Prop Strike Repair Cost

[kortopates]

15 minutes ago, Shadrach said:

This is ridiculous logic. There is absolutely no reason to hold part 91 ops to the same regulatory standard as part 135. I support your right to maintain your aircraft to any standard you wish over and above what is required by the administrator. To each there own, but blanket statements like that are just silly.

Do you really think a J3 operating out of a farm strip in Idaho should be held to the same regulatory standard as 135 air carrier, or where you just being reactionary?

I can totally relates to Peter's sentiments. PT 135 isn't air carrier, but taxi ops. Its germane IMO since I could conceivable get a PT 135 approved operation with my Mooney, and then provide air taxi service to my friends willing to pay for taxi service in my Mooney or of course the public at large. So if I take my friends up for a ride in my hypothetical Mooney that had a prop strke without a tear down, the FAA doesn't care per se, but in court the plaintiff likely sues my pants off for not maintaining according to best practices and acceptable industry standards when they find out that is the prudent thing to do and required if they were paying passengers on a commercial op. If that's getting too tangential, consider what your friends comfort would be taking a ride with you in yours or a friends hypothetical Mooney with prop strike sans inspection if you also go on to explain the taerdown is considered the prudent thing to do in the industry even if you may not agree (I don't know if you are disagreeing with that - I am not meaning to pick on you at all). 

Regardless though. I never understood the relevance to the cost concern this thread is based on at all unless the owner in question has no insurance or shall we say is "self insured". Because no insurance company is going to not pay for the complete engine inspection and rebuild. And they'll certainly pay for any damage found that is sudden stop related. So that only leaves an owner paying for any betterment. Such as if they would opt to major the engine. But what a great opportunity for getting your major subsidized unless your engine was very low time, in which case it gets put back together on the insurance company's nickel except for what almost always includes some betterment for a new prop.

So bottom line for me is why are we worried at all whether or not its really legally required by the FARs to perform the tear down inspection; especially when its covered by our insurance. 

[Shadrach]

59 minutes ago, PTK said:

I was referring to the prop strike teardown inspection when someone was suggesting it was not needed. I think it'd be silly not to do it especially when there is the published mandatory SB and its covered by insurance.

I don't disagree with you or Peter (if it's his personal choice). A tear down is the most conservative thing to do. That does not change the fact that it is statically "make work".  I would never suggest that an engine not be dialed after a prop strike. Nor would I suggest that hubs and cranks don't get damaged as we all no they do.  I do however think the current "one size fits all" policy that Lycoming takes could be smarter and save resources and time.  Tall grass at the end of the runway is not going to destroy a crank or a hub nor is a break away taxi or runway light. When lawyers dictate what is mechanically prudent The result is only slightly better than hiring a mechanic to practice law.

[Alan Fox]

5 minutes ago, PTK said:

I was referring to the prop strike teardown inspection when someone was suggesting it was not needed. I think it'd be silly not to do it especially when there is the published mandatory SB and its covered by insurance.

This I actually agree with Mr. Garmin , Because it is not the insurance paying , it is the insured , I tried to explain it to another member ,  People ask me why would an insurance company pay for it , if it is not needed....  The answer is they don't , you do .....Their actuary team assess the averaged loss over the fleet , includes it in the premium , marked up with a profit.....  They make money on prop strikes.....  If it is an insurance job , do it , out of pocket is a whole different story....Also when it comes to insurance claims , familiarize yourself with the term "betterment"   They will not pay the full teardown cost , on higher timed engines.....

[PTK]

12 hours ago, Shadrach said:

I don't disagree with you. It's the most conservative thing to do. That does not change the fact that it is statically "make work".  I would never suggest that an engine not be dialed after a prop strike. Nor would I suggest that hubs and cranks don't get damaged as we all no they do.  I do however think the current "one size fits all" policy that Lycoming takes could be smarter and save resources and time.  Tall grass at the end of the runway is not going to destroy a crank or a hub nor is a break away taxi or runway light. When lawyers dictate what is mechanically prudent The result is only slightly better than hiring a mechanic to practice law.

