PPONK 470-50 Question

[RaisedByWolves]

Hey guys,
Here is one for you. Got a 180 in for annual, and it has a freshly overhauled 470-50. It was a TSIO-520-P converted via the STC to be a 470-50 (520 C.I.) While doing an AD search I came across the VAR crank Ad 97-26-17 says at overhaul or whenever the crank is removed from the engine to replace it with a VAR Crank. Northpoint when I called said well its technically a grey area and because its technically a 470 that AD doesn't apply to it. Whats the consensus? Am I over thinking it? Just trying to cover my a$s. Seems like if I was overhauling one that is a 520 and the only change is fuel delivery I would have changed cranks, but maybe I'm using too much logic?

Thanks

[skywagon8a]

I looked up AD 97-26-17 and got this "No results were found; try another search."

Based upon what you said, that engine was an TSIO-520 when the crank was removed. So the AD would apply.

Now if it is permitted to later install that same crank in an O-470, it would be legal.

What does the AD say to do with the crank when it is removed?

I would want to see some documentation that it is legal to use that crank in that engine. Unless the person who did the overhaul specifically shows approval, I would not accept it. Make them give you some documentation. Once you sign it off, they are off the hook.

[skywagon8a]

Found it.

"Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously."

Also ... " remove the crankshaft from service and replace with a serviceable crankshaft manufactured using the VAR process."

Is there something in the records which documents "approval for an alternative method of compliance"?

[RaisedByWolves]

Interesting, this was in the critical SB
“DO NOT USE NON-VAR CRANKSHAFTS IN ANY ENGINE NOT AFFECTED BY THIS SERVICE BULLETIN UNLESS IT CAN BE SUBSTANTIATED THAT IT HAS NOT PREVIOUSLY OPERATED IN AN AFFECTED ENGINE.”

http://www.tcmlink.com/pdf2/CSB96-8.pdf

Here is a link to the AD

https://rgl.faa.gov/Regulatory_and_G...25684800545EBB


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[RaisedByWolves]

Found it.

"Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously."

Also ... " remove the crankshaft from service and replace with a serviceable crankshaft manufactured using the VAR process."

Is there something in the records which documents "approval for an alternative method of compliance"?

No the ad search done buy the engine builder was for “470 series engines” which doesn’t have the VAR ad, as it’s not a 520. The ATP program I used didn’t allow 470-50 or just straight 470 so I searched it using the TSIO-520-P model number. That lead me to call the stc holder who verbally told me over the phone that it’s a grey area and technically doesn’t apply to this engine because it’s now a 470-50


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[RaisedByWolves]

There is no V on the crank flange, and the original log books for the engine aren’t with the new engine. They have the total time of the engine, but started a new log book. The yellow tag for the crank doesn’t mention var at all.


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[skywagon8a]

If the engine was originally one of the applicable engines then the AD does apply. The fact that it now isn't doesn't make it a grey area. The guy on the phone is passing the buck.

[stewartb]

This topic has been discussed among Pponk owners for many years. The engine type is changed legally to O-470-50 so most believe there is no AD requirement for the VAR crank. In fact there’s a market for non-VAR cranks as a result. In this case the absence of early engine logs is probably intentional.

[skywagon8a]

If the engine was originally one of the applicable engines and it can be proven, should something happen which can be traced to the crankshaft then the last IA or A&P who signed the log book is liable. He in turn can pull the person who signed off the overhaul into the law suit.

Don't forget, an annual is not signed off in the engine log book. That doesn't remove liability.

Using an applicable crankshaft in an engine to which the AD does not apply defeats the original intent of the bulletin which was to remove the cranks from service.

[stewartb]

I guess not everyone agrees. Bottom line, the AD does not apply to 470 series engines. A non-VAR crank can be removed from a 520 and installed in a 470.

I have no skin in this game myself. My crank is a VAR 520 crank.

[skywagon8a]

Look at this on page one stewart,

http://www.tcmlink.com/pdf2/CSB96-8.pdf

"DO NOT USE NON-VAR CRANKSHAFTS IN ANY ENGINE NOT AFFECTED BY THIS SERVICE BULLETIN UNLESS IT CAN BE SUBSTANTIATED THAT IT HAS NOT PREVIOUSLY OPERATED IN AN AFFECTED ENGINE."

[stewartb]

Are SBs regulatory?

[skywagon8a]

When the AD specifies the following, yes.

(f) The actions required by this AD shall be done in accordance with the following TCM service documents:

Document No.	Pages	Date
CSB96-8

Link to AD: https://rgl.faa.gov/Regulatory_and_G...25684800545EBB

Shall be done means must be done.

[stewartb]

There you go Tom. The high road has been defined. Still lots of those cranks out flying, though.

[skywagon8a]

Stewart, If you ever get the opportunity you should attend an IA renewal meeting when the FAA lawyers give a talk.

Tom can sign off the annual with a letter of non compliance describing the discrepancy. This will cover his a$$. I'm certain he will discuss this with the 180's owner first.

Let us hope that none of those "lots of those cranks out flying, though." don't have a failure. Well we don't have to hope, the IAs who signed the annuals are the ones who need to hope.

[stewartb]

You’re reading things not written. The AD is very specific. FAA regs are full of ambiguity. Many see that as opportunity. We all do it to some degree. Regs say what they say. They don’t say what they don’t say.

