The Qantas Airways Airbus A380 that had a mid-air uncontained engine failure after take-off from Singapore in November 2010 has finally returned to Australia.

The aircraft, which has the registration VH-OQA, took off from Singapore's Changi airport on the evening of 21 April and landed in Sydney on the morning of 22 April. It used the same QF32 flight number as the original flight, although this will now be retired. Passengers included Australian media, Qantas CEO Alan Joyce and Richard de Crespigny, who was the captain of the original flight. "I have absolute confidence in this aircraft," says de Crespigny.

It will return to active service on 28 April on the Sydney-Hong Kong route.

"She's running a little late, by about 18 months," Qantas chief executive Alan Joyce said before the flight to Sydney. "But looking at the repairs, it has been worth it. She is almost brand new."

Shortly after take-off on 4 November 2010, the aircraft's No 2 engine had an uncontained failure over the Indonesian island of Batam, but the pilots managed to fly the aircraft back to Singapore safely.

Australian investigators have finished collecting data for an investigation into the uncontained failure of the Rolls-Royce Trent 900 engine. The data is being analysed and a final report is expected in the third quarter of 2012.

So far, the investigations identified a defect in an oil feed tube as the cause behind an oil fire, which led to the engine failure. The defect caused a section of the oil tube to thin out and crack, leading to an internal engine oil fire that weakened the intermediate pressure turbine disc. This was then separated from the turbine shaft, puncturing the engine case and wing structure.

Repairs took almost 18 months to complete, and used almost 40,000t of tooling and parts. The entire tab of A$139 million ($144 million) was picked up by insurance companies. Another A$95 million came from Rolls-Royce, which supplied the Trent 900 engines, as compensation.

"The aircraft, with everything that we have put into it such as the in-flight entertainment, is worth A$300 million. So repairing the aircraft, instead of writing it off, was definitely the right decision for us," says Joyce.

Almost 70,000 man hours went into the repairs, which were conducted at the SIA Engineering A380 hangar in Singapore. Most of this focused on damage to the left wing between ribs six and 13, primarily on the forward spar and upper and lower wing sections.

"At the start of the project, we had to get as much information as possible. There was a lot of pressure to get the repairs going as soon as we could. But we made a conscious decision to relax and examine this as closely as possible and make the right decisions," says Alan Milne, head of the Qantas integrated operations centre.

Much of the work entailed fixing a custom made patch to the upper wing skin, which was pierced by debris from the No 2 engine. Part of the front spar and lower wing skin was also replaced. Inside the wing, various components were replaced including harnesses, fairings, flaps, fuel pipes, and various other hydraulic and electrical systems. All four engines were also replaced.

All of this added almost 200kg to the aircraft's weight, but Airbus and Qantas officials say that this will have negligible impact on the aircraft's performance.

After the repairs, the aircraft was put through a test schedule usually reserved for brand new aircraft. This included a four-hour long test flight, in which Qantas and Airbus pilots took the aircraft to 43,000ft. There was also a second test flight to test cabin equipment.

"The aircraft is now as good as new," says Derek Blackham, Airbus director of customer support and services. "That's what we planned from the start of this project and that's what we've got."

Source: Air Transport Intelligence news