Author Topic: prop FOD  (Read 8553 times)

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Offline allen

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prop FOD
« on: May 04, 2008, 08:48:41 PM »
Landed at Smith Mountian lake this afternoon. When I took back off to come home I thought I noticed a new vibration when I was at a certain RPM. Landed and found this. Do you think it can be fixed.  

Noticed a Velocity turning a metal prop today. Seems the way to go. Any recommendations?
Allen
Long-Ez N701DS
1998 O-320 160HP
http://www.freewebs.com/wonderingwingnut

Offline Bruce Hughes

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Prop FOD
« Reply #1 on: May 04, 2008, 09:26:37 PM »
Hi Allen

I think metal props on Longezes are VERY RARE.   Probably there
is a good reason, wouldn't you think?

Call your CSA state rep, Steve Volovsek at 757-538-8992 and see
what he thinks.   You ARE a member of CSA, right.   If not, call him
anyway and promise to join.   Best $30 you will spend this year.

Bruce Hughes   :D
Yelm, WA
Longeze N199BH
retired
taught at Maui Community College

Offline allen

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prop FOD
« Reply #2 on: May 05, 2008, 07:12:40 AM »
I am a member. I will give him a call and see what I can do. My gut says the prop is trash at this point.

Looking on line I became a bit of a fan of the Prince props. WAY more than I had intended to spend, but if they can take the beating as advertised I would be a fool to not do it.

Is there one prop out there that is "the" prop to have? Specifically I am looking for something that can take rain, rocks or a wondering fastener.

Catto makes some nice mods to his props. At this point its a toss up between Catto and Prince.
Allen
Long-Ez N701DS
1998 O-320 160HP
http://www.freewebs.com/wonderingwingnut

Offline Tom

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prop FOD
« Reply #3 on: May 05, 2008, 07:36:35 AM »
Hi Allen,

from the pics, I would think your prop should be easily repaired, For the 2k for a prince, I would certainly try!



Tom

Offline Bruce Hughes

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« Reply #4 on: May 05, 2008, 08:24:52 AM »
The prop can be fixed, I think.   It would be a lot cheaper than buying a
new one.   :D

Ask Steve and some other builders; I am not expert on props or anything
else for that matter. :cry:

You might send your picture to Ken Miller or call him at 516-381-5382 or
kenezmiller@optonline.net

I guess it hit a rock on takeoff?

Bruce Hughes  :)
Yelm, WA
Longeze N199BH
retired
taught at Maui Community College

Offline Drew

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prop FOD
« Reply #5 on: May 05, 2008, 08:28:55 AM »
Send the pix to the prop manufacturer and have them give you a quote.  My prince got a real good slice through the fiberglass exterior.  I had them not only repair it---but switched to carbon.

In the end (along with shipping prices back and forth) It would have probably been cheaper to just get a brand new one.

What in the world did you hit?  Looks big whatever it was...
Drew Swenson
Cozy N171ML

Offline allen

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« Reply #6 on: May 05, 2008, 08:54:48 AM »
The field is a small lake airport. I landed there a few weeks ago and after I got home I noticed a couple little dings to teh prop. I had noticed when I was there that the field had some pea gravel on the taxi ways.

The irony is that I had been talking with Joe, the owner, about that issue just minutes before I took off. I have even made a mental note not to ever land there again until that runway was swept.  :?

It looks like one of the mains picked something up and pitched it through the arc. This prop had been repaired by Velocity and was coated with fiberglass for added protection.

If it is repairable I will have that done and set it aside as a spare. In the meantime I will keep looking for a better prop. I.E. something that can handle rain and a few pebbles. Prince seems to have a neat prop.

Anybody ever failed a Prince?
Allen
Long-Ez N701DS
1998 O-320 160HP
http://www.freewebs.com/wonderingwingnut

Offline rglos

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« Reply #7 on: May 05, 2008, 08:55:23 AM »
There is a sound reason why metal props are not used. It is in one of the Canard Pusher issues. Something to do with the pulses created by the way air hits the pusher prop. It is not the same as a prop out in front with clean air.

On the back end the metal props fatigued where the wood flexed with the pulses. Someone else could explain this better.

Looks like the prop is repairable, don't get too down.

If it did that it was a large obstruction that hit it.
Long EZ, 0-235L2C, 1986

Offline allen

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« Reply #8 on: May 05, 2008, 12:19:09 PM »
Just got off of the phone with Lonnie at Prince. He looked at the photo and said its repairable. I will be shipping it off to him in the next few days to be overhauled and converted over to Carbon Fiber with his leading edge protector.

Carbon Fiber looks so cool that now I don’t know if I want to have it painted back white or not.  8)

The cost to repair and convert to carbon fiber was significantly cheaper than to purchase a new one. I will keep my eyes out of another prop just so that I can have a spare should this happen again.
Allen
Long-Ez N701DS
1998 O-320 160HP
http://www.freewebs.com/wonderingwingnut

Offline Waiter

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prop FOD
« Reply #9 on: May 05, 2008, 06:21:03 PM »
OUCH - %$#^&@*(&^#%$  (to quote what you said when  you seen it)


It looked repairable to me.  Did you find out what caused it??

I've had several "dings" that I filled in with FLOX or JB weld.

Metal Props - Rutan recommended to NOT install a metal prop. Seems that a Metal prop is like a tuning fork. The frequency resonance of a prop/engine combination is part of the testing thats performed for spam can certification, i.e. avoid the resonanat frequencies as these will set up airframe osscilations that could shorten the life/destroy the airframe.

