Prop Strike m20F

[Newguy]

Fellow aviators

Here's a linlk to a incident on 6802V and I need your input.

http://verdenews.com/main.asp?SectionID=1&SubSectionID=1&ArticleID=37192

Tell me if that prop looks bent to you?  In Canada, we would have to tear that engine down  but apparently under AD 2004 10 -14 it allows for the AP to decide if you can get away with only an accessory case and gear box inspection and that is what the sellers AP is only doing?  

My gut says this was a prop strike on a hard surface and the engine should be torn down and inspected.

I want to be cautious here folks and not negatively affect the seller in any way but I am looking for input.

Here's the Lycoming definition of a prop strike:

C.M.'s Service Bulletin 96-11, in a nutshell, says that if a propeller must be removed from the aircraft to be repaired following a propeller blade impact of any sort or if the engine physically lost R.P.M.'s from the incident, then the engine has experienced a propeller strike and it should be removed from service and completely disassembled and thoroughly inspected for damage from the incident.
Textron Lycoming, in their Service Bulletin 533A, takes the approach that the safest procedure is to take the engine apart for inspection following any incident involving propeller blade damage. However, they have the caveat that the inspecting mechanic may override that position and return the engine to service without disassembly and inspection if he feels that it is the prudent and responsible thing to do.
Textron Lycoming has also published Service Bulletin 475C which requires, in the event that the engine has experienced a propeller strike, inspection and possible rework of the accessory gear train as well as the rear of the engine's crankshaft. Compliance with this service bulletin is mandatory in the eyes of the F.A.A. by A.D. note 2004-10-14, if and only if, the engine has experienced a propeller strike as defined in the context of the A.D.. It should be noted that to comply with A.D. note 2004-10-14, the engine does not need to be completely disassembled and that access to the accessory gear train can be accomplished, in most cases, with the engine still installed in the aircraft.
What this all boils down to is that in the case of any accidental damage to a propeller installed on a aircraft operating under Part 91 of the F.A.R.'s, it is up to the inspecting technician to determine if the engine should continue in service without total disassembly and inspection. A Textron Lycoming engine, that is being operated on a Part 91 aircraft, that had a propeller strike, must comply with A.D. note 2004-10-14 and Service Bulletin 475C at a minimum.
Teledyne Continental powered aircraft operating under Part 135 of the F.A.R.'s, that have to comply with all manufacturers service bulletins, would have to comply with Service Bulletin 96-11 requiring total disassembly and inspection after any incident that required removal of the propeller for repairs or if the engine physically lost R.P.M.'s during the incident. An aircraft, operating under the same regulations, that is powered by a Textron Lycoming engine, would have to comply with Service Bulletin 475C after a propeller strike of any kind and would also have to comply with A.D. note 2004-10-14. On these Textron Lycoming powered aircraft, it is the responsibility of the inspecting technician to determine if the engine should be removed from service for disassembly and inspection.

[N601RX]

I would say that all 3 of them are bent.  It says the gear collapsed about 50 ft after touchdown, so the plane was still moving pretty fast and the prop was still spinning.

[jetmech1972]

As an A&P I would not risk my license and a lawsuit, that engine needs to be disassembled and inspected per the maintenance manual...

[231Pilot]

Quote: jetmech1972

As an A&P I would not risk my license and a lawsuit, that engine needs to be disassembled and inspected per the maintenance manual...

[tony]

First I need to start out by saying that I am not an A&P.

The answer to your question is, it depends.  If I were purchasing the aircraft, yes I would absolutely want the engine broken down, 8130’s on every part, and then reassembled.  If I was the owner/operator, maybe not and I would exercise some judgment where the regulations would let me.

The intent of the AD isn’t well if I crack open the accessory case and put it back together I’m good.  The intent is to look around and see if you see any damage.  If not then do you need to go any further?  If you do find something well then you bought yourself an overhaul.  It’s the judgment of the A/P and how much risk the guy whose butt is going to be sitting at the controls wants to take. 

If it were my airplane and I had 1800 hours left on the engine I would eddy current inspect the bolt that fastens the crankshaft gear to the crankshaft?  That’s the softest piece of metal in the system that’s in shear. That’s number 27 on page 1-10 of the IPC.  If no damage was found, I would stop.  If I were purchasing the aircraft, I think I would walk away or lower the purchase price to cover an overhaul.

[N9937c]

Looks to be strike 2 for this mooney. First was in 1975. Could it be that it's been flying all these years with the gear out of rig?

larry

[richardheitzman]

Prop strike= engine teardown

Correct in saying that any IA who releases a aircraft for service after a prop strike (such as a landing gear collapse) without a engine teardown inspection is risking not only his/her own license but is risking the life of the owner/operator.

I have seen teardowns as a result of engine out landings were the gear failed to extend, the owner shut the engine down on final, and still dinged the prop. Face it folks, there is NO way around the fact that you ding the prop hard enough (not just loss of RPM on the engine) then you are getting a teardown. You will save your life and those who are in the aircraft with you.

[acronut]

Quote: tony

First I need to start out by saying that I am not an A&P.

The answer to your question is, it depends.  If I were purchasing the aircraft, yes I would absolutely want the engine broken down, 8130’s on every part, and then reassembled.  If I was the owner/operator, maybe not and I would exercise some judgment where the regulations would let me.

