What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

New (February 2020) FAA AD - Superior Air Parts Crank Shaft

...A very prominent engine expert one told me that the border between nitrided area and non-nitrided areas acts as a stress riser and if someone is attempting to remove the affected area, AFTER THE ENGINE HAS BEEN RUN, should probably subject the crank to a commercial X-ray study to see if fracture planes have started.

FWIW

I'm not a metallurgist, and I did not stay in a Holiday Inn last night. But, ...

After reading and looking at the pictures in the Hurst reports, showing the fracture planes emanating from the origin, this is kinda what I was thinking.

But, I wonder if you could really know whether or not you'd fixed the problem with what they call "isotropic super-finishing" of an already run crank without destructive metallurgical analysis.


I've dug through the entire docket. And, the conclusion I have reached is that the determination of the root cause is inconclusive. We just don't know what we don't know. And, since uncle Sam has passed judgement, its a moot point anyway! :-(
 
Last edited:
Rocket Bob said:

"The FAA is saying the white layer is the root cause, so if its gone, problem solved."

I'm assuming the text after "cause" is Rocket Bob's and not the FAA's

A very prominent engine expert one told me that the border between nitrided area and non-nitrided areas acts as a stress riser and if someone is attempting to remove the affected area, AFTER THE ENGINE HAS BEEN RUN, should probably subject the crank to a commercial X-ray study to see if fracture planes have started.

FWIW

Would grinding the crank pins M003 remove any initiated micro-crack planes at the boundary where the nitriding stops? If so, this seems like a good solution.

Adding to the hassle of time and cost to comply, there is a huge shortage of cranks (one post said 12-18 months lead time) so if a crank could be re-ground, inspected and put back into service, that would be a big saving in lost time.

And for those who have engines with essentially zero flight time, just the factory dyno run-in, could they do the re-grind with good confidence that there are no micro-crack planes started? Seems like there are several 'victims' in that situation here - sitting on an essentially new engine.
 
I would think that not all of the cranks in the AD are bad.

Is there someway to inspect the crank then use it if it passes inspection.
 
Some metallurgist out there should help us with the details. My practical association with nitriding is it is shallow in depth, and if gaseous it will do the whole part although it has better results in the focus region.

Are the fillets rolled and nitrided or just the whole crank nitrided. I say gaseous as it is the most environmentally friendly, therefore more easily obtained.

This white (martensitic) layer would form on the surface, so it must have been thick for a near to finished part.

Do the cracks always initiate on the surface, or barely subsurface at a white layer boundary? are they always in the filets? It is very unusual for a crack to initiate sub surface.

If this stuff is all in the AD, say so and I will look there. Thanks . . .
 
It is my understanding that the cranks are gas nitrided after machining. The journals are polished after nitriding.
 
Some metallurgist out there should help us with the details. My practical association with nitriding is it is shallow in depth, and if gaseous it will do the whole part although it has better results in the focus region.

Are the fillets rolled and nitrided or just the whole crank nitrided. I say gaseous as it is the most environmentally friendly, therefore more easily obtained.

This white (martensitic) layer would form on the surface, so it must have been thick for a near to finished part.

Do the cracks always initiate on the surface, or barely subsurface at a white layer boundary? are they always in the filets? It is very unusual for a crack to initiate sub surface.

If this stuff is all in the AD, say so and I will look there. Thanks . . .


The tour I took at Lycoming showed their cranks being gas-nitrided after forging and initial machining. I suspect SAP uses a similar process.

What I found interesting is that SAP makes a big deal about the steel ingot they use for their forgings being formed with Electro-Slag Remelt. This is supposed to result in fewer oxide inclusions than the VAR process. Yet, the Baker Risk reports on the 2 cranks they anayzed said there was "significant" oxide inclusions at the fracture site. I didn't see where "significant" was quantified. But, it seemed like it must be a relevant point to me.
 
Bummer . . .

