Treviso (Italy)

IPACO expert report
Expert name
Report date
Last update
François LOUANGE
October 18, 2012
February 07, 2015
Type
UFO
Document
Photo
Class
Explanation
B
Probable solar balloon
Imaging location
Over Treviso airport,
Italia
Complement
Imaging date
June 18, 1979
Important note: this little analysis concerned exclusively the above picture, without any knowledge of the
“Cecconi file”, nor any access to the other existing data (photographs, testimonies, investigations, radar
plots).
I. Photographic parameters

Picture taken on June 18th 1979, above the Treviso airport (Italy), with a Vinten F-95 camera

Film format 70x70 mm

Unknown focal length, with 4 possible preset values:
76 mm, 100 mm, 152 mm or 300 mm.
II. Geometric parameters
Consider the following points:
O
: camera’s lens
H
: vertical projection of O on the ground
A and B
: extremities of a known parcel on the ground
B’
: projection of point A on OB
Assuming points H, A and B are aligned (approximately), we have the following sketch in the vertical plane
that contains H, A and B:

Known flying altitude:
OH = 7000 ft = 2134 m

Known length of the AB parcel spotted on the ground:
AB = 381 m

Unknown  angle between the OH vertical and the OA line
III. Attempt to determine the focal length.
After inputting the film’s dimensions (70 mm x 70 mm) and the focal length (76 mm, 100 mm, 152 mm or
300 mm) into the Camera menu of IPACO, one may measure the  angle and infer the value of the r ratio,
thanks to the Length/Distance function:
r = AB’ / OA
Knowing that:
AB’ = AB cos 
OA = OH / cos 
One infers:
r = (AB / OH) cos2 
Thus:
 = arccos  (r / 0,17857)
Measurements with IPACO (see diagram below) give the following results:
In order to determine the most probable value for the focal length, we shall make use of the horizon line,
visible on the picture.
Let us compute first the angle value between the line of sight towards the horizon and the horizontal from
the camera, which is at an altitude of 7000 feet (2134 m).
The following sketch shows the Earth, with its R radius, the previously defined points O, H and A, the
horizon line and the horizontal passing through O.
The wanted angle is:
Knowing the values of the altitude OH = hc and of the Earth’s radius R:
hc = 2134 m
R = 6371000 m
One computes:
 = arccos [R / (R + hc)]
 = 1, 5 °
The angle  between the camera’s line of sight towards point A and the camera’s line of sight towards
horizon is inferred from, previously estimated for each of the possible focal lengths, and from the  angle:
For each possible value of the focal length, we shall measure  with the Angle function of IPACO, and
compare the result to that given by application of the previous formula.
Measurement for f = 100 mm
The most coherent result, expressed by a minimum difference in absolute value (taking into account
simplifications in computations and uncertainties in measurements), corresponds to:
f = 100 mm
It should be noted that values of « computed» and of « difference », indicated in the table above, increase or
decrease if the flying altitude increases or decreases as compared to 7000 feet. More precisely, calculation
shows that the “difference” would be null if we assumed:
f = 76 mm and h = 7800 ft
OR
f = 100 mm and h = 6400 ft
Without discarding the value of 76 mm, for which coherence is not significantly worse, we shall therefore
retain the value of 100 mm for the following study, bearing in mind that the residual uncertainty will not
call into question the orders of magnitude which will be evaluated.
IV. Study of the unidentified object
The object appears approximately in the form of a “cigar” (cylinder), the nearest extremity of which is dark.
Flying at an altitude slightly lower than that of the plane, it is lighted from above, which is compatible with
natural lighting by the sun, and its main axis is parallel to the ground.
The angular measurement of its diameter gives 3,473°:
To this angular size corresponds a ratio between the  diameter of the object and its distance d from the
camera:
V. Attempt to estimate the distance from the UFO
If the nearest extremity of the object is really black or very dark, comparison of its apparent luminance
with that of the darkest elements of the ground should provide information on the ratio between camerato-object and camera-to-ground distances, taking into consideration atmospheric diffusion.
The following illustration displays the measurement of the darkest pixel, respectively in 3 strips of the
image and at the dark extremity of the object.
It appears that dark points on the ground are far darker than the object. This would imply, if the object was
really black, that it would be farther away than the ground in the strips, i.e. farther than 10000 feet.
If it had been 10000 feet away from the camera, the object would have had a diameter in the order of 200
m. On the other hand, the value of its h ufo altitude would have been inferred from the hc value of the
camera’s altitude through the following simplified formula:
hufo = hc – d sin (  + )
where  is the above-defined angle and  the angle between the camera’s line of sight towards the object
and the camera’s line of sight towards the horizon line.
Measurement of 
hufo = 7000 – 10000 sin (5,49 + 1,5)
hufo = 5800 ft
Now, an object with a 200 m diameter, flying at an altitude of 5800 ft (1800 m), could certainly not have
gone unnoticed from the ground, in particular in an urban area and on a relatively clear day.
This only proves that the original assumption was wrong: the object was not completely dark, and
therefore could be at any distance from the camera (less than 1000 ft).
VI. The conceivable conventional explanations
The type of known object which is most comparable to the cigar-shaped object displayed on the
photograph is a balloon: either an airship, or a toy “solar airship”.
Airship
Modern airships, produced by around 15 manufacturers around the world (Airship Industries, Zeppelin ,
Goodyear, Huajiao Airship, Voliris, WDL, etc.) have diameters ranging from 8 m to 16 m, the value of 14 m
appearing to be the most common one. They can fly at altitudes far higher than 7000 ft.
Under that hypothesis, estimated distance between airship and plane:
For a diameter of 8 m :
For a diameter of 14 m
For a diameter of 16 m
130 m
:
230 m
:
260 m
However, the general aspect of the picture, the impression of the object’s closeness, and - above all - the
object’s irregular shape, do not really suggest a commercial or military airship.
Toy solar airship
This type of toy has been popularized in France by the Pif Gadget fanzine (special issues in July 1981 and
June 1982), but it already existed before in several countries, in particular in Germany, with the similar YPS
fanzine (YPS n° 450 and Yps-Extra n°3 in May 1980: the Solarzeppelin triggered then a wave of UFO
reports), Pif in Spain and Romania, and, above all, Ufo Solar in Italia (Issues n°1 and 2 of June 1979).
The solar balloon, or “solar UFO”, appears as a cylinder with a length from 2 to 3 m and a diameter from 60
cm to 2 m, 1 m being the most current value. Certain models are supposed to fly up to 30000 ft.
An experiment conducted by students of the “Jacques de Vaucanson Lycée – Tours – France”, in 2008, was
able to show that an experimental solar balloon had been able to reach an altitude of over 30000 ft.
Under that hypothesis, estimated distance between balloon and plane:
For a diameter of 60 cm
For a diameter of 1 m
For a diameter of 2 m
:
:
:
10 m
16 m
33 m
The solar balloon hypothesis seems credible, if one considers:





