Buying a plane with prop strike

mondtster said:
Not necessarily, see Charlie's response...

I've been collecting pictures of cracked cranks and noting the circumstances under which they cracked for a while now. There are cracked cranks that occur under conditions which the average person would think "no big deal, there's no way I hurt it". The problem is, you don't know if it's cracked until you look. To me, not doing the inspection is like playing with fire. You may or may not get burned by leaving it alone.
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And there are cracked cranks with no strikes on them.
who knows what cracked it.
yes you can blame it on anything you like.
 
mondtster said:
Not necessarily, see Charlie's response...

I've been collecting pictures of cracked cranks and noting the circumstances under which they cracked for a while now. There are cracked cranks that occur under conditions which the average person would think "no big deal, there's no way I hurt it". The problem is, you don't know if it's cracked until you look. To me, not doing the inspection is like playing with fire. You may or may not get burned by leaving it alone.
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one thing you do know.....after a period of use....it's fine.
 
Checkout_my_Six said:
one thing you do know.....after a period of use....it's fine.
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No dispute there. The question is how long is it going to take before it is considered ok and are you willing to pilot it in the interim? What are the risks if you're blessed with one of the cranks that is damaged?

I'm not willing to take those risks but others obviously are. And FWIW, I'm flying an airplane with multiple prop strikes in its past and at a minimum the last one was not inspected. The reason it wasn't inspected was purely money driven with no concern for safety. An all too common occurrence unfortunately.
 
mondtster said:
No dispute there. The question is how long is it going to take before it is considered ok and are you willing to pilot it in the interim? What are the risks if you're blessed with one of the cranks that is damaged?

I'm not willing to take those risks but others obviously are. And FWIW, I'm flying an airplane with multiple prop strikes in its past and at a minimum the last one was not inspected. The reason it wasn't inspected was purely money driven with no concern for safety. An all too common occurrence unfortunately.
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150-200 hrs should be good to go.....lol ;)
 
Geographic location plays into the risk. Flatlands with lots of nice fields to put down into? Maybe I’d do it. Where I live it’s all hills, mountains, and trees. Nope.
 
mondtster said:
Got that in writing from the manufacturer? Or is that opinion? ;)
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Whaaaat?.....this is the internet, where we're all experts. ;)


so....no one asked Charlie what parts they were trashing during the teardown inspections. :D
 
Checkout_my_Six said:
Whaaaat?.....this is the internet, where we're all experts. ;)
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Glad we're all on the same page now. :)

Checkout_my_Six said:
so....no one asked Charlie what parts they were trashing during the teardown inspections. :D
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You mean the parts that don't meet spec and can't be unseen? Like the failing cam and lifters or the junk cylinders? That never gets discovered does it? I figured everyone around here maintained their engines better than that. :D
 
It was originally IO540 in the first post. Edited to TCM IO520.

Besides the crank, I would be concerned for the accessories.
 
unsafervguy said:
Last time I read that ad it doesn’t apply to a continental io520.......
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He said we were dealing with an IO-540. Original post.
Edit: should have read the entire thread first...

And I should have remembered that the Viking had the Continental.

There are ADs on some of the aftermarket cylinders on those engines. You want those caught.
 
I'm a nervous sort. I had a crankshaft break in flight due to an old, unaddressed propstrike. It's entirely possible. It's no fun.
 
Thanks to all you guys as always. Great points in both directions.

I did list the wrong engine originally. My bad. It is the TCM that comes on the Viking.

We walked from this deal. Upon further review, I would not be able to justify flying with a known potential defect. If I can't afford to do it right, I should not be buying and flying airplanes!

You all are a great resource and I sincerely appreciate it.

Dan
 
Danny Dub said:
Thoughts on the risk of buying a plane with a prop strike history but no tear down inspection?

My local mechanic says walk from any deal like this but obviously people buy and sell and fly planes where this has happened.

We are looking at a Super Viking (TCM IO520) that is in this condition and would love to hear your thoughts.
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My thought is that there's little risk if there's a 25k discount on the otherwise fair value of the plane.

