Spar Wedges

[jeffreyK]

The plans for the fuselage show spar wedges only placed between spars 2-3, 4-5, and 5-6. Is that it? I don't see any reference to put spar wedges on any of the others nor between the longerons and the spars. I realize this area carries a lot of weight and stress so maybe they are the only spars to be reinforced. Do I understand that correctly?

[tom kreiner]

Without looking at the plans which are out of my shop, I would have to say that the reason for this is because the forward part of the fuselage is sheathed with 1/8 inch plywood from firewall to the rear pit.

Along with the sheathing, wedges provide additional joint strength needed in this area due flight loads imposed by the cabanes and struts.

From the rear pit to the tail end of the fuselage, you will see that 1/8 inch gusset plates are used on the outside of the fuselage.

Hope this helps...

[Earl Brown]

There are also blocks added to the top of #3 and #5 for mounting the cabane struts.
Depending on how you attach the rear seatbelts, the UK plans show a large wedge added behind #7 at the lower longeron.
Also, 1/8 gussets are used on the outside and the inside of the fuselage from the rear cockpit back, not just on the outside.

[jeffreyK]

Thanks for the added knowledge. I am aware of the blocks and the gussets and I have been thinking about seat belts. I appreciate getting the clarification.