On June 1, 2009, Air France Flight 447 flew into a tropical storm over the Atlantic with the captain asleep in the crew rest area and two co-pilots at the controls. Ice crystals blocked the plane's pitot tubes and the autopilot disconnected, handing the Airbus A330 to pilots who had spent years monitoring flight computers rather than hand-flying at cruise altitude. Within seconds, the pilot flying pulled the nose up into a steep climb, and a stall warning sounded for most of a minute. Neither co-pilot diagnosed the stall, because neither had practiced manual recovery from one at high altitude since training.

The BEA's investigation found a deeper design problem behind the human error. Airbus's fly-by-wire system enforces stall protection automatically under normal law, but that protection vanishes the moment the automation drops out, so the pilots lost their safety net at the exact moment they were suddenly asked to fly manually. The jet fell for three and a half minutes, engines at climb power and nose still pitched up, before it struck the ocean and killed all 228 people aboard. Cockpit recordings later showed the pilots calling out contradictory instructions, unable to agree on what the aircraft was doing.

Investigators named the underlying pattern automation dependency: the more a system absorbs routine control, the less practiced its operators become at the exact skill retained for emergencies. Regulators and airlines responded within a few years by mandating recurrent manual-handling and stall-recovery training worldwide, an admission that heavy automation had quietly hollowed out a core piloting skill it was never meant to replace. The lesson generalizes past aviation: any system that removes the thinking step from routine work must deliberately reintroduce moments where the human practices it, or that skill atrophies exactly when it's needed most.