Mr. John Britten, Transportation Safety Board (TSB) of Canada, presented an overview

of the investigation of the SwissAir 111 accident that occurred September 2, 1998 near Peggy’s

Cove, Nova Scotia, Canada. The TSB’s mandate is to advance transportation safety; conduct

independent investigations; report findings as to accident causes, contributing factors and safety

deficiencies; make safety recommendations; and effect safety communications. The approach

taken by the TSB is advance safety through the identification and validation of safety

deficiencies that are found through the investigation process, focus on “why” and “how” (i.e.,

“systems approach”, and communicate to the authorities who can best effect change including

regulators and the aviation industry. The TSB’s safety products include aviation safety

recommendations, aviation safety advisories, aviation safety information letters, dialogue with

“change agents,” confidential draft reports with safety issues under consideration, and final

reports with recommendations and safety concerns.

Mr. Britten reviewed the flight path and events timeline of the SwissAir 111 accident

from the time the flight crew detected an unusual odor in the cockpit until the flight data recorder

stopped recording. A synopsis follows (all times are UTC):



� 01:10:38 Flight crew detects unusual odor in cockpit

� 01:12 No unusual odor reported in cabin area. Odor suspected to be from air conditioning system. Decision is made to divert and land. Bangor, Maine and Boston, Massachusetts are seen as options for divert destinations.

� 01:13 Assessment made of some smoke visible in ceiling area of cockpit.

� 01:14:15 Flight 111 declares “PAN, PAN, PAN,” reports smoke in cockpit, and requests a diversion to Boston. Flight 111 is cleared to descend to FL310 and starts a right turn for the diversion.

� 01:15:08 Moncton Centre advises Flight 111 Halifax airport is a closer alternative

for landing.

� 01:15:36 Flight 111 indicates that Halifax is the preferred diversion airport.

� 01:19:37 Flight 111 is informed by Moncton Centre that they are 30 miles from the threshold of Runway 06.

� 01:19:50 Flight 111 informs Moncton Centre that they will need more than 30 miles (at 21,000 feet).

� 01:21:27 Flight 111 informs Moncton Centre that they must dump fuel before landing.

� 01:21:56 Flight 111 indicates to Moncton Centre that they are able to accept a turn to the south to dump the fuel.

� 01:22:01 Flight 111 is cleared by Moncton Centre to turn left to a heading of 200 degrees, and to maintain 10,000 ft.

� 01:23:30 Flight 111 is cleared by Moncton Centre to continue turning left to a heading of 180 degrees.

� 01:24:09 The aircraft autopilot disconnects.

� 01:24:42 Flight 111 informs Moncton Centre that they are declaring an emergency.

� 01:24:53 Flight 111 informs Moncton Centre that they are starting fuel dumping and must land immediately.

� 01:25:40/41 FDR and CVR stop recording information.

� 01:31:18 Aircraft strikes the water.



The initial operational elements following the accident were:

� Communication – families considered first; providing facts, not speculation, was very important

� Coordination – initial participants included various Government and public services organizations, as well as the US NTSB, Swiss AAIB, SwissAir, and Boeing

� Family Assistance – SwissAir and Delta had primary responsibility, with the RCMP, Medical Examiner and TSB having roles as well.

� Criminal (Police) & Coroner’s Investigation

� TSB Safety Investigation

� Recovery of human remains

� Identification of remains

� Recovery of wreckage

� Personal effects



The aircraft wreckage was located in 200 meters of water, in a debris field approximately

the size of a football field. Surface ships were the first units to arrive on scene for search and

rescue efforts, and were later joined by aircraft. Side-scan radar operations from surface ships

were conducted to assist in locating the wreckage, and a Canadian submarine also assisted with

the search. Initial recovery efforts, involving dive teams, concentrated on the recovery of human

remains. Joint US-CA diving efforts continued for approximately two weeks. The six main

recovery methods were water surface and beaches, divers (CDN Navy, CCD, USN Grapple),

heavy lift barge, scallop dragger, remotely operated vehicles, and a dredge ship. Each of the six

main recovery methods contributed effectively to the retrieval of victims and wreckage, and

much of what was done was without precedent. By December 1998, 100% victim identification

had been completed. More than 2 million aircraft pieces were recovered during the operation,

representing 98% of the total wreckage.



