Wrongheaded Industry Reassessing Vulnerable Pitot Tubes vs Ice Procedures instead of Brainstorming Next Generation


Pitot tubes use external air temperature and pressure to calculate changes in speed. Ice crystals that get caught in pitot tubes are considered a contributing factor in a dozen significant events, and the crash of Air France flight 447. As a result of ice crystal accumulation, air temp and pressure readings are false, autopilots shut off, pilots lose altitude readings and receive false warnings. In a fly by wire plane, this is disastrous. In Air France Flight 447, it killed everyone aboard the plane.

Today’s news is full of aviation-safety experts looking for changes in procedures and more-precise checklists. There’s a lot of buzz out there about a new study. I hope that the study, as it has been explained, is not just about adapting to broken technology. I hope this is not the only study out there.

Air France and Boeing are now examining how these ice crystals function (or more correctly, malfunction.) That seems wise.

But one questions why the next step of the anti-icing drive will be to get consensus on how pilots should respond to pitot tube failure.

George’s Point of View

This is like figuring out the best way to drive on a flat tire, instead of making a tire that doesn’t go flat. Sure, pilots should have procedures, but shouldn’t a study be designed with the ultimate goal being to give the pilots a dependable speed sensor, not methods how to mitigate an oncoming disaster? Are designers afraid to trade a known quantity, even though it is flawed, for something unaffected by ice crystals? Even if it is cheaper for airlines to figure out how to muddle on with existing systems than to devise an alternative technology to pitot tubes, shouldn’t the focus of studies be on creating technology that is not disabled by ice crystals?

Not being an engineer myself, I have no ideas on the subject—but somewhere there’s an aviation engineer with a brilliant idea of either a safe design of reconfigured pitot tubes or a completely different system. Let us hope that engineer is able to step up, and be recognized. But it may not be so simple. Apparently Airbus and Air France had been aware of chronic pitot tube problems for years and were content to continue using the same design anyway.

Come on engineers. It’s time for a better mousetrap.


Originally Posted by George Hatcher Wednesday, November 24, 2010