Some in-service aircraft have had cracks form in the aft fuselage bottom skin, on either side of bulkhead F-01408. Vans issued a Service Bulletin SB 18-09-17 to install the parts shown above to reinforce the areas concerned.
Since I had already finished this part of the aft fuselage, these have to be retro-fitted.
So I placed the aft fuselage on its side with carpet underneath for protection …
… and then placed cushions inside to lay on.
Now you have to drill out 10 lovingly set rivets. Foohey Fudge Cake!
I had previously primed the area which will be covered by the external F-14148A Skin Doubler.
I took things very slowly and they all came out nicely.
Here are all 10 removed.
Once the stiffener clips are clecoed in place, the #30 holes have to be match drilled into the bulkhead.
As advised I clamped a wooden block on the back side of the bulkhead when drilling.
I placed a bits of carpet everywhere something could drop onto the fuselage skin … just in case!
First hole match drilled and clecoed ready for the second hole.
Deburred the holes.
In order to get access to the rivets on the stiffener doublers it’s necessary to remove the SB625-7 bushing from the UAT Antenna Cable. Then you can push the cable aside.
I managed to get my pneumatic squeezer on the top 470 rivets attaching the stiffener clips to the bulkhead, but not the bottom ones shown by the arrows. Maybe a hand squeezer would fit?
Anyway, we used a long rivet set and bucking bar for these.
Obviously help is needed to set the 426-3’s.
Access for a bucking bar is straightforward …
… apart from this little fella. Inside it’s very tight against the rear of the bulkhead. We managed to get an edge of a bar onto it eventually.
All in all not too hard a job, but I’m glad it’s done!