Jeff Wise in Nautilus:
For any pilot, losing engine power is a nerve-wracking experience. Engine failure in a plane like the ATR-72-600 is not in itself a catastrophe. It’s an eventuality that the planes are designed for—it’s why they have multiple engines—and pilots train for. But Liao had to take the right steps immediately. His heart pounding, he knew that he had to throttle back the stricken engine and turn it off to reduce the risk of fire. Once that was done, he’d have enough power from the remaining engine to maintain altitude and maneuver back to the airport for a safe landing.
The plane’s black boxes recorded what happened next. Liao reached forward and pulled back on one of the engine throttle levers. But he pulled back on the left one—the one for the good engine. Now the plane was 1,000 feet over one of the most densely populated cities in the world, 25 tons of metal, fuel, and human flesh, with no engines to keep it in the air. A worrisome but manageable problem had suddenly become an imminent and severe one.