Legal prop for 54B?

[ALASKA99762]

Today I found a McCauley 1A75/GM8242 for sale. Is this prop legal for my 54B? Thanks in advance for any help. Bryan

[blueldr]

Check the hub dimensions and bolt pattern and----- if the mukluk fits---
what the heck!
I spent four years in Fairbanks with my airplane on Weeks Field (Now long gone) and those guys used any prop that would bolt on the shaft. The FUZZ was very understanding up in that part of the world.

[ALASKA99762]

After a few searches on this sight, I came to the same conclusion. The bolt patterns don't match up, so thats that. The FUZZ are definetly losing their sense of humer...even up here! Thanks, Bryan

[alaskan99669]

Today I found a McCauley 1A75/GM8242 for sale. Is this prop legal for my 54B? Thanks in advance for any help. Bryan

I've never heard of one installed on a 170 and I don't see it listed as an STC here:
http://www.airweb.faa.gov/Regulatory_an ... enFrameSet
I've got the 1A175-DM-8042 on mine, STC from Kenmore Air.

[johneeb]

Corey,

Somebody had to ask. Alaska99762 & Alaska99669 are those zip codes

[alaskan99669]

Corey,

Somebody had to ask. Alaska99762 & Alaska99669 are those zip codes

Yep, you guessed it!

[ALASKA99762]

What kind of short field performance can I expect with the 8042 vs. the 7651 I have now? Just can't leave well enough alone.

[alaskan99669]

I never got to fly the plane with the cruise prop, but the previous owner put the plane on floats with the cruise prop first. He thought he had just made a huge financial error as the performance was horrible. So he sunk some more money into the climb (seaplane) prop and now it performs satisfactorily on floats. On wheels it's very impressive. I'm still new to flying but can consistently leave the pavement in about 400' (alone, full of fuel) and cruise is about 98 MPH.

[ALASKA99762]

Thanks Corey, thats what I wanted to hear. I too am new to this and now I need to convince the wife. "But honey its for saftey...think of the kid!!"
Too bad she's too smart to fall for that line.

[AR Dave]

99726, this is previously 99645. You don't have short field performance with the 7651. The only comparison between an apple and a bannana is that they are both fruit. The safety statement is absolutely correct! Most Alaskans end up tweaking their 80 props to 8043. The previous owner of my 55, had his prop at 8044, 42, & finally 43. There are plenty of Alaskan, 80" prop, 170B's, for you to catch a demonstration in. What tire's do you have? We need to go to PM, so we can talk without causing prop envy!

[GAHorn]

Props not specifically approved are ... not approved. And for good reason.
A prop that bolts up and fits....doesn't necesarily have the necessary vibration/harmonics with the engine. (In fact, there's actually some approved props that have limitations in that regard.) Lots of props are specifically NOT good in some installations for this reason. Vibration can destroy your engine and lead to serious loss of balance depending on what it takes with it when it leaves the airframe in flight and/or throws a blade with the resulting loss of control.
I've actually seen engines hanging from their hoses/wires/cables when they've been ripped out of their mounts due to defective props or unapproved prop installations.
Please don't simply assume a prop that will bolt onto the crank is all that's necessary to acheive an airworthy combination.