EVER since Thursday night's crash of USAir Flight 427, local authorities have been helping federal investigators comb through debris to piece together what went wrong. It is the United States' worst airline disaster in seven years; none of the 132 people aboard survived.
So far, the cause remains a mystery. ``We're still at wits' end,'' says a source close to the investigation.
Mike New had just finished celebrating his wife's birthday, eating cake and ice cream, when the call came that a major airliner had crashed near Pittsburgh International Airport.
As Beaver County Medic Rescue supervisor, he had worked plenty of crash sites. But nothing prepared him for this. ``Never in a million years,'' he says, shaking his head at the thought of the Boeing 737 slamming into the hillside. ``There's no big pieces of the airplane out there.''
By all indications, Flight 427 was on a normal approach to Pittsburgh from Chicago when, at 6,000 feet, something happened. The jet rolled to the left, and the plane turned upside down. Then it plunged, nose first, into a hillside about six miles from the runway.
The experienced crew was aware something was wrong. Six seconds after exclamations of surprise, they alerted air-traffic control. According to a transcript of radio transmissions, one crew member called it a ``traffic emergency.''
Since this is not a standard phrase, and the transcript has not yet been certified by the National Transportation Safety Board, NTSB member Carl Vogt suggests ``catastrophic emergency'' might have been said. (The NTSB, an independent federal agency, is heading up the investigation.)
In any case, investigators are looking into the possibility that something entered the jet's path, even though radar reported no aircraft in the area.
Another possibility is whether an engine went into reverse thrust. One of six reverser mechanisms was found on Saturday in the ``on'' position, but it could have been knocked that way on impact, Mr. Vogt says. In any case, the reverse thrust should have come from the other engine to cause the plane's left roll.
The USAir disaster is similar to a United Airlines crash three years ago in Colorado Springs, Colo. Both involved 737s; both involved an unexplained steep turn near mountainous terrain; both were described as plummeting to earth nose first. The Colorado Springs crash is one of only four airline accidents that the 27-year-old NTSB cannot explain.
That crash was also what prompted union officials to alert USAir about a potential rudder problem on Boeing 737s. Federal investigators had determined in that accident that rudder controls had gone awry. USAir officials agreed to inspect their 737s, says John Goglia, a flight-safety coordinator with the International Association of Machinists union, which represents USAir mechanics.
Federal authorities soon made such inspections mandatory. The 737 in Thursday's crash had passed those inspections four times, according to the NTSB.
The Pittsburgh disaster was the fifth USAir crash in five years, which has earned the airline increased scrutiny from aviation authorities. But officials - from US Transportation Secretary Federico Pena to USAir chairman Seth Schofield - said they could find no common link among the incidents. Others agree.
``I would not single out USAir as being particularly of concern in this area, even though, in terms of safety records, they are now leading the list of accidents,'' says Leo Janssens, president of the Aviation Safety Institute, a nonprofit watchdog group based in Worthington, Ohio.
Paul Dempsey, a law professor and aviation expert at the University of Denver, says airline-industry spending on maintenance per plane has declined, and the average age of planes has increased since deregulation in 1979. But the Boeing 737 that crashed was only seven years old.
Despite the airline's financial troubles, USAir mechanics have felt no pressure to cut corners, Mr. Goglia reports. In terms of safety, ``they're out front of everybody.''
*Staff writer Mark Trumbull contributed to this story from Seattle.