TransAsia GE235: Taiwan crash plane ‘lost engine power’

http://www.bbc.com/news/world-asia-31162351

Unfortunately, recent news indicates possible pilot error in the crash of TransAsia 235. The referenced article quotes experts who are commenting on the recovered black boxes. As a pilot, the term ‘pilot error’ has a personal meaning.

Apparently, the pilot may have turned off the good engine when he lost power in the bad engine. Most of you are asking, ‘how can that happen?’ Surprisingly it happens, not a lot, but it does happen. When an engine fails, the pilot has only a few seconds to diagnose the problem. In a previous blog posting, I talked about ‘winding the clock’. I talked about how critical it is for a pilot to take his time diagnosing any problem. In a crisis, the pilot’s internal clock accelerates and a second seems like a minute. They are trained to react and waiting a few seconds seems counter to their training. In fact, it is an essential part of their training. Taking the wrong steps usually aggravates the problem.

The only answer in these situations is training. A pilot needs to go through the procedure many times and preferably in simulators and ideally in training flights. Particularly during takeoff, the pilot has to ‘step on the good engine’, which means they need to step on the rudder pedal to keep the airplane flying straight. The rudder compensates for the yawing caused by the loss of thrust. The phrase also helps the pilot identify the ‘good’ engine so he can diagnose the problem faster. This usually happens naturally, because in a twin-engine airplane, the engine loss is evident in the cockpit and the pilot’s natural instinct is to straighten the airplane with rudder. In a four-engine airplane, the feel in the cockpit is much less.

When I was flying, I found that it was a good cockpit procedure to talk with the other pilot and verify the good engine and which one needed to be shut down. It takes a few extra seconds and it is a great way to make sure the pilot doesn’t do something he might regret. I don’t know what the TransAsia procedures are in that situation, but it makes sense regardless.

Once the good engine was shut down it takes 30-60 seconds for it to restart and get to flight power. If done close to the ground, there likely isn’t time to recover.

In the case of a flameout, the procedure is simple. Depending on the sophistication of the flight controls, the pilot identifies the bad engine and pulls 2-3 levers in a particular sequence. If the pilot makes a mistake and shuts down the wrong engine then they have to reverse the lever movement and wait for the engine to start and come back to flight power.

During an inflight emergency, the cockpit is a busy place. The cockpit will have alarms, one of the pilots is trying to read emergency procedures, there is usually radio traffic and as the old saying goes ‘ass holes and elbows.’ Another old pilot saying describes flying as ‘thousands of hours of boredom, interrupted by a few seconds of panic.’

My sympathies to the crew and passengers.

 

Ray Jay Perreault

Science Fiction