Ok so i've acquired another bird, and this bird had a prop strike. It is a lycoming o-360. So the guy I bought it from had the required inspection done as per AD: 2004-10-14.

SUMMARY: The FAA is adopting a new airworthiness directive (AD) that supersedes an existing
AD, for Lycoming Engines (formerly Textron Lycoming), direct-drive reciprocating engines (except
O-145, O-320H, O-360E, LO-360E, LTO-360E, O-435, and TIO-541 series engines). That AD
currently requires inspection of the crankshaft gear installation and rework or replacement of the
gears where necessary after a propeller strike, sudden stoppage, at overhaul, or whenever gear train
repair is required. This AD requires the same actions but makes the correction that the existing gear
retaining bolt and lockplate be removed from service and new hardware installed, and revises the
definitions for sudden stoppage and propeller strike. This AD results from a change to the definition
of a propeller strike or sudden stoppage. We are issuing this AD to prevent loosening or failure of the
crankshaft gear retaining bolt, which may cause sudden engine failure.

To summarize from what I can tell this ad calls for only inspection of camshaft gears and replacment of retaining bolts on the back of the engine. This is also what the mechanic who signed it back into service interprets the ad to read. They dailed the crank and it was very straight and it was flown 2 hours post . I got a new prop to put on the plane and am going to have it ferried here this week (it's in annual and seems very airworthy)

So my question is can i trust this engine ? From myresearch most seem to point to overhaul. However if there was dangers wouldn't the ad require further inspection of the crank or am i completely mislead. Engine has 1400 smoh.

I know i haven't said what my new plane is.....and it's a mooney (don't laught) thought it would compliment a stinson nicely. I figure if anyone else is going to tell me to slap a prop on it and fly the s*** out of it till tbo they might reside here.

Mike

I would speculate that the reason that those who would suggest to slap a prop on it and fly it to TBO reside here because they might be flying crafts that would be a little more forgiving in the event of an off field forced landing. There's a big difference between dead sticking in to a road, field, desert, beach, tree topss, etc... at 40 knots and 60 knots. Just something else to consider if you haven't already. Maybe you should swap FWF between the stinson and the Mooney?

As it is legal, and quite expensive to remedy, I would probably run it, monitor it's behavior and conduct oil analyses regularly, while casually shopping around for a deal on a replacement motor. I would also be reluctant to fly at night and in IMC over mountainous terrain. My $.02.

I second that

A stinson and a mooney. Sounds like a perfect combo.

Had a prop strike, sudden stopage, in a 182 in 2000. the insurance co paid for a tear down and magniflux of crankshaft. did not know it was different on a Continental and a Lycoming

Tim

I would be overly cautious with one my kids were going to ride with me in. I know of more than one crankshaft failure that didn't have forewarning. It would suck to be crashing in the trees of northern N.Y. because you were trying to "save" money.
Be careful.

I've not seen a crank condemned from a prop strike unless there was significant other damage. Mooneys, especially the bigger ones have prop strikes often. I would fly it, but if I took it apart to do a "real" inspection, then I would overhaul it.
People often try to force a mooney to the ground when they float, and get into a pogo type of movement. The bigger Mooney's have very little prop clearence.

Another factor to consider is what did the prop strike consist of. The Lycoming definition includes everything from a crash and sudden stoppage to going into tall grass and chewing up the grass..a big difference from striking an object and/or sudden stoppage.

AKGrouch wrote:Another factor to consider is what did the prop strike consist of.

Exactly, According to Lycoming, the engine does not even have to be running, bump it with no visable damage = prop strike. Now, I don't think anybody would do anything there, but there is a difference in my opinion from "kissing" the prop tips from wheel barreling a landing and a nose gear collapse.

I would not trust it. I bought a Mooney (1964 M20D) that had a prop strike and the engine was high time so I went ahead and had it overhauled (Custom Airmotive-Tulsa, OK) thinking that if the crank was bad the engine shop would know. That engine was the best running 0360 Lycoming I ever sat behind for about 240 hours right up until the crankshaft broke in two. No running bad, no making metal, no oil consumption. Had a weak spot about the size of a quarter in the MIDDLE of the crank, unable to be seen by standard Lycoming overhaul procedures, (I was told). Still have the airplane, but don't fly it much, wonder why?

