The discovery of a key engine part from a jumbo jet that crashed in July has intensified the search of Iowa cornfields for other pieces to the puzzle of what caused the DC-10's rear engine to fly apart, officials said Wednesday.
"We don't know yet whether this is the golden nugget we're looking for," said Jim Burnett, a member of the National Transportation Safety Board, of the discovery of the engine's fan disk. "But we're glad we found it."
Spokesmen for General Electric Co., which made the engine, said that the fan disk of the crippled DC-10 that crashed on July 19 when trying to land at the Sioux City airport is vital to the investigation into what happened to United Flight 232.
"This is the key to the whole search," said Jerry Clark, a flight safety investigator for GE.
Clark spoke at the Storm Lake airport before the fan disk was flown to GE's Evandale jet engine plant in suburban Cincinnati, where it arrived later in the day. GE spokesman Rick Kennedy said that federal inspectors would oversee analysis of the part.
One hundred searchers hired by GE will walk newly harvested fields in northwest Iowa this weekend looking for additional parts.
Flight 232 crashed at the Sioux Gateway Airport after its aft engine disintegrated in flight, throwing off parts that severed the plane's hydraulic lines. The jet cartwheeled across the runway in a fiery crash that killed 112 people; 184 survived.
Farmers have been recovering small pieces of the No. 2 engine for several weeks, but investigators said that the key to what happened is apparently the 290-pound titanium disk that holds fan blades.
Tuesday, about two-thirds of the disc assembly was found by Janice Sorenson, who was running a combine through corn a half mile from her house on her farm about 10 miles north of Alta. Alta is about 80 miles northwest of Des Moines.
"I felt a resistance against the combine, so I backed up, and I looked and I could see the fan blades protruding from the ground," Sorenson said.
She said the disk "was buried between 6 and 8 inches. It was all in one piece but there were pieces of fan blades that had been broken off."
Burnett said it is too early to assume that a flaw in the disk caused the crash. "The metallurgical examination of the disk itself, if in fact the problem originated there, should . . . reveal the cause," he said.
It is unlikely, he said, that the NTSB will disclose results of tests before a hearing that begins Oct. 30 in Sioux City.
In Evandale, GE plant spokesman David Lane would not theorize about what might have gone wrong with the disk, which probably was made in the early 1970s, but he said that GE was eager to see the part.
"This is a very significant find, in our eyes," he said.
GE lawyer Stephen Gadd said Sorenson will receive a part of the $50,000 reward it offered for the disk equal to the percentage of the disk she recovered, plus separate rewards for each fan blade. The company is paying up to $1,000 each for recovered blades.