Consider that according to Continental a prop  strike is any incident with engine running or not that requires repair to the propeller other than minor dressing of the blades, or an incident while engine is running in which the prop comes in contact with any object that results in a loss of engine RPM. So a prop striking tall grass can conceivably cause loss in RPM and component damage even though the propeller may continue to rotate. Also consider that Lycoming takes this further by not caring about prop damage. Lycoming is concerned about sudden rpm drop while contacting water, tall grass, or similar "yielding medium", where propeller damage does not normally occur.

Also consider that the FAA defines suddenstoppage as the engine stopping suddenly in under 1 rpm.

As far as dialing the flange, since Continental nitrides their cranks I don't see the value. A ntrided crank will break before it bends. On Lycoming engines the flange can be bent. But dialing the flange is useless in a prop strike which may have pushed the crank back cracking the case and damaging the slinger ring area.  

I remember reading somewhere that internal damage is found in about 20% of the engines torn down post prop strike. That to me is a high enough percentage that warrants tear down inspection.

[Shadrach]

2 hours ago, kortopates said:

I can totally relates to Peter's sentiments. PT 135 isn't air carrier, but taxi ops. Its germane IMO since I could conceivable get a PT 135 approved operation with my Mooney, and then provide air taxi service to my friends willing to pay for taxi service in my Mooney or of course the public at large. So if I take my friends up for a ride in my hypothetical Mooney that had a prop strke without a tear down, the FAA doesn't care per se, but in court the plaintiff likely sues my pants off for not maintaining according to best practices and acceptable industry standards when they find out that is the prudent thing to do and required if they were paying passengers on a commercial op. If that's getting too tangential, consider what your friends comfort would be taking a ride with you in yours or a friends hypothetical Mooney with prop strike sans inspection if you also go on to explain the taerdown is considered the prudent thing to do in the industry even if you may not agree (I don't know if you are disagreeing with that - I am not meaning to pick on you at all). 

Regardless though. I never understood the relevance to the cost concern this thread is based on at all unless the owner in question has no insurance or shall we say is "self insured". Because no insurance company is going to not pay for the complete engine inspection and rebuild. And they'll certainly pay for any damage found that is sudden stop related. So that only leaves an owner paying for any betterment. Such as if they would opt to major the engine. But what a great opportunity for getting your major subsidized unless your engine was very low time, in which case it gets put back together on the insurance company's nickel except for what almost always includes some betterment for a new prop.

So bottom line for me is why are we worried at all whether or not its really legally required by the FARs to perform the tear down inspection; especially when its covered by our insurance. 

I always get 35 and 21 backwards (I think higher number = higher standard, faulty logic). I'm sure you understand that there is far more to the cost than merely the bill (no matter who pays it). We part ways intellectually on the utility of performing hundreds of cases of "make work" because of the up shot that it subsidizes a rebuild for the owner (Alan touches on why I don't care for it above).  The insurance companies have the data. It would be interesting to see how many tear downs are simply reassembled because no damage was found (disregarding the owner elective parts replacement).  In the case of a Lycoming, striking anything bigger than a butterfly with the prop starts a chain of events that is often tragically unnecessary.  We certainly need  to consider consider liability but if it's the only thing considered, then best course of action is to stop doing everything involving a risk to life and limb, limit interactions with others and placard all products with warnings for every conceivable danger (did you know that airport gangways are known to the state of California to cause cancer?).  Every year, the pendulum swings just a hair more in that direction.

[DonMuncy]

Also remember that "insured" is not the same as "free". We all pay for the teardowns in our premiums.

[Alan Fox]

2 hours ago, PTK said:

Consider that according to Continental a prop  strike is any incident with engine running or not that requires repair to the propeller other than minor dressing of the blades, or an incident while engine is running in which the prop comes in contact with any object that results in a loss of engine RPM. So a prop striking tall grass can conceivably cause loss in RPM and component damage even though the propeller may continue to rotate. Also consider that Lycoming takes this further by not caring about prop damage. Lycoming is concerned about sudden rpm drop while contacting water, tall grass, or similar "yielding medium", where propeller damage does not normally occur.

