Flight One Ninety-One: Thirty-One Seconds

Near this location, on the afternoon of May twenty-fifth, nineteen seventy-nine, two hundred and seventy-three people died in thirty-one seconds.

American Airlines Flight One Ninety-One was a McDonnell Douglas DC-Ten bound for Los Angeles, departing Chicago's O'Hare International Airport at three oh five in the afternoon. It was carrying two hundred fifty-eight passengers and thirteen crew members on what had been a routine afternoon departure. The plane never cleared the airport perimeter.

As the aircraft was accelerating through its takeoff roll, the left wing engine, engine number one, broke free from the airframe. It did not simply fall. The engine flipped up and over the top of the wing. As it separated, it severed hydraulic lines that held the leading-edge slats, the small wing extensions that generate extra lift at low speeds, in their deployed position. Without those slats, the left wing lost lift. With the right wing still generating full lift, the plane rolled violently to the left.

The pilots, tragically, had no warning. The same hydraulic damage had also cut the electrical system feeding the cockpit warning instruments. They could not know that one of their wings had effectively stopped flying. The DC-Ten rolled to a near-vertical bank angle and nosed into the ground just beyond the end of the runway.

The investigation revealed that the engine had not simply fallen off. It had been weakened during a maintenance procedure weeks earlier, when mechanics used a forklift to remove the engine and pylon together as a single unit, rather than the manufacturer's specified method of removing them separately. The shortcut cracked the pylon mounting flange. Under takeoff stress, the crack gave way.

All two hundred seventy-one people aboard were killed, along with two on the ground. It remains the deadliest aviation accident in United States history not involving a deliberate act. The National Transportation Safety Board issued sweeping new maintenance requirements in the aftermath, and the FAA temporarily grounded all DC-Ten aircraft operating in the country.