After a prop strike a teardown inspection is not optional. The aircraft is not airworthy until then and every operator should know that.
 
bflynn said:
After a prop strike a teardown inspection is not optional. The aircraft is not airworthy until then and every operator should know that.
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This is not true..
 
Danny Dub said:
I would not be able to justify flying with a known potential defect. If I can't afford to do it right, I should not be buying and flying airplanes!
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Wish more pilots and owners had that attitude.
 
bflynn said:
Argue that with Lycoming. They require it. The words Mandatory and "Before further flight" are used.

Unless you're saying that a Mandatory Service Bulletin is not mandatory.

https://www.lycoming.com/sites/default/files/SB533C Recommended Action for sudden Engine Stoppage, Propeller_Rotor Strike or Loss of Propeller_Rotor Blade or Ti (1).pdf
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The service bulletin is not mandatory, unless required to be complied with by AD. Neither Lycoming or Continental have an AD requiring such action.

Lycoming does however have an AD requiring crank gear inspection after a strike but the engine does not have to be completely disassembled to comply with it.
 
mondtster said:
You mean the parts that don't meet spec and can't be unseen? Like the failing cam and lifters or the junk cylinders? That never gets discovered does it? I figured everyone around here maintained their engines better than that. :D
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I would consider the discovery of a spalled cam during a sudden stoppage inspection a benefit.
 
bflynn said:
Argue that with Lycoming. They require it. The words Mandatory and "Before further flight" are used.

Unless you're saying that a Mandatory Service Bulletin is not mandatory.

https://www.lycoming.com/sites/default/files/SB533C Recommended Action for sudden Engine Stoppage, Propeller_Rotor Strike or Loss of Propeller_Rotor Blade or Ti (1).pdf
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Airworthiness Directives are mandatory, Service Bulletins are not (even when the manufacturer says they are) unless they are accompanied by an AD.
 
Danny Dub said:
We walked from this deal. Upon further review, I would not be able to justify flying with a known potential defect. If I can't afford to do it right, I should not be buying and flying airplanes!
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A 'sudden stoppage inspection' on a 520 is between $,9600 and $16,500 + removal/install.
You could have made an offer taking the cost of the inspection into account.
 
weilke said:
I would consider the discovery of a spalled cam during a sudden stoppage inspection a benefit.
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Sane people would, but not all aircraft owners are sane. I’ve dealt with owners before who were mad at me for finding a junk cam or cracked case because “it ran fine when I brought it in”. And people continue to wonder why I limit my client base for maintenance activities...

The simple answer is, I haven’t opened up an engine that had a prop strike incident that didn’t need parts beyond the inspection. Some need more than others. The question is, do you think yours is going to be the one that needs more or less work and parts? Nobody is going to know for sure until it is opened up. I suspect this is why some guys do the minimum possible after a strike, so they can avoid the bills that will start piling up.
 
weilke said:
A 'sudden stoppage inspection' on a 520 is between $,9600 and $16,500 + removal/install.
You could have made an offer taking the cost of the inspection into account.
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I wonder why that number is so high. These engines come apart quickly, and go together quickly. I figure that with five or six practice runs, I could whip one out in perhaps sixteen billable hours, plus the magnaflux charge (we had one in our old shop, so add two hours labor for that.) Plus gaskets, etc. When ours was inspected due to a prop strike, we had it back in four days, fly-in and fly-out, with new rings and bearings (it only had a couple of hundred hours SMO, but I always do this to any engine I open up.) Insurance paid for all but the optional parts.
 
Juliet Hotel said:
Airworthiness Directives are mandatory, Service Bulletins are not (even when the manufacturer says they are) unless they are accompanied by an AD.
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Yep. But, that just keeps the feds happy. You still have to consider the liability aspect. A shark representing someone who had an engine quit, with said engine having had a prop strike without being "properly inspected", would have a field day. Not performing the service bulletin would be like chumming the water.
 