As far as dialing the flange, since Continental nitrides their cranks I don't see the value. A ntrided crank will break before it bends. On Lycoming engines the flange can be bent. But dialing the flange is useless in a prop strike which may have pushed the crank back cracking the case and damaging the slinger ring area.  

I remember reading somewhere that internal damage is found in about 20% of the engines torn down post prop strike. That to me is a high enough percentage that warrants tear down inspection.

That article quotes 10 to 20 %  , and says they cant discern what may have caused the damage .... (its a Mike Busch article)

[Alan Fox]

6 hours ago, nels said:

Question on dialing the crank flange. Do yo check it at the face of the flange or at the OD of the flange??

The face...

[Alan Fox]

6 minutes ago, DonMuncy said:

Also remember that "insured" is not the same as "free". We all pay for the teardowns in our premiums.

Whether we tear em down or not we pay..

[BKlott]

3 hours ago, PTK said:

Consider that according to Continental a prop  strike is any incident with engine running or not that requires repair to the propeller other than minor dressing of the blades, or an incident while engine is running in which the prop comes in contact with any object that results in a loss of engine RPM. So a prop striking tall grass can conceivably cause loss in RPM and component damage even though the propeller may continue to rotate. Also consider that Lycoming takes this further by not caring about prop damage. Lycoming is concerned about sudden rpm drop while contacting water, tall grass, or similar "yielding medium", where propeller damage does not normally occur.

As far as dialing the flange, since Continental nitrides their cranks I don't see the value. A ntrided crank will break before it bends. On Lycoming engines the flange can be bent. But dialing the flange is useless in a prop strike which may have pushed the crank back cracking the case and damaging the slinger ring area.  

I remember reading somewhere that internal damage is found in about 20% of the engines torn down post prop strike. That to me is a high enough percentage that warrants tear down inspection.

What concerns me is the stress that they can't detect that may manifest itself sometime later...hundreds of hours later. 

[Cody Stallings]

1 hour ago, BKlott said:

What concerns me is the stress that they can't detect that may manifest itself sometime later...hundreds of hours later. 

Bingo, There it is.

[Tom]

5 hours ago, BKlott said:

What concerns me is the stress that they can't detect that may manifest itself sometime later...hundreds of hours later. 

If I suffered a prop strike and the crank dialed okay I reckon 15k spent installing a chute would offer equal or better aggregate safety than a 13K teardown (in addition to significantly increasing the utility offered by the plane).  Also feel much better flying beyond TBO further saving money.  To each there own, and this isn't an option with a Mooney.

 

[Tom]

On 2/27/2017 at 4:43 AM, Alan Fox said:

You are not worth referencing the bulletin , My reputation in the automotive repair industry is the best.... That is why you paid me to fix your Jeep, I retired with a 5 star yelp rating .....   Your dentistry , may well be another subject..

To loosely paraphrase Erasmus, in the career field where people don't RTFM the guy who does RTFM is king (or at least enjoys a good Yelp rating).  Congratulations on choosing a relatively simple career where you enjoy the luxury of an assured good outcome if you simply RTFM.  Others of us are not afraid toil in much more complicated endeavors where bad outcomes are a natural occurrence even when everything is done right and are more resilient in the face of failure  We stopped equating our sense of self worth with Gold Stars somewhere in grade school. 

 

 

[Alan Fox]

33 minutes ago, Tom said:

To loosely paraphrase Erasmus, in the career field where people don't RTFM the guy who does RTFM is king (or at least enjoys a good Yelp rating).  Congratulations on choosing a relatively simple career where you enjoy the luxury of an assured good outcome if you simply RTFM.  Others of us are not afraid toil in much more complicated endeavors where bad outcomes are a natural occurrence even when everything is done right and are more resilient in the face of failure  We stopped equating our sense of self worth with Gold Stars somewhere in grade school. 

