What puts chips on the face of a propeller?

arnoha

Cleared for Takeoff
Joined
Jul 25, 2015
Messages
1,329
Location
Saratoga, CA
Display Name

Display name:
arnoha
An as-yet unidentified renter came back and left the plane with chips in the face of my prop. What can cause that and how to avoid it? Any experience with this sort of thing? Particularly that light scratching around the deep scratches. Weird.

08.12.20_OBS64927_N194SP#2.jpg 08.12.20_OBS64927_N194SP#3.jpg08.12.20_OBS64927_N194SP#4.jpg
 
Those aren’t chips. More like scrapes. A WAG, but it seems like the unidentified renter taxied into something.
 
Since this is the Internet, time for a pedantic correction: Those scratches aren't on the face, they're on the back. For a tractor airplane, the face of the prop is the side toward the cabin.

Think about a propeller turning... the relative wind is impacting the side facing backwards.

Ron Wanttaja
 
Since this is the Internet, time for a pedantic correction: Those scratches aren't on the face, they're on the back. For a tractor airplane, the face of the prop is the side toward the cabin.

Think about a propeller turning... the relative wind is impacting the side facing backwards.

Ron Wanttaja
LOL. Details, Details.
 
Those are scrapes caused by something dragged across the prop, or the prop pushed into something, when it wasn't running. They tried to sand it out and left the lighter scratches.

I'm thinking hangar rash. Or a fuel hose dragged across it. Or a fuelling ladder.
 
Those are scrapes caused by something dragged across the prop, or the prop pushed into something, when it wasn't running. They tried to sand it out and left the lighter scratches.

I'm thinking hangar rash. Or a fuel hose dragged across it. Or a fuelling ladder.

On both the left and right side at the same time? Note, there's pictures of both blades.
 
Particularly that light scratching around the deep scratches. Weird.

Put this in the rental agreement :-

The use of nail files and keys to remove paint deposited on the propeller during a collision with the fuel truck or otherwise is prohibited.

Ideas - No chocks/brakes, blew/ran away into a fence?
 
Oh, and side note: it's being sent out to American Propeller Service for an IRAN as we speak. I'm not looking for what to do with this; I already know it needs service.
 
Put this in the rental agreement :-

The use of nail files and keys to remove paint deposited on the propeller during a collision with the fuel truck or otherwise is prohibited.

Ideas - No chocks/brakes, blew/ran away into a fence?

Oh crap, I didn't think about actual vandalism. The light scratching is swirling. The deep scratches have steps in them. Some of the light scratching isn't oriented the same as the deep ones. We'll see what the shop's investigation turns up. It was reported by a later renter as an observation. No one stepped forward as responsible yet. The obvious person the look at would be the renter immediately before, but it's always possible they regarded it as still airworthy and didn't note it. Not something I'd mess with. Propeller failure leads in scary things, right behind airframe structural failure.

Dammit. I may be out 2 or 3 AMU.
 
Oh crap, I didn't think about actual vandalism.

I didn't mean to imply deliberate damage, possibly an attempt to conceal or mitigate damage using available means was what was in my mind.

Good luck getting it sorted out.
 
Looks like a hard metal object (tow bar, fuel nozzle, ladder, something of that sort) fell on the prop and gouged it nearly longitudinally. I don't see how you could get those long scratches on the front hitting something at decent rpm without dinging both the back and edge of the blade. The attempts to rub out the scratches with a key or file or whatever was the coup de grace.
 
It was reported by a later renter as an observation. No one stepped forward as responsible yet.
Now there's a shocker.

I once preflighted a C182RG that was missing about 1/4" off each prop tip and the flap tracks were bent. That takes some serious skill to accomplish both of those in one flight.

So, are you missing a tow bar?
 
What’s the definition AMU?

Atomic mass unit

In 1961, the convension was changed and 1 amu was defined as one twelveth of the mass of one carbon - 12 atom.

Or

$1,000
 
arnoha

Why do you think it needs to be repaired ?

WAG= some one used the tow bar to push the aircraft.
 
Check the air filter for grass, weeds, etc. Also the brakes and wheels. I wouldn't be surprised if some off airport or off runway fun was had.
 
I’m thinking traffic cone not moved before taxi.


Sent from my iPad using Tapatalk Pro
 
How is it that the renter Is unknown? Or for the purpose of the form do you mean unnamed?

Does it really matter what happened to the plane and why? It falls back onto the renter, as he is financially liable for damage not squawked when he checked out the plane on his preflight.
 
When you have multiple people flying the aircraft. The first person to notice something doesn't always mean the previous renter did the damage. It could be that they didn't notice (or report) it.
 
How is it that the renter Is unknown? Or for the purpose of the form do you mean unnamed?

Does it really matter what happened to the plane and why? It falls back onto the renter, as he is financially liable for damage not squawked when he checked out the plane on his preflight.

