Communiqués

TSB # A 12/2000

(Hull, Quebec, 29 August 2000) - The Transportation Safety Board of Canada (TSB) is continuing its investigation into the crash of Swissair Flight 111 which occurred on 2 September 1998. A major part of this investigation has consisted of the examination, partial reconstruction, and documentation of aircraft debris at Hangar A, Canadian Forces Base Shearwater, Nova Scotia. It is anticipated that the TSB's investigation activities in Hangar A will be completed sometime this fall, although analysis, report writing, and additional laboratory work will continue in other locations. Much of the work underway is focusing on where, why, and how the fire started.

Early in the investigation, various projects were initiated to identify, assemble, and document as many pieces of wreckage as possible from the heat-damaged area in the forward ceiling of the aircraft to help assess the origin of the fire. Some of these sub-projects are as follows:

• Considerable effort has been expended in attempting to identify and describe the various pieces of aircraft wreckage that pertain to the forward ceiling area of the aircraft where the fire damage took place.
• Selected pieces of aircraft structure that have been identified, have been placed in a reconstruction "jig"or "frame" that replicates in shape and dimension the front10 metres of the MD-11 aircraft. When required for investigation purposes, sections of reconstructed air ducts, circuit breaker panels, and various other pieces have been placed in this frame to assist in the analysis.
• To assist in assessing the relationships between selected wiring, other electrical components, air ducts, circuit breaker panels, cockpit liner material and other pieces from the fire-damaged area, a "forward drop ceiling mockup" has been built separate from the reconstruction frame. After further photo documentation and assessment, these pieces will be integrated into the forward reconstruction frame.
• The identifiable pieces from the three front galleys have been placed into three "galley jigs" to help assess what involvement, if any, the galleys may have had in the fire sequence.

A project to integrate the aircraft structural pieces, and various other pieces, into the frame is now complete, and the documentation of the structure pieces is nearing completion. The project to place and document the identified galley pieces, using the galley jigs, is complete. The galleys will now be placed inside the frame for further overall documentation and analysis. The project to complete the forward drop ceiling mockup is also complete, and the documentation of this area is nearing completion. Once this documentation is complete, the material from the ceiling mockup will be placed inside the frame for further overall documentation and analysis.

To complete these projects, investigators have had to identify, rebuild, match, and position thousands of small pieces of aircraft structure, wire, air ducts, circuit breaker panels, liner materials and numerous other components.

At each stage, photogrammetry and other documentation methods have been used to transfer information into 3D computer modelling. The completion of these projects will allow investigators to analyse the fire pattern, and the extent of the fire utilising both direct visual reference and computer modelling.

Other aspects of the investigation are also continuing, including those involving operational issues and human performance.

Investigators are continuing to seek means to distinguish between arced wires that either initiated or were burned in the fire. From the 20 arced wire segments that were found, 32 individual arc "beads" are being examined and documented by various methodologies, some of which have not been used before for these purposes. It is not yet possible to predict the outcome of these investigation activities.

Analysis of the inflight airflow testing, involving a specially instrumented MD-11, in the space above the ceiling in the forward section of the aircraft's fuselage is continuing. The interpretation of information from the airflow tests will be completed when more information from other aspects of the investigation is available, particularly from further detailed wreckage examination.

As part of the investigation process, a time line of events is being prepared using data from various sources including Air Traffic Control and on-board flight recorders. An abbreviated time line of events is attached (Attachment A).

The investigation into this accident is complex and time-consuming. As the investigation continues, more fact-finding and safety analysis is being undertaken to validate other safety issues. The identification, validation and notification of safety deficiencies, by the TSB, does not wait until the publication of the final report. To date, this investigation has led to the identification of a number of safety deficiencies and to safety actions concerning: the inspections and follow-on activities regarding wiring in the upper forward fuselage; an emergency power supply for flight recorders; the increase in recording capacity of cockpit voice recorders; the separation of electrical power sources for the flight recorders; the flammability risk of metallized polyethylene terephthalate (PET) covered thermal acoustical insulation blankets; the flammability test criteria used for the certification of these materials; and the potential source of heat from flight crew reading lights. As well, once this information was disseminated, follow-up safety action was taken by manufacturers, operators, and regulators in the form of service bulletins, operational procedural changes, and airworthiness directives.

NOTE: This update is based on information assembled by the investigation staff and will be amended as other facts are gathered. The investigation is not complete and one should not attempt to infer findings as to the causes and contributing factors of this accident on the basis of this update.

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This document contains selected information from the Time Line of Events which remains under development by the Flight 111 investigation team. Therefore, this information is subject to change.

