A 1960 version of the Discoplan 2 aircraft’s structure appears to have been based on a wooden or steel truss covered with lacquered canvas — standard lightplane and glider construction. Apparently the disc-shaped vertical “fin” was designed to revolve on a horizontal axis like a bicycle wheel — possibly to provide some sort of gyroscopic stabilization to the aircraft’s control system via a system of cables and struts.
The construction was carried out by Lavochkin. The circular wing has neither ribs or longerons. The light alloy edging around the perimeter of the “wheel” serves only to give a streamlined form to the tip. It is controlled by ailerons and rudder.
Reported in March 1963, the circular wing Discoplan II was successfully tested on an airfield near Moscow in the previous Autumn.
The Discoplan-II was piloted by Vladimir Ivanov, a glider expert.
One of the main features of the machine discovered during tests was the aerodynamic effect of the ‘air cushion’. Owing to the proximity of the wing to the ground, and thanks to its circular form, the influence of the cushion on the landing and take-off characteristics proved most beneficial. At a height of 1.5-2m / 59-79 in Discoplan-II automatically stabilised both in the lateral and transverse directions and could fly without the pilot touching the controls. In gliding down to land the pilot also felt how the Discoplan was “padded” by the air cushion. Thus, the landing was also of an automatic.
Wingspan: 5 m / 16 ft 5 in Wing area: 20 sq.m Empty weight: 240 kg Gross weight: 240 kg / 529 lb Wing loading: 12 kg/m2 Seats: 1
.During 1949-50 Master of Technology M.V.Sukhanov built an experimental single seat glider having a wing and control surfaces circular in planform, which he called Discoplan-I. The wing diameter was 3.5 m / 11 ft 6 in, and the gross weight was 230 kg / 507 lb.
The flight trials of the Diskoplan-I were carried out under the direction of the designer by a team of young engineers from the Voluntary Society for Assisting Army, Air Force and Navy, and covered aerobatics. It proved absolutely spin-proof.
It was flying in 1957.
Sukhanov “Discoplan I” 1957 on the Ground and in the air.
Developed from the SO.7050 and SO.7055 two-seat cabin monoplanes, the SO.7060 Deauville differs primarily in having the 75 hp Mathis 4GO replaced by a 105 hp Walter Minor 4-III.
The first of two Deauville prototypes flew on 22 March 1948. Of all-metal construction, dual controls are provided and a third seat may be fitted aft of the side-by-side front seats.
SO.7050 Engine: 75 hp Mathis 4GO
SO.7055 Engine: 75 hp Mathis 4GO
SO.7060 Deauville Engine: 105 hp Walter Minor 4-III Wing span: 34 ft Wing area: 161.4 sq.ft Length: 21 ft 10 in Height: 7 ft 11 in Empty weight: 1140 lb Loaded weight: 1760 lb Max speed: 127 mph Cruise: 105 mph at 3280 ft Range: 500 mi
The Deltaviex is an experimental aircraft designed by ONERA for development of supersonic aircraft. designed in 1953 by ONERA, the prototype was built by SNCASO in Courbevoie, under the direction of engineer Aliette.
The aircraft was intended for multiple testing, including a roll stabilization device obtained by the profile of the trailing edge landing flaps. This device was developed lift while providing propulsion. Conventional ailerons were located at the ends of the wings. At 3.40 m they were partly intended to produce a very low inertia and damping in roll. The jet was formed by air bled from the engine in a small proportion (about 2%). The system has a switchable ramp equipped with many output holes. The steering was done with an extremely short period of around five hundredths of a second, producing a flap ange of + / – 2 °. The 70° wing thickness does not exceed 6%. It is adjustable in flight to 1 ° -4 °. The tricycle undercarriage is retractable.