Kenny Phillips said:
I wonder why that number is so high. These engines come apart quickly, and go together quickly. I figure that with five or six practice runs, I could whip one out in perhaps sixteen billable hours, plus the magnaflux charge (we had one in our old shop, so add two hours labor for that.) Plus gaskets, etc. When ours was inspected due to a prop strike, we had it back in four days, fly-in and fly-out, with new rings and bearings (it only had a couple of hundred hours SMO, but I always do this to any engine I open up.) Insurance paid for all but the optional parts.
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The rotating accessories should also get inspected. Mags, prop governor, vaccum pump, alternator, etc. Get an engine shop that isn't real busy and knows what they are doing, for sure it can be an in and out affair. Get Joe doing you a solid for a case of beer and because you are a "good guy", you get what you get!

Seen it many times, trying to fix the mess afterwards.
 
JAWS said:
The rotating accessories should also get inspected. Mags, prop governor, vaccum pump, alternator, etc. Get an engine shop that isn't real busy and knows what they are doing, for sure it can be an in and out affair. Get Joe doing you a solid for a case of beer and because you are a "good guy", you get what you get!
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The numbers I quoted were the low and the high bid out of the three we got for the job. The insurance told us that they would only pay what their 'reference shop' quotes. So we got a quote from 'their shop' and it came in $300 above our high-bid ;-)

And yes, there are SBs for magnetos, alternator and governor to be overhauled during a SSI. Again, not mandatory, but that's what the respective manufacturers specify.

Part of the inspection is the NDT on all the metal bits, the gasket set and new rings. And sure, the shop wants to get paid for his time.

(teaching point, when getting bids have each bidder spell out which component overhauls are included so you end up with comparable bids)
 
JAWS said:
Yep. But, that just keeps the feds happy. You still have to consider the liability aspect. A shark representing someone who had an engine quit, with said engine having had a prop strike without being "properly inspected", would have a field day. Not performing the service bulletin would be like chumming the water.
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No argument there. Doesn't change the fact that claiming they're required is incorrect.

There is also the perspective that says if you have genuine liability concerns, the one and only way to truly protect yourself is to not fly a personally owned airplane ever.
 
Kenny Phillips said:
I wonder why that number is so high. These engines come apart quickly, and go together quickly. I figure that with five or six practice runs, I could whip one out in perhaps sixteen billable hours, plus the magnaflux charge (we had one in our old shop, so add two hours labor for that.) Plus gaskets, etc. When ours was inspected due to a prop strike, we had it back in four days, fly-in and fly-out, with new rings and bearings (it only had a couple of hundred hours SMO, but I always do this to any engine I open up.) Insurance paid for all but the optional parts.
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I think you’re being quite optimistic. The cost of parts and labor alone to inspect the components IAW either the Lycoming or Continental service bulletin is going to run up close to the lower number that Weilke posted. That doesn’t account for the R&R of the engine on the airplane or disassembly and reassembly. The last 520 I did was around $13k and I didn’t really get compensated for my time out of that.
 
Juliet Hotel said:
No argument there. Doesn't change the fact that claiming they're required is incorrect
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Private operation, service bulletins are not required, unless referenced by an AD, generally. Never said otherwise.
 
Kenny Phillips said:
I wonder why that number is so high. These engines come apart quickly, and go together quickly. I figure that with five or six practice runs, I could whip one out in perhaps sixteen billable hours, plus the magnaflux charge (we had one in our old shop, so add two hours labor for that.) Plus gaskets, etc. When ours was inspected due to a prop strike, we had it back in four days, fly-in and fly-out, with new rings and bearings (it only had a couple of hundred hours SMO, but I always do this to any engine I open up.) Insurance paid for all but the optional parts.
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Magnaflux doesn't work on everything. Aluminum, for instance, must be tested with dye penetrant or eddy current. That takes time. And almost everything needs testing: case, crank, rods, pistons, gears, rotating accessories.

The crank that failed on me had had a prop strike many hours before. Just the tiniest start of a crack is all it takes, and a lot of hours can go by before it breaks.
 
Juliet Hotel said:
There is also the perspective that says if you have genuine liability concerns, the one and only way to truly protect yourself is to not fly a personally owned airplane ever.
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There is also the perspective that the regs are the bare minimum required. Being proactive and actually complying with a SB can be good for reducing the risk of problems down the road, as well as enhancing the value of the aircraft.

Some SB's are worth completing.
 