Abbreviated Time Line of Events (Attachment A)

Note:	All times below are Coordinated Universal Time (UTC) beginning 2 September 1998 For New York time (EDT) subtract four hours For Nova Scotia time (ADT) subtract three hours Times are written as Hours: Minutes: Seconds To derive an approximate altitude from a Flight Level, add two zeros to the indicated FL (e.g. FL330 is approximately 33,000 feet).
23:37	Flight 111, parked at Gate Six at John F. Kennedy (JFK) airport in Jamaica, New York, receives Air Traffic Control clearance for a planned flight to Geneva, Switzerland. Flight planned altitude is FL330.
23:50:15	Push-back from Gate Six.
00:17:08	Start of take-off roll, runway 13R.
00:18:33	Flight 111 transferred from Kennedy Tower frequency 123.9 to New York Departure frequency 135.9.
00:19:48	Flight 111 cleared by New York Departure for a deviation in heading to avoid weather (cloud buildups).
00:22:30	Flight 111 cleared to change to Boston Centre frequency 132.3 - altitude approaching 11,000 ft. - cleared to maintain FL190.
00:27:46	Flight 111 cleared to change to Boston Centre frequency 124.52 - cleared to maintain FL230.
00:30:29	Flight 111 cleared by Boston Centre to maintain FL240.
00:32:00	Flight 111 cleared by Boston Centre to maintain FL250.
00:33:00	Flight 111 cleared by Boston Centre to maintain FL270 - cleared to Boston Centre frequency 128.75.
00:47:17	Flight 111 establishes contact with Boston Centre on frequency 128.75. Flight 111 is cleared to Boston Centre frequency 133.45. Boston Centre had attempted to contact Flight 111 on frequency 128.75 during the previous 13 minutes, but had not been successful.
00:48:14	Flight 111 is cleared by Boston Centre to maintain FL290.
00:52:35	Flight 111 is cleared by Boston Centre to maintain FL330.
00:58:04	Flight 111 is cleared by Boston Centre to change to Moncton Centre frequency 135.2. The aircraft has reached a cruising altitude of FL330.
00:58:16	Flight 111 established contact with Moncton Centre on frequency 135.2.
01:10:45	The flight crew of Flight 111 detects an unusual odour in the cockpit.
01:12	There is no unusual odour being reported in the cabin area. The odour is suspected to be from the air conditioning system. A decision is made to divert and land. Bangor, Maine and Boston, Massachusetts are seen to be options for potential diversion destinations.
01:13	Some smoke is visible in the cockpit.
01:14:15	Flight 111 declares Pan Pan Pan (an international call sign indicating a problem that is not yet an emergency), reports smoke in the 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	Flight crew oxygen masks are in use.
01:15:08	Moncton Centre advises Flight 111 that Halifax airport is a closer alternative for landing.
01:15:36	Flight 111 indicates that Halifax is the preferred diversion airport.
01:15:41	Flight 111 is cleared by Moncton Centre to descend to FL290.
01:16:34	Flight 111 is cleared by Moncton Centre to descend to 10,000 ft.
01:17	A flight attendant is summoned to the cockpit to move the Instrument Approach publications for Halifax to within closer reach of the Captain.
01:17:50	Information is passed to the cabin crew from the flight crew that Flight 111 is diverting to Halifax.
01:18:16	Flight 111 is cleared to Moncton Centre frequency 119.2.
01:18:44	Flight 111 is cleared by Moncton Centre to descend to 3,000 ft.
01:18:49	Flight 111 indicates a desire to level at about 8,000 ft. to prepare the cabin for a landing.
01:18:58	Flight 111 is cleared by Moncton Centre to descend to 3,000 feet, and authorized to stop the descent at any intermediate altitude they wish.
01:19	The flight crew is passed a crew bag which contains approach charts.
01:19:23	Flight 111 accepts an approach, via radar vectors, to Runway 06 in Halifax.The flight crew is passed a crew bag which contains approach charts.
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.
01:19:57	Flight 111 is cleared by Moncton Centre to turn to a heading of 360 degrees.
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	The flight crew inserts data into the aircraft Flight Management System (navigation system).
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.
01:24:25	Flight 111 informs Moncton Centre that they must fly the aircraft manually.
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.
01:24:58	The Moncton Centre controller informs Flight 111 that he will get back to him in a couple of miles. Flight 111 acknowledges the transmission and restates that they are declaring an emergency.
01:25:06	ATC loses transponder Mode C (aircraft altitude) information from Flight 111.
01:25:16	Flight 111 is cleared by Moncton Centre to commence a fuel dump. There is no response from Flight 111, and no further communication with the aircraft.
01:25:40/41	DFDR and CVR stop recording information.
01:25:50	ATC regains transponder Mode C (aircraft altitude) information from Flight 111.
01:26:04	ATC loses all transponder (Mode A and Mode C) electronic radar information from Flight 111.
01:31:21	Aircraft strikes the water.