Low climb rate-RPM indicator in red

Many thanks, Roger., for ascertaining that you believe it's the propeller to be focused upon and not the engine / Gear box (overload clutch). 

That's a very valuable input. Let our team wok in these lines. I will get back to you with the results. 

Thank you once again.

Ray

Hi All

Just to touch base on your issue.  As Roger has pointed out it may be a prop incorrectly loading the engine.  it is not that hard to determine if you have an issue with the overload clutch.  First be sure that an overload clutch is installed.  Check your configuration.  If you have 30 degree "free play" with the crankshaft locked in place via the crankshaft locking pin then it has an overload clutch.  

To inspect the break away limits see your LMM, line maintenance manual, for the spec and the way to brace the aircraft to do this test.  You will need to make a fixture to bolt to the gearbox and I would recommend you use a torque "multiplier" to get the reading.  The value we are looking for is very high, 600 NM, therefore you cant simply use a spring scale like we do for friction tests on the Belleville washers.  

One other note is be sure that you did not use an oil with friction modifiers, automotive oils are not recommended for this reason as they can defeat the clutch pack and let it slip.  Oils that are suitable with a friction clutch (use the Aeroshell Sport Plus 4 or similar) must be used when your gearbox is fitted with an overload clutch.  If the clutch is slipping remove it and return to an approved and qualified shop for inspection and resetting of the pack pressure.  

Cheers

Thanks for reminding. 

Confirmed that overload clutch is fitted on this engine. Break-away torque check is definitely required to be done. That will eliminate doubt on the clutch slippage. 

Many many thanks for all valuable suggestions.

Regards,

Ray