One pilot was heard on the cockpit recorder referring to "engine failure" just before the crash.

Union officials threatened to prevent further taping by having members turn off the cockpit recorders unless new legislation was written.

Currently, the only commuter craft required to carry cockpit recorders are turbojet planes with seats for 10 or more passengers.

Its union employees were so distrustful that some pilots were illegally disconnecting their cockpit recorders for fear management was listening in.

At that investigation the tape from the cockpit recorder would be played.

He said, 'Let me guess - the original tape from the cockpit recorder was destroyed in the lab fire.'

It was Air Force One's cockpit recorder.

If the cockpit recorder worked properly and was not disconnected by the hijackers, it would have taped the last 30 minutes of flight.

There was just a loud, final noise on the plane's cockpit recorder before it went dead.