The remotely operated Helios Prototype aircraft was
destroyed when it crashed into the Pacific Ocean, June 26.

Helios, a proof-of-concept solar-electric flying wing, was
designed to operate at extremely high altitudes for long
duration. It crashed during a checkout flight from the U.S.
Navy Pacific Missile Range Facility (PMRF) on Kauai, Hawaii.

No property damage, other than the prototype, or injuries
occurred as a result of the mishap. The remotely piloted
aircraft came down in the ocean, within the confines of the
PMRF test range, west of the facility. The cause of the
mishap is under investigation.

The solar-electric, propeller-driven aircraft had been
flying under the guidance of ground-based mission
controllers for AeroVironment, Inc., of Monrovia, Calif.,
the plane’s builder and operator. The lightweight flying
wing had taken off from PMRF at about 5:00 a.m. EDT on a
functional checkout flight. Helios had been aloft for about
29 minutes. The mishap occurred during a shakedown mission
in preparation for a long-endurance flight planned for next

The Helios Prototype is one of several remotely piloted
aircraft whose technological development has been sponsored
and funded by NASA under the Environmental Research Aircraft
and Sensor Technology program. NASA’s Dryden Flight Research
Center, Edwards, Calif. manages the program.

Current to power Helios’ electric motors and other systems
during the day was generated by high-efficiency solar cells
spread across the upper surface of its 247-foot long wing.
At night Helios was powered by an experimental fuel cell-
based electrical system.

The Helios Prototype was designed to fly at altitudes of up
to 100,000 feet on single-day atmospheric science and
imaging missions, as well as perform multi-day
telecommunications relay missions at altitudes from 50,000
to 65,000 feet. The Helios Prototype set a world altitude
record for winged aircraft, 96,863 feet, during a flight in
August 2001.

NASA, supported by AeroVironment and the U.S. Navy, to
determine the exact cause of the Helios Prototype mishap,
will form an accident investigation team.

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