MT Prop strike

[Shadrach]

I am well versed in the post prop strike protocol in Lyc SB533C. However, I was wondering if there is any correlation between engine damage and the prop construction material. It would seem that the MT wood core composite would transmit less shock to the crank, but I was wondering if anyone had any thoughts, experience or data on the subject.

 

[carusoam]

Thoughts....

Most likely, the stresses will be different...

But... are they different enough to change the most recent changes to the protocol...?

Probably not...

The current definition of what is now considered a prop strike requiring a teardown and inspection are pretty light compared to history...

let’s invite our prop guy... @Cody Stallings....   Theoretical question regarding prop strike and composite materials...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Cody Stallings]

I’m not gonna be much help on this one.

However I will say, I haven’t seen any documentation that states that a Composite Prop strike is any less of an event than with Aluminum blades.

[philiplane]

The crankshaft speed changes more quickly with a light weight prop, since there is much less flywheel effect. In a prop strike, it's the rate of speed change that dictates the amount of damage incurred to the rotating components.

[orionflt]

the truth is it doesn't matter what type of propeller you have on your airplane if you strike the propeller it is more the type of impact.

impacting a hard surface VS a soft where the blades can bite in

slowly lowering the blades onto a surface vs a rapid lowering. 

engine speed and blade angle at time of impact

anyway you look at it, a prop strike just is not a good way to end your flight and it does not matter what kind of prop you have.

[ShuRugal]

it does not matter what kind of prop you have.

https://www.towerhobbies.com/cgi-bin/wti0001p?&I=EFLA1910&P=FR&gclid=Cj0KCQjwrJ7nBRD5ARIsAATMxsvkDSbUj-laaRhC7gkcJqW1yDk70Yr1LQPt0Wv6uNgelnXPm1B0U2YaAsmJEALw_wcB







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[N201MKTurbo]

I went to a maintenance seminar last year on MT props. I had to chuckle at the mil spec lag screws.

[Austintatious]

I was considering going the MT route.  I thought long and hard about it and decided not to do it since there is no STC for it and it has to be field approved.  Engines are designed with a certain prop weight in mind and when you deviate from that you can be inviting trouble.  My guess is that there is no STC for my engine because the counterweights have issues and the FAA wont approve an STC when the consult with continental (who no doubt says DONT put that prop on engine XX)

[carusoam]

Austin,

It would help if you put your plane in your avatar data...

MT has STCs that covers many Mooneys...

Which Mooney do you have...?

I went with a TopProp about a month before the MT STC was completed for my plane... timing is everything.

I have seen MTs on J, K, R, and Ms...

I didn’t want to be the first to go with the low inertia prop...

It’s been years since I needed a prop.

Best regards,

-a-

[Shadrach]

9 hours ago, philiplane said:

The crankshaft speed changes more quickly with a light weight prop, since there is much less flywheel effect. In a prop strike, it's the rate of speed change that dictates the amount of damage incurred to the rotating components.

That depends. A tail dragger nosing over at idle can stop an aluminum prop in one blade. An MT by comparison will just shed material.

Edited May 25, 2019 by Shadrach