A Feb. 8 article about aircraft accident investigations incorrectly said that a June 2002 crash in Meridian, Miss., was caused by a faulty crankshaft bolt made of zinc rather than harder cadmium. The bolt failed because it had been improperly heat-treated.
NTSB Goes to Fewer Crashes
Wednesday, February 8, 2006
Strapped with a backlog of cases and a tight budget, the National Transportation Safety Board is sending investigators to fewer and fewer fatal airplane crashes -- particularly those involving small planes. And that has safety experts worried.
Last year, the agency's accident investigators showed up at 62 percent of all fatal plane crashes, compared with 75 percent of all fatal crashes in 2001, according to NTSB numbers. But data from the Federal Aviation Administration -- which is required to send an investigator to every accident and take note of whether the NTSB is on the scene -- indicate that NTSB investigators showed up less than half the time last year.
The NTSB chafed at the FAA numbers, calling them inaccurate. After a back-and-forth between the agencies, the FAA backed down, acknowledging that its numbers may be unreliable.
Whether the NTSB showed up at 62 percent or less than half of all fatal crashes last year, the downward trend since 2001 has alarmed former accident investigators.
Most of the nation's 1,700 crashes last year involved small planes, such as turboprops owned by individuals. About 350 of those accidents caused at least one fatality.
"The consequences are, you're going to miss some things," said Gene Doub, a former NTSB accident investigator who teaches at University of Southern California. "Every one of these are not just dumb pilots. Some are airspace-system or training issues or airworthiness issues."
Acting NTSB Chairman Mark V. Rosenker said the agency wants "more safety payback" for the accidents where it spends its time. Beginning in 2004, investigators stopped going to small crashes in which the cause seemed to be obvious, such as an inexperienced pilot who flew into trees or a crop-duster that struck a utility pole.
Under the current process, he said, investigators can focus on crashes where a new safety lesson is likely to be gained. Investigators have been encouraged to whittle away at the agency's backlog of 944 accident investigations, each of which is more than six months old. (In 2001, the backlog was 2,400 cases.) "Investigators were showing up to a scene, writing down facts and sticking it in a pile," Rosenker said. "There is a greater payback in doing it the way it is currently being done."
If an NTSB investigator does not arrive on the scene, the agency relies on the FAA to handle much of the field work and eventually an NTSB investigator writes up a probable cause. The NTSB has about 70 accident investigators, and the FAA has several hundred inspectors who also serve as investigators.
Seasoned investigators worry that showing up at fewer accidents means the NTSB could miss an opportunity to improve safety.
The NTSB did not send an accident investigator to a June 2002 crash in Meridian, Miss., after a pilot flying a Piper aircraft reported engine trouble, declared an emergency and crashed in a field short of the airport. The pilot, who was flying alone, was seriously injured.
At first glance, the accident appeared to be caused by an engine failure, which is not unusual to investigators. After examining the engine, FAA investigators learned that a crankshaft gear bolt had failed because it had been improperly made of zinc rather than harder cadmium. The engine's manufacturer, Lycoming, had made a similar part for helicopters, which had also failed and caused several accidents.