When Air Inter Flight 148 crashed into the Vosges Mountains near Strasbourg in France on January 20, 1992, killing 87 people, the cause wasn’t lack of machine-human communication, but a confusing user interface. The pilots entered “33” on a keypad because they wanted to descend at an angle of 3.3 degrees, but the autopilot interpreted this as 3,300 feet per minute because it was in a different mode—and the display screen was too small to show the mode and allow the pilots to realize their mistake.
