Highest altitude in horizontal flight

USAF Capt. Robert C. Helt (pilot) and USAF Maj. Larry A. Elliott (RSO) reached an altitude of 25,929.031 m (85,068.997 ft) in sustained horizontal flight in a Lockheed SR-71A Blackbird at Beale Air Force Base, California, USA, on 28 July 1976.

For comparison, a Boeing 747 cruises at an altitude of 10,000 m. (35,000 ft.).

This is not an official FAI record. See 'Highest altitude by an aircraft (official FAI)'.