Final moments of Air France 447 revealed

Final moments of Air France 447 revealed

Final moments of Air France 447 revealed. The ill-fated Air France flight 447, which crashed into the Atlantic ocean on June 1, 2009, en route from Rio De Janeiro to Paris, killing all 228 people onboard, had plunged at nearly 11,000 feet per minute during the final few minutes even as its pilots struggled to regain control following failure of speed sensors, French authorities revealed, Friday.
The 2 black boxes or data recorders recovered from the crash site in early May have given the investigators an insight to the dying moments of flight 447.

France's Bureau of Investigation and Analysis (BEA) said, Friday, that the aircraft ran into severe thunderstorm and the engine stalled, prompting the pilots to respond by pulling the nose up.

The aircraft climbed to 38,000 ft when "the stall warning was triggered and the airplane stalled," the BEA report said.

The report said speed sensors also failed as speed displayed on the left primary flight display was "inconsistent" with those on the integrated standby instrument system (ISIS).

The aircraft rolled in air before stalling. The stall warning system sounded thrice.

The two co-pilots and the captain attempted to pull up the aircraft but failed. Flight 447 began its rapid, nightmarish descent into the ocean at 10,912 feet per minute.

The pilots also lost contact with air traffic controller due to heavy turbulence.

After 3 minutes and 30 seconds, the aircraft crashed into the ocean, killing all 228 people onboard.

The black boxes also enabled the investigators to listen to the communications that went on inside the aircraft.

The investigators said that four hours and six minutes into the flight, one co-pilot, referred to as PF, told the cabin crew to expect heavy turbulence. "In two minutes we should enter an area where it'll move about a bit more than at the moment, you should watch out... I'll call you back as soon as we're out of it," the co-pilot said. Turbulence, brought on by icy, windy conditions, was typical in that flight route.

Four minutes later, the autopilot and auto-thrust disengaged and the co-pilot said "I have the controls." Around that time the stall warning sounded twice in a row.

The second co-pilot, referred to as PNF, said "So, we've lost the speeds." A second later, the stall warnings sounded again.

At about that time, the speed displayed on the left side "increased sharply." The aircraft was flying at an altitude of about 37,500 feet.

Sensing trouble, the co-pilot PNF called Capt. Marc Dubois, who was on a routine rest break, back to the cockpit.

At around 4 hours 11 minutes and 40 seconds into the flight, the captain re-entered the cockpit. The aircraft was then flying at an altitude of 38,000 feet.

Soon thereafter, both the co-pilots said they couldn't receive any speed indications. The stall warning also stopped.

About a minute later, co-pilot PF said the aircraft is "going to arrive at level one hundred (10,000 feet)." It meant the rapid descent had begun.

The last recorded measurement shows the plane plummeting at 10,912 feet per minute.

All recordings stopped at 4 hours 14 minutes and 28 seconds into the flight.

Investigators suspect the speed sensors, known as pitot tubes or probes, malfunctioned because of ice formation at high altitude. Failure of pitots led to a series of automation failures, disconnects, warnings and alarms for Flight 447.

Since the accident, Air France has replaced the pitots on its Airbus fleet with a newer model.

The report did not say whether the pitot tubes or the temporary absence of Dubois from the cockpit had any impact on the quickly unfolding events. Though Dubois returned to the cockpit, it seems he did not take back the controls.

Final moments of Air France 447 revealed

Final moments of Air France 447 revealed

Final moments of Air France 447 revealed. The pilots of Air France flight AF447, which plunged into the Atlantic killing 228 people, saw conflicting speeds on their instruments as the Airbus A330 stalled.

That is one of the findings of France's BEA aviation safety agency which has analysed the black box flight recorder for the 2009 accident .

"We have no valid indications," one pilot of the Rio to Paris flight was quoted as saying as the aircraft dropped towards the sea, three minutes before it hit the water.

The 58-year-old captain, who had left the cockpit to take a routine rest, returned but did not retake control of the plane.

"There was an inconsistency between the speeds displayed on the left side and the integrated standby instrument system," BEA said in a statement following its study of the recovered flight data recorders.

"This lasted for less than one minute."
According to the chronology of the flight provided by BEA, the two co-pilots decided at two hours and eight minutes into the flight to turn slightly to the left to avoid an area of turbulence.

Two minutes later the autopilot disengaged, the instruments began showing that the speed had slowed dramatically and the engine stall warning began to sound.

"During the following seconds, all of the recorded speeds became invalid and the stall warning stopped," said the BAE preliminary report.

"So, we've lost the speeds," it quoted the second of the two co-pilots as saying. The responses by the co-pilot flying the aircraft "were mainly nose-up" and "the airplane climbed to 38,000ft".

BEA said: "The descent lasted 3 min 30, during which the airplane remained stalled. The engines were operating and always responded to crew commands."

The last data on the recorder showed that plane's nose was up at a sharp angle as it plunged at 10,912ft (3,300m) per minute.

BEA director Jean-Paul Troadec said: "These are so far just observations, not an understanding of the events."

A fuller report into the cause of the tragedy is expected to be released in a few months time.

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