Schweizer / SGS 1-36 NASA prototype

Glider Reg. Number: N502NA

1979

Design & Development

In the early 1980s, a Schweizer SGS 1-36 sailplane was modified for the NASA controlled, deep-stall flight program. The aircraft, flown at the Ames-Dryden Flight Research Facility (ADFRF, both before and after that time called the Dryden Flight Research Center, Edwards, California), was used for controllability research in the deep-stall region at an angle of attack of above 30 degrees.

Schweizer modified the horizontal stabilizer (T-tail configuration) so that it could pivot as much as 70 degrees with the leading edge down. Once the aircraft arrived at ADFRF, it was further modified, including modification of the cockpit area to permit easier pilot egress and addition of a NASA instrumentation system in the fuselage. After the modifications were completed, radio-controlled-model and ground tests of the aircraft were performed prior to flight tests. These preliminary tests included use of a simulator.

In September and October 1983, the modified Schweizer SGS 1-36 was flown in the ADFRF’s high-angle-of-attack program. The Schweizer was chosen for the program because of its slow speed and because its high-angle-of-attack aerodynamics were dominated by long wings rather than a long, pointed nose or forward strake. The objectives of the program were to demonstrate the feasibility of piloted, controlled flight at very high angles of attack and to refine piloting techniques required to make a safe transition into, maneuver in, and recover from controlled flight at very high angles of attack. Of particular interest during the 20 flights of the sailplane were the stability-and-control derivatives, trim data, and piloting techniques required to safely enter and exit the very high-angle-of-attack flight regimen.

The Schweizer 1-36 Sprite modified by NASA is available to view in our Heritage Hangar during regular business hours. See staff for a tour! 

Specifications

Span: 46.17ft

Length: 20.58ft

Wing Area: 140.7ft²

Empty Weight: 475 lbs

Wing Loading: 5.05 lbs/ft²

Glide Ratio: 1:31 @ 53mph

Minimum Rate of Sink: 2.25 ft/sec @ 42mph