The pilots of an American Airlines Boeing 757-200 that overran the runway on landing in Jackson Hole, Wyoming, in December 2010 could not deploy the aircraft's thrust reversers, according to a transcript from the cockpit voice recorder.
The aircraft came to a stop 110m (361ft) past the end of the runway in hard-packed snow.
Earlier in its investigation, the National Transportation Safety Board (NTSB) determined that the thrust reversers on the Rolls-Royce RB211 engines were not fully deployed until 18s after touchdown.
No discrepancies were found in the air-ground sensor and thrust-reverser system in operational testing conducted by the investigators.
But an examination of the auto speed-brake mechanism in the cockpit showed an improperly-installed component with a missing bushing.
After the overrun the captain told the first officer, who was operating the aircraft: "We did everything right, we didn't get the thrust reversers."
The NTSB released a transcript of the cockpit conversation as part of its inquiry.
The first officer also had problems with the aircraft's brakes, and told the captain that "they did not release". He also said: "We were sliding and I couldn't get the thrust reverser, would not come out, they were stuck."
In communication with passengers, one of the pilots said: "Our thrust reversers didn't come on. I've been here 19 years and we got virtually no assist on the braking.
"I'm not sure why the brakes - they didn't take and the thrust reversers didn't come on."
Prior to the landing - after the captain received a briefing from the Jackson Hole automatic terminal information service - the captain briefed the first officer on the field conditions and braking action.
He also expressed concerns about the condition of the last third of the runway.
A Bombardier Challenger executive jet that had previously landed at the airport reported braking action in the first two-thirds of the runway as good, but poor in the last third, the NTSB said.
The runway condition was reported as thin loose snow over patchy thin snow and ice.
Shortly after the incident the NTSB banned American from the investigation, after carrier personnel downloaded the flight data recorder.
American said it downloaded the data as part of its normal safety investigation.
Source: Flight International
