The fan disc which exploded in the right engine of an American Airlines 767 at O’Hare during a takeoff roll in October of 2016, contained a flaw which had been present since the day the molten alloy for that critical part was forged. Cracks in the disc grew over the course of as many as 5700 takeoffs and landings.
The captain stopped the burning aircraft seconds before it would have lifted off from the runway. Everyone survived, although 21 people were injured, one seriously.
“American flight 383 came too close for comfort,” NTSB chairman Robert Sumwalt said during a hearing on the accident Tuesday. The agency said the flaw in the fan disc was essentially undetectable using current methods, and they called for revised inspection techniques to find such anomalies in the future.
“This is the first failure of its type of alloys made this way,” Sumwalt said in an interview with NBC 5. “This is not a widespread failure, especially when it leads to an event as spectacular as the American 383 flight.”
Indeed, the incident was magnified by the chaos which ensued aboard the burning aircraft in the seconds after it rolled to a stop.
“Some passengers retrieved their baggage, despite flight attendant instructions to leave it behind,” Sumwalt said during the hearing. “One passenger even resisted a flight attendant attempting to take away a carry-on bag - in a burning airplane!”
The agency called for the FAA and the airlines to examine ways to mitigate such potentially deadly passenger behavior during future evacuations.
“Let me say a word to the public,” Sumwalt said. “Follow your crew’s instructions!”
Investigators also said there was a need to revamp engine fire procedures which do not differentiate between such occurrences in the air or on the ground. Because it wasn’t called for, the pilot did not immediately shut down the airplane’s left engine, which was undamaged, and that hindered evacuation efforts on the right side of the aircraft.
“The most injured passenger was blown over by jet blast from that engine,” Sumwalt observed.
NTSB staff also pointed to a need for better training, on what can be a confusing array of 13 different intercom phones across the American Airlines fleet. Crew members said in the chaos of the pending evacuation, they were unable to reach the cabin crew.
American said in a press release, they have already begun procedures to revamp intercom training.
“Several flight attendants reported attempting to call the pilots, but then abandoning their attempts for reasons that included difficulty dialing the right code,” the airline said. “American is installing enhanced training aids, to include mockups of each specific type of intercom phones installed on its fleet.”
The NTSB chairman noted that the current FAA circular on crew-cockpit communication procedures was written in 1988, and repeated his agency’s ongoing call for an update.
“Many of the flight attendants working today weren’t even born when this thing was written!” he said.
Investigators questioned the wisdom of allowing left-side evacuations before the left engine was shut down. But overall, they praised the crew for a rapid evacuation.
“The passengers were rushing at the exits, pleading to get off the airplane,” Sumwalt noted. “We had 15 months to look at it - the crew had less than 180 seconds to perform their duties!”
Board member Christopher Hart echoed those sentiments.
“They pulled this off spectacularly,” he said. “I want to give kudos to the flight crew in managing to stop this airplane on the runway.”
