Both engines 'lost power' before Taiwan plane crash   

復興空難黑匣子解讀 失事原因：雙發動機失效

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 a.m. 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 a.m. that engine No.2 was not working. Around that time, the first warning of that the plane was losing speed sounded out.