Wednesday, November 17, 2010

GreenBkk Aviation | Flying on a wing and a Prayer: Analysing the A380 Incident

Flying on a wing and a Prayer: Analysing the A380 Incident

Credit: Bangkok Post (http://www.bangkokpost.com)

Standing by the nose of the Airbus A380 when it first arrived in Thailand, I was awestruck by its size. Its huge, airship-like proportions challenge perceptions of what a flying machine should be and, more importantly, push the boundaries of acceptability.

Prophetically, the same was said about the Hindenburg and the maritime behemoth the Titanic. However, a similar disaster was averted last week with a Qantas A380 taking off out of Singapore landing safely landing after experiencing an uncontained engine disintegration.

Fortunately, the extremes of safety, systems redundancy and survivability that had been designed into the A380 airframe meant the aircraft was able to land safely without loss of life despite significant damage to its wings and systems. Without question, however, it was also the incredible skill of the pilots in dealing with the damage and multiple systems failures and then landing the crippled aircraft that averted certain disaster.

Complex supply chain: The A380 is the heaviest and costliest commercial passenger aircraft ever built, and has involved a global mobilisation of parts and components that is unequalled for any industrial project. Some 18,000 suppliers in 30 countries have a hand in its construction. After delivering 16 airframes to date, there are still thousands of A380 parts crisscrossing the globe daily en route to factories in Europe. Plants in Britain assemble the wings, workers in Germany build the fuselage, and these major sections are then shipped to Toulouse, France for final assembly.

On the wings of eagles: Of all the components for the A380, the wings are considered the most crucial, and they illustrate the great lengths to which Airbus has gone to design and build-in as much redundancy and safety features that technology will allow. Modern aircraft are all designed to continue to fly on one engine if necessary in the event of engine failures. However, not many would have survived the damage to the wings and systems sustained from the exploding engine in this latest incident.

Divine intervention? Here are just some of the problems, compiled in part from media releases and anonymous sources, that the Qantas crew had in Singapore earlier this month aboard QF32, as a result of the engine disintegration that sent shrapnel slicing through the plane's wing and littered the ground below prior to an emergency landing:

Massive fuel leak in the left-mid fuel tank (the A380 has 11 tanks, including one in the horizontal stabiliser on the tail).

Massive fuel leak in the left inner fuel tank.

A hole on the flap canoe/fairing that you could fit your upper body through.

The aft gallery in the fuel system failed, preventing critical fuel transfer functions.

The aircraft could not jettison its fuel due to the previous problem above.

"Damm" great hole in the upper wing surface.

Partial failure of leading-edge slats necessary for safe landing.

Partial failure of speed brakes/ground spoilers.

Extensive shrapnel damage to the flaps.

Total loss of all hydraulic fluid in one of its two 5,000 PSI systems.

Manual extension of landing gear _ the passengers could feel the undercarriage being lowered manually.

Loss of one complete generator and associated systems.

Loss of brake anti-skid system resulting in a near over-shoot of the 4,000-metre runway.

Unable to shut down adjacent #1 engine after landing due to major damage to systems.

Failure of the fire kill switch and engine fire bottles for the adjacent #1 engine (serious!). Therefore, no fire protection was available for that engine after the explosion in #2.

Multiple system warnings about a major fuel imbalance due rupture of the left tanks, inability to cross-feed to correct the problem.

Fuel trapped in trim tank (in the tail). Therefore, possible major out-of-balance condition for landing. Yikes!

Many more issues are in process of being investigated.

Experience counts: Fortunately there were five experienced ex-military pilots in the cockpit (including a check and training captain) which normally requires only three pilots. With the multiple systems failures and complicated systems warnings all five were working flat-out in dealing with the return to the airport, emergency procedures, crew communication and passenger reassurance. Clearly, had there been a normal crew of three, or even had the check captain been in the left-hand pilot's seat, the outcome may have been tragically different.

Next week we will discuss the complexities of A380 aircraft maintenance and repair.

Credit: Bangkok Post (http://www.bangkokpost.com)


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