Aeroperú Flight 603
N52AW, the aircraft involved in the accident, seen at Miami International Airport in 1996.
|Date||2 October 1996|
|Summary||Maintenance error, instrument failure, CFIT|
near Pasamayo, Peru
|Aircraft type||Boeing 757-23A|
|Flight origin||Miami International Airport
Miami, Florida, United States
|1st stopover||Mariscal Sucre International Airport
|Last stopover||Jorge Chávez Int'l Airport
|Destination||Comodoro Arturo Merino Benítez International Airport
Aeroperú Flight 603 was a scheduled flight from Jorge Chávez International Airport in Lima, Peru (SPIM), to Comodoro Arturo Merino Benítez International Airport in Santiago, Chile (SCEL), which crashed in the early morning of 2 October 1996, killing all 70 people aboard.
The pilots struggled to navigate the aircraft after the failure of all the plane's instruments. With the pilots unaware of their true altitude, the plane's wing hit the water and it crashed shortly afterward. The cause of the instrument failure was a maintenance worker's failure to remove tape covering the static ports necessary to provide correct instrument data to the cockpit.
On October 1, 1996, AeroPerú Flight 603 from Miami International Airport had landed at the Lima airport using a Boeing 727–200 because of technical problems with the Boeing 757 that normally flew this route. 180 people were on the first leg of the flight. 110 had deplaned, and the remaining passengers were transferred to the Boeing 757 after maintenance checks.
On October 2, 1996, shortly after takeoff just past midnight, the Boeing 757 airliner crew discovered that their basic flight instruments were behaving erratically and reported receiving contradictory serial emergency messages from the onboard computer, such as 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 instruments, 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 pilot Eric Schreiber Ladrón de Guevara (who had almost 22,000 flight hours to his credit) and 42-year-old copilot David Fernández Revoredo (who had logged almost 8,000 flight hours) decided to cautiously 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 the pilots in the descent. Also, 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 a Boeing 707 take off to help guide the 757 back to land, but before the 707 could reach the 757, the 757's wingtip struck the water approximately 25 minutes after emergency declaration, making the pilots realize the true altitude of the airliner; the pilots struggled with the controls and managed to get airborne again for seventeen seconds, but the aircraft crashed inverted into the water. All 9 crew members and 61 passengers died. The pilots, distracted by the conflicting warnings, did not notice the radar altimeter after passing through 2,500 feet, according to the accident report.
After the crash recovery crews found 9 bodies floating; the rest of the bodies sank with the airliner.
The aircraft, a Boeing 757-23A was delivered new from Boeing on December 2, 1992, to Ansett Worldwide and it was leased to Aeroméxico on September 27, 1993, and subleased to Aeroperú on April 1, 1994.
Passengers and crew
Of the passengers, 21 originated from Miami; all of the originating passengers were Chilean.
Monus Albert, the brother in law and business partner of two passengers, said that some very early reports initially stated that the crashed flight flew on a New York City to Lima route, and that the agencies later corrected reports, stating that the flight was flying from Lima to Santiago. 
The Peruvian accident investigator, Guido Fernández Lañas, was the uncle of the co-pilot, David Fernández, but, despite originally holding some reservations about the potential conflict of interest, the National Transportation Safety Board -appointed investigator, Richard Rodriguez, determined that he could properly investigate the accident.
The Peruvian Navy collected the floating wreckage. After the Peruvian authorities asked for assistance, the United States Navy provided equipment to locate the underwater wreckage and black boxes of the Boeing 757.
Later investigation into the accident revealed that duct tape was accidentally left over some or all of the static ports (on the underside of the fuselage) after the aircraft was cleaned, eventually leading to the crash. Employee Eleuterio Chacaliaza left the tape on by mistake.
The static ports are critical to the operation of virtually all of those flight instruments that provide basic aerodynamic data such as airspeed, altitude and vertical speed, not only to the pilots but also to the aircraft's computers, which provide additional functions such as warnings when flight characteristics approach dangerous levels. The blockage of all of the static ports is one of the few common-failure modes resulting in total failure of multiple basic flight instruments and as such is regarded as one of the most serious faults that can occur within the avionics systems.
The design of the aircraft did not incorporate a system of maintenance covers for the static ports. Such covers are commonly employed in aviation for blocking access to critical components when the aircraft is not in operation and are generally a bright color and carry flags (which may have "remove before flight" markings). Instead, the design of the aircraft and the relevant maintenance procedure called for the use of adhesive tape to cover the ports.
As a result of the blocked static ports, the basic flight instruments relayed false airspeed, altitude and vertical speed data. Because the failure was not in any of the instruments but rather in a common supporting system, thereby defeating redundancy, the altimeter also relayed the false altitude information to the Air Traffic Controller, who was attempting to provide the pilots with basic flight data. This led to extreme confusion in the cockpit as the pilots were provided with some data (altitude) which seemed to correlate correctly with instrument data (altimeter) while the other data provided by ATC (approximate airspeed) did not agree. Although the pilots were quite cognizant of the possibility that all of the flight instruments were providing inaccurate data, the correlation between the altitude data given by ATC and that on the altimeter likely further compounded the confusion. Also contributing to their difficulty were the numerous cockpit alarms that the computer system generated, which conflicted both with each other and with the instruments. This lack of situational awareness can be seen in the CVR transcript. The fact that the flight took place at night and over water, thus not giving the pilots any visual references, was also a major factor.
