Buying a plane with prop strike

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Danny Dub

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Danny Dub
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.

Thanks as always!

Dan
 
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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 (IO540) that is in this condition and would love to hear your thoughts.

Thanks as always!

Dan
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Walk. Especially if this AD wasn't complied with: www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/9fa5e5f8683a0a4686256e9b004bc295/$FILE/041014.pdf

Scroll down to page 7 for the actual AD.
 
Unless you want to spend $35K+ or more on an overhaul or new engine.
And more for the R&R. And while you're at it, replace all the hoses.
 
Devil’s in the details. Price it as if it needs a new engine and get the airframe thoroughly inspected. Might be a good deal, might not.

Not enough info to say one way or another.
 
The price we are looking at reflects a discount (maybe not 35k but a discount).

This AD is for Lycoming motors. There is only a SB regarding the Continental motors.

I know of places that sell Mooney's (Lycoming engine) with prop strike history with less than a full tear down but maybe that is not legal?
 
It’s a gamble, are you usually a lucky person?
 
Danny Dub said:
The price we are looking at reflects a discount (maybe not 35k but a discount).

This AD is for Lycoming motors. There is only a SB regarding the Continental motors.

I know of places that sell Mooney's (Lycoming engine) with prop strike history with less than a full tear down but maybe that is not legal?
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A complete disassembly and inspection is not mandated by AD for either Lycoming or Continental engines.

It's your choice how you feel about it. I'd buy an airplane with prop strike history and no teardown but my offer would factor in the expense of complying with the recommended service bulletin.
 
Greg Bockelman said:
How much money are you willing to spend for safety? There isn’t enough money in the world to make anything 100% safe.
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True, but I’d think a prop strike is something you’d want to investigate.
 
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 (IO540) that is in this condition and would love to hear your thoughts.

Thanks as always!

Dan
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If the AD has been complied with, You are good to go.
 
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 (IO540) that is in this condition and would love to hear your thoughts.

Thanks as always!

Dan
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Read this article maybe? TLDR: What else is being addressed in a similar fashion? And, more importantly, does the owner know the insurance company will pay for the inspection? Or, ugh, no insurance...I see now.
 
Tom-D said:
If the AD has been complied with, You are good to go.
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I haven't seen an AD for this situation. Only action taken is a measure of the run out (?) I think it is called. It has been flown a handful of hours since.
 
How long has it been since the prop strike?
 
Eric Stoltz said:
Read this article maybe? TLDR: What else is being addressed in a similar fashion? And, more importantly, does the owner know the insurance company will pay for the inspection? Or, ugh, no insurance...I see now.
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Good article! In this case, the plane was bought with the plan of fixing the damage and then selling it. I can't attest to how the mx has been done previously other than the logs which seem to be on good order.
 
Danny Dub said:
So other than the pin, the rest is inspect and repair as necessary?

Hardly a complete tear down! Am I reading that correctly?
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Correct. That AD can potentially be complied with while the engine remains installed on the airframe.
 
Danny Dub said:
So other than the pin, the rest is inspect and repair as necessary?

Hardly a complete tear down! Am I reading that correctly?
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Pretty much,, the inspection is to replace the required pin, bolt and washer. the accessory case and all accessories must come off.
 
JOhnH said:
Subtract the price of a new engine from your offer.
You might not get it, but there are other planes out there.
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And the price of a prop overhaul.

After an engine teardown inspection and prop overhaul, a plane should actually be more trustworthy than it was before the prop strike. That’s because there’s a smaller chance of something unknown lurking.
 
NoHeat said:
And the price of a prop overhaul.

After an engine teardown inspection and prop overhaul, a plane should actually be more trustworthy than it was before the prop strike. That’s because there’s a smaller chance of something unknown lurking.
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99 times out of a 100, the engine will be sent in for overhaul. Now infant mortality kicks in.
 
Tom-D said:
99 times out of a 100, the engine will be sent in for overhaul. Now infant mortality kicks in.
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So Tom, are you a proponent of comply with AD as previously discussed and don't be overly invasive until you have a reason to be?