I just checked ... I have an engine with a bad superior cranshaft. I was just getting ready to drain the preservative and add mineral oil.
:mad:
 
Mine is also bad

Not much to add other than support for you all. Mine is effected as well. We have 4 in my local flying group that are affected. I'm sure RV's represent a large part of the 77 experimentals on the list. I was just working on my condition inspection, guess there's no rush finishing that now for awhile. Time to do some research and see what the options are.

Yep I'm one of the Un-lucky 4, from out here in the Pacific North West.
I did talk with Bill Ross for Superior yesterday and they are working on the issue and he said there will be some more information coming soon.
 
My engine was built in 2014 and has a solid crank (O-360-A4M). I haven't been to the airport to check the SN. Anyone know if solid crank shafts are affected?
 
My engine was built in 2014 and has a solid crank (O-360-A4M). I haven't been to the airport to check the SN. Anyone know if solid crank shafts are affected?

I think the best way to confirm whether your engine crank falls into the AD would be to email Superior your engine serial number and ask. They know exactly which engines have crank shafts affected by the AD. They will respond to your query.
 
Martin I know your pain. In the same boat but I had to pull 2 cylinders because one of the pull rivets on the snorkel decided to break off and goirged two cylinders.
That problem with the snorkel will never happen again especially with a 42h pulled rivet.
Have added a full outside plate removed all the pop rivets and hard riveted the snorkel to the baffling

A friend has just completed his RV7 with a snorkel and after 150 hours a couple of his pop rivets are loose too
Well with the upcoming engine removal for the AD
There apparently will be a lot of time waiting for a rebuild.
My engine guy Carlus Gann of Gann Aviation said one thing ****!!
604 hours.
 
We feel for everyone affected...

All of us who were subject to the Superior XP-400 recall feel everyone’s pain. I had completed flight testing and flew my new -14 from Washington to Florida planning for a winter of flying in the Southeast. She had been running flawlessly. Instead I had to remove my engine and send it in for tear down and inspection. I removed the engine in January of 2019, then ultimately had to get a new engine. It took till December of 2019 to receive the new engine due to delays for various reasons including demand, crankshaft availability and cylinder availability. I finally got her flying again and I flew the plane back to Washington planning on spring and summer flying in the Northwest. Then COVID.

Through it all I have been learning patience. I also got to know my plane really well having had to install, remove and re-install engines.

I feel you.
 
...As I understand it, Superior is trying to work out an AMOC. Even with that, it still might entail removing the crank for some polishing and inspection, but hopefully in many cases it will negate the actual replacement of the crankshaft. That would be a huge saving, open the way to a significant shortening of downtime, and I could envision they could be in a position to offer a much better measure of support. I hope they succeed.

Dan

I'll be curious to see what they come up with for an AMOC. I've already got money out for a brand new crankshaft. So, its not going to do anything for me. But, I really want to know how they're going to mitigate liability concerns for sticking any of those cranks back into an engine, given that the FAA and the two Baker-Risk reports have so muddied the waters.
 
yep, it's muddy and the trouble is the number of AD affected units never contract they only expand. I can't imagine a worse problem for an engine or a company.
 
Last edited:
Just so ya know...

I attempted to purchase a new SL36500-A31 crank through ACS. The agent told me there was a 12 month lead time. I thought it would be treated as a "backorder". It is not. They want full payment up front. That's paying $4,200 for something I won't get for at least 12 months.

Then I got a "shipping status" for it on my ACS account. And an "in stock" status from ACS West. I called to confirm that. And, the person on the phone said that that was wrong. That the "manufacturer" is not even accepting orders. ---End result was I told them to block the pending charge. That I didn't want to pay if the "manufacturer" isn't even accepting orders.

So, now I'm looking elsewhere for a suitable crank.
 
