When the engine exploded in mid-air on a Qantas Airways flight from Singapore to Sydney, Australia, captain Richard de Crespigny had to act fast to avoid catastrophe—and he did, saving the lives of all 469 people on board, even though the situation was far different from anything he’d experienced in training.

On November 4, 2010, captain Richard de Crespigny had just performed a practically perfect takeoff from Singapore’s Changi Airport with Qantas Airways. The weather was ideal, and…