Backgrounders

Swissair Flight 111 Abbreviated Investigation Chronology

September 2, 1998: At 21:18 Atlantic daylight time (ADT), Swissair Flight 111 (SR 111), a McDonnell Douglas MD-11 aircraft, departs John F. Kennedy Airport, New York, en route to Geneva, Switzerland, with 215 passengers and 14 crew members on board. Approximately 53 minutes after take-off, while cruising at 33 000 feet, the crew notices an unusual smell in the cockpit. Within approximately three and a half minutes the flight crew notes visible smoke and declares the international urgency signal "Pan Pan" to Moncton Area Control Centre, advising the air traffic services (ATS) controller of smoke in the cockpit. SR 111 is cleared to proceed direct to Halifax International Airport, Nova Scotia, from its position 56 nautical miles southwest of the airport. While the aircraft is manoeuvring in preparation for landing, the crew advises ATS that they must land immediately and that they are declaring an emergency. At approximately 22:31 ADT, the aircraft strikes the water near Peggy's Cove, Nova Scotia, fatally injuring all on board.

An Exclusion Zone at the SR 111 crash site is implemented and rescue/recovery operations begin immediately, around the clock, seven days a week, with extensive initial rescue and recovery efforts voluntarily undertaken immediately by local residents. The wreckage field comprises an area of approximately 70 metres by 30 metres, littered with pieces of the aircraft.

September 6, 1998: SR 111 Flight Data Recorder (FDR) is recovered and transferred to TSB Engineering Branch Flight Recorder Laboratory in Ottawa, Ontario.

September 11, 1998: SR 111 Cockpit Voice Recorder (CVR) recovered and transferred to TSB Engineering Branch Flight Recorder Laboratory in Ottawa, Ontario.

September 15, 1998: The TSB investigation team determines that both the FDR and CVR stopped recording while the aircraft was at an altitude of approximately 10 000 feet, approximately six minutes before the aircraft struck the water.

October 2, 1998: TSB announces initiation of heavy lift operations to retrieve the major portion of the wreckage in the debris field from the deep-water site (approximately 55 metres) before winter storms complicate the recovery effort. By now, more than 3000 people from the Canadian Forces, the Canadian Coast Guard, the RCMP, the United States Navy, the Transportation Safety Board of Canada, the Department of Fisheries and Oceans, the Nova Scotia Chief Medical Examiner and other provincial departments, the U.S. National Transportation Safety Board (NTSB), volunteers with the federal and provincial Emergency Measures Organizations (EMO), and many local volunteers have been involved in the recovery effort.

October 21, 1998: A TSB Investigation Update reports that approximately 27 per cent of the aircraft, by weight, has been recovered. Recovered material is brought to the Canadian Forces Base (CFB) Shearwater jetty, where it is washed and readied for the sorting operation at the Shearwater operations hangar.

October 29, 1998: A TSB Investigation Update reports that technical examination of recovered materials from SR 111 has revealed that some of the wiring and structure, located in the ceiling in the vicinity of the cockpit, shows signs of heat damage. Some of this wiring is associated with the aircraft's in flight entertainment network (IFEN) system. After discussions with TSB, U.S. NTSB and Swiss Federal Aircraft Accident Investigation Bureau, Swissair voluntarily disables the IFEN system on MD-11 and Boeing 747 fleets.

November 4, 1998: A nine-metre-long reconstruction frame is built to allow investigators to systematically reconstruct the forward portion of the aircraft.

December 21, 1998: TSB reports that 85 per cent of aircraft by weight has been recovered, including about 60 per cent of the forward fuselage. TSB signifies intent to pass on to regulators, manufacturers, and operators, information about safety deficiencies as they come to light.

December 22, 1998: TSB issues Aviation Safety Advisory (ASA) (980031-1) to U.S. NTSB, noting anomalies in cockpit wiring.

 

March 5, 1999: Work continues at CFB Shearwater on identifying, examining, analyzing, documenting, and matching aircraft nose section pieces; as well, examination, identification, heat damage analysis, documentation, and matching of wire from the aircraft continues. Approximately 88 per cent of the aircraft structure, by weight, reported recovered.