The intent of the AD isn’t well if I crack open the accessory case and put it back together I’m good.  The intent is to look around and see if you see any damage.  If not then do you need to go any further?  If you do find something well then you bought yourself an overhaul.  It’s the judgment of the A/P and how much risk the guy whose butt is going to be sitting at the controls wants to take. 

If it were my airplane and I had 1800 hours left on the engine I would eddy current inspect the bolt that fastens the crankshaft gear to the crankshaft?  That’s the softest piece of metal in the system that’s in shear. That’s number 27 on page 1-10 of the IPC.  If no damage was found, I would stop.  If I were purchasing the aircraft, I think I would walk away or lower the purchase price to cover an overhaul.

[N601RX]

Does anyone know what this plane is selling for, or have a link to the ad?  Is it listed for 12-15K less than most of the comparable planes? 

There are plenty planes out there without this questional history.

[Newguy]

Quote: N601RX

I would say that all 3 of them are bent.  It says the gear collapsed about 50 ft after touchdown, so the plane was still moving pretty fast and the prop was still spinning.

[Newguy]

Quote: N601RX

Does anyone know what this plane is selling for, or have a link to the ad?  Is it listed for 12-15K less than most of the comparable planes? 

There are plenty planes out there without this questional history.

[Newguy]

Quote: acronut

I agree 100%.  As long as the price is significantly reduced then I see no problem with the accesory case inspection. 

I've flown behind quite a few engines that had idle to low power prop strikes without overhauls with no problems.  It's pretty common from what I've seen actually.  You also want to dial the crank to make sure it's not bent.  If it's within tollerance chances are your fine.  I'm not an A&P either but I've built an airplane and been working on airplanes since 93.  Far from the most experience here but you wanted my opinion.  

Kendal

[Newguy]

Quote: richardheitzman

Prop strike= engine teardown

Correct in saying that any IA who releases a aircraft for service after a prop strike (such as a landing gear collapse) without a engine teardown inspection is risking not only his/her own license but is risking the life of the owner/operator.

I have seen teardowns as a result of engine out landings were the gear failed to extend, the owner shut the engine down on final, and still dinged the prop. Face it folks, there is NO way around the fact that you ding the prop hard enough (not just loss of RPM on the engine) then you are getting a teardown. You will save your life and those who are in the aircraft with you.

[N33GG]

Whether I am an owner, seller, buyer, pilot, broker, or anything else, here is my answer:

1.  Engine tear down.

2.  Go to #1 above.

Things like this make me nervous when I am the buyer years later, and things have gotten a little fuzzy in the logs and memories.  If you want to take a chance with your safety, that is one thing.  But that may translate into taking a chance with someone else's safety at a later date, without their knowledge at that. 

Whatever the regs say, the engine needs to be torn down and fixed right.

[Newguy]

Quote: tony

First I need to start out by saying that I am not an A&P.

The answer to your question is, it depends.  If I were purchasing the aircraft, yes I would absolutely want the engine broken down, 8130’s on every part, and then reassembled.  If I was the owner/operator, maybe not and I would exercise some judgment where the regulations would let me.

The intent of the AD isn’t well if I crack open the accessory case and put it back together I’m good.  The intent is to look around and see if you see any damage.  If not then do you need to go any further?  If you do find something well then you bought yourself an overhaul.  It’s the judgment of the A/P and how much risk the guy whose butt is going to be sitting at the controls wants to take. 

If it were my airplane and I had 1800 hours left on the engine I would eddy current inspect the bolt that fastens the crankshaft gear to the crankshaft?  That’s the softest piece of metal in the system that’s in shear. That’s number 27 on page 1-10 of the IPC.  If no damage was found, I would stop.  If I were purchasing the aircraft, I think I would walk away or lower the purchase price to cover an overhaul.

[tony]

Quote: N6719N

Whatever the regs say, the engine needs to be torn down and fixed right.

[N33GG]

Quote: tony

And this is based in good sound engineering judgment, or is this just an emotional decision? 

The FAA is just about one of the most conservative and old fashioned organizations I have ever had to deal with.  If there is an AD out there that says something, you can rest assured that there is an engineering analysis, with plenty of margin, from the manufacturer backing it up.

 

[Newguy]

Quote: tony

And this is based in good sound engineering judgment, or is this just an emotional decision? 

The FAA is just about one of the most conservative and old fashioned organizations I have ever had to deal with.  If there is an AD out there that says something, you can rest assured that there is an engineering analysis, with plenty of margin, from the manufacturer backing it up.

 

[RJBrown]

Check with the insurance carrier I bet if there was one they paid for a teardown. The only reason there would be no teardown was because there was no insurance? Well maybe the owner decided to pocket that $ and DUMP the plane?

I was taxied into a gofer hole while idling by a lineman at BJC where I had flown in to an airshow. The insurance bought a prop and a look see by Western Skyways.

For me this would be a deal breaker unless the discount was big enough to cover the engine.

[drapo]

Looks like a M20F, so it has a Lycoming 200hp IO360, and there is an AD that requires the crankshaft inspected or replaced at overhaul or after a prop strike on certain models. That needs to be looked at seriously...

[takair]

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/07577b0b9213888985256930005117ca/9fa5e5f8683a0a4686256e9b004bc295/$FILE/041014.pdf

This is the AD which applies to prop strikes on our 360s.

[Newguy]

And that AD specifically doesn't require a tear down so now Im confused.

 

[tony]

Thats what I was trying to tell you, its not required.  They are just worried about the bolt that attaches the crack gear to the crankshaft.