Speaking of fly-by-wire… William Langewiesche is one of my favourite technical writers. He finds a way to explain complex aviation aspects really well, and then add a certain amount of beauty and poetry on top of that. His style was a big influence on my book, and I like him so much I once compiled links to his writing so that others could find it more easily.

Here’s Langewiesche’s essay from 2014 about the 2009 Air France Flight 447, where an implementation of fly-by-wire – which means disconnecting the flight stick and attendant levers from immediately controlling flight surfaces via physical linkage, and instead putting motors and software in between – caused a fatal accident, as the pilots’ mental model of the system diverged too far from what was happening:

The [Airbus] A330 is a masterpiece of design, and one of the most foolproof airplanes ever built. How could a brief airspeed indication failure in an uncritical phase of the flight have caused these Air France pilots to get so tangled up? And how could they not have understood that the airplane had stalled? The roots of the problem seem to lie paradoxically in the very same cockpit designs that have helped to make the last few generations of airliners extraordinarily safe and easy to fly.

It’s an interesting read today in the context of robotaxis and self-driving, but also AI changing software writing:

This is another unintended consequence of designing airplanes that anyone can fly: anyone can take you up on the offer. Beyond the degradation of basic skills of people who may once have been competent pilots, the fourth-generation jets have enabled people who probably never had the skills to begin with and should not have been in the cockpit. As a result, the mental makeup of airline pilots has changed. On this there is nearly universal agreement—at Boeing and Airbus, and among accident investigators, regulators, flight-operations managers, instructors, and academics. A different crowd is flying now, and though excellent pilots still work the job, on average the knowledge base has become very thin.

It seems that we are locked into a spiral in which poor human performance begets automation, which worsens human performance, which begets increasing automation.

I was devastated to discover, while writing this post, that Langewiesche died last year. Rest in peace.