Les Gray, a former RAF officer, says that the RAF has been aware of the danger for nearly 20 years. A BAe 146 of the Queen's Flight suffered a fire as a direct result of the wiring problem. It was on the ground at the time.
According to a BBC1 Panorama programme, to be shown tonight, a type of wiring extensively used in aircraft and known as Kapton can explode and cause fierce fires. Asked whether the Queen or VIPs should travel in a Kapton-wired jet, the RAF's former senior engineer, Sir Michael Alcock, said: "I wouldn't want anybody to travel in it."
Kapton is in use in some 40 per cent of all the world's aircraft. The programme reveals that defects in Kapton wiring are suspected of causing a number of major jet disasters. It is the most likely cause of the world's sixth worst air disaster, when 301 passengers of a Saudi Tristar jet were burnt to death while the aircraft was still on the ground in 1980. Last year, a Swissair MD11 crashed into Peggy's Cove, Canada, killing 229 crew and passengers. A fire had broken out in the cockpit.Kapton is the principal suspect.
Kapton wiring was invented by the chemical company Dupont in the Sixties, and was considered a breakthrough because it was extremely light. it was used by all the major manufacturers - Boeing, McDonnell Douglas, Lockheed and later Airbus Industries - who regarded it as the best wiring available.
The first known problems were spotted by a senior engineer at the airline TWA in the early Seventies. Nine incidents involving TWA Tristars were put down to problems with Kapton.
In the late Seventies, the United States Navy became concerned after unexplained flash fires in its fighter planes. Experts discovered that with Kapton wiring the insulation round the wire breaks down and can cause electrical arcing. The US Navy banned Kapton,and in 1980 sent a team of experts to Farnborough, Hampshire, to demonstrate the problems to RAF officials.
The RAF's Tornadoes and Harriers use Kapton wiring. As a warrant officer, Les Gray was then a top military wiring expert with the Joint Armed Services Wiring Authority and was assigned to look into the problem.
"There is enough of a danger with Kapton to make me believe it should not be used in aircraft," he said.
In a statement, the Ministry of Defence said it had "thoroughly and continuously reviewed the use of [Kapton] insulated wires in our aircraft". It said it was satisfied that there was no danger.
Slowly concern over Kapton has mounted in the airline industry and the Civil Aviation Authority has forbidden the use of Kapton insulation in new aircraft. Boeing has not used Kapton in new aircraft since 1992; Airbus Industries uses a version of Kapton in its new planes; British Airways admits that Kapton is still extensively used, but insists that it meets the regulatory standards.
t A British Airways jumbo jet carrying 400 passengers came within 200 yards of colliding with a cargo aircraft over western China two weeks ago, it has been revealed. The pilot of flight BA027, from Heathrow Airport to Hong Kong, had only moments to react after a computer warning system ordered him to descend as a Korean Air cargo 747 emerged from a cloud. British and Chinese aviation authorities are to investigate the incident.Reuse content