Europeans Require Pitot Tube Modifications for A330/A340 >> The Cranky Flier®

29
Sep
2009

Europeans Require Pitot Tube Modifications for A330/A340

Filed under: Accidents/Incidents, Safety/Security;
Though the ultimate reason for the Air France A330 crash in the South Atlantic will likely never be known for sure, the European Aviation Safety Agency (EASA) has recently issued an urgent Airworthiness Directive to replace certain Thales-manufactured pitot tubes on A330/A340 airplanes. A pitot tube problem is one of the possible explanations for that Air France crash.

For those who don’t know, a pitot tube is a goofy little thing that sticks out from the aircraft into the air. You can see a great example of one at left. These little guys use pressure measurement to determine airspeed. One of the theories regarding the Air France accident is that the pitot tube incorrectly measured airspeed and that triggered all kinds of problems that ultimately led to the accident.

Now, EASA is saying that any A330/A340 aircraft with the Thales pitot tubes need to be changed (and the FAA has followed as well). There are apparently two different types of Thales pitot tubes. The “AA” version must be replaced no matter what. The “BA” version is ok in one place, but the other two places must have Goodrich ones involved.

So what exactly is the problem? According to EASA:

Occurrences have been reported on the A330/A340 family aeroplanes of airspeed indication discrepancies while flying at high altitudes in inclement weather conditions.

The Thales AA pitots have “a greater susceptibility to adverse environmental conditions” than the Goodrich ones. The Thales BA pitots are better, but “it has not yet demonstrated the same level of robustness to withstand high-altitude ice crystals as the Goodrich . . . probe.”

While they say that they haven’t actually found any safety issue and that this is a precautionary measure, the fact that these all need to be replaced within 4 months certainly makes it seem somewhat rushed.

By the way, Air France had Thales pitot tubes, but they’ve already made these changes. Delta has also already made the changes to their A330s. Both US Airways and Lufthansa have always had Goodrich.

http://www.flickr.com/photos/neepster/ / CC BY-SA 2.0
7 Comments

7 Responses to “Europeans Require Pitot Tube Modifications for A330/A340”

David SFeastbay September 29th, 2009 at 8:21 am

Can’t really think of anything to say on todays blog other then….

better safe then sorry as the saying goes.

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JayB September 29th, 2009 at 10:09 am

A little slow here today, what with the discussion on that “goofy little thing” called the “pitot tube,” as important we’ve learned it is.

Tomorrow, perhaps…”‘change-of’-gauge’…what airlines might not be telling you!”

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Oliver September 29th, 2009 at 10:15 am

I know airlines get to pick the engines for their aircraft (assuming there is a choice), but do they also get to pick the manufacturer/type of seemingly minute detail parts like these tubes? Or did Airbus simply switch manufacturers at some point in time, and US/LH happened to get their aircraft when Airbus was using the good ones? Or are the tubes tied (hehe) to the avionics and the airline gets to pick different versions of that?

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CF September 29th, 2009 at 10:29 am

Oliver wrote:

Or are the tubes tied (hehe) to the avionics and the airline gets to pick different versions of that?

I think that’s probably how it works here. Goodrich and Thales both had options, and I think it is tied to the avionics.

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Frank V September 29th, 2009 at 3:23 pm

Lest we forget, these innocent looking devices, that are so very critical to flight safety, are the exact same devices that some of the geniuses at TSA used as hand and foot holds (a year ago) when trying to gain access to parked aircraft at a major US airport — all in the name of security theater.

http://www.airliners.net/aviation-forums/general_aviation/read.main/4165535/

http://forums.ifdg.net/index.php?showtopic=6626&mode=threaded&pid=95015

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enplaned September 29th, 2009 at 4:52 pm

Good explanation of how pitot tubes and static ports work at wikipedia:

http://en.wikipedia.org/wiki/Pitot-static_system

Includes references to the Birginair and AeroPeru crashes, both of which were caused by either blocked pitot tubes or static ports, as well as the Air France crash this past summer.

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AirborneWithoutFear October 2nd, 2009 at 2:04 pm

It should be pointed out that no actual evidence exists which points a finger at the Thales probe, as both the Thales and Goodrich probes are manufactured to the same specifications. I smell an EASA/Airbus scapegoat, and it looks like it’s Thales’ turn to get flushed.

Article correction, US Airways always had the Thales probe–not the Goodrich probe.

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