Continuing onward, the plans have the builder prepare seat ribs for assembly. Some of the ribs receive seatbelt mounting lugs. The seatbelt lugs are sandwiched between the F-1215 seat ribs and a smaller F-1216 seatbelt lug support … followed by match drilling the rivet holes to #30 per the plans. Access was good for the pneumatic squeezer so the four ribs that received the seat belt mounting lugs were all riveted with AN470AD4-6 solid rivets as opposed to LP4-3 pop rivets.
Securing the seatbelt mounting lugs onto one of the F-1215L ribs with Clecos.
Match drilling the rivet holes in the seatbelt mounting lugs, F-1215R seat rib and F-1216 lug support to #30.
Using the pneumatic squeezer to rivet the seatbelt lug components onto an F-1215R rib with AN470AD4-6 solid rivets.
Four F-1215 ribs with the seatbelt mounting lugs riveted in place with AN470AD4-6 solid rivets.
Because the landing gear service bulletin added stiffener plates onto the bottom of the fuselage, rivet holes on the seat ribs at those locations were not dimpled for the flush rivets being used on the project … instead, the stiffener plates were thick enough to machine countersink. To keep track of everything, early on I assigned numbers to the F-1215-L&R seat ribs. The seat ribs were numbered R1 to R4 and L1 to L4 and their positioning was marked on the drawings and in the instructions. So while assembling or adding nutplates, etc. the correct seat rib for that particular location needed to be located. Those builders not using exterior flush rivets won’t have to worry about which left or right rib to choose … however, because of bottom skin stiffeners used in the service bulletin, I needed to keep track of seat rib positions because not all ribs received the same number of dimples for the exterior flush rivets being utilized on the project.
Quite a few nutplates were dimpled and installed yesterday onto the F-1215 seat ribs. Some of the F-1215 seat ribs also needed to have #19 holes drilled at some of the nutplate locations.
Using the pneumatic squeezer to attach nutplates onto one of the F-1215L seat ribs with AN460AD3-3.5 rivets.
After dimpling and installing quite a few nutplates onto the F-1215 seat ribs, the plans called for sandwiching the previously assembled pulley assembly between a F-1215L seat with a seatbelt lug installed and a regular F-1215L rib. Access was poor for the pneumatic squeezer so the pulley assembly was riveted between the two F-1215 seat ribs using the pop rivets called for in the plans.
Using the hand rivet puller to rivet the pulley assembly between two F-1215L seat ribs with LP4-3 pop rivets.
The flaperon mixer arm assembly was next in line to be sandwiched between two F-1215R seat ribs one of which with seatbelt lugs attached. Five of the fifteen rivets attaching the mixer assembly had to be pop rivets because of poor access … but the remaining ten rivet locations offered good access for the pneumatic squeezer, so AN470AD4-4 and AN470AD4-4.5 rivets were installed depending on metal thickness at the rivet location.
Using the pneumatic rivet squeezer to rivet the flaperon mixer arm assembly onto an F-1215 seat rib.The locations of the solid rivets attaching the flaperon mixer arm assembly onto the F-1215R seat rib can be easily seen here. Of note, the two rivets on the left of the flaperon stop plate are flush pop rivets per the plans.
Autopilot servo mounting plate detour to Section 39 of the plans. For those builders installing an autopilot, there is a detour at this point in the plans to allow for easy install of the autopilot servo mounting bracket. The autopilot instillation instructions have the builder open up a slot in one of the F-1215R ribs (one without the seatbelt lugs) that will sandwich the flaperon mixer arm assembly. I elected to make the cuts using the nibbling tool and made fast rough cuts then another pass to trim to the line followed by a small amount of filing to smooth the edges.
Slot that requires opening for the auto pilot servo mounting bracket is marked in red on the F-1215R seat rib.
Using the nibbling tool to create the require slot in the F-1215R seat rib for the autopilot servo mounting bracket.
Finished autopilot servo mounting bracket slot in the F-1215R seat rib.
The autopilot servo bracket has four holes in it that align to holes already in the F-1215R seat rib. After the mounting bracket is Clecoed in place, there are seven holes that need to be match drilled to #30 and four of those holes are enlarged further to #12. Access was good for the pneumatic squeezer, so the autopilot servo bracket was riveted in place on the F-1215R seat rib using AN470AD4-4.5 rivets.
The seven holes in the autopilot servo bracket that require match drilling are marked in red.The autopilot servo mounting bracket drilled and riveted in place on the F-1215R seat rib using AN470AD4-4.5 solid rivets in place of LP4-3 pop rivets.
The finished seat rib was then Clecoed onto the flaperon mixer arm assembly and the flange on the autopilot servo bracket was riveted onto the aft intercostal (which already had holes). Access for the pneumatic squeezer was tight but doable, so the autopilot servo bracket’s flange was riveted onto the aft intercostal with AN470AD4-4.5 solid rivets as opposed to LP4-3 pop rivets.
Pointing to where the autopilot servo mounting bracket’s flange is riveted onto the aft intercostal with three AN470AD4-4.5 solid rivets in place of LP4-3 rivets.
It was getting late so did not finish riveting the remaining rivets which will secure the flaperon mixer arm assembly onto the F-1215R rib so will knock that out first thing during the next work session later today.