Sunday, April 25, 2010
The 200 million dollar write-off
On 15 November 2007, a four-engine Airbus A340-600 was in the process of being delivered to Abu Dhabi-based Etihad Airways was undergoing ground engine testing at the Airbus Technical Center in Toulouse, France. During those tests, the aircraft somehow broke loose and crashed into the test-pen wall as pictured above. According to press reports, nine people — two Airbus employees and seven employees of Abu Dhabi Aircraft Technologies (ADAT), a service provider contracted by Etihad — were aboard the airliner at the time, and four of them were injured.
Although the accident did occur while ground engine tests were being conducted with the plane's parking brake applied, a report released by French investigators in December 2008 did not confirm that claim made above that the crash was caused by ADAT technicians who were unfamiliar with the aircraft and overrode a vital safety feature: French investigators have found that an Airbus to be delivered to Etihad Airways crashed during ground engine tests because the wheels were unchocked and attempts to steer away from a wall had decreased brake pressure.
A 30-page report released by the Bureau d'Enquetes et d'Analyses (BEA) said the four Trent 500 engines, carrying 56,000 pounds of thrust each, were being tested at high power and the wheels were left unchocked.
"Surprise led the ground-test technician to focus on the braking system, so he did not think about reducing the engines' thrust," said the report.
"It was all over in 13 seconds," said David Kaminski-Morrow, an editor at Air Transport Intelligence. "The aeroplane shouldn't haven been running with engines at higher power and the aeroplane should have had chocks on the wheels to stop [it] moving, and these things didn't happen. It was basically a schoolboy error."
"The report does not say who made the decision to put the aeroplane in the position which led to the accident in the first place. What part ADAT played and what part Airbus made is not publicly clear," Mr Kaminski-Morrow said.
"This will probably be the subject of Airbus internal inquiries. But I find it hard to believe suddenly all the rules got broken because ADAT came along. It was at the Airbus headquarters, it was an Airbus test pen, it was an Airbus engineer at the right-hand seat, which the report said is where control inputs were coming from. An ADAT engineer was in the left seat."
In the run-up to the accident, the full-power engine test with wheels unchocked was testing the limits of the parking brake. As the aircraft began to move, an ADAT engineer reported the aircraft was moving. According to the flight recorder, at that point the pedal brake was applied and the parking brake deactivated, said Mr Kaminski-Morrow. Finally, the steering wheel was turned to avoid crashing into the test-pen wall, but that had an opposite effect as it instead reduced the hydraulic system braking pressure.