Seconds from disaster - AeroPeru Flight 603 Flying Blind

Aeroperú Flight 603 was a scheduled flight from Miami International Airport in Miami, Florida (KMIA) to Comodoro Arturo Merino Benítez International Airport in Santiago, Chile (SCEL), with stopover in Peru. On 2 October 1996, the aircraft flying the final leg of the flight crashed, killing all 70 people aboard.

Because a maintenance worker had failed to remove tape covering the static ports, the air data computers were unable to report the correct airspeed and altitude. The pilots struggled to navigate the aircraft as they were unaware of their true altitude and did not effectively use their alternative means; being midnight, they also had no external visual references. The aircraft wing hit the water and it crashed shortly afterwards.
On 1 October 1996, Aeroperú Flight 603 from Miami International Airport had landed at the Lima Airport. 180 passengers were on the first leg of the flight on a similar Boeing 757. 119 had disembarked, and the remaining passengers were transferred to another Boeing 757 after maintenance checks.

Just after midnight on 2 October, shortly after take-off, the Boeing 757 airliner crew discovered that their basic flight instruments were behaving erratically and reported receiving contradictory serial emergency messages from the flight management computer, including rudder ratio, mach speed trim, overspeed, underspeed and flying too low. The crew declared an emergency and requested an immediate return to the airport.

Faced with the lack of reliable basic flight instrument readings, constant contradictory warnings from the aircraft's flight computer (some of which were valid and some of which were not) and believing that they were at a safe altitude, 58-year-old Captain Eric Schreiber Ladrón de Guevara, a veteran pilot who had logged almost 22,000 flight hours, and 42-year-old First Officer David Fernández Revoredo, who had logged almost 8,000 flight hours, decided to begin descent for the approach to the airport. Since the flight was at night over water, no visual references could be made to convey to the pilots their true altitude or aid their descent. As a consequence of the pilots' inability to precisely monitor the aircraft's airspeed or vertical speed, they experienced multiple stalls, resulting in rapid loss of altitude with no corresponding change on the altimeter. While the altimeter indicated an altitude of approximately 9,700 feet, the aircraft's true altitude was in fact much lower.

The air traffic controller had instructed a Boeing 707 to take off and help guide the 757 back in to land, but before the 707 could take off, the 757's left wingtip struck the water, approximately 25 minutes after the emergency declaration, revealing to the crew the true altitude of the airliner; the pilots struggled with the controls and managed to get airborne again for 17 seconds, but the aircraft crashed inverted into the water. All 70 passengers and crew died.