With this aircraft it was possible on August 13, 2001 over Hawaii to break the world record for non-rocket propelled aircraft . With an achieved altitude of 29,413 meters, the nearly 25-year-old record of 25,929 meters was a SR-71 Blackbird - spy plane outbid. This type of aircraft should represent an alternative to satellites or be used for research tasks at very high altitudes.
The first test flights took place in September 1999 with battery operation. The later record flight was carried out exclusively using solar energy . The climb alone took about 6 hours.
Almost 66,000 high-performance solar cells from SunPower with an efficiency of 22 percent were mounted on the wing surface , which provided 30 kW of electrical power with full solar radiation. The price of the solar cells used was just under $ 9 million. The flight speed was about 30 to 50 km / h. The information in the sources on the range, reached height and the old SR-71 record are partly contradicting, but are in the same order of magnitude.
Helios crashed into the Pacific about 10 miles west of Kauai , Hawaii on June 26, 2003 . NASA cites a problem with the control of the aircraft as the cause of the crash. The divergent phygoid oscillation could not be stopped in time, even by initiated emergency procedures. Excessive speed limits ultimately led to the failure of the structure and thus to a crash.
Helios in flight
Helios flies over Kauai, Hawaii
- NASA: Investigation of the Helios Prototype Aircraft Mishap. (PDF; 3.6 MB) Retrieved February 19, 2013 .