After the accident, Aeroperú changed the number of its evening Miami-Lima-Santiago Boeing 757 service to Flight 691. The Flight 603 incident contributed to the eventual demise of Aeroperú, which was already plagued with financial and management difficulties. The airline filed for bankruptcy three years later, to avoid millions in claims from the relatives of the victims aboard Flight 603. Boeing took the blame for failing to train officers to deal with these emergencies which would have been avoided by turning off the computer on board and flying with analogue instruments. Finally in 2006, Boeing paid substantial compensation – the figure has not been revealed – to the families of the victims.
In November 1996, Mike Eidson, a Miami attorney from Colson Hicks Eidson, said in an interview that many of the passengers survived the initial impact and drowned afterwards. Eidson represented 41 passengers and crew in a lawsuit contending that the aircraft's manufacturer, Boeing, bore responsibility for the disaster, as the company ought to have foreseen the misuse of its products. The suit was filed against Boeing in federal court in Miami in May 1997. According to the complaint, the control panel errors were caused by careless maintenance by Aeroperú and negligence and defective design by Boeing. Boeing argued that it was not at fault, and that responsibility for the accident lay with the employee who did not take the tape off the static ports, and the aircraft's pilot for not finding the tape. Richard Rodriguez of the NTSB said that it was understandable that Schreiber did not find the tape because the maintenance worker used duct tape instead of the brightly colored tape that he was supposed to use. In addition, Rodriguez said that the pitot-static ports were high above the ground. Therefore Schreiber did not see the tape against the fuselage. After extensive litigation, the parties agreed to transfer the case against Boeing and Aeroperú to an international arbitration in Santiago, Chile, for a determination of the damages. The defendants agreed not to contest liability in Chile.
On December 13, 1999, family members of the flight's passengers received one of the largest cash awards stemming from an aviation accident outside the United States aboard a non-U.S carrier, averaging nearly 1 million dollars per victim. The episode "Flying Blind" from Mayday (Air Crash Investigation, Air Emergency) stated that the manner of the crash resulting in the passengers' drowning was responsible for the large settlements.
Peruvian justice sentenced Chacaliaza for negligent homicide; it did not sentence any other staff members of the airline. Guido Fernández criticized the move; he argued that Chacaliaza, who was relatively uneducated, had little understanding of what he did, and that his supervisors had more responsibility.
The accident was featured in the episode "Flying Blind" from Mayday (Air Crash Investigation, Air Emergency) and was also featured in the Mayday special "Who's Flying the Plane?". The cockpit voice recording of the incident became part of the script of a play called Charlie Victor Romeo.
- Lists of accidents and incidents involving commercial airliners
- Pitot-static system
- Spatial disorientation
- "Flying Blind", Mayday [documentary TV series]
- "Searchers comb Pacific for more bodies after Peruvian crash." CNN. October 2, 1996. Retrieved on June 11, 2009.
- "Murieron 70 personas en un avión peruano que cayó al mar." Clarín Digital. October 3, 1996. Retrieved on June 11, 2009.
- "CRONICA," Consorcio Periodístico de Chile S.A. October 2, 1996. Retrieved on June 11, 2009.
- Walters, James M. and Robert L. Sumwalt III. "Aircraft Accident Analysis: Final Reports." McGraw-Hill Professional, 2000. 98. Retrieved from Google Books on May 11, 2011. ISBN 0-07-135149-3, ISBN 978-0-07-135149-2. "Robles, Ricardo, Presidente, Commission of Accident Investigations (CAII), Director General of Air Transport (DGAT) of Peru. 1996. Final report, Boeing 757-200 Accident, Aeroperu, October 2, 1996. Lima, Peru."
- "World News Briefs; $29 Million for Victims Of 1996 Peru Air Crash," The New York Times. Thursday January 22, 1998. Retrieved on June 11, 2009.
- Casey, Steven. The Atomic Chef, Caught on Tape. Aegean Publishing Company, 2006: Santa Barbara.
- Volando (Aeroperú's inflight magazine), Issue 17, July-August 1997
- "Aeroperu Crash Victims Win Landmark Award." Colson Hicks Eidson. December 13, 1999. Retrieved on June 1, 2009.
|airliners.net's Photo gallery|
- Final Report (unofficial English translation) (Archive) hosted at SKYbrary
- The original Spanish report, available via mail, is by the Accident Investigation Board, Directorate General of Air Transport, Ministry of Transportation and Communications
- "In reply refer to: A-96-141." National Transportation Safety Board. November 15, 1996.
- AvWeb - AeroPeru 603 Cockpit Voice Recorder transcript (English)
- Youtube - AeroPeru 603 Cockpit Voice Recorder Original Audio Parte 1
- Youtube - AeroPeru 603 Cockpit Voice Recorder Original Audio Parte 2
- Youtube - AeroPeru 603 Cockpit Voice Recorder Original Audio Parte 3
- AvWeb - AeroPeru 603 Alarms activity from the CVR
- "Computer failure puzzling in Peruvian crash." CNN. October 3, 1996.
- "Searchers comb Pacific for more bodies after Peruvian crash," CNN. October 2, 1996.
- List of passengers
- News and Comment on the Aeroperu B757 Accident - University of Bielefeld