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Oil on prop

Posted: Fri Oct 23, 2020 1:38 am
by JW Scud
Have you ever heard of this?


"Hartzell also recommends wiping metal props before each flight with a thin film of motor oil to help resist dirt striking the prop (sandblasting). Oil has a high film strength that helps protect the prop from high velocity dust."

Re: Oil on prop

Posted: Fri Oct 23, 2020 1:42 am
by Colonel
Yup. I thought it was for corrosion protection of metal blades, though.
Didn't know it would help with abrasion.

Prop abrasion from sand is a big problem with nosedraggers - you
can watch them suck it up. Really hard on the prop blade tips.

Not so much with taildraggers, who have lots of prop clearance.

Generally, oil on the prop blade - that you didn't put there - is pretty
bad news. It's either leaking out of the prop hub, or the crankshaft
is cracked and the prop is about to depart the aircraft in flight.

Re: Oil on prop

Posted: Fri Oct 23, 2020 2:43 pm
by Slick Goodlin
Hang on... shitty prop seals are HELPFUL??!!

Re: Oil on prop

Posted: Fri Oct 23, 2020 2:45 pm
by Colonel
Not for my cardiac health, they aren't. I almost had a heart attack
the first time I saw that red oil from the Macauley prop hub on the
blade in cold temps.

I solved that by moving someplace where it never freezes, so I'm ok
now. Don't worry.

Re: Oil on prop

Posted: Sat Oct 24, 2020 2:17 pm
by Liquid_Charlie
prop seals and 40 below, the perfect storm in the making :mrgreen:

When I was flying the Herc all our aircraft were modded that engines and props were preheated but the APU and it was the bible and if by chance the APU system was inop ground preheat was mandatory. Explain that heat is your friend to the visiting military Herc -- they jumped in and cold cocked that old girl and basically limped back with 3 inop engines due to prop failures. Pitch locked props on the herc can be catastrophic. This all happened with in seconds of their departure, lucky it was clear and cold because in IMC I doubt if they would have made it back. Yup heat is your friend, in the north you have to make it not like down south where it is self generating -- :D

Re: Oil on prop

Posted: Sat Oct 24, 2020 3:01 pm
by Colonel
ground preheat was mandatory
Dear Old Dad loved it when they put the -104 in the warm hangar at
Cold Lake in the winter. Jump in and away you go. If you tried to start
it cold, it would pee hydraulic fluid everywhere. Same thing - seals in
the cold.

They learned that lesson in 1986, when the Challenger exploded shortly
after takeoff due to shrinkage of a seal in cold temps. Even Seinfeld
understood that, even if all the NASA PhD's didn't.

Depresses me how generations keep having to relearn the same thing
over and over again.

I don't mind arrogant. And, I can deal with stupid. But it is a character
flaw of mine that when you put the two together, it makes me want to
vomit. I need to work on that, and learn to suffer fools gladly.

Re: Oil on prop

Posted: Sat Oct 24, 2020 3:14 pm
by Colonel
Back to prop seals. Years ago, doing the import on a Pitts S-2B with a
Hartzell "claw". Gorgeous prop, but 9 years old. So, off it comes for the
TC-mandated overhaul, drive to Toronto to a Very Big Prop Shop You Have
Heard Of, drop the prop off, drive back. Very Big Prop Shop calls us, overhaul
is done, we drive to Toronto, pick up the prop, drive back, re-install it.

And, it's fucked. Even in warm temps, the prop won't cycle. Nothing.

So, off comes the prop. Drive to Toronto to the Very Big Prop Shop and drop
it off again, drive home. Very Big Prop Shop says, "Oh yeah, we used the wrong
prop seals" which is why the blades can't rotate. Different seals ordered,
we drive back to Very Big Prop Shop in Toronto, pick it up again, drive back
home again, re-install it again.

The paperwork on that totally fucked prop overhaul that converted a
perfectly-working prop into a piece of useless shit was amazing, though.

The things we do, to try to keep TC happy. All this shit we eat, and they
hate us so much for it.