Air France Crash Probe Shows Crew Errors

By Laurence Frost and Heather Smith - Oct 6, 2011 8:01 PM GMT+0700

Air France Flight 447’s crew reacted badly to an autopilot shutdown and misread instruments showing the plane’s rapid descent before it plunged into the Atlantic, killing all 228 people aboard, a report shows.

“I’ve lost VSI,” the junior co-pilot said of the Airbus’s vertical-speed indicator, according to a recording detailed in the report from court-appointed experts. In fact, the instrument was functioning normally, its analog needle immobilized at the lower limit because the plane was hurtling toward the ocean at 15,000 feet a minute, the document seen by Bloomberg News shows.

Flight 447 from Rio de Janeiro to Paris crashed on June 1, 2009, after ice-blocked speed sensors shut down the autopilot and the crew reacted incorrectly by pulling the jet into a steep climb until it slowed to an aerodynamic stall, France’s BEA accident investigation bureau said in May. The interim report from the criminal probe broadly endorses those findings.

“The aircraft’s stall went completely unnoticed by the crew, who made no reference to it,” according to the report, which was presented to victims’ families yesterday. Faced with unusual readings, the two co-pilots, alone at the controls while the captain was on a rest break, “rejected them en masse.”

Focus on Airline

The document identifies no fault with the Airbus SAS A330, beyond the failure of Thales SA (HO) airspeed sensors which caused the autopilot shutdown. Manslaughter charges have been filed against Paris-based Air France and Toulouse, France-based Airbus as part of the criminal investigation, which could increase damages payouts if any criminal liability is proven.

“The emphasis on the crew’s handling of the situation does seem to put the focus on Air France, rather than Airbus,” said Simon Foreman, a Paris-based attorney with Soulez Lariviere & Associes who has represented French authorities in previous crash investigations and isn’t involved this time.

To put the airline on trial prosecutors would have to go much further in linking pilot error to Air France procedures or training, he said. “Based on what I’ve seen so far, it’s hard to see where criminal liability might be established,” he added.

Interface Issue

Airbus spokesman Stefan Schaffrath declined to comment on the judicial report, while Air France attorney Fernand Garnault said it was “impossible to draw any conclusions” from the interim findings.

“The real focus of this investigation is the man-machine interface, and why the pilots didn’t have everything they needed to understand what was happening,” Garnault said.

Air France had earlier suggested that a stall alarm confused the A330’s pilots by initially sounding when the jet began to lose lift and then shutting down as it slowed to a point where the computer was receiving no useful information, before coming back on again when the air-speed picked up -- misrepresenting what was actually a positive development.

In reality, the junior copilot began pulling the nose up again -- deepening the stall -- before the alarm resumed, the criminal report suggests.

While referring to the aircraft’s artificial horizon as they struggled to keep its wings level, the copilots also disregarded its indications that the jetliner was at a dangerous nose-up angle, the document says.

Psychologists

“The information was there, but the question is why they were blind to it,” said David Learmount, a former Royal Air Force pilot and safety editor for Flight International magazine.

“This is all about human cognition,” Learmount said. “Even if we’re left guessing about what was going on in the pilots’ heads, that doesn’t absolve us from the responsibility of trying to understand.”

BEA crash investigators have convened a “human factors” working group of psychologists, doctors and pilots to examine how the Flight 447 crew analyzed and responded to cockpit information. A spokeswoman for the agency declined to comment on the legal investigation today.

The criminal report also notes the captain’s failure to consider a detour around bad weather shown on the radar, despite concerns repeatedly voiced by a copilot, and questions his decision to take a break while crossing the so-called inter- tropical convergence zone, which is generally stormy.

While the captain broke no regulations by leaving the cockpit, the report says, staying put would have been “the safety-minded choice.”

To contact the reporters on this story: Laurence Frost in Paris at lfrost4@bloomberg.net; Heather Smith in Paris at hsmith26@bloomberg.net.

To contact the editors responsible for this story: Chad Thomas at cthomas16@bloomberg.net; Tony Aarons at aaarons@bloomberg.net.