Onishi OSG3

OSG3
Role	Single-seat powered sailplane
National origin	Japan
Manufacturer	Yuichi Onishi
First flight	1977
Number built	1

The Onishi OSG3 is a 1970s Japanese single-seat motor glider, designed and built by Yuichi Onishi (大西勇一,Onishi Yuichi).[1] This was his second motor-glider design; the first being a high-wing monoplane, powered by a Subaru car engine, with which he made a 120 km (75 mi) flight between Chigasaki and Oshima Island in July 1970.[2][3]

Design and development

The OSG3 is unusual in being powered by six model aircraft engines, which are arranged along a transverse strut-braced boom near the front of the fuselage. Together, the six engines produce 7.5 kW (10.1 hp) for take-off, and 5.6 kW (7.5 hp) for cruising flight.[4] There are six throttle levers and also six cut-out switches for the engines.[4] The aircraft has a cantilevered monoplane wing, in a shoulder-wing position on the fuselage. The empennage has a T-tail configuration.[1][4]

Design of the OSG3 began in January 1976, with construction commencing in July of that year. By January 1977, the aircraft had been completed and taxiing trial conducted.[1]

Specifications

Data from Jane's all the world's aircraft 1977-78[1] and Gliders & sailplanes of the world[4]

General characteristics

• Crew: 1
• Length: 6.50 m (21 ft 4 in)
• Wingspan: 14.60 m (47 ft 11 in)
• Height: 1.6 m (5 ft 3 in)
• Wing area: 17.2 m^2 (185 sq ft)
• Aspect ratio: 11.6
• Airfoil: Göttingen 535 modified
• Empty weight: 65 kg (143 lb)
• Gross weight: 135 kg (298 lb)
• Powerplant: 6 × OS-60 FSR 10cc two-stroke glow plug engines, 1.12 kW (1.50 hp) each
• Propellers: 2-bladed, 0.30 m (1 ft) diameter

Performance

• Cruise speed: 39 km/h (24 mph, 21 kn)
• Stall speed: 34 km/h (21 mph, 18 kn)

References

1. Taylor, John W. R.; Munson, Kenneth, eds. (1977). Jane's all the world's aircraft 1977-78. London: Jane's Yearbooks. pp. 500–501. ISBN 0354005510. Retrieved 15 July 2023.
2. "「ヒコーキ野郎」大空語る 茅ケ崎「宇宙まつり」で講演会 (Lecture at Chigasaki Space Festival)". kanaloco.jp (in Japanese). Kanagawa Shimbun. 20 June 2018. Archived from the original on 15 July 2023. Retrieved 15 July 2023.
3. "Car Engine-Powered Plane Makes Flight". The Japan Times. 29 July 1970. p. 3. Retrieved 15 July 2023.
4. Hardy, Michael (1982). Gliders & sailplanes of the world. London: Ian Allan Ltd. p. 162. ISBN 978-0711011526. Retrieved 15 July 2023.

External links

• Images of the OSG3