Cockpit voice-recorder evidence shows one of the pilots of the Continental Airlines Boeing 737-500 involved in the runway excursion accident at Denver called for a rejected take-off.
The US National Transportation Safety Board says the call came just four seconds after the recorder picked up a "bumping and rattling sound" as the jet accelerated down runway 34R on 20 December.
During a briefing on the accident a spokesman for the NTSB stated that the CVR showed "nothing out of the ordinary" during pre-flight checks and taxi-out for the service to Houston. The NTSB has also reportedly said there is no evidence of any problems with the CFM International CFM56 engines, thrust reversers, brakes or flaps.
Twenty-eight seconds after the brakes were released, says the spokesman, one of the pilots stated that take-off power was set. But 41s after release, a "bumping and rattling" began, and the call to reject take-off came at 45s.
There was no debris on the runway, which was bare and dry. Main landing-gear tyre marks started 865m (1,900ft) from the runway 34R threshold and nose-gear marks began 100ft further on.
The jet then began to veer off the centreline, says the spokesman, exiting the runway at 2,650ft from the threshold. It travelled into a grassy area before crossing taxiway WC and striking a berm.
As a result of the inertia from the impact, and the profile of the terrain, the aircraft "slightly became airborne". From the point at which it left the runway, the 737 travelled around 2,000ft before coming to rest.
The rattling sound continued to the end of the cockpit-voice recording, at 51s. The spokesman indicates that the recording was ended by the triggering of a deceleration 'g-switch', probably from the aircraft's impact with the ground after it struck the berm.
Information from the flight-data recorder information is "very good", he adds, and shows that the jet reached a maximum speed of 119kt. At the point where the flight-data recording ceased - again, possibly due to the ground impact - the aircraft was moving at 89kt.
Despite the aircraft's suffering severe structural damage and a fire around the right rear fuselage, none of the 115 occupants was killed, although dozens were taken to hospital with varying degrees of injury.