What is this Bump on tail of my RV-7?

[dilamipo]

Thank everybody spent some time to reply me.
To be true the first photo is the tail of one RV9 that one friend of mine is looking to buy. This RV9 is in spain and we have fly it last week end.
Seem everything ok except that problem on the tail, so we consider to buy that airplane and then when it will be in italy to made the fix.

About my RV7 it has also these bumps on the tail even if the problem is very light.
Indeed every RV7 that I have seen in Italy have that problem, less or more.
I attach the pics of the tail of mine

[Smilin' Jack]

Went to the airport and inspected my RV7. I too have this problem. Hardly noticeably there but it is.. mine is slightly less than Dimitri. So I walked over to a friends hanger and looked at his 6. He too has a ever so slight bulge but putting your hand on it you can feel it... So off to look at another 7. Same as mine...
I took photo's outside and inside of mine sent them to Van's
We'll see what they say, I also included the 6 photos. On mine there is no distortions on the inside, in fact you can not even notice any bulge on the inside.
There are no working rivets nor bulkhead distortions.

I will continue to look at other RV7's. Perhaps we do need a continuation of a small channel across the lower section of the inspection plate which attaches to the two bulkheads.

I am waiting for a response from Van's

[maniago]

FWIW weve had this issue on the Mustang2 for many years as well (not sure about the midget) and the factory change is to make a full skin doubler that fits inside the tail cone between the last two buklheads - a double skin wall if you will - the inside doubler is .032 and the original skin .025. I also added an additional bulkhead at the factory suggestion as I plan on a lot of grasswork, and have therefore leaf springs and 7" TW. The additional BH is rivetted to the back of second to last BH so I have BH flanges facing forward and facing aft and obviously a double line of rivets there picking up the skin. We have a longitudinal skin flange extending all the way back to the vert spar, but no additional longerons extending back there like you guys do.

Of additional note, a post build fix in our case is to add the full skin doubler outside the skin - same idea. Not sure how youd do that with your inspection cover. We have our inspection hole in the previous bay.

[Smilin' Jack]

I have installed a beef up to the area described after talking to Scott McDaniels,
It is not a item recommended by Van's or Scott at this time.
Since the 7 fuselage is a RV9A the mid horizontal J angle was not carried through to the aft bulkhead as in the RV6, RV 8 or the RV14. I talked to Scott and he said he had seen it but not in sufficient quantity.
It took two days, did not have to remove the tail as all work was done through the aft inspection panels.
I did this as I had a extremely slight bulge and after looking at several other RV7" decided it was a nice improvement to the area. The nice part is the bulge was eliminated.
It is about 5 pages long and if you would like me to email you a copy please send me an email.

Thanks
Jack Hunt
jethound@comcast.net

[BillL]

Originally Posted by Smilin' Jack

I have installed a beef up to the area described after talking to Scott McDaniels,
It is not a item recommended by Van's or Scott at this time.
Since the 7 fuselage is a RV9A the mid horizontal J angle was not carried through to the aft bulkhead as in the RV6, RV 8 or the RV14. I talked to Scott and he said he had seen it but not in sufficient quantity.
It took two days, did not have to remove the tail as all work was done through the aft inspection panels.
I did this as I had a extremely slight bulge and after looking at several other RV7" decided it was a nice improvement to the area. The nice part is the bulge was eliminated.
It is about 5 pages long and if you would like me to email you a copy please send me an email.

Thanks
Jack Hunt
jethound@comcast.net

Email sent Jack. My non-flying 7 has the pucker in that last station. I thought it was just due to the second bulkhead pulling it in. The pucker will allow it to buckle at a much lower load in compression.
Thanks,