When you have multiple people flying the aircraft. The first person to notice something doesn't always mean the previous renter did the damage. It could be that they didn't notice (or report) it.

This, yeah. ^^^

Though how you do a real preflight and miss this is beyond me. Other options: The direct previous renter didn't see it as serious enough to abort the flight or even mention it. The responsible party is actually the renter who reported it.

EDIT: Also, though it is true that the contract lays the responsibility directly on the previous renter, it's unusual for that clause to be enforced at 100%. Being stuck with a $3000 bill because you made a judgment call that something was airworthy and not worth mention and someone else made a different call would suck royally, even if technically it is your responsibility by contract.

In this case, at least four pilots deemed the plane airworthy before two pilots and Mx didn't. Even here, Tom implied he didn't see an issue needing repair, so the A&P don't agree. Hard to slam someone for this one.
 
Last edited:
arnoha

Why do you think it needs to be repaired ?

WAG= some one used the tow bar to push the aircraft.

Two reasons: first, paint is missing. If nothing else, it needs a coat of paint. If my airframe paint were scratched by renter negligence, it would be repaired and covered by the renter. This is no different.

Second, although I didn't handle the prop personally before it was sent off, I'm told by both the reporter of the issues and the mechanics that the scratches and dents were deep enough to be easily felt and catch edges. The club didn't hesitate to ground the plane as unairworthy almost instantly when they saw it (even though the reporter only marked it as an observation, not a squawk).

Granted, on the flip side, both the reporter and their CFI, along with the next student and CFI, chose to fly the plane before the club had a chance to inspect the observation. The final pilot before inspection, on the next day, shows only 30 minutes on the schedule, which usually means they did a preflight and didn't fly. That's reflected in the fact that there is no charge to that pilot. They may have brought it to the A&P's attention, not sure right now.

There was one student/CFI combo before the reporter. And before that, the previous pilot was...me. I certainly know I didn't hit anything. I don't remember any rock chips and I didn't even go anywhere. Just pattern work. I do not remember seeing that on preflight. I feel like that would have been a huge error had I missed so many scratches and dents; I don't remember any. It'll be interesting to see how this turns out.
 
Heh, well, kudos to my Mx shop. With the plane down, they did the pitot/static and transponder inspections that were due that I'd forgotten about. There's definite advantages to having a professional manage your plane. (Thought, admittedly, I'm too cheap to do that if it weren't on leaseback.)
 
This, yeah. ^^^

Though how you do a real preflight and miss this is beyond me. Other options: The direct previous renter didn't see it as serious enough to abort the flight or even mention it. The responsible party is actually the renter who reported it.

EDIT: Also, though it is true that the contract lays the responsibility directly on the previous renter, it's unusual for that clause to be enforced at 100%. Being stuck with a $3000 bill because you made a judgment call that something was airworthy and not worth mention and someone else made a different call would suck royally, even if technically it is your responsibility by contract.

In this case, at least four pilots deemed the plane airworthy before two pilots and Mx didn't. Even here, Tom implied he didn't see an issue needing repair, so the A&P don't agree. Hard to slam someone for this one.
I had a plane on leaseback for about 5 years. Expecting renters to treat your plane like you do simply never happens.

Some people aren't as diligent on pre-flights.

Some look at something and mentally flip a coin as to whether it needs reporting. These are pilots, not A&P's.

The alternative is the pilot who reports EVERYTHING. I had a guy once who flagged the plane, didn't make a trip because there was oil on the floor under the breather tube. And complained about the plane not being available.

This is life in leaseback.
 
Oh crap, I didn't think about actual vandalism. The light scratching is swirling. The deep scratches have steps in them. Some of the light scratching isn't oriented the same as the deep ones. We'll see what the shop's investigation turns up. It was reported by a later renter as an observation. No one stepped forward as responsible yet. The obvious person the look at would be the renter immediately before, but it's always possible they regarded it as still airworthy and didn't note it. Not something I'd mess with. Propeller failure leads in scary things, right behind airframe structural failure.

Dammit. I may be out 2 or 3 AMU.
Darn, that's my favorite 172. I haven't flown it in quite a while, but I love the avionics!
 
Two reasons: first, paint is missing. If nothing else, it needs a coat of paint. If my airframe paint were scratched by renter negligence, it would be repaired and covered by the renter. This is no different.

Second, although I didn't handle the prop personally before it was sent off, I'm told by both the reporter of the issues and the mechanics that the scratches and dents were deep enough to be easily felt and catch edges. The club didn't hesitate to ground the plane as unairworthy almost instantly when they saw it (even though the reporter only marked it as an observation, not a squawk).

Granted, on the flip side, both the reporter and their CFI, along with the next student and CFI, chose to fly the plane before the club had a chance to inspect the observation. The final pilot before inspection, on the next day, shows only 30 minutes on the schedule, which usually means they did a preflight and didn't fly. That's reflected in the fact that there is no charge to that pilot. They may have brought it to the A&P's attention, not sure right now.

