Despite its numerical designation, the Br 903 was a glider unrelated to the Br 900-906 family of sports and training gliders. This aircraft was initially developed in Villacoublay by the Arsenal de l’Aéronautique (Arsenal), based on pre-war projects and incorporating German research from World War II.
The initial work was conducted under the leadership of Jarlaud, Cartier, and Schneider. After the closure of Arsenal, the construction contract was transferred to SEVIMIA (Victor Minié Aéronautique), where this stratospheric glider received the designation S-10, under which it was expected to become known.
In March 1954, Breguet, having established a glider division, began the design and construction of the S-10 glider, assigning it the type designation Breguet 903. Manufacturing took place at the Aire-sur-l’Adour factory under the direction of Mr. Cartier, with Raymond Jarlaud maintaining overall program leadership.
Purpose and Structural Design
The Br 903 glider was intended for flights at very high altitudes, exceeding 12,000 meters. Its primary mission in the stratosphere was to conduct meteorological research and study atmospheric physics.
The glider’s wing featured a wooden load-bearing structure with two spars. The main spar was box-shaped and bore the primary loads, while the secondary spar was auxiliary, intended for attaching ailerons and flaps. The skin of the main wing section was plywood, while the control surfaces were fabric-covered.
Technologically, the wing comprised three main components: a center section attached to the fuselage and two outer panels. Airbrakes were installed on the upper and lower surfaces of the wing. Slotted ailerons occupied the entire trailing edge of the outer panels, and slotted flaps extended along the trailing edge of the center section.
The glider’s fuselage was separable and consisted of three parts. The front section housed a cylindrical, pressurized cabin, made from fiberglass-clad plywood. The rear end of this section served as a frame and was a caisson made of stainless steel. The nose, composed of three hemispherical shells covered by a Plexiglas fairing, served as the pilot’s access point and could be jettisoned in flight. The pilot lay in a reclining position on a kind of stretcher, designed to be ejected in an emergency; after ejection, the stretcher would stabilize with an anti-spin parachute, allowing the pilot to detach and land with a conventional parachute.
The central fuselage section, to which the pilot’s cabin, wing, and landing gear were attached, was based on a steel tube truss. The rear fuselage section had a wooden structure and fabric covering. The tail unit was of a classic wooden design.
The glider’s landing gear included a retractable single-wheel main strut with a shock absorber and hydraulic wheel brakes, a tail wheel, and retractable side stabilizing outriggers located at the ends of the wing’s center section.
Onboard Systems and Operation
The glider’s control system consisted of rods passing through seals in the rear of the pilot’s cabin. It was equipped with an air conditioning system that operated in a specific sequence: air streams were mixed by a fan; air was dried by passing it through carbo-gel; carbon dioxide was removed by passing it through soda lime; and finally, air was heated by an electrical system.
Oxygen supply was provided from gaseous oxygen bottles. The glider was also planned to be equipped with a VHF transceiver radio station. It was envisioned that the Br 903 would detach from the tow aircraft at the latter’s maximum flight altitude, at a speed of 200 km/h.
The Fate of the Breguet 903
Unfortunately, the Breguet 903 glider, whose construction was extraordinarily lengthy, never actually flew. In the Chausson company’s laboratory, the glider underwent static tests and strength tests of the pilot’s cabin (for pressure and low temperature). In 1958, the pressurized cabin was tested in a barochamber in Brétigny.
However, by this time, interest in the “S-10” had significantly waned. Furthermore, the company became less optimistic about the altitude this glider could achieve. As a result, the program was ultimately canceled in early 1960.
Technical Specifications
| Modification | Br.903 |
| Wingspan, m | 24. 20 |
| Length, m | 11.50 |
| Aspect ratio | 14.00 |
| Wing area, m2 | 41.70 |
| Wing loading, kg/m2 | 18.60 |
| Empty weight | 604 |
| Maximum takeoff weight | 775 |
| Maximum speed, km/h | 2 00 |
| Minimum sink rate, m/s | 0.56 |
| Minimum sink speed, km/h | 70 |
| Service ceiling, m | 12000 |
| Crew | 1 |
Image and diagram gallery of the Breguet 903
 Br.903 |
 Br.903 |