March 9, 1999: TSB reports that investigation has revealed heat damage consistent with a fire in the ceiling area forward and aft of the cockpit bulkhead.

March 9, 1999: TSB issues four Aviation Safety Recommendations (ASRs) with respect to the recording capacity and power source requirements of CVRs and FDRs:

  • As of 01 January 2003, any CVR installed on an aircraft as a condition of that aircraft receiving an original certificate of airworthiness have a recording capacity of at least two hours. (A99-01)
  • As of 01 January 2005, all aircraft that require both an FDR and a CVR be fitted with a CVR having a recording capacity of at least two hours. (A99-02)
  • As of 01 January 2005, for all aircraft equipped with CVRs having a recording capacity of at least two hours, a dedicated independent power supply be installed adjacent or integral to the CVR to power the CVR and the cockpit area microphone for a period of 10 minutes whenever normal aircraft power sources to the CVR are interrupted. (A99-03)
  • Aircraft required to have two flight recorders be required to have those recorders powered from separate generator buses. (A99-04)

August 11, 1999: TSB issues two ASRs dealing with the risks associated with flammability of metallized polyethylene terephthalate (MPET)-covered insulation blankets and test criteria that certified this material for use:

  • TSB notes that "it is likely that MPET cover material was a significant source of the combustible materials that propagated the fire" on SR 111, and believes "that the operation of aircraft outfitted with thermal acoustical insulation blankets incorporating MPET cover material constitutes an unnecessary risk." TSB asks regulatory authorities to confirm that sufficient action is being taken, on an urgent basis, to reduce or eliminate the risk associated with the use of MPET-covered insulation blankets in aircraft. (A99-07)
  • TSB notes that thermal acoustical insulation materials on aircraft must be judged against more rigourous flammability test criteria than prevailing U.S. Federal Aviation Administration standards, and asks regulatory authorities to validate all thermal acoustical insulation materials in use, or intended for use, in applicable aircraft, against test criteria that are more rigourous than current standards and that are representative of actual in-service system performance. (A99-08)

August 27, 1999: Tests begin to assess the significance of arcing found on 14 wire segments. TSB works in conjunction with a number of engineering laboratories to develop a method to test whether wires arced as a result of a short circuit in a normal environment or whether the arcing was a secondary outcome of a fire that damaged wire insulation.

September 1-3, 1999: Memorial services held near Peggy's Cove to mark the first anniversary of the accident. Family visits to investigation site organized as part of services. Many families visit the SR 111 reconstruction in CFB Shearwater Hangar.

November 1, 1999: Exclusion zone at SR 111 crash site is lifted.

December 15, 1999: Recovery operations are completed. Ninety-eight per cent of aircraft, by weight, has been recovered. Dredged material yielded estimated additional one million pieces of aircraft structure, components and cargo. An estimated two million pieces of wreckage are recovered.

 

March 2, 2000: TSB reports that, although the flight crew reading light (map light) was not involved in the origin of the SR 111 fire, deficiencies in its design had the potential for electrical arcing. Map light installations were located in confined areas near, or in direct contact with, combustible materials that could exacerbate the consequences of potential arcing. TSB issues ASA A000008-1 to U.S. NTSB.

December 4, 2000: TSB issues five ASRs related to in-flight

firefighting measures:
  • Appropriate regulatory authorities, in conjunction with the aviation community, review the adequacy of in-flight firefighting as a whole, to ensure that aircraft crews are provided with a system whose elements are complementary and optimized to provide the maximum probability of detecting and suppressing any in-flight fire. (A00-16)
  • Appropriate regulatory authorities, together with the aviation community, review the methodology for establishing designated fire zones within the pressurized portion of the aircraft, with a view to providing improved detection and suppression capability. (A00-17)
  • Appropriate regulatory authorities take action to ensure that industry standards reflect a philosophy that when odour/smoke from an unknown source appears in an aircraft, the most appropriate course of action is to prepare to land the aircraft expeditiously. (A00-18)
  • Appropriate regulatory authorities ensure that emergency checklist procedures for the condition of odour/smoke of unknown origin be designed so as to be completed in a time frame that will minimize the possibility of an in-flight fire being ignited or sustained. (A00-19)
  • Appropriate regulatory authorities review current in-flight firefighting standards, including procedures, training, equipment, and accessibility to spaces such as attic areas, to ensure that aircraft crews are prepared to respond immediately, effectively, and in a coordinated manner to any in-flight fire. (A00-20)