There was one student/CFI combo before the reporter. And before that, the previous pilot was...me. I certainly know I didn't hit anything. I don't remember any rock chips and I didn't even go anywhere. Just pattern work. I do not remember seeing that on preflight. I feel like that would have been a huge error had I missed so many scratches and dents; I don't remember any. It'll be interesting to see how this turns out.
Is it possible that someone could have pushed another plane into it while it was unattended? Or backed some kind of vehicle into it?

One of the reasons that I've stuck with this club so long is that they're serious about maintenance.
 
Is it possible that someone could have pushed another plane into it while it was unattended? Or backed some kind of vehicle into it?

One of the reasons that I've stuck with this club so long is that they're serious about maintenance.

Darn, that's my favorite 172. I haven't flown it in quite a while, but I love the avionics!

Glad you like the plane! Didn't realize you flew it. It'll be back online soon, don't worry. The only thing I would change right now with what's there right now is to move the USB power ports. I thought right in the middle would be a great location, central and convenient. It really just means there's always a cable in the way when you're using it. Live and learn.

It's unlikely, but not impossible, that someone backed into it. I've got the tiedown right outside the door for WVFC. And it's a dead-end, as you know. There's only one other aircraft that is parked where it could interfere with the plane. No other aircraft has any reason to be down at the end of that alley. Other vehicles would be WVFC fueling trucks and the like...and I hope they wouldn't lie about contact! I have a good relationship with everyone that works there, as far as I know.
 
I had a plane on leaseback for about 5 years. Expecting renters to treat your plane like you do simply never happens.

Some people aren't as diligent on pre-flights.

Some look at something and mentally flip a coin as to whether it needs reporting. These are pilots, not A&P's.

The alternative is the pilot who reports EVERYTHING. I had a guy once who flagged the plane, didn't make a trip because there was oil on the floor under the breather tube. And complained about the plane not being available.

This is life in leaseback.

Been doing this about 5 years as well. And, yeah. Some renters are diligent. Some are...less so. I probably don't see the flights that choose to fly on questionable observations. They'd get caught later and I wouldn't know how many flights went forward with the issue still in place. But I definitely see the piddly observations. The club has to investigate every one. And I get a bill for nearly every one. You put that pen to paper and I'm out around $50 right there. Most of the time, I have no qualms with that. $50 beats having the plane fall out of the sky and the tragedy that would entail.

The one that made me crazy is the failed avionics fan squawk. Repeatedly. After the now unneeded fan was removed in the panel update. And we put up a sticker saying "NO AVIONICS FAN". :mad2:
 
Since this is the Internet, time for a pedantic correction: Those scratches aren't on the face, they're on the back. For a tractor airplane, the face of the prop is the side toward the cabin.

Think about a propeller turning... the relative wind is impacting the side facing backwards.

Ron Wanttaja

next time i need help pushing an airplane back into a hangar I'm gonna say "dude, how about giving me a hand here and push on the back of that propeller.":D
 
Glad you like the plane! Didn't realize you flew it. It'll be back online soon, don't worry. The only thing I would change right now with what's there right now is to move the USB power ports. I thought right in the middle would be a great location, central and convenient. It really just means there's always a cable in the way when you're using it. Live and learn.

It's unlikely, but not impossible, that someone backed into it. I've got the tiedown right outside the door for WVFC. And it's a dead-end, as you know. There's only one other aircraft that is parked where it could interfere with the plane. No other aircraft has any reason to be down at the end of that alley. Other vehicles would be WVFC fueling trucks and the like...and I hope they wouldn't lie about contact! I have a good relationship with everyone that works there, as far as I know.
Maybe someone took a wrong turn on the way to the nearby vehicle gate, and then had to maneuver to turn around in the tight quarters to get out of the dead-end. It wouldn't necessarily have to be a club member or staff.

I once found a dent in my previously-undamaged car, and no note. (That was in a supermarket parking lot.)
 
The one that made me crazy is the failed avionics fan squawk. Repeatedly. After the now unneeded fan was removed in the panel update. And we put up a sticker saying "NO AVIONICS FAN". :mad2:
Has the checklist been modified to remove that item?
 
Those scratches really don't strike me as something from a running propeller strike. My guess is a ladder from fueling possibly. The surrounding scratches would indicate to me an attempt to cover it up by whoever the offending party was.
 
Maybe someone took a wrong turn on the way to the nearby vehicle gate, and then had to maneuver to turn around in the tight quarters to get out of the dead-end. It wouldn't necessarily have to be a club member or staff.

I once found a dent in my previously-undamaged car, and no note. (That was in a supermarket parking lot.)

Has the checklist been modified to remove that item?

Sort of? WVFC uses the list from the manual as just a photocopy and it's been crossed off. But that thing's a pain to use and everyone brings their own. I've never seen anyone use the provided checklist in the plane for a 172.

On the dent...it's on both blades. Another reason I doubt it was while the prop was stationary.
 
Back
Top