The Deltaviex made its first flight in 1954 with Robert Fouquet at the controls, registered F-WBHA c/n. 001. It was mainly flown by Robert Fouquet, chosen due to his small size, essential in the cramped cockpit of the minuscule aircraft. Its small size allowed testing it in the wind tunnel at Modane (Savoy) at full scale in order to precisely measure its behaviour in various flying situations. The aircraft served for trials with blown ailerons, whereby bleed air from its Marboré II engine was blown over the wing trailing edge, a system later installed for example on the F-104 Starfighter. An innovative directional control system was installed, using pressurised air instead of a rudder and elevator to change direction.
Testing remained secret until November 8, 1956, when the Deltaviex was introduced to the press.
During testing (at Brétigny, Meudon, and Modane), the Deltaviex changed canopy type three times.
The single example of the Deltaviex finished its career at Modane (Savoie). It was recovered in 1984, from a garage owner in the region, by the Association of Ailes Anciennes Toulouse. It is held association at: Ailes Anciennes Toulouse Derrière le 5 chemin de Laporte Saint Martin du Touch 31300 Toulouse
Engine: Turbomeca Marbore II turbojet, 400 Kp Wingspan: 3.40 m Length: 7.10 m Height: 2.50 m Empty weight: 550 kg Max weight: 920 kg Wing area: 5 m² Max speed: 400 km h Range: 300 km
Embodying experience gained with the SO 9000, the SO 9050 – two prototypes of which were ordered in 1954 – embodied considerable redesign, entrusted to Dassault. A smaller wing of reduced thickness/chord ratio was adopted, the cockpit was enlarged, air brakes were transferred from the wing to the rear fuselage, a taller undercarriage was provided and a two-barrel SEPR 631 rocket motor of 3000kg / 6614 lb was adopted, combined with wing-tip 2425 lb st Turbomé Gabizo turbojets. It could carry a 330 lb Matra self-homing missile under the fuselage.
Sud Ouest SO 9050 Trident II Article
The first prototype SO 9050 was flown on 19 July 1955, its first flight on rocket power taking place on the following 21 December, and the second prototype flew on 4 January 1956, but was destroyed during its second flight. A third prototype had meanwhile been ordered, this flying on 30 March 1956, and some 10 weeks later, on 11 June, a contract was placed for six pre-series aircraft, a supplementary contract for a further four following (although the latter was to be cancelled on 24 October 1957 as an economy measure). The pre-series SO 9050 differed from the prototypes primarily in having 1100kg Turbomeca Gabizo turbojets in place of the Vipers at the wingtips and provision for nose-mounted AI radar and a single ventrally-mounted Matra R 511 air-air missile. The first pre-series aircraft was flown on 3 May 1957 and the third on 30 January 1958, but three months later, on 26 April, the programme was cancelled. During tests, Mach=1.9 was achieved at 19500m and an altitude of 26000m exceeded.
Both prototypes were lost in aerial accidents, the second confirming the inherent dangers of a rocket engine with its immensely volatile fuel.
SO-9050 Trident II Engines: 2 x Turbomé Gabizo turbojets, 2425 lb st, 1 x SEPR rocket, 6614 lb thrust. Loaded weight: 5900 kg / 13007 lb Empty weight: 2910 kg / 6415 lb Wingspan: 6.95 m / 23 ft 10 in Length: 13.26 m / 44 ft 6 in Height: 3.20 m / 11 ft 6 in Wing area: 14.50 sq.m / 156.08 sq ft Max speed: M1.8 (1188 mph)
Stemming from the lightweight fighter philosophy that emerged from the Korean conflict, the SO 9000 Trident single-seat interceptor developed by a team led by Lucien Servanty was of unusual concept in employing turbojets for auxiliary power and a rocket motor for primary thrust. Two prototypes of the Trident were ordered on 8 April 1951, the first of these flying on 2 March 1953 solely on the power of two wingtip-mounted Turbomeca Marbore II turbojets each rated at 400kg, the more powerful Vipers being substituted in 1955. The second prototype was destroyed on its first flight on 1 September 1953, but development continued with the first example, which, on 4 September 1954, flew for the first time with its primary power plant, a triple-barrel SEPR 481 triple-chamber liquid rocket motor providing a total thrust of 4500kg. As the aircraft could not take-off on the power of the Marbores at fully loaded weight, these gave place to Dassault MD 30 (Viper ASV 5) turbojets of 745kg, with which it flew on 17 May 1955. Although conceived as a combat aircraft, the SO 9000 had meanwhile been overtaken by a more advanced development, the SO 9050, and its test programme was terminated on 10 December 1956, the prototype having achieved a speed of Mach=1.63 – the highest speed attained by any piloted aircraft in Europe at that time – and an altitude of 15,000m.
