Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
Nose Wheel Pant broke in Half !
- Thread starter Vern
- Start date
Pat Stewart
Well Known Member
[/IMG]
This happened on landing. The rear broke in a clean line and was on the runway.
Aircraft had just passed 500 hours recently.
I would call Vans, fiberglass does not break that way unless laid up that way, manufacturing defect.
Michael White
Well Known Member
Agree with Pat
I have done more than my share of fiberglass work and I have never seen a break like that. Somewhere in the production, it looks like something went wrong. I believe it would be difficult to cut the pant that straight with a grinder.
I have done more than my share of fiberglass work and I have never seen a break like that. Somewhere in the production, it looks like something went wrong. I believe it would be difficult to cut the pant that straight with a grinder.
burgundyja
Well Known Member
termites 
Severe shimmy was going to be my first guess.
Check the nose fork friction and let us know what the value is.
Chock-induced?
Just a thought... Is there damage right where a chock would rest behind the nose wheel? Tough to tell for certain the the pics, but the chock lines up with the break it seems.
Starting the engine with the chock aft of the wheel can cause the nose to squat down with the fairing getting damaged, possibly causing a weak spot that gave out during the landing roll.
Probably not the cause, but if there's any aligned indentation on the underside and this history it could be contributory. My 2 cents, and may be worth less!
Just a thought... Is there damage right where a chock would rest behind the nose wheel? Tough to tell for certain the the pics, but the chock lines up with the break it seems.
Starting the engine with the chock aft of the wheel can cause the nose to squat down with the fairing getting damaged, possibly causing a weak spot that gave out during the landing roll.
Probably not the cause, but if there's any aligned indentation on the underside and this history it could be contributory. My 2 cents, and may be worth less!
[/IMG]
This happened on landing. The rear broke in a clean line and was on the runway.
Aircraft had just passed 500 hours recently.
Were you at Signature at PDK? Mine cracked in half just like that. The line guys at signature rammed a chock up the back of the wheel. I left half of it on the center line at Savannah. I had to tell a USAir flight to go around.
Sure looks like a latent defect to me
I agree with the fellow that said he never saw a straight line break like that in fiberglass without some straight line weakening feature. Just from the location I would suspect the manufactured separation location was changed by some fiberglass splicing at adapt the existing fairing for this application or a repair of an incorrect cut to remove from a mold, whatever - no one is going to convince me that is a normal fiberglass fracture of a properly manufactured fairing without tampering.
Bob Axsom
I agree with the fellow that said he never saw a straight line break like that in fiberglass without some straight line weakening feature. Just from the location I would suspect the manufactured separation location was changed by some fiberglass splicing at adapt the existing fairing for this application or a repair of an incorrect cut to remove from a mold, whatever - no one is going to convince me that is a normal fiberglass fracture of a properly manufactured fairing without tampering.
Bob Axsom
Wayne Gillispie
Well Known Member
Ron,
I believe that bulkhead, bobbing up and down during 10-15 kt taxi speeds and left/right wagging when nose wheel contacts pavement on landing is what did it. We have to look at the fiberglass suppliers quality of work. The best piece was my spinner. I will be laying up a layer to reinforce that bulhead soon. You'll notice in the pic the chock(Epp's) has worn places on top left/right sides where everyones wheelpant hits it. So watch for cracks on rear bottom side of wheel cut out. Another area I will add a layer to.
I believe that bulkhead, bobbing up and down during 10-15 kt taxi speeds and left/right wagging when nose wheel contacts pavement on landing is what did it. We have to look at the fiberglass suppliers quality of work. The best piece was my spinner. I will be laying up a layer to reinforce that bulhead soon. You'll notice in the pic the chock(Epp's) has worn places on top left/right sides where everyones wheelpant hits it. So watch for cracks on rear bottom side of wheel cut out. Another area I will add a layer to.
Last edited:
rleffler
Well Known Member
Speaking of cutting the pant too close, what's the consensus on the best practice? Any opening up more than the plan calls for?
bob
Saw that one happen...
I was on my way to Oshkosh last year and stopped for fuel at Capt Ben Smith airfield in Monroe City Missouri. There was a steady stream of RV's landing for the cheap fuel and free hot dogs...(highly recommend the place by the way)
I watched the -A model RV land and the nose wheel shimmy was REALLY bad. Not surprised the fairing broke in half. My buddy ran out to the runway and retrieved the departed half... It was indeed a strange break, exactly like the pics in this thread...
