H-9 RV8 wing failure
#1
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H-9 RV8 wing failure
A fellow club member had a new Hanger 9 RV8 plane. This member is a regular "Sunday flyer" and really is gentle with all his planes.
The wing is a two piece held in place with a 4-40 metal bolt through the underside of the wing into a blind nut attarched to a plywood tab that sticks out the side of the body. He has had problems with the bolt staying in place BUT the last time he flew he was making a turn and the wing just pulled right off in the air sending the plane rolling down into our pit area!!! No one was hurt and we were lucky no one parked at that end of the field. When we inspected the plane, both wing bolts were still in place! The wing structure failed around the glue joins.
Anyone else have this problem?
Hanger 9 told our member to send the plane in for inspection.
The wing is a two piece held in place with a 4-40 metal bolt through the underside of the wing into a blind nut attarched to a plywood tab that sticks out the side of the body. He has had problems with the bolt staying in place BUT the last time he flew he was making a turn and the wing just pulled right off in the air sending the plane rolling down into our pit area!!! No one was hurt and we were lucky no one parked at that end of the field. When we inspected the plane, both wing bolts were still in place! The wing structure failed around the glue joins.
Anyone else have this problem?
Hanger 9 told our member to send the plane in for inspection.
#2
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RE: H-9 RV8 wing failure
Not [8D]. Sad, usually Hanger 9 has a good reputation for good design and quallity for a ARF. I have suspected Hanger 9 starting to get sloppy at times. Gee, just think of what rate these planes are built in high numbers in China? Well, maybe Horizon will come out with a Tech Update.
Glad no one was hurt.
Pete
Glad no one was hurt.
Pete
#3
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RE: H-9 RV8 wing failure
This sounds similar to the wing retention design used on the H9 80" Pawnee and the lower wing of their Fokker DVII. Each of those has the tab/440 bolt/blind nut arrangement you describe. I've had the tabs on both wings come out of the Pawnee, but that one has struts that also hold the wing on, so after they came out of the wing on disassembly I just epoxied them back in. No problems so far w/ the DVII, but that has the top wing and N struts that should keep things togetherif one of those tabs comes loose.
I don't know what was used to glue the tabs in the Pawnee wings, but it sure wasn't epoxy. Looked likw some sort of hot glue.
Sorry about your friend's airplane but I can see it happening...
Al
I don't know what was used to glue the tabs in the Pawnee wings, but it sure wasn't epoxy. Looked likw some sort of hot glue.
Sorry about your friend's airplane but I can see it happening...
Al
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RE: H-9 RV8 wing failure
MY FRIEND JUST LOST HIS RIGHT WING TODAY ON HIS RV8 FROM HANGER 9,, JUNE 5 2010,,, WAS FLYING AT HALF THROTTLE,,, PULLED UP, AND THE WING DISINTEGRATED ,, I ALSO LOST THE RIGHT WING OF MY HANGER 9 PIPER PAWNEE,,,, I THINK I AM GOING BACK TO KIT BUILDING,,,,,, DAY
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RE: H-9 RV8 wing failure
A chain is only as strong as it's weakest link. I found this out the hard way in one of my own designs. The wing was minimalistic, but plenty strong, the struts leading to the wing added plenty of support, the whole schema was very finely built to be light, yet very well designed and strong for that lightness. The only thing I failed to calculate well was the glue joints where the supporting struts met the wing. All of the pressure on all of those surfaces was equally distibuted through all of these elements....only those tiny little glue joints were the weakest link, with no mechanical advantage holding them fast.....only the glue itself. Result? After about 10 flights....pulling up from a shallow dive, one wing broke free from its supporting struts, folded back over the fuselage, and the whole shebang augured in quite fantastically. Ever since then, I learned to think of these connections more critically when designing, and use not just the glue, but mechanical advantage in the designs to keep this from ever ocurring again.
ZZ.
PS. Was pretty spectacular though!
ZZ.
PS. Was pretty spectacular though!
#8
RE: H-9 RV8 wing failure
Has Hanger 9 offered any fix for this? My wing panels seem loose on assembly and in no way can it fly until I get a perm fix on it.. The right wing more so than the left. I wonder if anyone put their own fix on this problem? Plane flies really nice. I am running it on a 5s Eflite power 52 set up. I generally fly very gentle airobatics and am not over flying the plane. Just cant seem to understand what has happened to my previously tight wing joints?
Paul
Paul