That is sort of where I fall but everyone makes great points.
 
Danny Dub said:
So Tom, are you a proponent of comply with AD as previously discussed and don't be overly invasive until you have a reason to be?

That is sort of where I fall but everyone makes great points.
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I'm an A&P-IA that builds engines, I want you to send it in for overhaul.
But I'll say this, Both Manufacturers are comfortable with their compliance methods.
Or we would have new ADs and SBs monthly.
 
unsafervguy said:
Last time I read that ad it doesn’t apply to a continental io520.......
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Ah ha! It does not apply to the engine in question so would it be correct that a tear down is required on the Continental IO520? That is basically what my local mechanic is saying, or at least he wouldn't sign off on it for an annual or anything else until that had been done.

Tom mentioned earlier that there is a process that can return a Continental to service without a tear down but I don't think I've seen that AD or SB.
 
Tom-D said:
99 times out of a 100, the engine will be sent in for overhaul. Now infant mortality kicks in.
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and those parts will be re-used on cleaned up, repainted crank cases....and delivered with fresh paper.
 
So, how many hours since the prop was either repaired or replaced? If it has more than 150-200 hrs....I'd go with it.
 
I’d say 50% or better chance the crankshaft will show up cracked at the next overhaul its only like $13k for a new one. That assumes it doesn’t fail in service and trash the engine or worse.
 
Continental crankshafts are surface hardened in the flange area. In my 44 years in the engine business seeing well over a thousand prop strike inspections I've seen Continental crankshafts that took a very light strike ie chopping up a lightweight towbar crack. OTOH I've seen things like a TSIO-520 shaft that hit the pavement at WOT turning 2700 not crack. I've seen a few that broke and shed the prop less than 20 hours post strike. Never seen a Lycoming actually break and darn few that were IMHO cracked due to a prop strike. The Lycoming AD only requires inspection of gears that do not require a complete teardown. True there is no AD mandating teardown on Continentals but it is stupid not to do it! Buying an aircraft with a known strike and no inspection should reflect the cost of R & R, Teardown and at least a used certified crankshaft. Entry price north of $20K.
 
I wouldn’t be comfortable putting my butt and that of my friends/family on the gamble of not doing a teardown. That said, your comfort may vary.

Assuming you are comfortable without a teardown, to me, that would be a route to go if you owned the airplane and are trying to keep costs down. In contrast, your only attachment to this airplane is the possible desire to own it. Your only risk is the seller not being willing to sell at a low price. If it were me, I’d make my offer reflecting a runout, funds for the “other” items that get replaced during overhaul, and Id walk if they balk. I’d also want to know more about the prop strike, and I’d be concerned that it was flown post-strike. That could be reflective of a casual attitude towards maintaining the aircraft in other areas.
 
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How many hours on it since the prop strike? My 180 had a prop strike (and much more damage) a thousand hours before I bought it. No mention of engine or prop in the logs. All the other repairs were well documented. I bought it without hesitation.
 
charlie said:
Continental crankshafts are surface hardened in the flange area. In my 44 years in the engine business seeing well over a thousand prop strike inspections I've seen Continental crankshafts that took a very light strike ie chopping up a lightweight towbar crack. OTOH I've seen things like a TSIO-520 shaft that hit the pavement at WOT turning 2700 not crack. I've seen a few that broke and shed the prop less than 20 hours post strike. Never seen a Lycoming actually break and darn few that were IMHO cracked due to a prop strike. The Lycoming AD only requires inspection of gears that do not require a complete teardown. True there is no AD mandating teardown on Continentals but it is stupid not to do it! Buying an aircraft with a known strike and no inspection should reflect the cost of R & R, Teardown and at least a used certified crankshaft. Entry price north of $20K.
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there is your answer. if you do not know charlies history ask around, he has forgotten more about engines than most people will ever know.
 
What kind of prop strike? Snapping off a break-away runway light is one thing, curling up both tips on the runway itself is another.
 
Juliet Hotel said:
What kind of prop strike? Snapping off a break-away runway light is one thing, curling up both tips on the runway itself is another.
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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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