David Learmount/LONDON

All commercial aircraft have dangerously inadequate cockpit and cabin fire detection and suppression systems, according to a report from the Canadian Transportation Safety Board (TSBC).

Following extensive studies, the Board has drawn up a list of five vulnerable points. These vary from inadequate crew fire training and flawed standard operating procedures (SOPs) to the need for fire detection systems in places where they have not been required before.

As part of its investigation into the 2 September 1998 Swissair Boeing MD-11 crash, the Board identified and studied records of cockpit and cabin fires in all commercial aircraft types. Although the MD-11 investigation is not yet complete, it is believed that the aircraft, which crashed off Nova Scotia, Canada, at night killing all 229 people onboard, went out of control when an electrical fire propagated above the cockpit ceiling panel, depriving the cockpit and flight instruments of power.

There have been 15 serious accidents due to "fuselage fires" since 1967, the Board reveals. In July 1973, a Varig Boeing 707 crashed on approach to Paris, France because of a fuselage fire. A report at that time called for "enhancements to smoke and heat detection throughout the aircraft, including areas behind the false ceiling".

The TSBC's study found that there are many critical areas in which the only fire detectors are the noses and eyes of the crew and passengers. It also determined that, under present regulations, crews are inadequately trained to locate and fight non-visible fires, and that there is no access to some critical parts of the aircraft in which fires have been known to start. These include the electrics and electronics bay - usually beneath the flight deck - and areas behind panels such as cabin walls, false ceilings, cockpit instrument panels, and circuit breaker or overhead panels. Wiring bundles, which run throughout the aircraft, are often the cause of fires, the Board found. Most of these spaces are inaccessible and contain no fire detection or suppression systems.

The TSBC says, "these deficiencies reflect a weakness in the efforts of governments and industry to recognise the need for dealing with an in-flight fire in a systematic and effective way." The Board's report warns that:

• The lack of a co-ordinated and comprehensive approach to in-flight firefighting increases the overall risk;

• Smoke/fire detection and suppression systems are insufficient;

• The importance of making prompt preparations for an emergency landing is not recognised;

• The time required [for the crew] to troubleshoot smoke/fire problems [using checklists] is excessive;

• Access to critical areas within aircraft is inadequate.

Flight crew awareness of the need to land as soon as possible when a fire has been detected has been heightened by the Swissair accident. But, warns the TSBC, "typically, this post-accident awareness will subside".

Source: Flight International