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 disaster stemmed not solely from pitot tube icing, but from the aircraft's computer relinquishing control to pilots who subsequently stalled the plane, highlighting a need for systems to maintain basic flight parameters during airspeed data loss.
While advanced alternatives like laser or ultrasonic true airspeed measurement exist, they are generally deemed too complex and costly compared to the typically reliable, heated pitot tube.
The article strongly advocates for the widespread adoption of Angle of Attack (AoA) indicators, particularly for approach and landing, as a superior and more reliable instrument than airspeed, which automatically compensates for factors like weight and bank angle.
In the absence of an AoA indicator, maintaining pitch and power, or using the attitude indicator in conjunction with a known glidepath, are suggested as emergency methods for flight control without reliable airspeed data.

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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.