Faucett Perú Flight 251

Investigation

The investigation was assisted by representatives from the US National Transportation Safety Board (NTSB) and Federal Aviation Administration, as well as Boeing and Pratt & Whitney, all of whom arrived at the scene of the crash by 1 March. The aircraft's flight data recorder (FDR) and cockpit voice recorder (CVR) were retrieved from the wreckage and on 5 March were sent to Washington D.C. for analysis by the NTSB.

Early press coverage reported that the FDR and CVR were already yielding information. However, while the FDR was found to be usable, the partly-burned and partly-damaged CVR had its magnetic tape broken at its beginning, and only isolated Spanish-language voices could be heard. These were seemingly recorded inside a hangar, possibly during maintenance, and thus no recording of the flight crew's final voices before the crash was made. The airline claimed to have acquired the CVR in July 1995 and to have done maintenance on it on two occasions immediately prior to the crash (December 1995 and February 1996), however, the CVR had not been maintained in six years, showing in its interior registry that the date of its last opening was December 1989.

It was found that the crew had been issued an outdated barometric altimeter setting after bypassing an ILS signal, causing them to fly almost 1000 ft lower than the altitude they believed they were flying at. In fact, they had the wrong impression the aircraft was flying at 9500 ft, when it actually was at 8640 ft, some 850 ft below the glideslope.