Potential of the QT-2 / Q-Star was such that Lockheed produced a refined version for the US Army: The YO-3A. Also based on the Schweizer SGS 2-32 Sailplane wings and tail unit, but with wings mounted low on the fuselage, retractable landing gear, upgraded (SLAE) avionics, State-Of-The-Art Sensor (NVAP with LTD) and the Tactical Observer seated forward for better visibility. A 156.5kW IO-360D Continental Engine provided propulsion power. The YO-3A was deployed in Southeast Asia from mid-1969 to late-1971.
It was the first military aircraft to employ an integrated NOD Sensor with a YAG Laser. It also had an Infrared Illuminator for other tactical sensors (INFANT LLTV, NODs, etc). The YO-3A was deployed in Vietnam for more than a year.
It was later operated by the LDWF and FBI. NASA yet operated the former 69-18010 as NASA 818 (or similar).
One YO-3A is preserved in the Army Aviation Museum at Fort Rucker, Alabama.
Engine: Continental, 210 hp.
Wing span: 57 ft 0 in (17.40 m).
Length: 30 ft (9.14 m).
Gross weight: 2,167 lb (983 kg).
Max speed: 149 mph (240 km/h).