French accident investigators on Friday are expected to release a report confirming their initial findings and offering new details of how pilot errors, combined with a fluke of cockpit automation, led to the 2009 crash of an Air France jet into the Atlantic Ocean, air-safety experts said.
By Andy Pasztor
Visit Original Article at: WSJ – Air France Crash Report Likely to Alter Pilot Training
The latest revelations, according to safety experts and others familiar with them, are likely to add to pressure to revamp training practices to help both new and experienced pilots cope with high-altitude stalls, upsets and faulty airspeed sensors. Such changes are bound to include more emphasis on manual flying techniques.
Safety experts said the new report backs initial conclusions that airspeed sensors malfunctioned, and that pilots stalled the twin-engine Airbus A330 shortly after making the plane climb unusually steeply. The pilots then disregarded extensive stall warnings and—for more than three minutes—failed to realize the cause of their dangerous predicament.
The cockpit crew was distracted by fluctuating airspeed indications and—contrary to standard practice—kept pulling back on the controls and raising the nose of the plane while reducing engine thrust, as the roughly 200-ton airliner plummeted toward the water.
All 228 people aboard the June 2009 night flight to Paris from Rio de Janeiro died, and the accident has prompted a broad reappraisal of pilot training and the potential dangers of undue reliance on automation.
Increasingly, aviation experts believe the tragedy of Air France Flight 447, with all of its engines and basic flight-control systems operating normally, could have been avoided if the pilots had received more training, particularly in manual flying and recognizing stalls at high altitudes.
“It’s not just an Air France issue, but rather an industrywide problem” according to Bill Voss, head of the Flight Safety Foundation of Alexandria, Va., a global independent safety advocate. If the crew of Flight 447 had followed basic airmanship and kept the plane flying level until airspeed indications returned to normal, “it would have been a log entry, instead of a crash,” Mr. Voss said Thursday in an interview.
Based on the anticipated findings by investigators, “we really have to overhaul the way pilots are trained” because now “they typically aren’t taught how to react to a stall at high altitude,” Mr. Voss said.
Air France declined to comment.
Previously, a French judge ordered the carrier to pay €126,000 ($177,000) in compensation to the families of each victim, according to a lawyer for the victims’ families. The sums, which will be paid out by Air France, and its insurer, AXA SA, amount to a provisional payment against possibly higher compensation to passengers on the flight, said lawyer Marc Fribourg.
A spokesman for one of the airline’s unions defended the actions of the pilots, and largely blamed the crash on erroneous airspeed indications. “Airbus said their aircraft could never stall, so clearly pilots were not trained for this situation,” according to Geoffroy Greneau de Lamarliere, a representative of the ALTER Air France pilots’ union. Since the accident, he said Air France pilots have received roughly two hours of training focused on dealing with a stall without the use of speed indicators.
An Airbus spokesman wouldn’t comment on details of the new report, but said the company is “hopeful it will provide additional information.”
Before the crash, relatively few commercial pilots practiced high-altitude stall-recovery techniques in simulators. Even fewer spent much time familiarizing themselves with the handling characteristics of big jets when autopilots suddenly disconnect during cruise, as occurred with the Air France flight.
Now, Airbus, the Air France unit of Air France-KLM group, other big airlines around the world and various study groups are specifically pushing to introduce and expand such training.
“There’s definitely a need for additional training in the high-altitude environment” because “pilots have so little experience hand flying in that regime,” according to Bryan Burks, a U.S. airline pilot participating in a training initiative sponsored by Britain’s Royal Aeronautical Society.
Aircraft respond much differently to engine-thrust changes and other commands at high altitudes—where the air is thin and planes almost always cruise on autopilot—than they do below 10,000 feet.
The latest interim report from the French Bureau d’Enquetes et d’Analyses is expected to underscore some of those differences, and also seek to at least partly explain the seeming confusion among the pilots, and the extreme inputs to their flight controls.
Disregarding a fundamental rule of airmanship that calls for lowering the nose of a plane to gain speed in the event of an aerodynamic stall, the 32-year-old co-pilot at the controls of Flight 447 continued to pull up the nose of the plane, despite extended stall warnings.
During the final minutes, the cockpit-voice recording doesn’t indicate any dissension among the pilots, nor a discussion of possibly lowering the plane’s nose to halt the rapid loss of altitude, according to people familiar with the details.
In addition to the airspeed fluctuations, the cockpit crew may have became further confused during later stages of the descent when the slow speed and loss of lift caused the plane’s automated stall-warning system to behave in unexpected ways, according to safety experts and others familiar with the latest findings.
The jet’s flight-control computers disregarded airspeed measurements and turned off automated stall-warnings at certain points, because the plane had decelerated so dramatically. The result, these experts said, was that during part of their struggle to regain control of the plane, the pilots didn’t get the stall warnings that would have been common as a consequence of raising the jet’s nose.
When the computers and airspeed indicators temporarily recovered, however, pushing down the nose of the jet sometimes prompted stall warnings. That was the opposite of how the warning system usually behaved, according to the air safety experts. The confused crew continued to pull the nose up and remained in a deep aerodynamic stall, finally falling at a rate of more than 10,000 feet per minute, until hitting the water, the experts said.
Investigators believe the distracted crew didn’t pay attention to, or didn’t trust, airspeed readings from the standby airspeed indicator, further complicating their situation.
Previously, investigators said they would release the third interim report about the high-profile crash on Friday, presenting “the exact circumstances of the accident with an initial analysis and some new findings.”
Beyond training issues, investigators also have delved into how the crew worked together. One big question remains unresolved: Why did the most junior pilot stay at the controls for nearly the entire time? Two more-senior pilots apparently failed to aggressively trouble-shoot problems or provide clear-cut commands, experts said after release of the previous update in May.
The captain of the flight, who was on a routine rest break in the cabin when the trouble started, rushed back to the cockpit. But that didn’t happen until the pilot who wasn’t flying–but was supposed to be closely monitoring the junior co-pilot– tried “several times to call the captain back,” investigators previously said. The roughly one minute it took the captain to return after the first call, safety experts said, could have added to the crew’s distraction during critical early phases of the accident sequence
Regarding automation, the plane’s design and the specifics of the upset meant that the crew no longer had the benefit of certain stall-protection systems Airbus pilots routinely are trained to rely on during normal operations.
The crash illustrates “another aspect of automation confusion,” according to Greg Feith, a Colorado-based industry safety consultant and former crash investigator for the U.S. National Transportation Safety Board.” The A330′s automated systems were “based on the concept that pilots would never get themselves into the position” in which they ended up on Flight 447, Mr. Feith said. So the sequence of events “defies all the logic built into the automation.”
The maneuvers initially used by the crew probably would have been acceptable at a lower altitude, according to Mr. Voss of the Flight Safety Foundation. But pilots need to be taught that “it was the wrong reaction, and turned into a deadly procedure at high altitude.”
—Max Colchester and David Pearson contributed to this article.
Write to Andy Pasztor at firstname.lastname@example.org