News from Barrett

Called Rhonda this morning after reading the latest posts here. Since I contacted her early as this situation unfolded, she confirmed it would be wise for me to get the engine ready to get back to her, as it's likely I won't be set back a year on this. They're currently closed for the last days of this year - Covid is ripping through Tulsa right now - but she anticipates progress will be made sooner than later. She acknowledged Superior's situation moving forward with the AMOC, but agreed that there will be no retraction of the AD. My engine definitely must come out and be rebuilt. Whether my crank will be polished into compliance or replaced remains to be seen, but I should stay the course and get to work. Prop's already off... jumping into dismantling today.
On a different note, I've been in touch with Allen Barrett. He continues his fight with cancer; the battle is at a stand-off right now so he's hanging in there and seems in good spirits. He's living in the country now, away from Tulsa and offline... and finding ways to keep enjoying life. Wishing him the best, always.
 
You’re aware of the AD applicability and that it does not affect experimental?

The AD applies to the impacted *engines* regardless of what aircraft they are installed on (in the U.S.):

"This AD applies to the reciprocating engine models identified in paragraphs (c)(1) and (2) of this
AD with a Superior Air Parts, Inc. (SAP) crankshaft assembly, part number (P/N) SL36500-A20 or
P/N SL36500-A31, with serial numbers 82976-01; 82976-02; SP12-0003 through SP12-0089,
inclusive; SP13-0034 through SP13-0150, inclusive; or SP14-0151 through SP14-0202, inclusive;
installed.
(1) With SAP crankshaft assembly, P/N SL36500-A20, installed:
(i) SAP Model IO-360-series and O-360-series reciprocating engines.
(ii) Lycoming Engines (Lycoming) Model IO-360-B2F, IO-360-L2A, O-360, O-360-A2A, O360-A2D, O-360-A2E, O-360-A2F, O-360-A2G, O-360-B2A, O-360-C2A, O-360-C2C, O-360-
C2D, O-360-C2E, O-360-D2A, and O-360-D2B reciprocating engines.
(2) With SAP crankshaft assembly, P/N SL36500-A31, installed:
(i) SAP Model IO-360-series and O-360-series reciprocating engines.
(ii) Lycoming Model AEIO-360-H1A, IO-360-B1A, IO-360-B1B, IO-360-B1D, IO-360-B1E,
IO-360-B1F, IO-360-M1A, O-360, O-360-A1A, O-360-A1C, O-360-A1D, O-360-A2A, O-360-C1A,
O-360-C1G, O-360-C1C, O-360-C1E, and O-360-C1F reciprocating engines."

Experimental or Type Certificated, the AD applies.
 
The AD applies to the impacted *engines* regardless of what aircraft they are installed on (in the U.S.):

What makes you so sure about that? The FAA seems to disagree as they write themselves in the AD cost of compliance section (as Patrick already point out on this thread):

"The costs of compliance with this AD consist of the cost to remove and replace a crankshaft assembly. The FAA estimates that this AD will affect 115 crankshaft assemblies installed on airplanes of U.S.registry. This cost estimate does not include 77 SAP crankshaft assemblies installed on experimental engines since this AD does not apply to these engines."

So unless you run a certified engine on your experimental aircraft it seems whoever wrote the AD at the FAA doesn't think it's mandatory for you. Couldn't be much clearer.

Now that says nothing about the wisdom of not complying of course ... .

Oliver
 
Fortunately, the crankshaft knows when it's installed on an experimental aircraft and is, therefore, prevented from breaking.
 
I am betting no self respecting DAR will sign off on an aircraft with an engine affected by this. Therefore it applies in his case even though experimental.
 
I am betting no self respecting DAR will sign off on an aircraft with an engine affected by this. Therefore it applies in his case even though experimental.

Isn't it true that there is a distinction between AD compliance at the time of issuance of the E-AB Special Airworthiness Certificate, and AD compliance as part of maintenance of "Condition for Safe Operation"?
 
Isn't it true that there is a distinction between AD compliance at the time of issuance of the E-AB Special Airworthiness Certificate, and AD compliance as part of maintenance of "Condition for Safe Operation"?

I think you are correct but don’t quote me. I don’t have enough knowledge on the matter.

