Engine Failure Characteristics

[Greedy]

A friend of mine has just been failed in the Sim for not attempting a relight of a turboprop engine. My question is what are the characteristics of engine failure due to lack of fuel supply in a turboprop.Does the engine wind down slowly or suddenly stop? (SAAB 340, GE CT7-9B)

[Capot]

In a Skyvan with Garrett TPE331 engines, I happen to know, if an engine is starved of fuel the loss of power is quite sudden; the loss of rotation speed is another matter that I can't comment on.

If the other one then does the same thing just as you complete the 180 Rate 1 turn to get back to where you left from, you know you've done something rather unusual like using crossfeed since the departure before last without realising it.

[barit1]

With fuel starvation, you'll see a rapid drop in torque and core speed, thus rapid prop autocoarsening (or autofeather with HSD prop), but core will not stop turning immediately.

On the other hand, if something breaks internally, core will go to zero speed quickly. In this case it's probably futile to attempt relight.

[Tee Emm]

A friend of mine has just been failed in the Sim for not attempting a relight of a turboprop engine

The first question I would ask of the checkpilot: Was the pilot given dual instruction training on the sequence before being tested? It is unfair to scrub someone for a perceived failure to take the correct course of action when he may have never seen a demonstration of this action in the first place. It is quite common to see "failures" in the simulator when in fact the pilot had never received adequate training on the exercise beforehand. Occasionally, check pilots are selected for the job - not because of demonstrated skills in training, but for other reasons.

[JW411]

Well, unless the engine has been shut down for a fire or severe damage, then (having secured the engine and got yourself into the hold and completed the shutdown drill) why not attempt a relight?

If it was a simple rundown, then the thing might restart and make life a bit easier. It's not just the engine that you have lost but the associated generator, hydraulic pump etc.

As an examiner, I would expect to see the crew attempt to get the engine back if at all possible.

[MarkerInbound]

The FAA has given "guidance" to the training center I work with that the student should "consider" a relight. The drill has been to clean up the plane and choose a checklist (Engine Failure v Engine Fire, Severe Damage or Separation) based on fire bell, N1 and N2. They'll go through the relight proceedure during training. If it was only an engine failure on a checkride, about the time the crew checks the restart envelope, the engine will seize because they have to shoot some approaches with an engine inop.

[Greedy]

I'm not sure when the failure was given however I do know that restarting has not been part of our sim exercises. They usually follow an approved format that by regulatory necessity leads to One Engine Inoperative Approach and Landing.There is a crew expectation that this is going to occur(rightly or wrongly). I have no objection to a Check Captain encouraging a crew to attempt a restart in appropriate circumstances but I think everyone should be aware of what is required to be demonstrated in Checks. One of the other posters makes reference to candidates having procedures demonstrated to them by training pilots. I think this is a valid point and sadly lacking in our industry. A physical and mental skill is effectively learned by watching someone do it and then trying to replicate it yourself. Too much of our training is "here's the FCOM go and learn it". First attempt is without any prior observation or demonstration.