear, if more universally
adopted, will greatly improve the safety factor of
the growing number of homebuilt aircraft—a
conclusion also supported by the classical flying
book “Stick and Rudder, by Wolfgang
Langewieche.
Design Group 2
Meeting # 12
January 27, 2007
10:00 am
At FlaBob Airport
M
eeetting
ing S
chedule:
Me
Schedule:
2007 Meeting Schedule
10:00 am
FlaBob Airport
Chapter One Hanger
January
27
February
24
March
17
April
28
May
26
June
23
July
No Meeting
August
25
September
22
October
27
November
24
December
15
Check this site for any schedule updates and
changes.
In Chapter One Hanger
http://www.eaach1.org/calen.html
Check this site for newsletters
http://www.eaach1.org/design.html
Starting the New Year
Presentation on the Volante Flying Car
January 27, 2007 Saturday 10:00 am
This flying car design is a combination of a two-place, 150 m.p.h. aircraft
and a useful, highway-speed car. It is a "take all parts with you on the road"
flying car, consisting of a flight section which is removable from the car
component, and which is transportable by the car in trailer fashion. At
flight time, the flight section is easily and safely re-attached to the
automobile. The flying car's conversion time goal, either way, is under five
minutes for one person and that goal appears to be easily attainable.