After One Engine Appeared to Have Malfunctioned, Fuel to the Other Was Cut Off
Taiwan President Ma Ying-jeou attends a funeral for victims of TransAsia Airways Flight 235.
By JENNY HSU, ARIES POON and COLUM MURPHY
Updated Feb. 6, 2015 5:50 a.m. ET
By JENNY HSU, ARIES POON and COLUM MURPHY
Updated Feb. 6, 2015 5:50 a.m. ET
TAIPEI—Fuel to the left engine of the ATR72-600 twin turboprop plane that was TransAsia Airways Flight 235 was manually cut off after the right engine appeared to have malfunctioned almost immediately after takeoff, according to flight data reviewed by investigators from the deadly crash in Taipei.
Both engines stopped producing thrust just before the crash, which occurred on Wednesday in four minutes after takeoff.
The data raise the possibility that the pilot may have mistakenly cut fuel to the only engine keeping the plane in flight.
In releasing the data on Friday, aviation safety authorities declined to provide any interpretation or speculate on the cause of Wednesday’s crash.
Also Friday, more bodies were recovered from Taipei’s Keelung River. The airline said 35 people were dead, 15 injured and eight people—all Chinese nationals—remain missing. The plane was carrying 53 passengers and five cabin crew members. Many of the passengers were tourists from China, from the mainland province of Fujian, next to the outlying island of Kinmen.
The data, retrieved from the voice and data flight recorders on the flight, show that the turboprop experienced trouble shortly after takeoff. According to the data, a warning alarm sounded around 37 seconds into the flight, at an altitude of 1200 feet, and indicated the right engine had a “flameout”—an aviation term for a loss of power.
Thomas Wang, the director of Taiwan’s Aviation Safety Council in charge of the crash investigation, told reporters that an examination of the data showed that the right engine “actually did not flame out.” Instead, he said, the engine “went into an auto-feather mode which it should not have.” An engine starts to auto-feather, a glide mode, when a propeller doesn’t produce any thrust.
Mr. Wang said the fuel to the left engine was eventually cut off manually. The plane then descended from 1,600 feet to around 500 to 600 feet, at which point there was an attempt to refuel that engine. But Air-traffic control lost communication with the plane’s pilots four minutes after takeoff from Taipei’s Songshan Airport en route to Kinmen, at about 10:53 a.m. local time on Wednesday, the Civil Aeronautics Administration said earlier.
The ASC on Friday said Flight 235 issued five speed-loss warnings before crashing.
The ASC presented its preliminary findings after analyzing the data retrieved from the plane’s two cockpit voice recorders and flight data recorder, commonly known as the ‘black boxes.’ A final report on the cause of the crash will be released in 12 months, said Mr. Wang.
The Wednesday crash into a river in Taipei was TransAsia’s second fatal air accident in seven months. Earlier Friday, the CAA said the carrier would be banned from adding new international routes for a year. TransAsia had already been excluded from new international routes after a crash in July killed 49 people. The second plane crash extends the ban to Feb. 4, 2016, the CAA said.
The airline said Friday that aviation-safety experts will conduct a year-long review of its fleet and overhaul the organization, particularly departments overseeing flight safety and mechanics. In addition, it said, all pilots flying ATRs will be required to take qualifying tests monitored by the Civil Aeronautics Administration and a third party.
Authorities previously said that Flight 235 lost contact with the control tower within four minutes after takeoff from Taipei Songshan Airport en route to the island of Kinmen, off China’s coast.
Given the quick series of problems so soon after takeoff, the pilots would have had little time and altitude to respond, said Mark Martin of Martin Consulting, an aviation advisory firm.
“It appears that from takeoff to impact was less than four minutes. There’s no way the pilot could recover from a situation like that as it’s less likely that the aircraft was within a safe recoverable altitude,” said Mr. Martin. “With four minutes and almost 60 passengers on board and at an altitude below 5,000 feet, you have hardly time to respond let alone read a checklist.”
Mr. Wang said at this stage of the investigation, the council isn’t determining what caused the right engine to go into auto-feather mode—a process that essentially turns out thrust to power the plane. He also declined to say why fuel was shut off to the left engine.
“What we know now is both engines did not produce power before it went into the river,” said Mr. Wang.
The plane was made by France’s Avions de Transport Regional, known as ATR, a joint venture between Airbus Group NV and Italy’s Finmeccanica SpA. The ATR72-600 turboprop last underwent routine maintenance Jan. 26.
TransAsia said Wednesday that when the plane was delivered in April in Macau, one of the engines was found to be functioning improperly. The official said the maker of the engines, Pratt & Whitney Canada, was notified immediately and a replacement engine was immediately provided. According to the airline, the plane’s total flight hours since it was delivered was around 1000 hours, the same as the right engine, while the left replacement engine had logged roughly 800 hours.
A spokeswoman for Pratt & Whitney said the company is cooperating with authorities and with its customers but declined to say more while the investigation is under way.
ATR representatives at the press conference said the plane is designed to have the capability to operate, including take off, with one engine. Mr. Wang said, before takeoff, both engines did not show any problems.
When asked about the possibility of a bird strike, Mr. Wang said it is not known at this stage of the investigation as pieces of the plane’s debris are still being salvaged from the river.
Earlier this week, the Civil Aeronautics Administrations said the weather condition at the time of the crash met the standard for flying.
Images of the plummeting aircraft, which clipped an overpass before hitting the water, were captured on dashboard cameras and spread quickly on social media.
Air-safety concerns in Asia have been growing as the region’s traffic continues to boom and in response to a number of tragedies last year, including the Dec. 28 crash of AirAsia Flight 8501, which went down in the Java Sea after taking off from Surabaya, Indonesia, on its way to Singapore. The exact cause of that accident remains unclear. The disappearance of Malaysia Airlines Flight 370 in March also remains a mystery, with recovery crews searching two vast areas in the Indian Ocean.
Taiwan, which has a mature regulatory system and has been actively engaged in international safety efforts for decades, generally isn’t considered among the Asian countries that outside safety groups worry about the most.
The latest analysis conducted by the International Civil Aviation Organization, a United Nations agency that sets nonbinding safety standards for carriers and regulators, indicates that Asia has at least three of the 10 countries around the globe deemed to have the most serious safety shortcomings.
Founded in 1951, TransAsia, a smaller carrier compared with larger rivals China Airlines and EVA Airways, has sought to aggressively expand its network beyond domestic Taiwan routes. The latest crash is likely to prove a challenge for the airline, but isn’t expected to havea major impact on Taiwan’s tourism industry ahead of the crucial Lunar New Year, a travel season on both sides of the Taiwan Strait.
Write to Jenny Hsu at jenny.hsu@wsj.com, Aries Poon ataries.poon@wsj.com and Colum Murphy at colum.murphy@wsj.com
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