Cracks in oil feed pipe blamed for 2010 Qantas engine blast

Cracks in an oil feed pipe caused an engine to explode on a Qantas A380 over the Indonesian island of Batam in November 2010, Australia's transport safety watchdog said on Thursday in its final report on the incident.

The airline grounded its entire Airbus A380 fleet after one of the Sydney-bound double-decker super-jumbos was forced to make a dramatic return to Singapore with smoke trailing from its Rolls-Royce Trent 900 engine and damage to its wing.

The mid-air blast sent debris raining down over Batam island in Indonesia, before pilots guided the plane carrying 469 passengers back to Changi Airport.

The Australian Transport Safety Bureau (ATSB) released its third and final report into the accident Thursday, which found that oil feed pipes in the A380's No. 2 engine did not conform to design specifications.

"The ATSB found that the engine failure was the result of a fatigue crack in an oil feed pipe," it said, calling the investigation one of the most complex it had ever undertaken.

"The crack allowed the release of oil that resulted in an internal oil fire. The oil fire led to one of the engine's turbine discs separating from the drive shaft.

"The disc then over-accelerated and broke apart, bursting through the engine casing and releasing other high energy debris."

The ATSB also found that the oil pipe, together with a number of similar pipes in other engines, had been made with a thin wall section and did not comply with design specifications.

"The thin wall substantially increased the likelihood of fatigue cracking," it said.

Since the incident, Rolls-Royce, aviation regulators, and operators of Trent 900-powered A380s have taken a range of steps to ensure that engines with incorrectly manufactured oil feed stub pipes were removed from service or fixed so aircraft could operate safely.

Rolls-Royce also introduced software that would automatically shut down a Trent 900 engine before its turbine disc over-speeds to prevent a similar occurrence, while improving their quality management systems.

The ATSB report absolved the plane's crew of any error, saying they completed the required actions for the multitude of system failures and safely landed.

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The root of the problem finally fished out after almost three years. It is heartening to know that a similar incident will not occur again now that a new software has been installed to arrest the problem. Salute to the pilots onboard that plane to bring it back to ground safely when they were so near to total disaster.

Tiger altitude data was wrong

An investigation into the low landing approach of one Tiger Airways' plane that contributed to the airline being grounded has found pilots used incorrect altitude information and the airline had an inconsistent safety management system.

The Australian Transport Safety Bureau (ATSB) investigated the June 7, 2011 low approach of a Tiger Airbus A320, after it approached Melbourne Airport at 2000 feet altitude rather than the 2500 feet cleared by air traffic control.

The ATSB official report, released on Monday, found that the flight crew based their descent profile on incorrect altitude data on the aircraft's display unit provided by a third party.

Flight crew were also using the flawed data for paper charts and had not identified the error when preparing for the landing approach, the ATSB report states.

It found there was an increased risk of Tiger unintentionally failing to follow published instrument approach procedures, because it was inconsistent in carrying out its safety management system for identifying and managing data base 'anomalies' or errors.

'In addition, different assumptions by the data suppliers and the operator compromised the quality assurance of the navigational data,' the report states.

CASA grounded Tiger's Australian fleet on July 2, 2011 after a series of safety concerns, including two low flight approaches into Melbourne and Avalon airports, saying it had lost confidence in the airline's ability to manage safety appropriately.

After a six-week grounding, it cleared Tiger to resume flying in August that year.

In its report released on Monday, the ATSB said that after being alerted to their low approach by air traffic control, the Tiger crew corrected their altitude to 2500 feet, continued the approach and landed.

Tiger had responded to the incident by implementing 'an auditable process for identifying and managing any navigational database anomalies in its aircraft fleet'.

The ATSB said the incident 'reinforces the safety benefits of a resilient safety management system and operator procedures' and that 'the accurate application of those procedures by all key personnel, is also important as a safety defence'.

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The truth has come to light. So it wasn't 100% pilot error but rather following an incorrect set of data during descend. But why is it that only two flights were affected? This is baffling.