A98H0003 - In-Flight Fire Leading to Collision with Water - Swissair Transport Limited McDonnell Douglas MD-11 HB-IWF - Peggy’s Cove, Nova Scotia 5 nm SW - 2 September 1998
Synopsis
On 2 September 1998, Swissair Flight 111 departed New York, United States, at 2018 eastern daylight savings time on a scheduled flight to Geneva, Switzerland, with 215 passengers and 14 crew members on board. About 53 minutes after departure, while cruising at flight level 330, the flight crew smelled an abnormal odour in the cockpit. Their attention was then drawn to an unspecified area behind and above them and they began to investigate the source. Whatever they saw initially was shortly thereafter no longer perceived to be visible. They agreed that the origin of the anomaly was the air conditioning system. When they assessed that what they had seen or were now seeing was definitely smoke, they decided to divert. They initially began a turn toward Boston; however, when air traffic services mentioned Halifax, Nova Scotia, as an alternative airport, they changed the destination to the Halifax International Airport. While the flight crew was preparing for the landing in Halifax, they were unaware that a fire was spreading above the ceiling in the front area of the aircraft. About 13 minutes after the abnormal odour was detected, the aircraft's flight data recorder began to record a rapid succession of aircraft systems-related failures. The flight crew declared an emergency and indicated a need to land immediately. About one minute later, radio communications and secondary radar contact with the aircraft were lost, and the flight recorders stopped functioning. About five and one-half minutes later, the aircraft crashed into the ocean about five nautical miles southwest of Peggy's Cove, Nova Scotia, Canada. The aircraft was destroyed and there were no survivors.
Between September 1998 to March 2003, the TSB issued several Interim Recommendations. You can find these, along with TC's responses at the following links:
Interim Aviation Safety Recommendations on Flight Recorder Duration and Power Supply
Interim Aviation Safety Recommendations on In-flight Firefighting - Swissair Flight III
Interim Aviation Safety Recommendations on Material Flammability Standards
A98H0003 - In-Flight Fire Leading to Collision with Water
Peggy’s Cove, Nova Scotia - 2 September 1998
Due to the length of the Transportation Safety Board (TSB) report, the following web pages have been organized so that the user can easily access the report.
Safety Action Required
| 4.2.1 | Thermal Acoustic Insulation Materials |
| 4.2.2 | Interpretation of Material Flammability Test Requirements |
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| 4.2.3 | IFEN – Supplemental Type Certificate Process |
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| 4.2.4 | Circuit Breaker Reset Philosophy |
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| 4.2.5 | Accident Investigation Issues |
| 4.3 | Safety Concern |
A98H0003 - In-Flight Fire Leading to Collision with Water
Peggy’s Cove, Nova Scotia - 2 September 1998
Safety Action Required
Other Thermal Acoustic Insulation Materials at Risk
Transport Canada Response A03-01
TC agrees with the intent of this recommendation, in that action needs to be taken to address unsafe materials.
TC is aware that testing by the FAA has identified some materials which do not meet the Radiant Panel Test (RPT) criteria. This testing, which was neither exhaustive nor specifically controlled with regard to material specification, definition or condition (e.g., some materials may have been contaminated), was intended to provide baseline data to validate RPT performance against full-scale tests and, as such, does not (and was not intended to) definitively quantify the performance of existing materials tested.
TC has taken action to ensure that materials, which have been identified as unsafe – MPETs – are not used on Canadian-registered aeroplanes. MPET was considered unsafe because it exhibited a propensity to both be ignited by a small ignition source and propagate flames; current information indicates that most of the materials identified in the FAA testing are more difficult to ignite, and therefore present a lower level of risk than MPET.
TC has contacted the FAA to request that this issue be considered by its International Aircraft Materials Fire Test Working Group (IAMFTWG). The IAMFTWG, which involves CAAs (including TC) and industry from around the world, is the prime focus for the development of materials’ flammability test criteria and standards.
TC has developed proposed regulations to implement the RPT on new transport category aeroplane type designs as well as future production of existing designs. Going beyond this recommendation, the subject proposed regulations as well as pertinent FAA proposed rules, incorporate criteria to require that thermal acoustic insulation also provide a barrier against the penetration of external fuel-fed fires into the fuselage (“burnthrough”).
TC has, and will continue to actively work with its ‘partner’ CAAs to identify unsafe and increased risk materials in service to either eliminate such materials or identify means to reduce or mitigate pertinent risks, as needed.
