The crew of the doomed ValuJet Flight 592 headed back to Miami just half a minute after an unidentified noise signaled trouble, the cockpit voice recorder shows. But it was too late.
The National Transportation Safety Board released an outline of the cockpit recording Thursday, though without any exact conversations or interpretations.The outline shows that 5 minutes and 47 seconds into the May 11 flight the pilot questioned an unidentified sound.
Seventeen seconds later she "stated the need to return to Miami" and five seconds later voices from the cabin reported fire.
The first officer requested clearance to return to Miami 11 seconds later, getting immediate approval, but it was too late to save the plane, which plunged into the Everglades, killing all 110 aboard.
Prior to the unidentified noise, the board said, 28 minutes of recording show "normal preflight and departure communications, including the accomplishment of checklists and procedures."
The statement said there were two apparent interruptions of power to the voice recorder, the first 1 minute and 39 seconds after the unidentified sound and the second shortly before the end of the tape. Power interruptions to the separate flight data recorder had been noted previously but it was not clear whether they occurred at the same time.
The statement stressed that the work on deciphering the tapes is still going on.
Safety Board investigators say it will be weeks, at least, before the recordings are analyzed and they piece together details of the DC-9's brief flight.
Air traffic control conversations showed the pilot also reported smoke in the cockpit and was unable to locate the nearest airport, an indication that heavy smoke may have obscured her vision.
Meanwhile in Atlanta, about 50 ValuJet flight attendants have resigned since Flight 592 crashed, more than three times the average monthly turnover rate, the airline said.
ValuJet records indicate 20 attendants left because of the crash, a typical number after such an accident, and others left for unspecified or more routine reasons, spokeswoman Marcia Scott said Thursday.
The airline' average turnover for a month is 15, she said.