Building C-140 Patroller Doors
Building C-140 Patroller doors
Patroller doors are one of those things that look really cool but are pretty hard to find. A number of people have modified regular cessna doors to make them, and this is my attempt at that.
This is the starting point. I marked out the cutout based on dimensions taken from the cessna drawings and then used a cutoff wheel to cut it out. Go slow, this will leave a nice cut that requires minimal effort to finish later. I left the corners like that so they can be rounded out nicely later on.
There's the outside skin cut. Had to drill out a few rivets to get that free from the inside skin.
Working on the inside. Notice how it's pressed outwards - that's for rigidity, but will make this modification a little more trouble because we need that to be flat now. Next step is to separate the door skins. This means drilling out a lot of 3/32 rivets. I used a 3/32 bit, drilled the head "just enough" and then used a pin punch to drive the rivet out the back. It goes quicker than you would think.
This was my solution to getting the pressed inner skin to lie flat, making a number of relief cuts.
Additionally, my door had some cracks by the latch so I made a doubler to go inside this area. Next step is fabricating the 'Z' channel stiffeners. I didn't find a place to buy this stuff, it's kind of a specific dimension... so I made it on a sheet metal brake.