In Search of Lost Airspeed

Peter Garrison

Monday, October 31, 2011 at 05:37 PM ET

Verified

** The only backup for the pitot tube is the
flying skill of the pilot.**

Key Takeaways:

The Air France 447 crash highlighted a critical design flaw where the autopilot disengaged upon losing airspeed data, failing to maintain a stable flight state instead of implementing a "coast mode."
While advanced alternatives like laser and sonic systems for airspeed measurement are explored, heated pitot tubes remain the most common and cost-effective solution despite their rare failures.
The author strongly advocates for Angle of Attack (AoA) indicators as a superior primary instrument for flight, especially during approach and landing, as they automatically compensate for weight and bank angle.
Pilots can mitigate the loss of airspeed indication by maintaining pitch attitude and power, and can even perform approaches using the attitude indicator in conjunction with known flight path angles.

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(October 2011) Air France 447 went down in the mid-Atlantic in 2009 because all three of its pitot tubes iced up.

Well, not exactly. It wasn’t the loss of functioning pitot tubes that doomed the airplane; it was what the A330’s autopilot, and human pilots, did next. The autopilot — but it would be more proper to say computer, since fly-by-wire airplanes are controlled by decision-making systems far more complicated than the word autopilot suggests — the computer, seeing that it had lost reliable airspeed information, immediately turned over control of the airplane to its human minders.