A perfect example of resonant frequancy response is the Highpitch signer shattering a crystal glass The singers voice was able to match the resonant frequency of the glass, AND instill enought power to cause it to shatter.

A wooden prop also has a resonant frequency, BUT, because of the dampaning effect of the wood, its impossible to instill enough energy into the prop to get it to vibrate like the tuning fork.


NOTE - Do you have a spare prop????

Waiter
LongEZ-RG   >>    N961EZ
O-320 160hp  >>    MT Constant Speed Prop
F-16 Performance, On a Piper Cub Budget
www.iflyez.com

Offline allen

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« Reply #10 on: May 05, 2008, 08:24:47 PM »
Waiter my friend, you got the quote right! No spare prop…yet.

I think I picked up a small rock when I took off from Smith Mountain Lake airport. It has a fair amount of loose gravel on it. They really need to get a sweeper truck to run the runway and taxi ways. Until that happens I will not land there again. The damage is too far out to be a fastener, and nothing is missing on the gear. I feel certain that it was FOD that was kicked up rather than falling off.

After work I went by the airport tonight and pulled the prop off. I brought it home tonight and tapped out the bolts and inspected them. No corrosion or chips were seen.

I will ship the prop off tomorrow to Prince. He is going to repair it and put on the carbon fiber and leading edge protection. In the near future I will look into buying another prop and use this one as a spare.

As far as metal props go I am noticing more and more Velocity’s spinning constant speed props. The CP’s referenced the issue about resonance as well as metal fatigue. Velocity is obviously subject to both of these issues. I’ll being looking into this more and give a call to the guys at Velocity and see what they have to say.

I learn something new every flight. I’ll be back in the air soon. :wink:
Allen
Long-Ez N701DS
1998 O-320 160HP
http://www.freewebs.com/wonderingwingnut

Offline Radioflyer

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« Reply #11 on: May 07, 2008, 07:30:29 AM »
This is not the first time that kind of damage has happened to your prop. That prop is most definately repairable, especially so because the damage is at the tip. The tip is the least loaded part of the blade. The thing is that what you do to one tip, you'll have to do to the opposite tip also. What i would have done is to shave down the tips to some common depth, build up with some light flox and bid cloth. You'll need to do a little reshaping and painting.
Gary Hertzler used to make probably the best 2 blade prop for the Long Ez, the Silver Bullet, and the repair method was recommended to me by him at one time. I never got to try the repair because Velocity did it and then you bought the plane. :-)
I have a Prince prop, now but have not used it yet. It is beautiful and I've heard some LongeZ pilots say good things about it.

Offline Radioflyer

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« Reply #12 on: May 07, 2008, 08:14:46 AM »
Repeated damage to our props is a fact of life with our Pusher planes. One best get used to owning several props.

By the way, RAF always recommended against metal props and constant speed props. Pusher harmonics were not flight qualified on this plane, though obviously they have been qualified on other planes such as the Cessna Skymaster. I would think a metal prop would weigh much more than a wood/composite and ruin your basic empty weight or W&B.

Don't most Velocitys use a composite/wood MT constant speed prop? I know the Velocity people are quite friendly with the MT prop people in Deland, Florida. A Velocity is balanced quite differently from a Long Ez. The canard and CG are configured for extra weight on the nose. That is why they can sit on all 3 gears without a worry, unlike the LongEz. So what applies to a Velocity does not always apply to a Long. A metal prop on a Velocity I would think is a more viable option, especially with their larger engines, but still, most use the Composite/wood MT 3 blade props.

My take on the prop situation for our planes is that all-wood props were definately the proper choice when the plane was designed. They still are, especially factoring in the price/performance issue. However. wood props with engineered carbon/glass layering (i.e., not just a cosmetic/anti abrasion layer of cloth) is probably the best way to go now. IMHO, their extra cost is offset by greater durability/safety, if not also performance. The next step is an all plastic, coreless prop such as the ones now being made by Sensenich. I can't wait for people to start using these Sensenich props on our planes and report their findings.

Offline allen

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« Reply #13 on: May 07, 2008, 09:22:03 AM »
I remember Robert telling me about his prop adventures. He said that a fastener had gone through a blade. He gave me a bunch of photos and I suspect I have the photo he took right after the damage happened. As you stated Velocity did the repair and repainted the prop. They had used a layer or two of fiberglass on the leading edge as a kind of armour, and you can seen where it had “torn” around the damaged area. Who knows, perhaps the reason the prop tip did not jettison was thanks to the glass holding everything together.  :shock:

After it happened I did some searching and found some directions on repairing the dmaged area. As I am very new to this and we are talking about a critical flight component I decided to send it off to the pro’s.

As you mentioned the carbon fiber route is the way to go I feel. After speaking with Lonnie (great guy by the way!) the price to repair and upgrade to carbon fiber was well within my budget. In the future I will buy a scratch built prop and retire this one to stand-by status.

FYI, Robert has gone back over the pond with his family. When I bought the plane from him he used the money to finish his IFR and commercial tickets. He was headed home to pursue a life as a professional pilot. He was a very interesting individual and I really enjoyed our conversations. Hopefully he will send me an email once he gets settled. I wanted to make Sun-N-Fun this year and take him for a ride in “his” plane one last time, but my schedule wouldn’t allow it. Perhaps another time. I’m sure our paths will cross again.  8)
Allen
Long-Ez N701DS
1998 O-320 160HP
http://www.freewebs.com/wonderingwingnut