BOSTON (AP) -- Excessive wear on a throttle linkage part has been blamed for more than a dozen crashes or forced landings of older Cessna planes, The Boston Globe reported Wednesday.
In the most serious crash blamed on the throttle control arm, a Cessna 206 lost power and crashed during a sightseeing flight in Alaska in 1996, killing the pilot and two passengers, the newspaper reported, citing federal records. Cessna stopped using engines with the part in 1992.
The crash of the plane, operated by Stearns Air Alaska, occurred on Sept. 23, 1996. Seconds after the plane lifted off the surface of Lake Hood the throttle control arm, which controls the power produced by the engine, failed.
Just when pilot Nels Kasperson needed power, the engine idled. He tried to reach nearby tidal flats, but before the water's edge, the plane became entangled in high tension wires, crashed, and burned. Kasperson and two of the three friends from Everett, Mass. - Dolores McLaughlin, 68, and Joan A. Keefe, 64 - were killed. The third woman, Carmella Vetrano, then 75, was injured, along with another passenger.
Over the last decade, pilots and some of the Federal Aviation Administration's own inspectors have urged the agency to issue an order fixing the problem, the Globe reported.
However, FAA spokeswoman Laura Brown said the agency believes poor maintenance, rather than design problems, leads to rapid wear of the part, which is made of bronze rather than more durable steel.
The FAA, Cessna and Teledyne Continental Motors -- which made engines for Cessna planes before 1992 -- have all urged pilots and mechanics to make frequent checks of the part in older Cessnas.
Cessna officials say more than 1,000 of their aircraft built before 1996 have the part, and Teledyne officials said they have produced about 175,000 engines in the last 50 years with bronze throttle arms.
When Providence, R.I.-based Textron bought Cessna in 1992 for $600 million, it switched to using only Textron Lycoming engines, which uses steel linkage parts.
Cessna and Teledyne have blamed each other for the bronze throttle arm's tendency to wear quickly.
More than a year before the Alaska crash, Cessna urged Teledyne to make the arm out of steel, but the request went unheeded, the Globe said. Cessna officials refused to comment.
Teledyne said any wear was due to Cessna's design of the linkage, adding that some mechanics servicing the thousands of engines in the field were to blame for not making certain that connections were tight, the newspaper said.
John Barton, chief technology officer for Teledyne Continental Motors, said the arm cannot wear if its connection is properly tightened.
At least 25 failures of the throttle arm have been reported to the FAA since 1975, according to the Globe. Some were discovered in routine maintenance. However, at least 15 times before the fatal Alaska crash -- and twice since -- planes were forced to make emergency landings because of failure of the throttle arm, the newspaper said, quoting voluntary reports to the FAA.
Both the FAA and the National Transportation Safety Board found that the failure of the part caused the Alaska crash.
The families of those killed in the Alaska crash received six-figure settlements from the companies last year.
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