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206 C20J Rotor Droop


lineworker
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I agree on the fuel pump, but would try the fuel nozzle first simply because its easier. I had a C20R that wouldn't start and had poor power checks from a nozzle that by all accounts sprayed fine and was visually fine. I don't think it's the compressor because your n1 isn't screaming high and the discharge tube would give you a poor power check but not likely a droop.

I'd be curious to hear the end result as well

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I've had that droop problem twice now. Pull collective, as soon as the torque hit 100%, it drooped down to 92% Ng.

 

The first time, it was the FCU.

The second time, it was the engine driven fuel pump.

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That doesnt sound right at all, why is you n2 @ 92% in an auto? inncorrect auto revs can definitely lead to Nr droop. Sounds like your doing your auto checks wrong, or I am reading this wrong.

 

In my experience Nr droop is most likely 3 things, incorrect auto's, N1 topping, or N2 rigging. I would aim more towards autos and n2 rigging personally ... also just because your beep range is 97-100.5 doesnt necessarily mean everything is rigged correctly.

In Lineworker's post he stated that the Revs were high, which is better than low. A needle split between the N2 and NR is normal, the N2 should fall away indicating that the freewheel is disengaging. He used the collective to keep the NR rpms from going too high.

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yes incorrect autos, set them up as per the MM, your alive thats great....

 

change out your dual tach, it will help your trouble shooting, needles shouldn't 'stick'

 

FCU rigging has nothing to do with your N2 rigging.

 

Not entirely true. If the FCU control isn't fully "open" it will restrict high power operation regardless of how much fuel the governor calls for.

 

The fuel nozzle filter requires you to take apart the nozzle itself, most people send them away for that.

 

My question about the particle sep was about erosion, depending on where in China you are operating, you can eat up your compressor and turbine nozzles pretty fast. But if your N1 is low it likely doesn't have to do with it. Most aircraft sent to china to work have a barrier filter installed.

 

I am sure we would all like to hear what ends up being the solution.

 

Good luck.

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I definitely concur about getting those auto rev's set properly before anything else. Just a note, it sounds like the fuel nozzle was taken apart and the little filter was dirty (if I'm reading that correctly). The book calls for fuel nozzle replacement if contamination is found in its filter. Just sayin'

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