Propeller Erosion Question (Caravan)

[gliderboy]

Our new Caravan is already showing some significant prop erosion. We fly only on paved strips, most which are pretty clean.

What's the most likely cause of the erosion?

A. Debris sucked up during normal use?
B. Debris sucked up when using reverse when slowing? (We don't use reverse at slow speeds.)
C. Rain? (Yes, someone told me that rain erodes props.)
D. Hobbits?

 

[esa17]

If you live near a beach or a desert then sand could be the culprit.

 

[BajtheJino]

Yes, all of the above. It just happens. Though on a paved runway there should be no reason for reverse.
I will never forget a flight instructor from the school across the ramp came over and talked to me about the job, while talking I was rotating the prop (which freaked him out) and then he proceeded to roughly run his down part of the leading edge and cut the crap out of his finger. All I could do was laugh at his blood (his anguish sustained me).

 

[jynxyjoe]

Our new Caravan is already showing some significant prop erosion. We fly only on paved strips, most which are pretty clean.

What's the most likely cause of the erosion?

A. Debris sucked up during normal use?
B. Debris sucked up when using reverse when slowing? (We don't use reverse at slow speeds.)
C. Rain? (Yes, someone told me that rain erodes props.)
D. Hobbits?

Sounds like someone is using reverse at slow speeds if you are only flying on paved strips. But, it could be one ramp you are constantly going to that may have one area you keep taxing over that does the job. I'd have someone ride along for a day/night just to keep a second set of eyes out for what the problem is.

 

[AviatorGator]

Our new Caravan is already showing some significant prop erosion. We fly only on paved strips, most which are pretty clean.

What's the most likely cause of the erosion?

A. Debris sucked up during normal use?
B. Debris sucked up when using reverse when slowing? (We don't use reverse at slow speeds.)
C. Rain? (Yes, someone told me that rain erodes props.)
D. Hobbits?

We've got a caravan that runs around the SE US every night. As was said above, there should be absolutely no reason to use true reverse on any paved strip you're going to. Managing your approaches correctly will still allow you to make any turn off on any reasonable runway. We use beta but never reverse and of course reverse should not be used below 40kts (if I remember the AFM correctly).

Even still, it is flies a bunch you're still going to see erosion over time.

 

[Chris Barnes]

How come a turbine prop erodes and a piston prop on say, a 172, can go for many thousands of hours before ever needing to be replaced?

 

[trafficinsight]

pretty sure the prop they're talking about is composite.

piston props erode too.

 

[Chris Barnes]

Sure, I agree that piston props would have to erode too but I've seen fixed pitch props go for 8 or 9 thousand hours and not have any problems.

Are turbine props made from a different material than a prop on a small craft?

 

[trafficinsight]

Sure, I agree that piston props would have to erode too but I've seen fixed pitch props go for 8 or 9 thousand hours and not have any problems.

Are turbine props made from a different material than a prop on a small craft?

Depends on the prop

A fixed pitch prop, being what it is, is pretty reliable, you're right! we have ours overhauled every engine change, as long as you're conservative with how you dress the leading edges they usually pass, sometimes they don't. I don't know of any that have gone 8 or 9000 hours either way... that is, unless the owner has never had it overhauled. There's no requirement to do so, but 8000 hours without an overhaul, to me, is asking for trouble.

 

[jynxyjoe]

Sure, I agree that piston props would have to erode too but I've seen fixed pitch props go for 8 or 9 thousand hours and not have any problems.

Are turbine props made from a different material than a prop on a small craft?

Turbine aircraft generally have a composite prop with a nickle guard running halfway up the prop.

Small aircraft usually use some sort of metallic prop (much more resilient, but heavier).

 

[LatitudeDancer]

Turbine aircraft generally have a composite prop with a nickle guard running halfway up the prop.

The DA42 had a similar concoction. Melted like butter. Nothing to file. I was never sure what to call "too big a nick."

Oh yea, and I flew it in/out of a lot of near beach runways (=sand).