Proposed Certification Standard for Thermal Acoustic Insulation Materials
Transport Canada Response A03-02
TC agrees with the objective of this recommendation, and considers that the concerns raised by the TSB have already been or are being addressed.
The RPT is a very stringent test, which incorporates a realistic ignition source, as well as a radiant heat source. It was developed with due consideration of the effects of the various installation factors that may influence its validity and the consistency of its results, as well as the need for it to be a ‘practical’ test.
Comparative testing conducted to validate the RPT has shown that its results closely correlate with those of full-scale tests, and that it provides an effective and realistic pass/fail criteria for a broad range of materials, configurations and conditions.
An advisory circular (AC) to address the testing of material/component variants and combinations is presently being developed by the FAA and is scheduled to be published concurrently with the issuance of its rules implementing the RPT. TC intends to adopt the RPT and will be reviewing this AC, when available, for application to its own pertinent regulations.
Further, TC has contacted the FAA to request that this issue be further considered by its IAMFTWG. The IAMFTWG, which involves CAAs (including TC) and industry from around the world, is the prime focus for the development of materials’ flammability test criteria and standards.
Interpretation of Material Flammability Test Requirements
Transport Canada Response A03-03
TC shares the TSB’s objective to achieve consistent and accurate application of flammability standards.
TC has been addressing various elements of this issue at regular meetings with its regional personnel, as well as with industry through its Delegates Conference held bi-annually. In addition to putting increased emphasis on the subject within these activities, TC will continue to monitor the issue and will pursue efforts to improve this aspect of flammability certification. TC will, as appropriate, develop advisory material to provide advice to regional personnel and delegates regarding the applicability and implementation of flammability standards.
Further, TC has contacted the FAA to request that this issue be considered by its IAMFTWG. The IAMFTWG, which involves CAAs (including TC) and industry from around the world, is the prime focus for the development of materials’ flammability test criteria and standards.
In addition, going beyond this recommendation, a broad program of work is underway under the auspices of the IAMFTWG to ascertain the adequacy of present flammability criteria and standards for materials in hidden and isolated locations and, as needed, to develop improved test criteria and standards. The objective of this work is to bring the level of performance of these materials to that provided by the RPT for thermal acoustic insulation. The first task is the development of test criteria for wiring - this work is already underway and is expected to be completed this year. Pertinent advisory material will be developed, as needed, to support the new standards as their formulation and implementation progress.
IFEN – Supplemental Type Certificate Process
Transport Canada Response A03-04
TC does not agree that a quantitative assessment is always required for every system installed through the STC process. The regulatory requirements in place already require a systematic and comprehensive assessment for the approval of STCs including those for stand alone installations or those which may involve integration with the basic aircraft systems. This structured and qualitative approach includes design and installation evaluation and may also include Failure Mode and Effects Analysis and/ or Fault Tree Analysis. This is required to verify that the level of safety of the original aircraft design is not degraded by the modifications and that there is no hazard introduced by the STC.
TC will develop improved advisory material to emphasize the need to verify that system integration requirements are adequately addressed when a new system is installed through the STC process. In addition, TC will initiate awareness level sessions and training for industry delegates and TC certification engineers to highlight the need for thorough and rigorous analysis of system integration, associated requirements, potential pitfalls and lessons learned. Particular emphasis will be placed on the safety impact of installations involving “non-essential, non- required” systems.
TC will continue to be involved in FAA/JAA Joint Aviation Authorities) harmonization activities related to FAR 25.1309 and other systems integration issues.
Circuit Breaker (CB) Reset Philosophy
Transport Canada Response A03-05
TC concurs with the TSB recommendation. TC has recently requested that the Transport Aircraft and Engines Issues Group (TAEIG) initiate a task to establish the requirements and industry standards for circuit breaker resetting in order to produce harmonized standards for the regulatory authorities of the major aircraft manufacturing states (FAA, JAA and TC).
TC has adopted FAA guidance material concerning circuit breaker reset criteria. Where TC is the prime design responsible authority, Transport Canada will conduct a review of Aircraft Flight Manuals (AFM) and Flight Crew Operating Manuals by January 2004, in order that the adopted criteria for circuit breaker resetting instructions are included. TC will also conduct a review of existing guidance material regarding the inclusion of the circuit breaker reset criteria in the content of the AFM.
