Flying wing may broken up in flight

By Jan TenBruggencate
Advertiser Science Writer

By Jan TenBruggencate
Advertiser Science Writer

MANA, Kaua‘i — The unmanned Helios solar flying wing appeared to break up in flight before its wreckage fluttered out of the sky Thursday, NASA officials said.

Helios, a more than $15 million aircraft and part of a $130-million NASA funded research program, was just a half-hour into its flight from the Pacific Missile Range Facility when its high-tech wing collapsed. It was at an elevation of about 3,000 feet and about 10 miles from Kaua‘i, just north of the channel between Kaua‘i and Ni‘ihau.

The Navy had boats at the wreck site, monitoring the drift, as NASA, the Navy and AeroVironment, the firm that designed and built the plane, planned its salvage. The agencies did not say early this morning whether the wreckage has sunk or is floating, or whether any parts of the plane have been recovered.

"It is possible that there are some parts that have been recovered. We just don't know at this time," said Alan Brown, spokesman for NASA's Dryden Flight Research Center in Edwards, California.

There was a helicopter with a camera on board following Helios, but it got no still photos of the breakup and it was unclear what video images were available, he said. The plane continued sending data throughout its 29-minute flight, and that information has been "saved and impounded" for use in the investigation of the crash. A five-member investigative panel was named just before noon today. Its members are Thomas E. Noll, chairman, Langley Research Center, Hampton, Va.; John M. Brown, NOAA's Forecast Systems Laboratory, Boulder, Colo.; Stephen D. Ishmael, Dryden Flight Research Center, Edwards, Calif.; Marla E. Perez-Davis, Glenn Research Center, Cleveland; Geary C.Tiffany, Ames Research Center, Moffett Field, Calif.

Helios had a 247-foot wingspan. The wing was nearly a foot thick at its deepest part, and was eight feet from leading to trailing edge.

The vast, bendy wing was supported by a tubular spar that appears to have failed, although it was not clear yesterday how it did. Brown said there was no evidence it was struck by a flying object, but he could not say whether it had been damaged at some point earlier, was overloaded by weather conditions or had been weakened by the stress of multiple flights. The spar was built of carbon fiber. It as tubular in shape, but the tube was thicker at the top and bottom to take the stresses of bending during flight. It was also wrapped in other high-tech materials, Nomex and Kevlar, for additional strength where needed.

Helios two years ago flew from the Pacific Missile Range Facility and set a world altitude record for winged aircraft. This flight used the same solar photovoltaic cells for daytime power, but had an additional power system in the form of a fuel cell fed by two tanks of hydrogen that were slung from the ends of the wing.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com or (808)245-3074.