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Highest propeller driven flight by an aircraft

Highest propeller driven flight by an aircraft
Who
AeroVironment, Helios Prototype
Where
United States (Kauai,)
When
13 August 2001
The highest ever altitude reached by a propeller-driven aircraft is 29,524 m (96,863 ft), by the unmanned, solar-powered Helios Prototype flying wing over the Hawaiian Island of Kauai on 13 August 2001. Commissioned by NASA and developed by AeroVironment Inc. of Monrovia, California, USA, Helios is one of a new breed of slow-flying, high-altitude aircraft that its makers believe will present a viable alternative to communications satellites in the future.

See attached fact sheet for detailed specifications. Helios crashed into the Pacific Ocean during a test flight on 26 June 2003.

FAI recognises this as the highest ever flight by an unmanned aircraft.