Two co-pilots facing faulty instrument readings and a stall fought to regain control of an Air France flight before the plane slammed into the Atlantic in a three-and-a-half minute fall, killing all 228 people aboard, accident investigators said today.
A preliminary report into the crash of Flight 447 from Rio de Janeiro to Paris also revealed the captain was on a routine rest break when the trouble began on June 1st 2009 and he never retook the controls.
The new information came from data gleaned from the Airbus 330’s black boxes, which were recovered earlier this month.
But the report does not answer the key question: what caused the crash?
Asked whether faulty sensors, other mechanical issues or the crew’s actions were responsible for the disaster, air accident investigation agency director Jean-Paul Troadec said: “It’s a combination of all of this.”
The report by the French air accident investigation agency BEA was a factual description of the chain of events beginning with take-off in Rio de Janeiro until recordings fell dead nearly four hours later.
Some families of victims who said they were given information in a meeting with the agency said it was possible their loved ones went to their deaths unaware of what was happening because there was apparently no contact between the cockpit and cabin crew in the three-and-a-half minutes.
“It seems they did not feel more movements and turbulence than you generally feel in storms,” said Jean-Baptiste Audousset, president of a victims’ solidarity association. “So, we think that until impact they did not realise the situation, which for the family is what they want to hear — they did not suffer.”
The report revealed that the plane’s captain, Marc Dubois, was out of the cockpit on a routine rest break when the problems began.
The data flight recorder and cockpit recorder were dredged from the ocean in April, along with some bodies, in the latest effort by investigators to explain the disaster. Both of the boxes were readable.
They show inconsistent speed readings, two co-pilots working methodically to right the plane manually and a resting captain returning to the cockpit amid what moments later became an irretrievably catastrophic situation. The data also showed that the plane went into an aerodynamic stall — a loss of lift brought on by too little speed.
Investigators only provided partial quotes from the voice recorder in today’s report.
The plane was passing through ominous weather in mid-Atlantic, about three-and-a-half hours after taking off, when the problems began.
Turbulence caused the pilots to make a slight change of course, but was not excessive as the plane tried to negotiate a normal path — passing through a heavy layer of clouds.
Four minutes later, the plane’s autopilot and auto-thrust shut off, the stall alarm sounded twice and the co-pilot at the controls, 32-year-old Pierre-Cedric Bonin, took over manual control. A second co-pilot, David Robert (37) was also in the cockpit.
The interim report by accident investigation agency BEA did not analyse the data or cockpit conversations or assign blame. A full report on the crash is not due until next year.
Air France said in a statement that, based on the report, it appears “the initial problem was the failure of the speed probes which led to the disconnection of the autopilot” and loss of pilot protection systems.
The airline defended the captain, saying he “quickly interrupted his rest period to regain the cockpit”.
AP