December 29, 2000: TSB issues Aviation Safety Information Letter (ASIL) (A000061-1) with respect to the flight crew reading light, identifying more failure modes and aircraft to which they apply.

 

August 14, 2001: TSB issues ASA (A010020-1) to Transport Canada, suggesting it review controller training requirements, particularly with respect to emergency procedures.

August 28, 2001: TSB issues three ASRs, detailing concerns over flammability standards for certain materials, testing, and certification of aircraft wiring, and requirements when conducting system safety analyses:

  • For the pressurized portion of an aircraft, flammability standards for material used in the manufacture of any aeronautical product be revised, based on realistic ignition scenarios, to prevent the use of any material that sustains or propagates fire. (A01-02)
  • A certification test regime be mandated that evaluates aircraft electrical wire failure characteristics under realistic operating conditions and against specified performance criteria, with the goal of mitigating the risk of ignition. (A01-03)
  • As a prerequisite to certification, all aircraft systems in the pressurized portion of an aircraft, including subsystems, components, and connections, be evaluated to ensure that those systems whose failure could exacerbate a fire in progress are designed to mitigate the risk of fire-induced failures. (A01-04)

September 28, 2001: TSB issues ASA (A010042-1, A010042-2) with respect to standby (secondary) instruments on MD-11 aircraft, suggesting that requirements for standby instrumentation, including communications and navigation capabilities, flight crew training and design standards, be reviewed.

August 3, 2002: TSB distributes Confidential Draft Report to Designated Reviewers for review and comment. Designated reviewers are selected by the Board, and consist of the operators, representatives of the crew, regulators, agencies, companies and manufacturers whose performance, behaviour or products may be commented on in the final report, as well as those who may contribute to the completeness and accuracy of the report.

September 20, 2002: Designated reviewers submit comments on the Confidential Draft Report to the TSB. Preparation of the final report begins.

March 27, 2003: TSB issues final report on the investigation into the Swissair Flight 111 occurrence. Nine additional ASRs are included in the report:

  • Two recommendations deal with testing and flammability standards of in-service thermal acoustical insulation materials and one deals with the application of existing standards for certifying other materials (AO3-01 to AO3-03)
  • Two recommendations focus on aircraft electrical systems, including additional measures for certifying supplementary add-on systems and industry standards for circuit breaker resetting (AO3-04; AO3-05)
  • Four recommendations propose improvements to the capture and storage of flight data as it relates to cockpit voice recorders, flight data recorders and cockpit image recording systems (AO3-06 to AO3-09)

March 27, 2003: TSB Investigation into Swissair Flight SR 111 is officially closed.

 

Glossary of Terms

AD   airworthiness directive
ADT   Atlantic daylight time
ASA   aviation safety advisory
ASIL   Aviation Safety Information Letter
ASR   Aviation Safety Recommendation
ATS   air traffic services
CVR   cockpit voice recorder
FDR   flight data recorder
FOCA   Federal Office of Civil Aviation (Switzerland)
IFEN   In-flight Entertainment Network (System)
MPET   metallized polyethylene terephthalate
NRPM   Notice of Proposed Rule-Making (FAA)
NTSB   National Transportation Safety Board (U.S.)
PVF   polyvinyl fluoride
RCMP   Royal Canadian Mounted Police
ROV   remotely operated vehicle
STC   supplemental type certificate
SR 111   Swissair Flight 111
TSB   Transportation Safety Board (of Canada)