Aeroperú Flight 603

Aeroperú Flight 603 was a scheduled flight from Miami International Airport in Miami, Florida, US (KMIA), to Comodoro Arturo Merino Benítez International Airport in Santiago, Chile (SCEL), with stopovers in Quito, Ecuador and Lima, Peru. On 2 October 1996, the Boeing 757-23A aircraft flying the final leg of the flight crashed, killing all 70 people aboard.

The investigation determined that the air data computers were unable to show correct airspeed and altitude on cockpit displays, because a maintenance worker had failed to remove tape covering the static ports on the aircraft exterior. Flying at night over water with no visual references, the pilots struggled to control and navigate the aircraft, unaware of their true altitude. The crash resulted after its left wing and № 1 engine hit the surface of the Pacific Ocean.

Aircraft
The aircraft, a Boeing 757-23A was delivered new from Boeing on 2 December 1992, to Ansett Worldwide. It was leased to Aeroméxico on 27 September 1993 and then sub-leased to Aeroperú on 1 April 1994. The lease transferred back to Ansett in February 1995, and Aeroperú continued to operate the aircraft until it crashed.

Crew
The captain was 58-year-old Eric Schreiber Ladrón de Guevara, who had logged almost 22,000 flight hours (including 1,520 hours on the Boeing 757), and the first officer was 42-year-old David Fernández Revoredo, who had logged almost 8,000 flight hours, with 719 of them on the Boeing 757.

Accident
On 1 October 1996, Aeroperú Flight 603 from Miami International Airport had landed at the Lima Airport. One hundred and eighty passengers were on the first leg of the flight on a Boeing 757. One hundred and nineteen had disembarked, and the remaining passengers were transferred to another Boeing 757.

The aircraft took off 42 minutes after midnight (05:42 UTC) on 2 October, and straight away, 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 the altitude and airspeed indicator, rudder ratio, mach speed trim, overspeed, underspeed and flying too low. The crew declared an emergency and requested an immediate return to the airport.

The pilots incorrectly believed that they could figure out the actual aircraft altitude by asking the controller, but neither the pilots nor the controller realized that the altitude information displayed on the controller's screen was sent from the aircraft’s Mode C Transponder. As the transponder was receiving the same erroneous altitude information being displayed on the aircraft’s altimeter, the altitude on the controller's display was also incorrect.

Faced with a 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, the crew decided to begin descent for the approach to the airport. Since the flight was at night over water, no visual references were available to convey to the pilots their true altitude or to 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 much lower.

The air traffic controller instructed a Boeing 707 to take off and to help guide the 757 in to land, but before the 707 could do so, the 757's left wingtip clipped the water approximately 25 minutes after the emergency declaration, tearing off several feet of the left wing. The pilots desperately clawed for altitude and managed to get the 757 airborne again for 22 seconds, but due to the damage of the left wing the aircraft rolled over and slammed into the water inverted. All 70 passengers and crew died.

Passengers
About half of the passengers on the flight were Chileans returning to Chile. Of the passengers, 21 originated from Miami; all of the originating passengers were Chilean. An additional 10 passengers had boarded in Quito. The remaining passengers had boarded in Lima.