David Aronson's RV-4 Tech Page
Fabrication of Easy Off inspection Panels
During fabrication of my RV4 I was not happy with the time it took to remove the inspection plates in the wings. Besides the complications of having all the nut-plates and need to counter sink or dimple all those screw holes in the cover, I just didn't want to do the same for the fuselage inspection plates. So, I started looking for an alternate. I cannot tell you where the idea is stolen from, probably Tony Bingelis. The list of materials is found just after the pictures. Sizes are not included as you would adjust to your needs anyway.
1. Decide where you will need the access. Note that rudder cables, electrical wires, tubing, etc., may traverse the area after you install the plate. It would be no harder to install later, so maybe hold off planning these until you are ready to "close-up" the fuselage.
2. Use a hole cutter or carefully use a die-cutter to make access hole
in fuselage skin.
3. Fabricate doubler to reinforce hole, create a stop for the cover and
also a lock cut-out for the locking mechanism. Like the doubler on your
wing inspection panels, it must be smaller than the actual dimension for the
cover plate. The exception is that at the top and bottom it must have
cut-outs for the mechanism to slide and retain the plate against the back of the
skin.
4. Drill holes for doubler and countersink. Prior to riveting
doubler, use hole to trace exact size of cover.
5. Cut out cover, rivet doubler and finally fit cover.
6. Cut mechanism pieces as indicated in pictures. Assemble with
Boelube lubricant and rivets. The mechanism is actuated by the large 3/8
in rivet. I glue the rivet in place with J/B Weld.
7. The last picture shows the plate installed. Just pull down on the small extended rivet and the plate comes off. I have since drilled a hole through the length of the rivet and cut the rivet flush. Now I need a small tool to remove the plate but there is no additional drag. (Not worth effort probably)
Materials List:
Doubler
.040-.045
Inspection Plate .040 (same as skin)
Mechanism
.080 (3/4" strips)
3/32 rivets
1 3/8 rivet X 1.25"
1 3/8 rivet X 1/2
Spring