The end.

[skywagon8a]

Not true stewart, I'm passing on the information I've learned from the FAA after attending their IA meetings for almost 60 years. When you have an FAA ticket with authorization to approve something, you tend to pay attention to protect your own rear end. What I've said above is correct. ADs are regulatory. When an AD specifies "in accordance with", what ever the "with" is, also becomes regulatory.

[Steve Pierce]

If the data tag says it is a 470 then my take is that it is a 470 and the AD does not apply to a 470.

[skywagon8a]

Tom said it was a TSIO-520-P.

[Steve Pierce]

Some of the donor parts came from a 520. I converted a 520 to a 470-50 but luckily it had a VAR crank.

[Farmboy]

Steve, based on your viewpoint, whats your stance with superseded data plates.... OEM plate showing TSI0-520, with "modified" stamped into it, and P.PONK's tag added showing 0-470 STC.

Clearly it shows it was a 520 that was affected, so you know the history of the 470.
Do you still consider it non-applicable or do you consider the 520?

[Steve Pierce]

The data plate says it is a 470. I specifically found a 520 donor engine with a VAR crank so I didn't have to deal with a scenario like this. Pulled a jug on a factory new 520 back in the late 90s because Continental didn't know which engines they had put VAR cranks in and which ones they didn't. This same engine had the mags set at TDC when I did the first 100 hr after being a factory new engine. You can't make this stuff up.

[Farmboy]

. This same engine had the mags set at TDC when I did the first 100 hr after being a factory new engine. You can't make this stuff up.

Did you charge the owner for the power increase upgrade like CAT does?

[Steve Pierce]

SJ wines every time he talks about what his P-Ponk cost converting from a J engine.

[Sturgill]

I think I am pretty liberal in general when it comes to my signatures in logbooks, but I dont know how you can ignore the published statement from Continental as shown in Post #11. It my mind that is extremely clear about this situation.

[Steve Pierce]

Is that statement in the AD or in a service document called out in the AD?

[frequent_flyer]

Is that statement in the AD or in a service document called out in the AD?

I recently had a long discussion with my IA about the scope of an AD on PA-28 wing spar inspection (2020-24-05). The AD calls out specific paragraphs of the Piper SB but my IA insisted all the SB applied. I know he was wrong but I gave up the discussion when he found my aircraft met his interpretation of the AD requirements.

[Farmboy]

Is that statement in the AD or in a service document called out in the AD?

It’s in the SB called out in the AD, not in the AD.






Transmitted from my FlightPhone on fingers…

[mvivion]

Having experienced a crankshaft failure in an IO 520, I can't even imagine why anyone would want to fly ANY airplane with one of "those" cranks.....regardless of who might be liable......seems to me that Continental is pretty specific as to their thoughts on the subject.

MTV

[stewartb]

Keep in mind the vast majority of Pponk engines work fine using non-VAR 470 cranks. Just adding a dose of reality.

[SJ]

SJ wines every time he talks about what his P-Ponk cost converting from a J engine.

Not every time, but most times…

I remember discussing the var issue with you way back then!

sj

[skywagon8a]

Keep in mind the vast majority of Pponk engines work fine using non-VAR 470 cranks. Just adding a dose of reality.

That may be true. However it doesn't make them legal if the crank came from an engine as defined by the AD. Just because "everyone does it" doesn't make it legal. And as Mike points out, it can lead to a disaster. I think I saw a picture of his wreck in a BAS shoulder strap ad. He was lucky.

[Longsair]

This is a grey area to many and both sides are pretty well covered here, however one thing not brought up is the compression. If it has high comp pistons (naturally aspirated 520) and a NON-VAR
crank it's not per the STC. It takes a field approval to have the high comp pistons and the only guy I know of that's doing that requires a VAR crank.

[stewartb]

Good point, but lots of guys have snuck 8.5-1 pistons in and there’s essentially no penalty for doing so. And lots of guys exceed the 2700 rpm redline, too.

[RaisedByWolves]

Good news for the owner, I contacted the engine builder and he is pretty sure it has a VAR crank but is going to check tomorrow

[stewartb]

A good few minute read. Especially the last part about cranks.

https://www.aopa.org/news-and-media/...pilot/pe_savvy

[RaisedByWolves]

Oh boy don’t get started with mike Busch

Fact is it doesn’t matter that var has failed more. The faa said there is an AD and I have to comply with it as a mechanic. I don’t want a grey area. I’m covering my behind.


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[RaisedByWolves]

I was talking to a FAA friend (one of the good guys) and he said any time the AD calls out, or mentions a SB it becomes mandatory. He said you can't use a non VAR crank in an engine if it has been in an engine affected by the AD.

Another interesting point, he said it is technically legal to sign off AD's on a 0-470-50, which there are no AD's for, but he said its fine until something happens and you're in front of a lawyer. He has done a lot of work, and crash investigations on the VAR AD. Learned a lot about it from talking to him.

The more you know

[180Marty]

I think Longsair is right. I just did a 470-50 that was converted from a 470U mfg'd about 1980 with non- VAR. It is good for the original low compression Pponk but would not qualify for the higher compression 8.5 pistons. What I think would be neat is to put a 550 crank with 7.5 pistons and get a few more ponies with car gas.