US investigators will not pursue any penalties or other actions against American Airlines, despite banning the carrier from an inquiry into a runway overrun at Jackson Hole.
American was banned after personnel downloaded the flight data recorder of the Boeing 757 involved in the overrun on 29 December.
Flight 2253 exited the usable portion of Runway 19 on landing, coming to rest about 107m (350ft) beyond the overrun area in hard-packed snow. There were no injuries to the 181 passengers and crew on board.
Passenger video taken on board shows that the aircraft's thrust reversers were activated well into the landing run rather than immediately after touchdown.
The National Transportation Safety Board learned that American Airlines technicians had downloaded the data recorder during a stopover in Tulsa, Oklahoma as it was being routed by the carrier to the NTSB in Washington. The airline did not download the cockpit voice recorder.
While the recorder data remained intact, NTSB chairman Deborah Hersman says the breach of protocol by American "violates the Safety Board's standards of conduct for any organisation granted party status in an NTSB investigation".
American admits it downloaded the data, but says it was "part of its normal safety investigation" of the incident: "At no point in the process was the data on the DFDR compromised. There was no attempt to circumvent any collaborative process with the NTSB or FAA."
American says it has begun an internal review of its procedures "to insure that it is in full compliance with the NTSB". The NTSB will not pursue further actions, saying the error is viewed as a "single incident" and officials have been assured "it's not going to recur".