As the spinny thing turns...or suddenly stops

[Tom-D]

Go to any web page you like, search for anyone who will declare outright that a wooden prop will damage a crank when it is involved in a strike.

 

[Cap'n Jack]

What's the difference between prudent and legal?

Using the Lycoming AD description of a Prop strike, for a C-75, Now there is a laugh

I did cite your post from another thread where you said that if the prop needs to be removed for repair, it is a prop strike. I'd say that breaking a wooden prop is cause for repair.

Now what's a real laugh, we went from 1920 something to present and neither major manufacturers having come out with a mandatory requirement requiring the tear down because of a prop strike.
and the FAA hasn't changed their rules on the subject ever.

Yet many go around screaming it must be torn down.
Seems the people in the know don't agree.

Isn't an Airworthiness Directive (AD) some sort of mandatory requirement for a certificated aircraft? The link I cited leads to an AD. I also cited your earlier post.
I realize this thread refers to an experimental plane. For an engine, I'd consider it wise to follow an AD that was issued for the same engine used in a certificated plane. Why do you not feel it is prudent?

 

[Cap'n Jack]

Go to any web page you like, search for anyone who will declare outright that a wooden prop will damage a crank when it is involved in a strike.

https://www.federalregister.gov/doc...y-textron-lycoming-direct-drive-reciprocating

(3) A sudden RPM drop while impacting water, tall grass, or similar yielding medium, where propeller damage is not normally incurred.

From Continental SB96-11B

A propeller strike is: (1) any incident, whether or not the engine is operating, that requires repair to the propeller other than minor dressing of the blades as set forth in Part I, B of this Service Bulletin or (2) any incident while the engine is operating in which the propeller makes contact with any object that results in a loss of engine RPM. Propeller strikes against the ground or any object, can cause engine and component damage even though the propeller may continue to rotate. This damage can result in catastrophic engine failure.

No mention of any propeller type. So it applies to wooden propellers too.

 

[Tom-D]

I did cite your post from another thread where you said that if the prop needs to be removed for repair, it is a prop strike. I'd say that breaking a wooden prop is cause for repair.


Isn't an Airworthiness Directive (AD) some sort of mandatory requirement for a certificated aircraft? The link I cited leads to an AD. I also cited your earlier post.
I realize this thread refers to an experimental plane. For an engine, I'd consider it wise to follow an AD that was issued for the same engine used in a certificated plane. Why do you not feel it is prudent?

Your Lycoming AD does not require a tear down, only AD compliance.
And Yes in the other thread we were talking Metal prop, and certified A/C.
WE are not here.
Here we are talking about a C-75, running a wooden prop on a E/AB aircraft and you are trying to apply a Lycoming AD that only requires an inspection of the gear, washer and dowel pin.
TCM has no such AD they only have a SB, that says "SHOULD" have the steel parts inspected by Mag-n-Flux (FPI) They don't even require any thing, they only advise.

Were we talking a normal prop strike on a larger engine running a metal prop, where the engine actually did a quick stop, I would not return it to service with out a teardown/overhaul.
If the owner had it dialed and some A&P returned it to service, I'd avoid it like the plague.
The little c-series engine's rotating group doesn't weigh enough to carry the energy to hurt a crank when they use a wooden prop.

 

[Cap'n Jack]

Your Lycoming AD does not require a tear down, only AD compliance.
And Yes in the other thread we were talking Metal prop, and certified A/C.
WE are not here.
Here we are talking about a C-75, running a wooden prop on a E/AB aircraft and you are trying to apply a Lycoming AD that only requires an inspection of the gear, washer and dowel pin.
TCM has no such AD they only have a SB, that says "SHOULD" have the steel parts inspected by Mag-n-Flux (FPI) They don't even require any thing, they only advise.

Tom, you really do have trouble with reading and comprehension. I'm not trying to apply any AD on anything. And threads drift. You do that often enough yourself.

Plus there is no FAR rule that requires a quick stopped engine be torn down, So what would you expect the FAA to do?

I did ask if an AD was regulatory for certificated aircraft. I then supplied an example of an AD related to an inspection of an engine stoppage. Are ADs FAA rules or not?

Were we talking a normal prop strike on a larger engine running a metal prop, where the engine actually did a quick stop, I would not return it to service with out a teardown/overhaul.
If the owner had it dialed and some A&P returned it to service, I'd avoid it like the plague.
The little c-series engine's rotating group doesn't weigh enough to carry the energy to hurt a crank when they use a wooden prop.

If you think so. I'd go by Continental's recommendation.

 

[benyflyguy]

Well call me nuts..
I bought a Christen Eagle a few years back with the same deal.... It was a composite prop strike... The crank was dialed. Airframe rebuilt and it is still flying. Don't overthink things.
A wood or composite prop will break and not tear up a steel crank.
Now if it was a metal prop that hit pavement that would be a whole completely different story.
I flew the crap out of the plane and pulled lots of G's. I never once thought about that crank.
I did have another Eagle with a 540 that the crank broke in half for no apparent reason. It never had a prop strike.
You never know.....
Sounds like this is a cheap little plane to toot around in. It would cost more for the engine teardown and rebuild than the plane is worth....View attachment 73108

Holy mackerel! What was that like when that decided to let loose ???