Crews searching for the wreckage of the Air France jet which crashed in the Atlantic have found a key part that could tell experts why the plane went down, Brazil’s air force said today.
Last night eight more bodies were found, bringing the total recovered to 24 since Air France Flight 447 disappeared on May 31 with 228 people on board, including five Britons.
Brazilian military officials refused to describe the large pieces of the plane they had found, but a video on the Brazilian air force website entitled “Vertical Stabiliser Found” shows footage of the piece – which keeps the plane’s nose from swinging from side to side – being located and tethered to a ship.
The part had Air France’s blue-and-red stripes, retained its triangular shape and bore no evident burn marks.
The discoveries of debris and the bodies are helping searchers narrow their search for the jet’s black boxes, perhaps investigators’ best hope of learning what happened to the flight.
Investigators are looking at the possibility that external speed monitors - called Pitot tubes – iced over and gave dangerously false readings to cockpit computers in a thunderstorm.
Peter Goelz, a former managing director of the National Transportation Safety Board, said the faulty airspeed readings and the fact the vertical stabiliser was sheared from the jet could be related – though he warned it would need to be determined if the stabiliser was torn off in flight or upon impact in the ocean.
The Airbus A330-200 has a “rudder limiter” which constricts how much the rudder can move at high speeds – if it were to move to far while travelling fast, it could shear off, and take the vertical stabiliser with it as they are attached.
“If you had a wrong speed being fed to the computer by the Pitot tube, it might allow the rudder to over travel,” Mr Goelz said. “The limiter limits the travel of the rudder at high speeds and prevents it from being torn off.”
Asked if the rudder or stabiliser being sheared off could have brought the jet down, Mr Goelz said: “Absolutely. You need a rudder. And you need the (rudder) limiter on there to make sure the rudder doesn’t get torn off or cause havoc with the plane’s aerodynamics.”
The wreckage and the bodies were found about 400 miles north east of the Fernando de Noronha islands off Brazil’s northern coast, and about 45 miles from where air traffic controllers last heard from the jet.
Two US Navy devices capable of picking up the flight recorders’ “black box” emergency beacons far below on the ocean floor were being sent to the area.
Meanwhile a union was urging pilots to refuse to fly Airbus A330 and A340 planes unless the monitors – known as Pitot tubes – were replaced.
An internal memo sent to Air France pilots yesterday urged them to refuse to fly unless at least two of the three Pitot sensors on each planes have been replaced. The instruments have drawn attention because of other incidents in which the monitors have iced over at high altitudes.
But the leader of another pilots’ union said that Pitot troubles probably did not cause the Flight 447 disaster.
Searchers must move quickly to find answers in the cockpit voice and data recorders, because acoustic pingers on the boxes begin to fade 30 days after crashes.
While large pieces of plane debris – along with 16 bodies – has helped narrow the search, it remains a daunting task in waters up to 1.5 miles deep and an ocean floor marked by rugged mountains.
“Finding the debris helps because you can eliminate a large part of the ocean,” said US Air Force Col. Willie Berges, chief of the US military liaison office in Brazil and commander of the American military forces supporting the search operation.
But ocean currents over the eight days since the disaster have pushed floating wreckage far and wide, complicating the search.
“In the sense that as the debris drifts away, you’re not sure exactly where the black boxes or other parts of the aircraft are on the bottom of the ocean,” Col. Berges said.
William Waldock, who teaches air crash investigation at Embry-Riddle Aeronautical University in Prescott, Arizona, who examined the photos and video of the stabiliser and rudder - said the damage he saw looked like a lateral fracture.
“That would reinforce the idea that the plane broke up in flight,” he said.
“If it hits intact, everything shatters in tiny pieces.”