AD doesn’t apply to experimental. There is an FAA document outlining AD’s and applicability to experimental. Where they apply to experimental a statement will be made. As specifically stated within this AD it doesn’t not apply to experimental. Right or wrong as stated by the FAA it is not applicable.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC 39-7D.pdf

I’m not disagreeing with your logic or the facts you point out from the FAA. I agree you are correct. However, when one goes to get the special airworthiness certificate it’s your DARs interpretation of things that matters, not necessarily what the FAA has said. I am just saying good luck finding a DAR that will sign it off.

All that aside, I think DanBaier has the most appropriate comment here. As well as Walt. ;)

I feel for everyone affected by this. I know what it’s like to have to take a new engine through a tear down and the price associated with it. I don’t wish it on anyone.
 
I am just saying good luck finding a DAR that will sign it off. All that aside, I think DanBaier has the most appropriate comment here. As well as Walt. ;)
I feel for everyone affected by this. I know what it’s like to have to take a new engine through a tear down and the price associated with it. I don’t wish it on anyone.

Actually, if you find a DAR that will sign it off, I would consider that BAD LUCK.
 
AD doesn’t apply to experimental. There is an FAA document outlining AD’s and applicability to experimental. Where they apply to experimental a statement will be made. As specifically stated within this AD it doesn’t not apply to experimental. Right or wrong as stated by the FAA it is not applicable.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC 39-7D.pdf

My DAR explained it thusly: If my aircraft had already been certified airworthy, technically "the AD is not applicable". But since my aircraft has not yet been certified as airworthy, he his duty-bound to make sure that any and all ADs that pertain to any components of my aircraft have been complied with before he will issue an airworthiness certificate... and that is as it should be, for practical reasons that are all too obvious. Making the legalese argument that the AD does not apply to experimental aircraft is pointless in this scenario.
 
The AD applies to the impacted *engines* regardless of what aircraft they are installed on (in the U.S.):

I was wrong.

FAR 39.3 says "FAA's airworthiness directives are legally enforceable rules that apply to the following products: aircraft, aircraft engines, propellers, and applicances." So I'd have expected an AD issued against a (TC'd) engine to apply, regardless of what aircraft the engine is on.

However, AC 39-7D (page 4) provides interpretation guidance, and draws a pretty clear contrast:

“This AD applies to Lycoming Engines Models AEIO-360-A1A and IO-360-A1A.” This statement makes the AD applicable to the engine models listed that are installed on TC’d aircraft."

“This AD applies to Lycoming Engines Models AEIO-360-A1A and IO-360-A1A. This AD applies to any aircraft with the listed engine models installed.” This statement makes the AD applicable to the listed engine models installed on TC’d and non-TC’d aircraft.

So the FAA is telling us that the absence of "... applies to any aircraft with the listed engine models installed." does exempt non-TC'd aircraft.

I guess I could legally stop maintaining the AD list for my RV-10. There's still, however, the matter of signing the condition inspection every year, wherein I have to state that the aircraft has been "found to be in condition for safe operation." It's hard for me to imagine signing that with an open AD.
 
Last edited:
I'm not going to have my plane inspected because I read it as being applicable to a product...SAP crankshaft...but not our planes. I will be sitting on my hands to keep from doing anything until SAP responds.
This is the week I was hoping to get inspected for AWC and it's pretty hard to distract myself from the disappointment I'm feeling. I know I'm not in this boat alone but the idea of maybe a year of hangar rent ($340.00 @ month), brand new ELT, batterys, etc. etc. makes for the most expensive new motor I've ever had and it's nothing more than a paperweight at this point.
I love the Superior motor. Hopefully we'll get some satisfaction soon.
 
I guess I could legally stop maintaining the AD list for my RV-10. There's still, however, the matter of signing the condition inspection every year, wherein I have to state that the aircraft has been "found to be in condition for safe operation." It's hard for me to imagine signing that with an open AD.

I would never ignore an AD but the fact that it doesn’t formally apply allows you to seek alternate solutions to rectify the issue at your discretion to maintain safe operation.

