Boeing has achieved a milestone in the development of its High Altitude Long Endurance (HALE) unmanned aircraft by successfully testing a hydrogen propulsion system in simulated conditions of 65,000 feet.

The test, conducted over more than three days using a Ford Motor Company-developed hydrogen engine is a further step towards the realization of a UAV designed to remain airborne for more than seven days.

“This test demonstrates the technical readiness of the hydrogen engine system and confirms the capability breakthrough in flight endurance and altitude that could be realized by a variety of military and commercial customers,” said Darryl Davis, vice president and general manager, Boeing Advanced Precision Engagement and Mobility Systems.

Its potential applications include border observation, port security and telecommunications as well as battlefield intelligence and surveillance.