Death toll from TransAsia Airways plane crash rises to 38

Relatives leave the rescue site after holding a memorial ceremony for plane crash victims in Taipei, Southeast China's Taiwan, Feb 7, 2015. Rescuers on Saturday morning recovered three more bodies, raising the death toll from the TransAsia Airways plane crash to 38. Five passengers are still missing. [Photo/Xinhua]

TAIPEI - The TransAsia Airlines flight that crashed in Taipei on Wednesday lost power in both engines before it went down, but one had its power cut rather than suffering any mechanical failure.

The Aviation Safety Council (ASC) said the plane ran into trouble 37 seconds after taking off from Taipei's Songshan Airport. Engine No. 2 (right) sent a "master warning" signal to the pilots, according to initial analysis of the flight data recorders. Data suggests that the crew tried to cut the fuel supply to the engine on the left.

Thomas Wang, managing director of the ASC, said the pilot announced a "flame-out", which can occur when the fuel supply to the engine is interrupted or when there is faulty combustion. However, Wang said there was in fact no flame-out, and the engine on the right side had shifted into idle mode without any change in oil pressure.

"The aircraft flashed a flame-out signal for the No. 2 engine at 10:53:28 when at an altitude of 1,200 feet," Wang said.

Engine No.1 was still operating normally at that point but was cut at 10:53:24 am for reasons unknown.

"During the flight's final moments, neither engine had any thrust. We heard 'Mayday' at 10:54:35," he added.

The 72-seater aircraft, an ATR 72-600 manufactured by Franco-Italian firm ATR, is able to fly or take off with just one functioning engine, said Yann Torres, of France's aviation accident investigation bureau (BEA) who has joined the investigation.

"We can't answer any question concerning the 'why' at the moment," Wang said.

According to the cockpit voice recorder, the crew discussed throttling back Engine No.1 at 10:52:43 a.m., just four seconds after the master warning for the other engine went off.

The voice data showed that the crew mentioned a procedure for handling engine flameout shortly afterwards, while confirming at 10:53:07 am that engine No.2 was not working. Around that time, the first warning of that the plane was losing speed sounded out.

At 10:53:19 am, the pilots mentioned that Engine No. 1's propeller was auto-feathering and fuel had been cut off , followed by second and third audible warnings of the aircraft losing speed.

Feathering describes the action when a propeller's blades are rotated parallel to the airflow in case of an engine failure to reduce drag.

The crew issued their first "Mayday" call and notified the control tower of an engine flameout at 10:53:34 a.m. Two more warnings that the plane would stall sounded shortly afterwards.

Things then went quickly out of control. The crew said the an engine had restarted just before another loss of speed warning. A master warning occurred at 10:54:34 a.m. and an unidentified noise was recorded, Wang said. Two seconds later the plane crashed to the river and both the flight data recorders stopped working.

At least 35 people, including 25 tourists from the Chinese mainland, died when the plane bound for Taiwan's Kinmen Island, crashed into the Keelung River in downtown Taipei. Seven passengers and one flight attendant are still missing two days after the tragedy. Fifteen people survived the crash.

The ATR72-600 aircraft was less than a year old but had a history of engine problems.

A more substantial report will be released within the next 30 days, ahead of the publication of a final report in the next three to six months.

The pilot, Liao Chien-tsung, had 4,914 flying hours under his belt and the co-pilot 6,922 hours. Both died in the crash.

Taiwan's aviation regulator has ordered TransAir to carry out extra oral and written training and tests among the 71 pilots of its ATR fleet within the next three to four days. Those who fail the tests will be suspended from flying.