On the flip side there won’t be an FAA approved AMOC for an experimental airplane ever for this AD. As the AD doesn’t apply neither does any AMOC to the AD.

Lots of freedom/responsibility the FAA puts on each of us.

Oliver
 
Cranky

I've been trying to pretend that this was all just a dream over the holidays, but now I need to get serious about finding a solution.
Does anyone have any info to share after talking with Superior? I've just sent out an email, but don't have a response, yet.
Darren at AeroSport Power, where I got my engine, said he has not heard about any restitution from Superior. Has anyone heard anything about Superior stepping up to the plate on this?
Does anyone have any info about alternative sources for a new crank?

Thanks for sharing,

Despondently yours,...:(
 
I've been trying to pretend that this was all just a dream over the holidays, but now I need to get serious about finding a solution.
Does anyone have any info to share after talking with Superior? I've just sent out an email, but don't have a response, yet.
Darren at AeroSport Power, where I got my engine, said he has not heard about any restitution from Superior. Has anyone heard anything about Superior stepping up to the plate on this?
Does anyone have any info about alternative sources for a new crank?

Thanks for sharing,

Despondently yours,...:(


As far as I know, Superior has been completely silent on this issue since their press release about their response to the NPRM, back in Feb '20. I sent emails and attempted a phone call after the FAA released the AD last month. So far, I've had no response.

Other's have posted in this thread that they talked to someone at Superior, who told them that the company is "working on an AMOC".

I think it will be quite interesting to see what kind of AMOC they can come up with for affected cranks that have already been installed and run.

-----Added----

We'll I guess they haven't been completely silent. There is this article from an earlier poster, dated 12/18/20: https://vansairforce.net/community/attachment.php?attachmentid=5865&d=1608329570
 
Last edited:
Superior response...

I just got this response from Bill Ross at Superior....only hours after I sent him MY questions:

"We are currently working on an Alternative Method of Compliance (AMOC) that will drastically reduce the impact to all. We are confident the FAA will approve the AMOC before the January 15 date on the AD."

I will be back in touch with you in the next few days with more information regarding the AMOC."

Nothing really "NEW", but not "silence" :)
 
I talked with Bill Ross at Superior on Tuesday this week and after he verified my
Crankshaft. He was very cordial and took about 30 minutes talking and answering my questions

He stated that Superior is very confident that the FAA with permit the AMOC on the crankshaft. It will entitle:
Removing the crankshaft
Sending the crankshaft to Aircraft Speciality Services where it will be inspected
Ground down .003 inches checked for fractures and then re nitrated and certified as overhauled.

He did speak about what he thought Superior’s contribution would be be that they were having meeting this week to finalize their thoughts


Hopefully we will hear soon. They are working on it.
 
He stated that Superior is very confident that the FAA with permit the AMOC on the crankshaft. It will entitle:
Removing the crankshaft
Sending the crankshaft to Aircraft Specialty Services where it will be inspected
Ground down .003 inches checked for fractures and then re nitrated and certified as overhauled.

Just one person's opinion, but that benefits Superior to not have to remanufacture crankshafts but will be cold comfort to anyone with one of these engines. It still requires removal, bulk strip, and replacement of all mandatory parts. Depending upon the condition of other major assemblies such as the crankcase not too different to a complete overhaul.
 
Smiling Jack,
Do you have any further on the AMOC?

I talked with Bill Ross at Superior on Tuesday this week and after he verified my
Crankshaft. He was very cordial and took about 30 minutes talking and answering my questions

He stated that Superior is very confident that the FAA with permit the AMOC on the crankshaft. It will entitle:
Removing the crankshaft
Sending the crankshaft to Aircraft Speciality Services where it will be inspected
Ground down .003 inches checked for fractures and then re nitrated and certified as overhauled.

He did speak about what he thought Superior’s contribution would be be that they were having meeting this week to finalize their thoughts


Hopefully we will hear soon. They are working on it.
 
