Nacelle Heat Shroud/shield twisting NP2000 equipped aircraft

[dexeadie]

Looking for maintainers who have seen the twisting and buckling on the Nacelle Heat Shroud/shields, NP2000 equipped aircraft. In the horse collar area near the wing front beam .I am a Quality Inspector and we are seeing more of these in Depot. At first a few, now all the aircraft in the past few months come in with this. Saw it on a few C-130s equipped with the 54H60 prop but this was usually due to an over torque condition. And not all four engines at once. See pics attached. Any feedback welcome.

 

This is one of the first aircraft equiped with the NP2000. All four are like this.

 

[tinyclark]

Wow! Wish I could help. May help reaching out to the units that have said props.

[Metalbasher]

what depot are you working at?  Robins has seen a lot of acft with NP2000s and I haven't heard of this problem. 

[Lkuest]

It doesn't surprise me that the NP2000 props would have more stress-related issues. I hear the RPM is much more stable, which means it does a better job of being an airbrake for the engine than the old props, which would magnify torque-related stress. I'd expect you to see more truss-related damages though.

I'd recommend reaching out to the Lockheed tech reps and see if they can identify a modification requirement for the E/H wings and nacelles that is newly necessary with a more responsive propeller. They may even have resolved a C-130J issue that they could retrofit into the older models. The NP2000 engines might just be easier to overtorque, a problem the C-130J wouldn't have with digital controls. Lockheed might just recommend a torque data-capture modification to make sure all overtorques are captured.