Race against time to find black box as explanations sought

OCEAN SEARCH: FRENCH GOVERNMENT ministers yesterday said lightning alone did not explain the disappearance of Air France flight…

OCEAN SEARCH:FRENCH GOVERNMENT ministers yesterday said lightning alone did not explain the disappearance of Air France flight 447 from Rio to Paris, carrying 216 passengers and 12 crew, on Monday four hours after taking off from Rio.

“All scenarios have to be envisaged,” French defence minister Hervé Morin said.

“We can’t rule out a terrorist act since terrorism is the main threat to western democracies, but at this time we don’t have any element whatsoever indicating that such an act could have caused this accident.”

The environment minister, Jean-Louis Borloo, described “a race against time” to find the wreckage and the plane’s black box flight recorder, without which the crash remained “incomprehensible”.

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He warned that the black box would only emit signals for 30 days. But the Atlantic search area between the coasts of Brazil and Africa remains vast and depths range from 3,000-6,000m, with currents so strong that the box might never be found.

Mr Borloo said that in 2004, when a jet crashed into the sea off Sharm El Shiekh, even with an exact crash point located, it took 15 days to find the flight recorder at a depth of 1,000m. In the case of the Air France flight, the ocean search area is much wider, there is no exact location and depths are estimated to be at least 4,000m. Submarines with underwater vehicles could be sent to explore the ocean depths if a location can be pinpointed to within one or two nautical miles.

The jet sent an automatic message reporting lost pressure and electrical faults before it went missing. But the mystery persisted last night as to how a modern aircraft operated by three experienced pilots could have crashed.

A law firm representing victims of a previous serious incident involving an Airbus A330 warned that the aircraft could be vulnerable to electrical interference. London-based Stewarts Law is preparing to sue Airbus, Australian airline Qantas and a computer manufacturer on behalf of 30 people injured when an A330 suddenly plunged 210m while in the air last October. Air accident investigators blamed the rapid descent at 11,000m over western Australia on a malfunctioning computer system. The A330 is a “fly-by-wire” aircraft that uses an air data computer to guide it and, if necessary, amend pilot errors.

The A330 has flown 707 million passengers since its launch 15 years ago and this week’s crash was its first fatal incident in active service. But in the Qantas case, the aircraft’s main navigational tool, the air data inertial reference unit, started emitting “electronic spikes” and plunged the A330 into a dive after mistakenly calculating that the aircraft was pitching its nose into the air. In fact, the aircraft was flying level and the dive catapulted 100 unbelted passengers around the cabin before pilots wrestled back control of the plane.

According to one theory being examined by lawyers, the Airbus computer systems could have been affected by inadvertent interference from a nearby naval communications station.

Jim Morris, a senior associate at Stewarts Law, said the Air France crash had again raised fears about the aircraft’s susceptibility to electromagnetic interference. “It was flying through or close to a thunderstorm and lightning. The high static charge from thunderstorm clouds can cause electromagnetic interference. “It could be that if the A330 is more vulnerable to electromagnetic interference, it could have caused the pilots to lose control of the aircraft during severe turbulence.”

He added: "The indications from the aircraft's datalink system are that there was a loss of electrical systems in a very short space of time, which indicates that there was a catastrophic failure. It could have been a structural failure due to the aircraft exceeding its airframe limitations. If there has been a sudden pressurisation failure it indicates that the aircraft may have been breaking up while in flight." Mr Morris said concerns remained that the full cause of the incident in Australia, on a flight from Singapore to Perth, had not been found. – ( Guardianservice)