Tuesday, July 10, 2012

Pilot Error? Let's Talk Airplane Error in Flight 447 Crash

One heartbreaking takeaway in the 224 page final report into the crash of Air France Flight 447 is that in the year prior to the plane's plunge into the Atlantic on June 1, 2009, there was plenty of warning that something like this could happen.

I'm not talking pilot error. Far too much attention has already been paid to how the pilots handled the problems arising on the flight. It is frustrating to see the seriousness of the situation in which these men found themselves dismissed by armchair aviators.




The BEA report tells story of missed opportunities to fix a repeated problem of inaccurate indicated airspeed on the A330. These incidents - 13 are counted in the report - provide another reminder of how incidents languish until they become accidents. The A330 that crashed en route from Rio de Janerio to Paris, killing all 228 aboard, was on course to have its airspeed problem fixed, but time ran out.

Could the pilots have saved the flight had they reacted differently? Probably, but let's move on, because as the head of the
Bureau d'EnquĂȘtes et d'Analyses said last week, "this crew and most crews were not prepared to face such an event." The final report makes it clear both Air France and Airbus made their own grave mistakes in the way they handled safety shortcomings in the Air France A330 fleet.


In the 13 months leading up to Flight 447's plunge into the Atlantic, pilots flying for Air France reported nine episodes in which they received erroneous speed information. In seven of these cases, the report included the fact that the stall warning triggered. Two captains were alarmed enough by the events on their flights to add that the failure was "detrimental" or "destabilizing" creating confusion and difficulty in analyzing what was going on. (This final characterization is a regular feature in the here-and-now as the ability to design highly-complex airplanes flies far ahead of pilots' ability to understand them.)

But getting back to the report, these nine events all occurred in cruise flight and altitude having its privileges, none took the fateful downturn to become accidents. To its credit, Air France did take the reports to Airbus along with its concern that the Thales pitot probes were the problem. The Airbus reply, and I'm printing it exactly as it appears in the report, is - pardon the pun - chilling.

"Airbus stated that there was no solution that could totally eliminate the risk of probe icing, that the three types of probes installed on the Airbus satisfy criteria that are much higher than the regulatory requirements for certification in relation to icing" Let me paraphrase because I've heard this argument before. Never mind how it performs, our calculations show it is safe.


In November 2008, in March 2009, on April 3 and again on April 15th that same year, Air France brought new cases of loss of airspeed to Airbus until finally, the plane maker acknowledged the airline was right; the probes should be replaced. Air France wanted to use BF Goodrich probes, but Airbus, for reasons I did not see in the report, wanted to stick with Thales. It offered up a new model with this caveat; ice crystals was a "new phenomenon that was not considered in the development" of the probe, but the new Thales probes should fix the problem, nonetheless.


Air France would replace probes on F-GZCP as soon as the new ones arrived, but of course, it was too late. Many passengers on the ill fated flight had already purchased their tickets when the first replacement probes arrived in Paris on May 26, 2009 and six days later, those travelers boarded the plane.

Of such timing great tragedies are made. But it would also be tragic if the legacy of this crash remains at the cockpit level, mired in criticism of pilot performance.

Long before the crew boarded the plane in Rio, air travelers had already been denied the safest possible environment and the responsibility for that goes to the airline and the airplane manufacturer who having realized they had a systemic problem that could leave pilots confused and disoriented, failed to promptly fix it.

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