Aeroperú Flight 603

Aeroperú Flight 603

N52AW, the aircraft involved in the accident, seen at Miami International Airport in January 1996.
Accident summary
Date	2 October 1996 (1996-10-02)
Summary	Maintenance error; instrument failure due to tape on the static ports.
Site	Pacific Ocean near Pasamayo, Huaral, Peru
Passengers	61
Crew	9
Fatalities	70 (all)
Survivors	0
Aircraft type	Boeing 757-23A
Operator	Aeroperú
Registration	N52AW
Flight origin	Miami International Airport Miami, Florida, U.S.
Last stopover	Jorge Chávez Int'l Airport Lima, Peru
Destination	Comodoro Arturo Merino Benítez International Airport Santiago, Chile

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.

The pilots struggled to navigate the aircraft after the failure of several of its cockpit instruments. With the pilots unaware of their true altitude, the aircraft wing hit the water and it crashed shortly afterwards. 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.

Overview

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.^[1]

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,^[2] and 42-year-old First Officer David Fernández Revoredo, who had logged almost 8,000 flight hours,^[2] 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.^[1]

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 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 seventeen seconds, but the aircraft crashed inverted into the water. All nine crew members and 61 passengers died. The official accident report concluded that the flight crew, distracted by the conflicting warnings, did not heed the radar altimeter reading after descending through 2,500 feet.

After the crash, recovery crews found nine bodies floating; the rest of the bodies had sunk with the aircraft.^[1]

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 airframe until it crashed.

Passengers and crew

About half of the passengers on the flight were Chileans returning to Chile.^[1][3][4]

Country	Passengers	Crew	Total
Chile	30	0	30
Colombia	1	0	1
Ecuador	2	0	2
Italy	2	0	2
Mexico	6	0	6
New Zealand	1	0	1
Peru	11	9	20
Spain	1	0	1
United Kingdom	2	0	2
United States	4	0	4
Venezuela	1	0	1
Total	61	9	70

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.^[5]

Reporting

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. ^[1]

Investigation

The Commission of Accident Investigations (CAI) of the Director General of Air Transport (DGAT) of Peru wrote the final accident report.^[6]

The chief Peruvian accident investigator, Guido Fernández Lañas, was the uncle of the co-pilot, David Fernández. There were some reservations about the potential conflict of interest, but the National Transportation Safety Board-appointed investigator, Richard Rodriguez, determined that Fernández Lañas could properly investigate the accident.^[1]

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.^[1]

Later investigation into the accident revealed that duct tape had been 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 had left the tape on by mistake.^[7]

The static ports are vital 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.^[8]

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.^[8]

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 erroneous altimeter data was also broadcast to Air Traffic Control, 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 was revealed by the cockpit voice recorder transcript.^[9] The fact that the flight took place at night and over water, thus not giving the pilots any visual references, was also identified as a major factor.^[8]

Legal settlement

After the accident, Aeroperú changed the number of its evening Miami-Lima-Santiago Boeing 757 service to Flight 691.^[10] 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 of dollars 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, said in an interview that many of the passengers had survived the initial impact but had drowned afterward. 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.^[1][11] The suit was filed against Boeing in federal court in Miami in May 1997. According to the complaint, the flightdeck 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 remove the tape from the static ports, and the aircraft's pilot for not noticing the tape still applied by visual check. Richard Rodriguez of the NTSB said that it was understandable that Schreiber did not find the tape because the maintenance worker had 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 could not have seen the tape against the fuselage.^[1] 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.^[11]

On 13 December 1999, family members of the flight's passengers received one of the largest compensations stemming from an aviation accident outside the United States aboard a non-U.S carrier, averaging nearly $1 million per victim.^[1] 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.^[1]

Chacaliaza was convicted in Peru for negligent homicide; but no other airline staff were convicted. 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.^[1]

Dramatization

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.

See also

• Pitot-static system
• Spatial disorientation

Similar events

• Air India Flight 855
• Birgenair Flight 301
• Air France Flight 447
• Adam Air Flight 574
• Turkish Airlines Flight 1951

References

External links

External image

airliners.net's Photo gallery

• Final Report (unofficial English translation) (Archive) hosted at SKYbrary
  • The original report, in Spanish, by the Accident Investigation Board, Directorate General of Air Transport, Ministry of Transportation and Communications is available via mail.
• "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
• "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 (Archive)
• News and Comment on the Aeroperu B757 Accident - University of Bielefeld

Coordinates: 12°02′S 77°30′W / 12.033°S 77.500°W / -12.033; -77.500