The Schweizer SGM 2-37 is an American two-seat, side-by-side motor glider, designed and manufactured by the Schweizer Aircraft Corporation of Elmira, New York. It is distinguished by its ability to self-launch using an internal combustion engine, eliminating the need for an external tow plane, and then retracting the engine for pure soaring flight. The aircraft is notable for its role in military pilot training and civilian sport flying.
Development
The SGM 2-37 was developed in the early 1980s by Schweizer Aircraft, a company with a long history of producing high-performance gliders and sailplanes. The design aimed to combine the efficiency of a sailplane with the independence of a powered aircraft. It was conceived as a self-launching motorglider that could take off under its own power, climb to soaring altitude, shut down and retract its engine, and then operate as a conventional glider. This concept offered significant operational flexibility and reduced the logistical requirements for soaring operations.Design
The SGM 2-37 features a conventional low-wing monoplane design, constructed primarily from aluminum, a common practice for Schweizer aircraft. Key design features include:- Seating: A two-seat, side-by-side cockpit configuration, offering excellent visibility and facilitating instructional flying.
- Engine: A retractable engine pylon houses a horizontally opposed piston engine, typically a Lycoming O-235, which provides sufficient power for self-launching and powered cruise flight. When not in use, the engine and propeller can be retracted into the fuselage to reduce drag for optimal gliding performance.
- Landing Gear: It is equipped with retractable main landing gear, further minimizing drag during soaring operations.
- Aerodynamics: The aircraft's aerodynamic design allows for a respectable glide ratio, enabling efficient soaring flight after the engine is shut down.
Operational History
The most significant operator of the SGM 2-37 was the United States Air Force Academy (USAFA), which adopted the aircraft for its introductory flight training program. Designated as the TG-7A by the USAF, it was used extensively for flight instruction, aerobatics, cross-country soaring, and cadet pilot familiarization. Its robust construction and versatile performance made it an ideal platform for training aspiring military aviators, bridging the gap between basic flight principles and advanced powered aircraft operations.Beyond military service, the SGM 2-37 was also operated by various civilian soaring clubs and private owners, appreciating its self-launching capability and dual-role utility as both a powered aircraft and a sailplane.
Variants
- SGM 2-37: The primary production model for civilian and military use.
- TG-7A: The military designation given to the SGM 2-37 when operated by the United States Air Force Academy.
Specifications (SGM 2-37 / TG-7A)
- Crew: 2
- Length: 26 ft 6 in (8.08 m)
- Wingspan: 57 ft 1 in (17.40 m)
- Height: 6 ft 6 in (1.98 m)
- Wing area: 180 sq ft (16.7 m²)
- Empty weight: 1,400 lb (635 kg)
- Max takeoff weight: 2,000 lb (907 kg)
- Powerplant: 1 × Lycoming O-235-L2C flat-four piston engine, 112 hp (84 kW)
Performance
- Maximum speed (powered): 130 kn (150 mph, 240 km/h)
- Stall speed: 45 kn (52 mph, 83 km/h)
- Range (powered): 500 nmi (575 mi, 925 km)
- Service ceiling: 15,000 ft (4,600 m)
- Rate of climb: 700 ft/min (3.6 m/s)
- Glide ratio: 23:1