The investigation team reconstructed the forward 300 inches of the aircraft, which is

where most signs of burning were found. Circuit breaker panels with indications they had been

subjected to extreme heat and arced wires, both ship and after market, were found in the

recovered wreckage. Investigation techniques included database tracking, temperature

templates, photogrammetry panoramas, object modeling, 3-D CAD modeling, and electronic

document conversion and management. Analysis of rotating components was also conducted.

The technical challenge that the investigation team faced involved the degree of destruction,

small/unidentifiable/missing parts, extensive fire damage, arced electrical wires, flight recorder

limitations, and the multiple investigative techniques that were required. The volume of the

pieces of wreckage also posed a significant challenge. Of the more than 2 million pieces of

wreckage recovered, more than 21,000 were tracked (14,700 aircraft wreckage related, 2100

personal belongings, 4200 medical/other). There were also more than 13,700 paper documents

and 100,000 emails, approximately 2000 heat damaged electrical wires and components, 160

miles of wire (average 3 ft lengths), and over 150,000 photos and 600 videos associated with the

investigation. Mr. Britten advised that selected SwissAir 111 safety communications are

available at the TSB Internet web site www.tsb.gc.ca.



As of 19 June 2002, the TSB has issued 14 Aviation Safety Recommendations, four

Aviation Safety Advisories, and two Aviation Safety Information Letters, and has conducted

informal liaison with “agents of change.” On 9 March 1999 the TSB issued a Safety Deficiency

for flight recorder duration and power supply that addressed the short (30-minute) duration of

cockpit voice recorders, the need for an independent power supply, and the concern for separate

electrical buses. On 11 August 1999 another Safety Deficiency was issued that identified

shortcomings in the in-service fire resistance of metallized polyethylene terephthalate (PET)

covered insulation blankets in aircraft, which was found to burn quite readily, and the

flammability test criteria currently being used. Another Safety Deficiency was issued on 4

December 2000 that identified the lack of a coordinated and comprehensive approach to in-flight

firefighting, insufficient smoke/fire detection and suppression systems, the need to recognize the

importance of making prompt preparations for a possible emergency landing, the excessive time

required to troubleshoot smoke/fire problems, and the inadequate access to critical areas within

aircraft. On 27 August 2001 another Safety Deficiency was issued that identified the need for

aircraft flammability standards that prevent the use of materials that sustain or propagate fires,

certification tests to evaluate a wire’s failure characteristics under realistic conditions, and

addressing systems whose fire induced failure may exacerbate a fire in progress (e.g., oxygen

systems).



Aviation Safety Advisories have been issued that deal with MD-11 wiring, MD-11 flight

crew reading light installations, controller knowledge of flight crew emergency procedures, and

MD-11 standby (secondary) instruments. Aviation Safety Information Letters have been issued

that address flight crew reading light design and overhead aisle and emergency lights. Mr.

Britten stated there have been numerous safety actions taken globally that involve procedures,

checklists, equipment, design and airworthiness directives (ignition sources and thermal acoustic

insulation material). He added that the FAA has taken safety actions regarding ignition sources,

flight crew reading lights, fuels (thermal acoustic insulation cover material), in-flight

firefighting, in-flight entertainment systems, wiring, flammability standards, and flight recorders.

Mr. Britten concluded with a review of safety issues that remain under consideration:



� Residual risk –

- MD-11 wiring

- Flight recorder duration and power supply

- Flight crew reading light

- Thermal acoustic insulation material

- In-flight firefighting

- Material flammability standards



� Supplemental Type Certificate Process

� Circuit Breaker Reset Philosophy

� Investigative techniques

- Quality of CVR information

- QAR data

- Image recording

- Non-volatile memory