Tom
I was on my way to Oshkosh last year and stopped for fuel at Capt Ben Smith airfield in Monroe City Missouri. There was a steady stream of RV's landing for the cheap fuel and free hot dogs...(highly recommend the place by the way)
I watched the -A model RV land and the nose wheel shimmy was REALLY bad. Not surprised the fairing broke in half. My buddy ran out to the runway and retrieved the departed half... It was indeed a strange break, exactly like the pics in this thread...
Tom
I was in the plane Dan mentioned on the way to Osh. The pilot landed to fast with a three point landing...maybe even on the front gear. For a minute, I thought the nosegear was gone. Not sure why it cracked so clean, just like this one, but I know why it happened. Too much speed forcing the plane to land.
Think of it as nose wheel flutter....
Everyone generally excepts that control surface flutter is an event that typically causes a catastrophic failure.
A severe case of nose wheel shimmy is very much the same and can violently abuse the nose wheel fairing (and sometimes other parts as well).
It can be violent enough that if we could capture it with a high speed camera, I think we would see the wheel paint flexing along the line where it failed.
Note how the break line transitions fwd at the top... likely caused by the way the this area flexed when the sides were flexing inward.
Flex any material enough times and it will result in a fatigue failure. The fatigue limit of three layers of of 9 oz glass cloth and resin isn't very high.
How to prevent it?
Properly maintain the nose wheel fork friction and use proper landing technique.
Everyone generally excepts that control surface flutter is an event that typically causes a catastrophic failure.
A severe case of nose wheel shimmy is very much the same and can violently abuse the nose wheel fairing (and sometimes other parts as well).
It can be violent enough that if we could capture it with a high speed camera, I think we would see the wheel paint flexing along the line where it failed.
Note how the break line transitions fwd at the top... likely caused by the way the this area flexed when the sides were flexing inward.
Flex any material enough times and it will result in a fatigue failure. The fatigue limit of three layers of of 9 oz glass cloth and resin isn't very high.
How to prevent it?
Properly maintain the nose wheel fork friction and use proper landing technique.
RV6airplanePilot
Well Known Member
Hey Bob
no one is going to convince me that is a normal fiberglass fracture of a properly manufactured fairing without tampering. Bob Axsom[/QUOTE said:Bob, I am a little disappointed; you did not ask him for a quote on the speed result.
Dale
RV6a
I just figured ...
I thought about it but I just figured He removed it with no test ... haha. I'm a little surprised that there is a bulkhead in his fairing. There is none in mine. A couple of years ago I bonded in blue foam bulkheads to see if there would be a speed increase associated with the reduced open air volume - just the opposite was true and I removed them after testing.
Bob Axsom
I thought about it but I just figured He removed it with no test ... haha. I'm a little surprised that there is a bulkhead in his fairing. There is none in mine. A couple of years ago I bonded in blue foam bulkheads to see if there would be a speed increase associated with the reduced open air volume - just the opposite was true and I removed them after testing.
Bob Axsom
Mine broke exactly like the picture you show
Same place , same traight line cut at 400 hrs
The brackets that hold the faring cracked as well
I plan to beef up the brackets. New nose wheel faing ordered from Vans
I have not installed it yet so we will see
Son Hoang
CFII MEI
RV 10 N 172 KT
Same place , same traight line cut at 400 hrs
The brackets that hold the faring cracked as well
I plan to beef up the brackets. New nose wheel faing ordered from Vans
I have not installed it yet so we will see
Son Hoang
CFII MEI
RV 10 N 172 KT
Phil
Well Known Member
I bumped one of my mains tonight just behind the split.
I knocked a chuck out of the pant that is over the size of a quarter and 3/16" deep. Unbelievable.
There was no glass anywhere in that section of the pant. It was a clean chunk of epoxy without any form of reinforcement underlying it.
Wow.
I knocked a chuck out of the pant that is over the size of a quarter and 3/16" deep. Unbelievable.
There was no glass anywhere in that section of the pant. It was a clean chunk of epoxy without any form of reinforcement underlying it.
Wow.
