The LTV L450F, also known as the L45ØF, was a prototype quiet reconnaissance aircraft, developed by Ling-Temco-Vought in the late 1960s for use in the Vietnam War by the United States. Based on the airframe of a Schweizer 2-32 sailplane, the aircraft flew in 1970, and was developed into the XQM-93 reconnaissance drone before the project was cancelled.
Developed as a follow on to the Igloo White program, the L450F was intended to provide a quiet reconnaissance and communications relay aircraft.[1] Under a $1 million USD contract by LTV Electrosystems, the L450F was developed from a Schweizer SGS 2-32 sailplane, modified by Schweizer to LTV's specifications.[1]
These modifications included stronger wing spars, thicker wing skin, installation of a Pratt & Whitney PT6A turboprop engine driving a three-bladed propeller, and main landing gear based on that of the Grumman Ag-Cat agricultural aircraft.[1] An alternative configuration, using a piston engine, was also proposed.[1]
The prototype L450F first flew in February 1970, but was destroyed during its third flight, on 23 March that year, the pilot successfully bailing out. A second prototype was then completed and flown, successfully completing the testing program, and a third prototype was ordered as the unmanned XQM-93 drone, under the Compass Dwell project. Four examples of the XQM-93 were contracted for by the United States Air Force, however the Compass Dwell project was subsequently cancelled.[1] [2]
27 March 1972 Donald R. Wilson reached the altitude of 15,456 m (50,708 ft) in horizontal flight flying the remaining L450F, registered N2450F, setting a new Fédération Aéronautique Internationale international record, Class C-1c, Group II[3] (Powered aeroplanes, takeoff weight 1000 to 1750 kg, turboprop). This record still stood as of 27 March 2012.