The object’s aspect
The object’s color (dark but not black, because reflecting)
The order of magnitude of the length/diameter ratio
The closeness between the camera and the object
The existence of other rather similar testimonies or photographs, sometimes with the established
presence of a toy “UFO airship”.
Examples found on the Internet for the same period (not checked):
-
Mestre (Italy), June 1979:
-
Hamburg (Germany), July 1980:
It should be mentioned that if the photograph under study effectively displays a balloon of this type, it
cannot be a model originating from Pif Gadget, taking into account the publication dates, later than the
picture. However, the publication dates of Ufo Solar in Italia are completely compatible with Cecconi’s
sighting.
VII. Conclusion
No formal demonstration could be made, but the most credible conventional explanation is that by a solar
airship (toy), which would have been photographed from the plane, at nearly the same altitude, from a
distance of around 15 meters.
… and a smile with Pif Gadget:
VIII. Sources – Photo credits – Acknowledgements
Main sources:
1- CISU
2- INU (link removed at the date of 07/02/2015)
3- “Phaeton the solar balloon” – High school “Vaucanson de Tours (37 – France)”
Secondary sources where the case is discussed:
4- What's all this, then?
5- Imagir's ATS thread
6- Ufoforum.it 2
7- Esos Misteriosos Objetos Celestes y sus Tripulantes (link removed at the date of 07/02/2015)
8- Misterio Del Planeta Azul
9- Ufoonline leonardo.it 1
10- Forum of the French radio "IcietMaintenant"
11- French forum "Ufo Scepticisme"
Third sources were the case is discussed:
12- Digilander Libero
13- Ufoforum.it 1 (link removed at the date of 07/02/2015)
14- Ufoonline leonardo.it 2
15- Theparacast
16- Fratellidiluce.it (link removed at the date of 07/02/2015)
Other Above Top Secret forum related threads:
- The Missing UFO Evidence Thread
- My very own 4th of July UFO sighting (Kandinsky's post)
- Cylindrical UFOs
All the original photographs of the case are from the UFO Italian group CISU.
Many thanks for their help in this study to:
-
Edoardo Russo, CISU director for his help in finding all the necessary material for this study, and
especially the original photo.
“Marcassite”, “Nablator” and “Gilles F.” of the French forum "Ufo Scepticisme" for their findings
about the Italian Ufo Solar and the altimetry data.