The 15th of Jan has come and gone. No new info? This has been dragging for such a long time. It looks as whatever the decision, the engine will have to come out.
 
Yes I talked with Bill Ross again at Superior on the 15th. They had another meeting with the FAA and he is very hopeful to have a resolution this coming week.

He said it is working out the details.

I am like all the other folks. I will fly my 25 hours that I have remaining an pray this comes to a conclusion on the approval AMOC.

The bulk of the planes are certified aircraft. If I recall his numbers. 77 experimental and 177 certified.
 
No update

Fellow RVer’s
I am like some on the board waiting to hear something positive from Superior
Air Parts on the AMOC

I am down to the 25 hours of the AD and am hoping that something transpires soon.

Just curious how many RV’s are affected!

I will call tomorrow Friday the 22nd to see what’s is up at Superior

Jack
 
Just curious how many RV’s are affected!

Hard to say, but I suspect most of the 70+ listed as experimental are RV's just by the nature of how many are built every year.

You're not alone in the wait for a solution. I grounded my 8 Jan 1 and am waiting to see what the options might be for repair. I suspect I will not fly this year unfortunately. But we will see.
 
How are the 70+ counted?

For instance, if my affected engine is still in the crate and not on a plane (and thus not on the FAA’s registry) am I still counted in the 70+ or am I adding to the count? Stated another way, does the count come from the FAA registry or from the number of cranks produced? I suppose my silver lining is that I don’t have to remove the engine from my plane. Something to be said for a SLOW build.
 
Having talked to Bilk Ross even yesterday 1/26
They are still waiting on the FAA

If I had an engine in the crate I would send it back and have it reworked !

I called the AOPA and the AD is not on their list so to say they are more concerned with the Piper spar. But I hope I awoke a sleeping giant at the AOPA and might get some response from them.

I called Aircraft Specialities and offered to send my crank into them for overhaul and they stated they could not overhaul it since it is subject to the AD and that nothing is resolved yet with Superior and the FAA

Also learned that according to the AOPA that experimental engines are not subject to the AD but in good judgment I would be very negligent if something did happen.

In my heart if there were 2 or more failures a year because of this coating then I can understand a major concern.

Still only 3 failures from my understanding.

Wish I had an answer
Jack
 
As there's been no news on this, I emailed the contact listed on the FAA AD document to ask about the AMOC.


A formal AMOC request for Superior Crankshaft AD 2020-25-12 has not yet been received by my office. Hope that helps.

Best,

Justin H. Carter
Aerospace Engineer, Propulsion.
 
Talked to the AOPA and here is what they stated
Jack,

AOPA has been working with Superior Air Parts and the FAA on an AMOC. However, it’s been going a little slower than anticipated. Much of the data and information that is needed is coming from SAP and they have been waiting on data from another party. AOPA checked in with them late last week and they said it should be soon…

If I can assist further, please let me know.


Craig Brown
Senior Technical Specialist (AOPA)
Airman Certification Representative (ASI)
[email protected]
301-957-3802
 
In an effort to keep our RV community updated I had another call with Superior Air Parts.
I mentioned it has been almost 2 weeks since I last talked to Bill Ross
I mentioned that we had found out no AMOC had been submitted and he said that the technical data was changed to make it in line with precious
Language that had been approved on other crankshaft replacements. It would help the AMOC be approved quicker.

He stated that the AMOC should be submitted within the next couple weeks.
I the asked him what was Superiors commitment to the cost involved in the rework of the crankshaft. He stated that the work at Aircraft Specialty would be covered by Superior as week as all gaskets and several other items required to put the engine back together. Aircraft Specilities is aware of discussions.

I asked if this had to be approved by the parent company a Chinese company and he stated no it is done in-house.

Asked if there would be an allowance for Labor required to take the engine apart and reassembly and he stated probably not.

Asked if there would be a discount on new cylinder assemblies in case an individual wanted to do a complete overhaul at this time and he stated it has been discussed but no final decision.

Fortunately some progress is being made abet slow

As of 2/8.

Jack
 
Back
Top