Explosion fears on Qantas aircraft

HIGH velocity shrapnel from the engine explosion on Qantas's QF32 severed a fuel pipe and narrowly missed the wing's fuel tank, according to official preliminary reports seen by The Age.

As investigations continue, as many as 40 Rolls-Royce Trent 900 engines fitted to the world's fleet of superjumbo Airbus A380s may have to be replaced worldwide, Qantas chief executive Alan Joyce said yesterday.

Qantas has already replaced three engines and could end up swapping about 14, he said.

The confidential reports reveal the extent to which metal components tore through the wing structure, severing wiring looms, chopping a main fuel pipe, puncturing structural spars and ribs and punching through wing surface panels.

Qantas was ''very, very lucky'' that thousands of litres of highly flammable jet fuel carried in the wings did not ignite from the ruptured fuel pipe or from a spark leaping from severed wiring, said Professor Adrian Mouritz, the head of aerospace and aviation engineering at RMIT University. ''If that fuel ignited, that aircraft would have exploded,'' he said.

According to the confidential reports, engine parts struck the fuselage immediately above the wings between the two decks of windows, while other high-velocity metal pieces damaged the plane's belly.

Skin on the leading edge of the wing was perforated on top and bottom surfaces, exposing the honeycomb structure within. The motor that operates the moveable flap on the front edge of the wing sustained a direct blow from the trajectory of the engine debris.

Three fairings under the trailing edge of the wings, which activate the flaps, were peppered with shrapnel.

Qantas and Rolls-Royce are still ''days away'' from identifying which engines might have to be replaced, as the engine maker had not told the airline and Airbus about two series of production changes to the engine.

They are believed to be changes to a gear bearing and its oil supply system. ''What Rolls-Royce have done is that they have modified certain parts of this engine,'' Mr Joyce said.