1.Transfer drill holes in Forward and aft mounts through upper longeron and bulkhead reinforcement angles. There is approximately 5/8” of material you are drilling through, so try to drill as straight and square as you can, a second person checking can be helpful. Drill initially the #30 holes, then upsize the holes in steps to #16, and finally ream to .1880 for close tolerance bolts similar to what is used in the wing spars. These bolts should be a light drive fit, some bolts that are on the high side of the tolerance may need to have the holes reamed slightly larger.
2.Transfer #30 holes in rear spar through the rear mounts. A 6” bit is also helpful here. Next upsize holes to #16 in steps and finally ream to 0.1880” for light drive close tolerance bolts. 4 holes total.
3.Transfer drill #30 holes in front spar into the forward mounts. A small standard drill can be used to drill these. Again upsize to #16 and ream to 0.1880” for light drive close tolerance bolts. 4 holes total.
