Continuing the countersinking work on prepping the forward fuselage parts.

Found out that my countersinks were not deep enough so needed to review the 4 floor stiffeners I did before. You must not be able to put a 0.002" feeler gauge between the skin and countersunk piece. I don't have such gauge at hand but looking at a light source with my test 0.032" dimpled plate clearly showed still some gap between the parts. Countersinking really is not my favorite work on the airplane.

Also countersunk the F713 auxiliary longerons and F717 lower longerons.

Had some doubts on the forward 5 rivets but then realized that these lay on top of the engine mounts so they also must be countersunk. Did that after the picture was taken.

The five read holes on the F717 lower longeron will be drilled later, you can see on DWG34 that these will go in in combination with the F7114 fuselage gusset and will be bolted with AN3 bolts.