Swissair cannot influence the course of these investigations, and has no free access to the information involved. We are however continuing to support the investigation in any way we can, and have a number of our specialists in Canada assisting the investigators in various capacities.

In consulatation with the Canadian authorities, internal investigations are also being conducted at Swissair and Boeing.

Examination of the Wiring

There are strong indications that problems with the aircraft's electrical wiring in the forward fuselage section may have played a role in the accident. More precise details are not yet available.

This uncertainty may seem surprising but it is actually quite easily explained. When electrical energy is carried along a wire, a number of complex processes are involved. This means that the number of possible sources of any electrical malfunction is correspondingly large.

Our efforts are concentrating on regular checks of the wiring in all our aircraft - checks that have been intensified since the loss of sr111. So far, these checks have not revealed any irregularities which might have an impact on flight safety.

 Examination of the Insulation Material

All civil aircraft are fitted with insulation material against heat, cold and noise. The material used for these insulation blankets is fire-retardant, but the adhesive used to manufacture these blankets can encourage the spread of a fire under certain conditions.

This is a problem that affects virtually every civil aircraft, not just the MD11. And the U.S. Federal Aviation Administration has been working for some time now to devise new testing procedures and certification requirements for these insulation blankets. The FAA is being supported in its endeavours by numerous airlines including Swissair. Needless to say, we will apply any new norms as swiftly and rigorously as ever.


Examination of the Power Supply for the Inflight Data Recorders

Civil aircraft carry two "black boxes", a cockpit voice recorder and a flight data recorder. The purpose of these two devices is to help determine the cause of the accident should the aircraft be lost.


Under current regulations the two black boxes draw their electrical power from one of the aircraft's normal electrical supply systems. In the case of sr111, the loss of electrical power caused these recordings on these devices to cease some six minutes before the aircraft crashed. We support the recommendations that have already been made by Canada's TSB with regard to this phenomenon.Examination of Cockpit Procedures

All pilots use checklists in their work. These checklists tell pilots exactly what to do in various inflight situations. Emergencies are dealt with using a series of special emergency checklists, which are designed to ensure that the crew continues to work as effectively as possible, even in situations of extreme stress and pressure of time. Nobody can ever predict the precise nature of a particular emergency, of course, but pilots are instructed to keep to their checklists as closely as possible, and only deviate from them if they are unable to make a reliable assessment of the particular circumstances concerned.

Whether the checklists need to be reviewed and/or adapted in the light of the investigation's findings is a separate issue.


The aim of all the above endeavours is to gain as much knowledge as possible which might help clarify the cause of the accident and generally enhance flight safety. The results of all these activities are placed at the disposal of the official investigating authorities.

We would like to emphasize that:

1. The investigation into the causes of the accident has been entrusted solely to the Transportation Safety Board of Canada, and

2. The investigating authorities are not yet able to make any kind of firm or binding statements on the cause of the crash.

Swissair is as keen as the TSB to establish the cause of the loss of sr111 as quickly as possible. Any technical or other improvements that emerge from the investiogations will be implemented immediately. And we will continue to inform you openly of anything we know.

Finally we would like to remind you that the Transportation Safety Board of Canada has its own website ( which offers regular updates on the progress of its investigations.


When all else fails, read the instructions

If there is a possibility of several things going wrong the one that will cause the most damage will be the one to go wrong

Everything that goes up must come down

If an experiment works, something has gone wrong