FAA considers Superior Air Parts crankshaft assembly AD

[Tandem46]

Originally Posted by Cannon

.....All three cranks were in a flight school environment.

This is news to me and very telling. Not saying the cranks should fail so easily but new students can definitely be very hard on engines. Maybe SAP has a case after all.

[JPGrobler]

I heard a rumour that should the AD go through, we will only start receiving cranks 12 months from now

Anyone else with first hand info on this? Would?ve loved to get back in the air after lockdown as we aren?t allowed to fly during our lockdown in South Africa.

Frustrating to say the least!

[Thermos]

Interesting, can you share the source of that information? But it doesn't surprise me...my engine builder says there are a limited number of companies producing crankshafts for Lycoming, Superior and ECi.

Dave

[JPGrobler]

Originally Posted by Thermos

Interesting, can you share the source of that information? But it doesn't surprise me...my engine builder says there are a limited number of companies producing crankshafts for Lycoming, Superior and ECi.

Dave

The AP across from our hangar mentioned to me that he heard from Superior that it will take that long to push out the crankshafts as he enquired about a new engine he want to purchase for his client.

So don?t quote me on this as it is far from first hand info, but hopefully it won?t take as long. If the risk was negligibly small, I would?ve been flying by now. But not sure what the risk is.

[airguy]

My day job is in oilfield compression, and we are having a hard time sourcing crankshafts for our compressors as well. There are just a small number of shops with the ability to do this work, and things get backed up sometimes. I can only imagine the headaches the FAA process would add to that.

[BillL]

Originally Posted by Tandem46

This is news to me and very telling. Not saying the cranks should fail so easily but new students can definitely be very hard on engines. Maybe SAP has a case after all.

With the exception of a ground strike, I don't know what an operator can do with an engine to fail the crank. This does not make sense to this engine engineer of 40 yrs.

I accessed the AD proposal and docket and it was lacking in detail information/documentation for the determination of root cause. Nothing on the engine specifications or hours.

One failure was 1/4" subsurface, which screams metallurgy and/or heat treat to me. I can not see how a surface site layer has anything to do with that. 99% of all part loading have peak stresses on the surface of the part.

[Thermos]

Originally Posted by BillL

With the exception of a ground strike, I don't know what an operator can do with an engine to fail the crank. This does not make sense to this engine engineer of 40 yrs.

I accessed the AD proposal and docket and it was lacking in detail information/documentation for the determination of root cause. Nothing on the engine specifications or hours.

I spoke with the FAA engineer overseeing this AD, I think that's their position as well. But they haven't publicly released their metallurgical analyses so we only have Superior's side of the argument.

ds

[walkman]

So has this actually turned into an AD now? Or is it still in the NPRM stage?

[Thermos]

Still an NPRM.

ds

[JPGrobler]

The 60-day extension period has come and gone. Any news from the FAA or Superior regarding the matter?

Does anyone know if Superior has been working on this? (not sure what the conditions in the US currently is with regards to lockdown etc from COVID-19)