HONG KONG — An initial finding by investigators suggested the pilots of an airliner that crashed Wednesday in Taiwan’s capital, killing at least 35 people, may have reacted to a stalled-engine alarm by shutting down the wrong engine.
With both of its turboprop engines stopped, TransAsia Airways Flight 235, which had just departed the Taipei airport, went into a dive, clipped an elevated road, and plunged into the Keelung River.
The finding announced Friday by Taiwan’s Aviation Safety Council, based on cockpit voice and flight data recorders, was preliminary and did not assign blame. It showed the pilots had been discussing shutting down the plane’s No. 1 engine after the cockpit alarm sounded.
The plane’s No. 2 engine stopped just as power to the No. 1 engine was shut down, the Aviation Safety Council said.
Thirty-five of the 58 people on the flight, which had taken off just before 11 a.m. Wednesday for the outlying island of Kinmen, are confirmed to have died, including both pilots. Eight people were still unaccounted for Friday.
The safety board said it would continue to investigate the loss of power to both engines. But aviation experts said the engine data suggested the pilots had misidentified which engine had malfunctioned.
“They had a misconception about which engine failed, and they shut down the good one,” said David Learmount, operations and safety editor at Flightglobal, an online publication covering the aviation industry.
The pilot, Liao Chien-tsung, 42, has been widely praised for avoiding buildings in Taipei’s dense urban center as the plane, an ATR 72-600, plummeted to earth. He had nearly 5,000 hours of flying time, including 3,400 on ATR 72s, and the copilot, Liu Tse-chung, 45, had nearly 7,000 hours of flight time, including 6,500 on ATR 72s, according to Taiwan’s Civil Aeronautics Administration.
At 10:53 a.m., one of the pilots broadcast an emergency communication to the control tower. “Mayday, mayday. Engine flameout,” the pilot said, signaling a loss of power. The black box recordings end a minute later, the agency said.
Dashboard camera videos from vehicles that were traveling along the elevated roadway show the plane narrowly avoiding buildings as it descended, then banking violently before crashing. The twin turboprop is capable of flying on a single engine, which has led analysts to conclude it probably suffered problems with both engines.
It could be a year or longer before the investigation’s final conclusions are released.