After fooling around with the Cessna hinge I decided to go back to the original drawing and use a standard hinge for the door. I fabricated a new hing and cut the slot for the hinge. I used a .025 shim to lower the hinge on the door side so it rides parallel with the hing part on the cowl. This also lowers the hinge line. I'm fabricating some side angles to keep the door from bowing under air pressure and I'll reinforce the center of the door with a couple of layers of fiberglass matting.
