IDENTICAL fuel-system faults have been found on two of Qantas's new A380 superjumbos, raising fears that a design flaw could threaten the multibillion-dollar investment that is critical to its future.
In the past 36 hours, passengers on two Los Angeles-bound flights have been forced onto replacement Boeing 747s after the Airbus A380s they were meant to be travelling on were declared unserviceable.
After a third A380 was also grounded due to mechanical problems, Qantas said both aircraft had experienced problems with the probe-like monitoring devices inside their fuel tanks.
"The monitoring device … had been affected by contaminants in the fuel tank - they were giving incorrect readings," said Lyell Strambi, the airline's executive general manager of operations.
"[Contamination] built up around the probes and sent a false reading to us. It didn't affect the safety of the aircraft; it just meant we were getting a false reading.
Mr Strambi denied the fuel-tank problem raised questions about the airline's decision to purchase 20 A380s from manufacturer Airbus for $350 million each, describing the issues as "a few teething problems".
But he refused to rule out the possibility of a problem with the aircraft's design.
"Is this a problem with design? It's too early to tell. We'll have to work out what's caused the contamination in the tank."
Airbus yesterday issued an alert to the other operators of the A380 - Singapore Airlines and Emirates - informing them of the problem and suggesting they take corrective action.
While there have been few publicised examples of problems with the fuel-monitoring devices since the A380 was launched by Singapore Airlines in November 2007, the superjumbos have experienced a number of fuel-system faults.
In February 2007 an electrical system that serviced a fuel pump on a Singapore Airlines flight failed, leaving 70 passengers stranded without a hotel room. An auxiliary fuel pump on another Singapore flight failed.
Qantas and Singapore Airlines played down the problems yesterday, insisting the introduction of the A380 had been trouble free compared with the entry of the Boeing 747.
"The A380 is actually a fantastic aircraft and, until now, we've had a very good entry to service with the aircraft," Mr Strambi said.
"This aircraft has had a better entry than the 747 program and its gone onto become a fantastic workhorse. You do have teething problems with new aircraft."
However, 311 passengers were forced to wait 14 1/2 hours for their flight from London to Melbourne on Monday.
It was discovered that the A380 known as the Nancy Bird Walton had a nosewheel steering problem. The plane was eventually repaired and passengers called back to the airport at 4am on Monday.
But engineers then discovered a leak as the plane was being refuelled.
With tensions in the departure lounge approaching breaking point, Qantas finally declared the plane unserviceable, placing passengers on a Boeing 747.
"We had a very bad day yesterday," Mr Strambi said. "I'm really disappointed for the customers."
March 2, 2009 Qantas A380 has nose-wheel ground steering issue and fuel leak. A 14½-hour delay before aircraft replaced.
March 1, 2009 Two Qantas A380s have fuel contamination faults.
January 27, 2009 Qantas flight grounded at LAX for hours.
July 27, 2007 Singapore Airlines flight delayed for six hours owing to an undisclosed fault.