SO 9000 Trident
SO-9000 Trident I 2 x Marboré II turbojets, 800 lb st
SO-9000 Trident I 2 x Armstrong Siddeley Viper 5 turbojet, 1640 lb st, 1 x SEPR 481 rocket, 9920 lb thrust Wingspan: 26 ft 8.75 in (8.15m) Length: 45 ft 11.25 in (14m) Wing area: 99.03 sq.ft (9.2 sq.m) Max wt: 12,125 lb (5500kg) Max speed: 1056 mph @ 36,000 ft Crew: 1
The subject of an order for two prototypes on 31 May 1946, the SO 8000 Narval (Narwhal) was conceived by a team under the leadership of Ing Dupuy at the Societe Nationale de Constructions Aeronautiques de Sud-Ouest (SNCASO) as a shipboard fighter and attack aircraft. Of twin-boom configuration with a sweptback wing – 24 degrees inboard and 13.5 degrees outboard on the leading edge – and a tricycle undercarriage, the Narval was powered by an Arsenal 12 H-02 (Junkers Jumo 213) engine rated at 2,250hp, installed as a pusher and driving contra-rotating propellers. Proposed armament comprised six 20mm cannon with provision for up to 1000kg of external ordnance.
Development was somewhat protracted, and the first flight (by the second prototype) did not take place until 1 April 1949, the second following on 30 December. Numerous problems arose during the test programme, dictating changes in the control surfaces, the air intakes and the propellers (Rotol propellers replacing the original Chauviere units); constant troubles were experienced with the engine, and, following the generally unfavourable results of evaluation at the Centre d’Essais en Vol in January 1950, development of the Narval was discontinued. The second prototype effected its 43rd and last flight on 8 January 1950, and the first prototype flew only once. Proposals to adapt the design for a Rolls-Royce Nene turbojet as the SO 8010 were not pursued. The quoted performance was not, in fact, achieved during flight test.
Loaded weight: 6606 kg / 14564 lb Empty weight: 4821 kg / 10629 lb Wingspan: 11.77 m / 39 ft 7 in Length: 11.83 m / 39 ft 10 in Height: 3.20 m / 11 ft 6 in Wing area: 26.30 sq.m / 283.09 sq ft Max. speed: 730 km/h / 454 mph Range w/max.fuel: 4500 km / 2796 miles
The first turbojet-powered single-seat fighter of French design to be built, the SO 6020 Espadon (Swordfish) interceptor was developed by the Societe Nationale de Constructions Aeronautiques de Sud-Ouest (SNCASO) under the design leadership of Lucien Servanty. Conceived to meet the requirements of a programme promulgated on 25 March 1946, and the subject of an order for three prototypes placed two months later, on 28 June, the SO 6020 was powered by a 2268kg Rolls-Royce Nene turbojet with, unusually, an aft-mounted ventral air intake. The SO.6020 featured flush inlets on the fuselage sides aft of the wing trailing edge. Proposed armament was initially to have comprised four 30mm cannon and four 12.7mm machine guns, this later being changed to six 20mm or 15mm weapons.
