When did Air France know about faulty air-speed sensors?
An internal document shows the airline was aware of the problem more than a year before flight 447 disappeared.
The latest wrinkle in the AF447 mystery is not the black box. French authorities say recent sounds picked up in the cavernous depths of the Atlantic are “false signals.”Skip to next paragraph
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The hunt for the black box – and the cause of the June 1 crash – continues.
But another Air France internal document has surfaced, which reinforces the theory that the problem was the air-speed sensors known as Pitot tubes.
In a detailed June 23 post (in French and English) on the European pilots association website, Eurocockpit (and in a story in the weekly Le Canard Enchaine in Paris today), Air France document NT 34-029 suggests that the Pitot tubes were known to have been faulty far earlier than August 2008.
August was the date offered last week by Air France CEO Pierre-Henri Gourgeon as the earliest instance of Pitot tube failure.
The NT 34-029 document recounts seven cases of faulty Pitot tubes prior to August 2008. Given an Airbus investigation into the Pitot tubes, the malfunctions may date back as far as a year or more before then. The cited problems include an Airbus owned by Air Tahiti, serviced by Air France, and six other cases on the Airbus 340 model aircraft.
On June 19, Mr. Gourgeon, in an interview with French radio RTL, stated, “For the A330 and A340, we’ve had no incident prior to August, 2008.”
(Eurocockpit states separately that NT 34-029 was “filed” in June, but it is dated August, 2008.)
An Air France spokesman contacted by the Monitor said the company cannot confirm or deny the authenticity of the document, citing a pending investigation.
When malfunctioning, the Pitot tubes can send incorrect measurements of the aircraft’s speed – a serious problem for pilots in turbulent or extreme weather.
The document suggests that “the AF447 experienced the same problems as all the other aircraft that encountered a Pitot defect, the only difference being that those other aircraft managed to free themselves from that situation,” according to the pilot’s web posting.
The faulty speed sensors were early raised as one of several possible causes for the June 1 AF447 tragedy – along with lightening, electric failure, a malfunctioning rudder, faulty computers, extreme winds, and others.