n5lp
fugio ergo sum
I have an RV-6 Quickbuild that first flew in 1999. It has an O-360, Sensenich fixed pitch and about 900 hours.
About two years ago I first noticed a possible crack in the steel bracket, inside the fuselage, that the engine mount bolts to on the other side of the firewall (WD-603). I could not verify that it was a crack and figured it was just an oil trail. Lately it got quite a bit bigger, and for the first time I could feel it with a knife blade so I grounded the airplane until I could find a mechanic.
This bracket is in a real bad place to work on, way up in the forward corner of the fuselage, next to the floor. It was apparent that the repair would require engine and engine mount removal as well as drilling off portions of fuselage skins. Then it would require aircraft welding in a confined place or complete bracket removal. I built my airplane in a TV repair shop, no longer in business, with mostly borrowed tools. There is no way I was going to attempt this repair, even if I still had a convenient shop and tools. I know my limitations.
I asked around and came up with Randy Richmond as a real good RV mechanic who could also get to the job in a reasonable time, and so ferried the airplane to Northwest Regional Airport near Fort Worth.
The repair consisted of all the removal I mentioned earlier then grinding the crack (Randy said it was very difficult to detect even with dye penetrant), welding it then welding a doubler over it. Several of the rivets in that area, which Randy said were somewhat loose, were replaced with structural screws. Rivets were also replaced with screws in the matching area on the left side.
What caused this problem, that I have not heard of before on a six? No one is sure. Randy first speculated in may have been related to engine/prop vibration or gear shimmy. I think later he believed it was probably because of a loose engine mount bolt in that location, which would be my fault. At any rate, I have not heard of this problem before and it might be something to watch out for. The airplane has never had a hard landing and it has few landings on rough surfaces. The propeller has been balanced, but comment after the balancing indicated it may not have been done real well. There is occasional mild gear shimmy, easily corrected with a slight brake application. I have the wood dampers on the main gear. Randy commented that the gear mount bolts are still very tight fitting.
The good part is that this is a great opportunity for a competent mechanic to look over the airplane and also correct several niggling problems, known and unknown to me, that have cropped up over the years. I have no local mechanic and no mechanic has looked at the airplane before. The bad part is that Doug Reeves sent me a picture today of Randy working on the airplane on Saturday, which I know he doesn't like to do, as he well shouldn't!
About two years ago I first noticed a possible crack in the steel bracket, inside the fuselage, that the engine mount bolts to on the other side of the firewall (WD-603). I could not verify that it was a crack and figured it was just an oil trail. Lately it got quite a bit bigger, and for the first time I could feel it with a knife blade so I grounded the airplane until I could find a mechanic.
This bracket is in a real bad place to work on, way up in the forward corner of the fuselage, next to the floor. It was apparent that the repair would require engine and engine mount removal as well as drilling off portions of fuselage skins. Then it would require aircraft welding in a confined place or complete bracket removal. I built my airplane in a TV repair shop, no longer in business, with mostly borrowed tools. There is no way I was going to attempt this repair, even if I still had a convenient shop and tools. I know my limitations.
I asked around and came up with Randy Richmond as a real good RV mechanic who could also get to the job in a reasonable time, and so ferried the airplane to Northwest Regional Airport near Fort Worth.
The repair consisted of all the removal I mentioned earlier then grinding the crack (Randy said it was very difficult to detect even with dye penetrant), welding it then welding a doubler over it. Several of the rivets in that area, which Randy said were somewhat loose, were replaced with structural screws. Rivets were also replaced with screws in the matching area on the left side.
Photo courtesy of Doug Reeves
What caused this problem, that I have not heard of before on a six? No one is sure. Randy first speculated in may have been related to engine/prop vibration or gear shimmy. I think later he believed it was probably because of a loose engine mount bolt in that location, which would be my fault. At any rate, I have not heard of this problem before and it might be something to watch out for. The airplane has never had a hard landing and it has few landings on rough surfaces. The propeller has been balanced, but comment after the balancing indicated it may not have been done real well. There is occasional mild gear shimmy, easily corrected with a slight brake application. I have the wood dampers on the main gear. Randy commented that the gear mount bolts are still very tight fitting.
The good part is that this is a great opportunity for a competent mechanic to look over the airplane and also correct several niggling problems, known and unknown to me, that have cropped up over the years. I have no local mechanic and no mechanic has looked at the airplane before. The bad part is that Doug Reeves sent me a picture today of Randy working on the airplane on Saturday, which I know he doesn't like to do, as he well shouldn't!
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