For anyone interested in going deeper down the rabbit hole of the problems of automation and the concurrent (and inevitable) deterioration of piloting skills, William Langewiesche wrote a great long-form recount of the crash and investigation of Air France 447:
For Flight 447, it was too late: the probes were quickly clogged. Just after 11:10 P.M., as a result of the blockage, all three of the cockpit’s airspeed indications failed, dropping to impossibly low values. Also as a result of the blockage, the indications of altitude blipped down by an unimportant 360 feet. Neither pilot had time to notice these readings before the autopilot, reacting to the loss of valid airspeed data, disengaged from the control system and sounded the first of many alarms—an electronic “cavalry charge.” For similar reasons, the automatic throttles shifted modes, locking onto the current thrust, and the fly-by-wire control system, which needs airspeed data to function at full capacity, reconfigured itself from Normal Law into a reduced regime called Alternate Law, which eliminated stall protection and changed the nature of roll control so that in this one sense the A330 now handled like a conventional airplane. All of this was necessary, minimal, and a logical response by the machine.
So here is the picture at that moment: the airplane was in steady-state cruise, pointing straight ahead without pitching up or down, and with the power set perfectly to deliver a tranquil .80 Mach. The turbulence was so light that one could have walked the aisles—though perhaps a bit unsteadily. Aside from a minor blip in altitude indication, the only significant failure was the indication of airspeed—but the airspeed itself was unaffected. No crisis existed. The episode should have been a non-event, and one that would not last long. The airplane was in the control of the pilots, and if they had done nothing, they would have done all they needed to do.
It's a great article. Read the rest here.
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