pitot

Take for instance the Air France 447 crash: the first problem was freezing of pitot tubes to measure airspeed.

The Pitot static systems (which are redundant) on a 777 are very far aware from the transponders.

Pilots have downed airplanes because of a malfunctioning pitot tube or fuel indicator light distracting them.

The common mode failure of the pitot tubes could have been anticipated and protected against.

All they do is hold course and speed by monitoring sensors such as the pitot tube, air density gauge, gyroscope, and compass.

BTW, it's guessed that iced up pitot tubes caused the autopilot to disengage.

Sometimes aircraft have mechanical problems - pitot tubes icing over, for example.

This system was off (in it's direct control law, more precisely) due to the pitot tubes sending non accurate data, because of the icing problem.

All pilots are trained to recognize issues like a frozen pitot tube and there is a very simple solution - activate pitot heat and maintain level flight using your attitude indicator until your airspeed indicator starts working again.

Also, the 330 is not equipped with pitot heaters?

> Pilots have downed airplanes because of a malfunctioning pitot tube or fuel indicator light distracting them.

In fact, the cause of Air France 447's instrumentation failure was understood before the crash - there was an an active airworthiness directive to fix the pitot icing.

AF447 was flying in "alternate law" with limited (or maybe no) automation capability due to iced over airspeed pitot tubes.

Key excerpt from halfway through: "Another of the pitot tubes begins to function once more.