The first prototype flew on 12 November 1948 and the second on 16 September 1949, the latter being modified, after initial test, with NACA-type lateral intakes in place of the ventral intake. It was appreciated at an early stage that the SO 6020 was underpowered and would offer inadequate performance, a major redesign as the SO 6021 therefore paralleling initial flight testing of the SO 6020. The third prototype, intended for tactical reconnaissance, was completed as the SO 6025 with lateral intakes and a ventrally-mounted SEPR 25 auxiliary rocket motor of 1500kg thrust, this flying on 28 December 1949.
Sud-Ouest SO 6021 Espadon
The SO 6021 represented an attempt to reduce the weight and alleviate some of the aerodynamic problems that had beset the SO 6020 from the outset of flight test. Retaining the same Nene engine, but having a 1.30sq.m increase in wing area, an entirely redesigned vertical tail and a 604kg reduction in empty weight, the SO 6021 was equipped with servo controls and flew on 3 September 1950. Armament comprised six 20mm cannon. In June 1951, a ground attack version of the SO 6021 was offered to the Armee de l’Air with an afterburning Rolls-Royce Tay engine and an armament of two 30mm cannon. However, testing of the SO 6021 indicated that some of the difficulties experienced with the SO 6020, notably the shortcomings of the air intake arrangement, had not been overcome. A speed of Mach=0.96 was attained in a shallow dive, but serious buffet occurred at Mach=0.75, and further development was abandoned, the sole SO 6021 serving as a test bed for small wingtip-mounted turbojets associated with the SO 9000 programme, continuing in this role until 1956.
SO.6025 Espadon
The second prototype, with a similar rocket motor installed in the rear fuselage, became the SO 6026, flying in this form for the first time on 28 March 1953.
In 1953 the third prototype built had its wings replaced by bigger ones and fitted with rocket engine SEPR. This resulted in being the first European aircraft to break the sound barrier in level flight on 15 December 1953.
Considerably more development followed, but by 1953 the type was clearly obsolescent and further work was abandoned.
The third prototype was once being used a target at firing range before being recovered to the Ailes Anceinnes museum in Toulouse by August 2018.
Sud-Quest SO 6025 Espadon 03
SO-6020 Loaded weight: 7454 kg / 16433 lb Empty weight: 5354 kg / 11804 lb Wingspan: 10.60 m / 35 ft 9 in Length: 15.00 m / 49 ft 3 in Height: 4.55 m / 15 ft 11 in Wing area: 25.20 sq.m / 271.25 sq ft Max. speed: 967 km/h / 601 mph
SO 6021 Espadon Loaded weight: 6870 kg / 15146 lb Empty weight: 4750 kg / 10472 lb Wingspan: 10.60 m / 35 ft 9 in Length: 15.00 m / 49 ft 3 in Height: 4.72 m / 16 ft 6 in Wing area: 26.50 sq.m / 285.24 sq ft
The Sud Ouest SO 6000 Triton, first flying on 11 November 1946, was the first French jet powered aircraft to fly. Five were built. The first was powered by a 1980 lb thrust Junkers Jumo 004-B2 with a nose intake. Later versions had a 4850 lb thrust H-S Nene with both nose and fuselage scoops.
They were used as test beds and side-by-side trainers.
The third built, SO-6000-03, is at the French Musee de L’Air.
Engine: Rolls Royce Nene 101, 21582 N Length: 34.121 ft / 10.4 m Wingspan: 32.644 ft / 9.95 m Wing area: 162.536 sq.ft / 15.1 sq.m Max take off weight: 10363.5 lb / 4700.0 kg Weight empty: 7056.0 lb / 3200.0 kg Max. speed: 513 kt / 950 km/h Cruising speed: 462 kt / 855 km/h Initial climb rate: 9842.52 ft/min / 50.0 m/s Service ceiling: 39370 ft / 12000 m Wing load: 63.76 lb/sq.ft / 311.0 kg/sq.m Crew: 2