Pat

I believe a Continental engine crank requires both a Magniflux and Ultra Sound along with Mic'd for specification to get it returned to service. Also would be a good idea if the rods were checked and the cam gear bolts were changed and get the cam gears checked. The sudden stopage could stretch a rod or crack a gear.
HC

A tear down inspection after a prop strike is not a tremendous amount of money if all is okay vs. doing the O/H. All you are out is the labor, incidentals, and downtime. The peace of mind is worth it.
I am not sure if the engine is a 1800 or 2000 hour TBO, so you have a bit of flying time left in the engine. Ask yourself how much will you fly it, 25-50-100 plus hours per year? See if your mechanic will work with you and let you do some of the grunt work to save money on the R&R. Good luck.

My family has owned an '82 M20J since 1986 (and we still have it). They among the strongest, most economical aircraft ever manufactured. If you have never flown a Mooney (especially later models with the higher Hp), you owe it to your self to fly the sportscar of airplanes.

If you want an example of just how strong these airplanes are, check THIS out: http://www.ntsb.gov/ntsb/brief2.asp?ev_ ... 065&akey=1

If you have a total engine failure in IMC (zero-zero Tule Fog conditions), it's nice to know you have a chance...

CHEERS!

I think the designer of the Mooney's was the same man who designed the V tail Bonanza? Legend has it that he was determined his new design would have no structual defects. Legend also has it that after pulling the metal spar wings for certification they decided to go ahead and pull them till failure. Story is they broke the fixture, but the wings were fine. Strong as they get, but they are a small mans airplane, fat people just don't fit. Wonderful to fly, and a nightmare to work on. No cables, and therefore no cable slop in the controls, push-pull tubes in a Mooney. Mooney's are also an all metal airplane, but the cockpit structure is 4130 steel tube. I love em, and have been trying to talk myself out of one for years.

I'm 75 years old. And, since I want to go another 75, my A&P/IA (who happens to be myself) says that I'll NEVER fly a prop strike engine until it has had the needed inspections. No doubt the pilot is well protected in a Mooney but pushing one's luck is not smart.
Maybe when I was younger and knew that I was indestructable?!

Bob

billybob wrote: I'll NEVER fly a prop strike engine until it has had the needed inspections. Bob

Unless I misunderstood the initial post, it has had, or will get the needed inspections to comply with the AD, to not do so at least would be illegal, and well not very smart at all.
I believe the question, unless I misunderstood, was do you need to exceed the scope of the AD?
I had my prop strike at 1800 on a 2000 hour engine. I elected to overhaul. I sent all ferrous parts out to be magnafluxed. That exceeds the scope of the AD, but I was more comfortable doing so.
From what I can tell, there does not seem to be a link between prop strikes and Crankshaft failures, at least not with Lycoming anyway. There have been enough crank failures on Lycomings so that I assume the AD would say replace the crank if there was a link.
Of course prop strikes only exist if they are reported.

That is what the AD requires, but Lycoming has a service bulletin that recommends a tear down. I would not sign it off without a tear down, but I'm sure that if you look long and hard enough, you will find someone who will. That doesn't mean that you are safe, it just means that you found someone who will sign it off.

Frankly, I'm kind of surprised that any mechanic in this day and age of liability would sign off a Lycoming with a prop strike without complying with the Lycoming Service Bulletin. That requires a teardown, no matter how hard the strike was.

You might get lucky, and fly it till TBO (600 more hours). Then again, you might NOT be lucky......


MTV

mtv wrote:Frankly, I'm kind of surprised that any mechanic in this day and age of liability would sign off a Lycoming with a prop strike without complying with the Lycoming Service Bulletin. That requires a teardown, no matter how hard the strike was.

You might get lucky, and fly it till TBO (600 more hours). Then again, you might NOT be lucky......

So, the question is: http://ca.youtube.com/watch?v=1-0BVT4cqGY

Well, Do You??

MTV

Good advice.

So I decided to send the engine out.....and today I got a call......
The crankshaft had a crack in it !! Feels good to know that I made the right decision , feels bad to have to buy a new crank !!

Lesson Learned, if it hit the ground get it tested. I flew it for about 50 hours after the prop strike. It ran great ! It started burning a bunch of oil from a bad cylinder exhaust valve so we decided it was time for OH. Sure glad we did it as I fly lots over unforgiving terrain of the Adirondacks.... Now the hard part opening up the wallet to buy a new one ( Zane we need a throwing up smiley to express that feeling)

Mike

Mike, Thanks for the follow up. While I am sorry you are out the money, I am glad it bought safety!

I really appreciate you closing the information gap on this thread. It is a powerful way of demonstrating how important this forum can be.