Shutting Down the Wrong Engine.
As mentioned by SND, if the engine fails then it is already shut down.
A PT6 failure I had (turbine let go) resulted in such a plethora of captions on the CWP that it was a case of fly the aircraft, read off the failure warnings and finally notice one row of engine gauges at zero. Oops!
Winding off the wrong throttle didn't even enter the equation as a single pilot operation. But I have had a very experienced pilot in the LHS retard a PCL before I had verified the call, fortunately without creating an issue at the time. Salutary lesson
A PT6 failure I had (turbine let go) resulted in such a plethora of captions on the CWP that it was a case of fly the aircraft, read off the failure warnings and finally notice one row of engine gauges at zero. Oops!
Winding off the wrong throttle didn't even enter the equation as a single pilot operation. But I have had a very experienced pilot in the LHS retard a PCL before I had verified the call, fortunately without creating an issue at the time. Salutary lesson
Avoid imitations
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A true high side failure makes the engine go to max power, which would, while at flat pitch on the ground, probably trigger the overspeed protection as the way to protect the aircraft.
IMHO, any pilot flying a twin who thinks he is immune to making this error is foolish. Having said that, shutting the wrong engine down is most likely NOT the pilot’s fault. The human factors and engineering in this area is abysmal. But in the end, it’s always the pilot’s fault.
Consider the number of aircraft that have caution lights stating something similar to “#1 ENGINE FAIL”. Yet the related emergency procedure typically contains considerable warning about the light's false activation. How about a warning panel directly in front of a pilot with the far left segment stating “FIRE”? I’ve heard many a pilot utter the left engine was on fire when responding to its illumination.
Actual emergencies involve failure modes and faults that combined, become confusing at best, and may not be covered in the flight manual (ask me about the loose DECU connector I experienced on a maintenance flight).
Many times the crew needs to evaluate multiple sources of data which are incomplete, inconsistent, conflicting or wrong. Often, multiple warnings with different color coding, location or associated horns and bells distract and tend to focus attention to the exclusion of other data.
I once flew a twin the military that had over 80 underlined emergency procedures. That’s purely ridiculous. I take the time to consult the checklist before accomplishing any critical procedure, especially when single pilot. You can easily "miss-remember" a step, the proper order or a crucial note. Obviously, if on fire, out-of-control or given no choice, youskip the checklist.
The golden rule of power lever/control manipulation is always to pause at idle, and confirm before proceeding. My current twin has a one-step memory item for single-engine emergency shutdown:
“ENG MAIN switch (affected engine) – IDLE, check then OFF.”
I break that down into at least 5 seperate steps!
Consider the number of aircraft that have caution lights stating something similar to “#1 ENGINE FAIL”. Yet the related emergency procedure typically contains considerable warning about the light's false activation. How about a warning panel directly in front of a pilot with the far left segment stating “FIRE”? I’ve heard many a pilot utter the left engine was on fire when responding to its illumination.
Actual emergencies involve failure modes and faults that combined, become confusing at best, and may not be covered in the flight manual (ask me about the loose DECU connector I experienced on a maintenance flight).
Many times the crew needs to evaluate multiple sources of data which are incomplete, inconsistent, conflicting or wrong. Often, multiple warnings with different color coding, location or associated horns and bells distract and tend to focus attention to the exclusion of other data.
I once flew a twin the military that had over 80 underlined emergency procedures. That’s purely ridiculous. I take the time to consult the checklist before accomplishing any critical procedure, especially when single pilot. You can easily "miss-remember" a step, the proper order or a crucial note. Obviously, if on fire, out-of-control or given no choice, youskip the checklist.
The golden rule of power lever/control manipulation is always to pause at idle, and confirm before proceeding. My current twin has a one-step memory item for single-engine emergency shutdown:
“ENG MAIN switch (affected engine) – IDLE, check then OFF.”
I break that down into at least 5 seperate steps!
Thread Starter
Judging by the number of responses to my thread that ATR 72 crew were not alone, and that's just from the rotary world.
However, should somebody reading it checks their actions if they have a similar problem in the future then it is worth it.
However, should somebody reading it checks their actions if they have a similar problem in the future then it is worth it.
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The problems of shutting down the wrong engine are not factored into the risk calculations for twin engined theoretical engine related risk.
and 'pilot error' is not always a fair label when too much is expected from the pilot.
It is stressful if one engine runs up to diagnose the idling engine as the good one.
Some good advice here along the lines of 'do nothing'
and 'pilot error' is not always a fair label when too much is expected from the pilot.
It is stressful if one engine runs up to diagnose the idling engine as the good one.
Some good advice here along the lines of 'do nothing'
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Shy: "Let's just say that the aircraft went out on a low loader. It was full power, btw and it was the second similar event on that airframe. The RTO's C+ also suffered the same problem with engines running away up."
so unreliable ?!
so unreliable ?!
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The C+ had a difficult time with the later DECU controlled French engines. Not the best version of the Sikorsky S76 by any means, in my own experience of operating the A+, A++, B, C and C+ models. I haven't flown the C++ but by all accounts the problems of its earlier brother were sorted but by a fairly involved redesign of the "engine room" including its controls.
If memory serves me right, the problem with the C+ when talking about erratic engines was the collective position sensor. They proved to be unreliable and on occasion would send erroneous signals to the DECU so that one engine would run up into blow-away power while the other engine would obviously go the other way. Significant torque splits ensue. If you don't take a wait and see approach, I can see how it would be easy to grab the wrong engine. Every time this happened while I was flying, it was only momentary and a change in collective pitch would restore normal engine operation. However, the Ng changes are rapid enough to really get your attention.
Thread Starter
Seeing we are discussing the S76--going back to the very beginning with the Allisons.
To brighten up a boring trip the Allisons had an overspeed protection device. You tested this when taxiing out by pulling one engine back until the needles split and then holding down its test switch. This would cause the engine to hunt about 10% up and down proving the system worked. This used to go off in the air so you had one engine galloping up and down with the other galloping down and up trying to compensate. They would never get in sequence so the aircraft would fishtail furiously with the swings in torque. One had to lower the lever and pull the throttles to see which one had gone wrong before it threw the passengers out of the windows. Pulling it back to idle cleared it and so on you went.
Fareastdriver, you take us back. Most of us used to fly with the breakers pulled following a few rundowns in less than ideal circumstances. We took no notice of the edict which came, from the FAA I think, that on single engine aircraft the overspeed was to be disabled, whereas on a twin the overspeed was to be used - both single/twin edicts were mandatory. Figuring that the overspeed trip was more or less equivalent to having an engine failure we were unable to discern the reasoning behind the single/twin logic, and still flew with the breakers pulled.
