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Prop Governor in Single Engine vs Multi Engine

Asked by: 6110 views Aircraft Systems

So, I'm trying to find right answer for this question.
So far I found out that:

In single engine oil pressure for the prop governor will be used when prop need to go to higher pitch (Lower RPM). In case of oil loss prop will be in Low pitch High RPM setting.

In multi-engine, oil pressure for the prop governor will be used when prop need to go to low pitch (higher RPM). In case of oil loss prop will be in feather position for less drag.


Okay so my questions are:

1. Engine can run without prop governor? if so why multi-engine prop needs to be in feather position during loss of oil pressure? because if both engine can run without prop governor, landing will be much easier as long as engine is fine.

2. If engine can not be ran without prop governor, why single engine prop goes into low pitch / high rpm setting during loss of oil pressure? Less drag = farther gliding distance right?

 

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1 Answers



  1. Robert Jankowski on Mar 05, 2016

    Yes, an engine can run without a prop governor, tens of thousands of non-complex aircraft flying around are proof of that.

    Loss of oil pressure in a single engine aircraft equipped with a hydraulic propellor governor will result as you said in the prop defaulting to the high RPM position. This is to give the pilot the ability to continue flight in the event of a governor failure, provided the engine is still operational as it would stop spinning if the engine seized from lack of lubrication.

    The multiengine aircraft have something to consider that the single engine aircraft don’t: asymmetric drag and thrust. The loss of an engine on a multiengine propellor aircraft creates quite a bit of yaw if the propellor is windmilling, this coupled with a loss of thrust on that side of the aircraft introduces a significant amount of yaw (caused by loss of thrust and also increased drag on the failed engine), which if not corrected swiftly and correctly could result in the aircraft departing controlled flight. If the propellor is feathered automatically at the sudden loss of oil pressure, that drag is reduced pretty substantially, giving the pilot a better ability to manage the situation.

    There’s also the issue that if the pilot isn’t able to feather the prop on the failed engine before the anti-feathering pins engage, then there’s a pretty good chance the pilot will be stuck with a windmilling propellor all the way thru the flight and landing… Landing with a dead and windmilling engine is not my idea of fun.

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