TC will publish advisory material in September 2003, which will, in part, require that inspectors responsible for the approval of company training programs re-evaluate air operator training programs by January 2004, in order that they contain clear and concise guidance materials on circuit breaker resetting procedures for appropriate crewmembers. Similarly, advisory material will be published in order to raise the awareness of maintenance personnel.
TC will issue initial advisory material in September 2003, concerning the proper reset criteria of circuit breakers and this will be distributed to all commercial and private aircraft operators in Canada. The advisory material will assist operators in the development of company policy.
TC has published information concerning the resetting of circuit breakers in a recent article (Issue 1/ 2001) in an Aviation Safety Letter and will publish another article in the Aviation Safety Maintainer. Aeronautical Information Publication Canada also contains information to caution the flight crew against resetting tripped circuit breakers unless the associated equipment is essential for the continued safety of the flight and in that case, resetting is limited to only one attempt.
Quality of Cockpit Voice Recorder (CVR) Recordings
Transport Canada Response A03-06
TC concurs with the intent of this recommendation. TC acknowledges that the clarity of the CVR recording is significantly improved when the flight crew uses the boom microphones, however their continuous usage can lead to crew fatigue, particularly on long flights. To improve the quality of the CVR recording in a practical way, TC will develop an initial Notice of Proposed Amendment (NPA) in September 2003, with the objective of submitting it to the Canadian Aviation Regulatory Advisory Council in December 2003, to increase the regulatory requirement for the use of boom microphones from a maximum altitude of 10,000 feet above sea level (ASL) to 18,000 feet ASL. The objective of this NPA would be to harmonize the altitude at which the crew must use boom microphones with that specified by the U.S. FARs.
Where the operating rules require the installation of a CVR, Canadian regulations prescribe an in-flight evaluation of the CVR recording system, at entry into service, and on an annual basis thereafter, with the objective to check the intelligibility of the CVR recordings and to detect any objectionable signal levels in order to minimize potential masking of the internal crew audio. TC, in consultation with other stakeholders, will evaluate the technical issues in order to improve the quality of the CVR recordings. Following this consultation, TC will assess the need for advisory material and standardization with other CAAs.
Quick Access Recorder Data
Transport Canada Response A03-07
TC does not support the inclusion of all FDM data on the FDR. However, TC will continue to participate with other CAAs and accident investigation boards in the harmonized activities, which may lead to practical enhancement in the required FDR parameters listing.
Participation in FOQA, FDM, or similar programs in Canada, is voluntary and on a non-punitive basis. FDM, and similar programs, have been established as safety enhancements and will in the future be an important reporting element for safety management systems. Employee groups involved have supported the FDM program based on the understanding that all parties concerned would treat the information contained in the data as confidential.
In Canada, the FDM program has been sponsored by TC, through the Transportation Development Center (TDC), and has involved the participation of Westjet, Air Canada and First Air. TC is concerned that the application of a recommendation such as is being proposed by the TSB would seriously jeopardize the entire FDM safety initiative.
It must be emphasized that modern aircraft equipped with data bus technology typically record far more parameters than that required by the regulations. This is limited only by the memory capacity of the installed crash protected recorder.
Image (Video) Recording
Transport Canada Response A03-08
TC supports the TSB recommendation concerning the installation of image recording systems to supplement the current flight recording requirements. TC will continue to participate with other CAAs in harmonization activities addressing the requirements for imaging recording systems.
TC has participated with the FAA, TSB, NTSB and other authorities in the WG-50 that is coordinated by the EUROCAE, which is tasked with the development of image recording system standards.
Once a harmonized approach is achieved, TC will develop and submit through the rule making process an NPA regarding the requirement to install video imaging equipment in cockpits of transport category aeroplane in commercial service. The submission of the NPA will take place once the installation requirements and operational procedures have been fully developed.
Image (Video) Recording Protection
Transport Canada Response A03-09
TC agrees that all cockpit voice and image recordings used for safety investigations should be protected. This protection is assured through Canadian legislation. The appropriate forum to gain the necessary international agreement and implementation of this recommendation is the International Civil Aviation Organization (ICAO) therefore Transport Canada will bring this recommendation to the attention of ICAO though Canada’s Representative.
Safety Concern
Should you require further information, please contact Aviation Safety Analysis at asi-rsa@tc.gc.ca