Searchers retrieve parts of Helios craft
By Jan TenBruggencate
Advertiser Kaua'i Bureau
MANA, Kaua'i — Search crews have recovered large sections of the frame of the Helios solar flying wing, but much of the wreckage is in the form of small pieces of foam and other debris, according to John Del Frate, NASA solar aircraft project manager.
A crash investigation team is interviewing those involved in the unmanned plane's final flight Thursday and expects within days to have the wreckage loaded into containers for shipment to designer AeroVironment in Simi Valley, Calif.
The five-member investigative team is on Kaua'i and will present its final report by Sept. 30.
Del Frate said he has not seen much of the video and other data sent from the aircraft before it crashed into the ocean north of the channel between Kaua'i and Ni'ihau. Most of that information has been locked up for review by the investigative team.
He said the aircraft's controllers experienced difficulty manipulating Helios in the moments before it began oscillating and came apart. Del Frate did not know if the control difficulty and the oscillation were caused by the same failure or whether loss of control caused the plane to undergo excessive stress.
The crew of a chase helicopter was tracking the remote-controlled aircraft and alerting its ground-based pilots about cloud formations to avoid. Helicopter crew members said they saw the 247-foot flying wing bend excessively, then start flapping before its skin tore off.
"We don't know what the cause is right now," he said.
Del Frate said that much of the damage occurred after the plane hit the water and was exposed to rough seas. Most of the wing's clear plastic skin is gone, and so are most of the $10 million worth of solar photovoltaic panels, he said. The solar cells may be on the ocean floor where the National Aeronautics and Space Administration said it's about a mile deep.
Search teams at sea were able to collect major structural components, such as the carbon fiber spar around which the wing was built, along with motors, propellers and the pods under the aircraft that held landing gear and other supplies. The heavy hydrogen fuel cell appears to have sunk, although both hydrogen fuel tanks, which automatically vented their hydrogen when the plane ran into trouble, were recovered.
Del Frate said much of the plane's structure was kept together by its cables and wires.
Some debris has been washing up on west Kaua'i beaches, mostly on the beach fronting the Pacific Missile Range Facility. Residents who see debris on other beaches are asked to call (808) 335-7835 and report the location. Beachgoers are asked not to pick up the debris, since there may be sharp edges.
Helios was the most recent of a series of solar remote-controlled aircraft that NASA hopes will lead to a plane that can remain aloft for weeks or months at a time. Proposed uses include a communications relay station much less expensive than satellites, as well as a platform to monitor conditions on Earth.
The plane has flown to nearly 100,000 feet above sea level — higher than any other winged aircraft. Its latest flight was to test a high-altitude fuel cell that officials hoped would be able to keep it aloft overnight when energy-generating sunlight is not available.
Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808) 245-3074.