Dan Thomas said:
Magnaflux doesn't work on everything. Aluminum, for instance, must be tested with dye penetrant or eddy current. That takes time. And almost everything needs testing: case, crank, rods, pistons, gears, rotating accessories.

The crank that failed on me had had a prop strike many hours before. Just the tiniest start of a crack is all it takes, and a lot of hours can go by before it breaks.
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For our strike, Continental recommended only checking the crank (O300).
 
You will need to discuss with the seller and get super deep discount. I've heard engine inspections to be between 5-15k for small 4 cylinders. With a sudden stoppage without the proper inspection/repairs that airplane is not airworthy and therefore should be considered salvage/parts airplane. I would only buy it If I could get it for very cheap, knowing that you would have to spend the money for the engine/repairs to get it airworthy again.

Yeah prop strikes, accident history, etc... will decrease the overall resale value of your airplane, but it's certainly not a deal breaker if repaired correctly.

my 2 cents.
 
Kenny Phillips said:
For our strike, Continental recommended only checking the crank (O300).
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So which service bulletin did they comply with? The one I’m aware of, that says it affects all Continental engines, calls for a lot more than just a crank inspection.

Even with only a crank inspection I think you’re going to have more than your 16 hours wrapped up in the investigation.
 
Juliet Hotel said:
Airworthiness Directives are mandatory, Service Bulletins are not (even when the manufacturer says they are) unless they are accompanied by an AD.
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They are for me. So going back to the original answer, if there's a 25k discount on the airplane in order to accomplish the tear down inspection, then there's very little risk in buying an airplane that has had a prop strike.

I mean realistically, the engine is possibly ok. It's unlikely to come from together on you in flight and it probably doesn't really need to really be inspected right? If you fly with this level of uncertainty, then you're a much bolder pilot than me.

Question though - if the inspection isn't mandatory, why would a FSDO ever issue a ferry permit?
 
bflynn said:
They are for me.
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That wasn’t what you said previously though. You said that the plane was unairworthy unless the inspection was performed. That is different than having a personal threshold of not flying something with no strike inspection. :)

bflynn said:
Question though - if the inspection isn't mandatory, why would a FSDO ever issue a ferry permit?
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Im not sure where this came from? Unless there is other damage rendering the airplane unairworthy a prop strike on a Continental does not create a need for a ferry permit. The crank gear inspection required by AD on a Lycoming however would render the airplane unairworthy and trigger the inspection prior to the next flight.

Been there, done that. I’ve driven to a remote airport, pulled the engine, brought it home to do a proper inspection on it, then drove back to put it on. The engine was fine. The plane did require a ferry permit to bring home because it was out of annual and we did not fix the gear collapse damage at the other airport.
 
mondtster said:
That wasn’t what you said previously though. You said that the plane was unairworthy unless the inspection was performed. That is different than having a personal threshold of not flying something with no strike inspection.
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Stated incompletely previously. Yes, I do consider mandatory things from the guys who built the thing to be mandatory. No, I'm not talking about the legal stuff. I don't need the FAA to tell me to be safe.

mondtster said:
Im not sure where this came from?
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It's a question. Lots of people get ferry permit for prop strikes. Why does the FSDO hand bother with them?
 
bflynn said:
Stated incompletely previously. Yes, I do consider mandatory things from the guys who built the thing to be mandatory. No, I'm not talking about the legal stuff. I don't need the FAA to tell me to be safe.



It's a question. Lots of people get ferry permit for prop strikes. Why does the FSDO hand bother with them?
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Because it is the rule. the FAA doesn't care what the A&P signs off.
 
bflynn said:
Stated incompletely previously. Yes, I do consider mandatory things from the guys who built the thing to be mandatory. No, I'm not talking about the legal stuff. I don't need the FAA to tell me to be safe.
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But you certainly were adament the "legal stuff" applied in your earlier posts.

Incompletely? Try incorrectly. Require (your emphasis) is unequivocal.

Your further post, "a prop strike a teardown inspection is not optional. The aircraft is not airworthy until then and every operator should know that.", is wrong too.

It's more than a little disengenous to claim that's not really what you said.
 
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