 

 

Yes because everybody is just thrilled when they have to spend 2000.00 on their car when the head gasket blows , because they were too ignorant to change the anti  freeze for the last 8 years ,    And if your talking about simple careers , at least Doctors get to BURY their mistakes...... The rest of us have to live with ours.......  My former career was one of the absolute worst when it comes to happy customers.......   Bad outcomes are a natural occurrence in my former career , I don't know too many people that haven't taken a car back to the dealer many times , for the same repair ,  Or worse , went to a shop for an oil change , and got sold a 900.00 bill of goods......   There are a lot more Doctors with 4 and 5 star yelp ratings , than car repair places.......  I earned the gold star...... Because I was honest , stood behind my product , and treated my customers as my employers , not profit centers.....

[201er]

3 hours ago, Alan Fox said:

My former career was one of the absolute worst when it comes to happy customers.......  

I doubt your new one is any better! Selling junk and scraps to CB Mooney pilots!? You always find the toughest crowd.

[mooniac15u]

14 hours ago, Alan Fox said:

This I actually agree with Mr. Garmin , Because it is not the insurance paying , it is the insured , I tried to explain it to another member ,  People ask me why would an insurance company pay for it , if it is not needed....  The answer is they don't , you do .....Their actuary team assess the averaged loss over the fleet , includes it in the premium , marked up with a profit.....  They make money on prop strikes.....  If it is an insurance job , do it , out of pocket is a whole different story....Also when it comes to insurance claims , familiarize yourself with the term "betterment"   They will not pay the full teardown cost , on higher timed engines.....

Chartis had no issue with paying the full teardown cost on my 1900 hour engine.  Betterment would involve replacing parts with damage or wear not associated with the prop strike.  The engine shops where I got quotes said they would be happy to provide separate invoices if I decided to go with a full overhaul while the case was open.

[N177MC]

On 3/3/2017 at 3:19 AM, Alan Fox said:

That article quotes 10 to 20 %  , and says they cant discern what may have caused the damage .... (its a Mike Busch article)

This !

One also has to remember that the tear down AD and "Mandatory" SBs are somewhat recent.

No, planes weren't falling out of the sky. Yes, there were (rare) crank failures directly due to the previous prop strike.

 

 

[Andy95W]

A few years back, a local flight school 172 went off the taxiway and sank the nose gear into the mud.  Didn't even deform the prop.

A year and a half later, the crankshaft broke on downwind at the first power reduction while doing pattern work.  Coincidence?

[carusoam]

That is why insurance covers the tear down and not just the dial indicator....

Best regards,

-a-

[PTK]

50 minutes ago, Andy95W said:

A few years back, a local flight school 172 went off the taxiway and sank the nose gear into the mud.  Didn't even deform the prop.

A year and a half later, the crankshaft broke on downwind at the first power reduction while doing pattern work.  Coincidence?

I think this is why the engine manufacturer is concerned with what they call "hidden internal engine damage." Overstressed crankshaft gear dowel or  connecting rod bolts for example.

[RudderMaster345]

Hello Friends, 

Had my wings in the UK in 2001 under JAR, now, EASA, with 528 Hrs,  Passed the FAA CPL in 2017, currently undertaking the A&P online course.

I should like to register my interest to liaise with Pilots and A&P experts with experience on restoration, upgrade to turbo charge, 'Prop Strike', and other forms of Aircraft Accident Repairs.

All your rational and properly referenced commentaries would be most appreciated.

Best Wishes,

RudderMaster345

[RLCarter]

@RudderMaster345 What online course are you using for you A&P? We have a local college with an A&P course but at 59 I have no desire to enroll even though the dept. chair and a few of the instructors hound me too

[ragedracer1977]

On 2/27/2017 at 10:20 AM, jetdriven said:

Yelp may not be aceptable ot you, but with a rating like that, i can see why.  Yelp is very much relevant when shopping for goods and services.

If you'd ever dealt with Yelp as a business, you'd never use their services as a consumer.  

What you see on Yelp is so far from reality, it's almost comical.

[RudderMaster345]

3 hours ago, RLCarter said:

@RudderMaster345 What online course are you using for you A&P? We have a local college with an A&P course but at 59 I have no desire to enroll even though the dept. chair and a few of the instructors hound me too

Contact Gleim Aviation's website, and tell them I referred you. It is likely that you would fine their online resources very helpful.

RudderMaster345