Hi all,
We were discussing repair of formers in a Citabria or Decathlon a few weeks ago and I found one that is broken at the bottom in the Decathlon I brought home not long ago. I crawled into the cabin and reached into the tail area to figure out how to approach the repair starting by trying to pinch the eyelet so it could be pulled from between the mounting tabs. It wasn't budging! So I looked at it and thought to myself, "Self", I said, "how about we sister a piece of 1/4 plywood to the front face of the former and through-bolt it with an AN3 bolt through the eyelet?"
We had previously discussed cutting off the bottom of the former and gluing in an extention with maybe 1/8" plywood doublers on each side to make it all rigid. The problem I found out with this is that the spruce stick that is glued to the aft side of the former needs to also be cut away to make the doublers work but that wouldn't be necessary if you just sister a piece to the front and bolt it to the tabs forward of the tabs. The eyelet being left in the tabs keeps the rather light duty tabs from being crushed by the bolt.
I cut a piece of plywood today and sistered it to the damaged former using cascophen glue and a pneumatic stapler. The hangar might be too cold for the glue to completely set up even though I left the heater on for a few hours after I left so I might have to also through-bolt the doubler. I'll know in the morning and will post pics.
My IA friend said it could have been done either way but he agreed it was easier the way I ended up doing it.
Opinions?
We were discussing repair of formers in a Citabria or Decathlon a few weeks ago and I found one that is broken at the bottom in the Decathlon I brought home not long ago. I crawled into the cabin and reached into the tail area to figure out how to approach the repair starting by trying to pinch the eyelet so it could be pulled from between the mounting tabs. It wasn't budging! So I looked at it and thought to myself, "Self", I said, "how about we sister a piece of 1/4 plywood to the front face of the former and through-bolt it with an AN3 bolt through the eyelet?"
We had previously discussed cutting off the bottom of the former and gluing in an extention with maybe 1/8" plywood doublers on each side to make it all rigid. The problem I found out with this is that the spruce stick that is glued to the aft side of the former needs to also be cut away to make the doublers work but that wouldn't be necessary if you just sister a piece to the front and bolt it to the tabs forward of the tabs. The eyelet being left in the tabs keeps the rather light duty tabs from being crushed by the bolt.
I cut a piece of plywood today and sistered it to the damaged former using cascophen glue and a pneumatic stapler. The hangar might be too cold for the glue to completely set up even though I left the heater on for a few hours after I left so I might have to also through-bolt the doubler. I'll know in the morning and will post pics.
My IA friend said it could have been done either way but he agreed it was easier the way I ended up doing it.
Opinions?
