Cabin Door and Windows

March 7, 2011

To save some time I got my cabin door and windows from Avipro. If you decide to make yours, make them in place with 1/8" gap from the door opening formers all around. Here is a quick representation of how I made the ones for my Bearhawk 4-place airplane from scratch. The same technique applies for the Patrol door, but the shape along the bottom of the door is a little different (there is no "mouse" door on the patrol door). Here's how to make your own door and windows from scratch.

Note:  The pictures below are from my 4-place Bearhawk build.  The door shape is a little different from that on a Patrol, but the techniques are the same.

Bend the forward tube for the door, to match the curve of the door opening former.  

Clamp the piece in place using 1/8" spacers (note I used 1/4" spacers for the Bearhawk, but recommend 1/8"):

Cut the bottom piece to fit and clamp it in place with 1/8" spacers, then tack weld (3 sides) it to the front tube:

Continue doing the same all the way around until you get to the top of the door. At that point you can cut and fit the top tube and tack it in place. Once you have all of the pieces for the door tack welded in place, you can un clamp the door and go ahead and complete the welds for each joint.

Here is the completed 4-place Bearhawk door:

The window works pretty much the same way but you have to fabricate a couple of hinges for the window.  These are made from 4130 tube as shown in the July 2010 Newsletter. I used square tubing to make the window frames for my 4-place but don't recommend it. Use the round, its easier to get a good fit of the window.  Anyway, here is how I made the window frame on the Bearhawk.

I started with the top tube, again clamping it in place with 1/8" spacers.  The tube used for the hinges was clamped in place with a 3/16" bolt inserted to prevent warping:

With everything properly lined up, the hinge tube was welded to the top window frame tube with a 1/2" bead on each side of the clamp:

The clamp and window frame was then removed and the bolt taken out.  Then the un-welded portion center portion of the hinge was carefully cut out just inside each weld, using a small Dremmel cut-off wheel.

The center piece was then reinstalled in the window frame hinge using a 3/16" bolt, the top window tube was repositioned on the fuselage. With the window frame top tube properly aligned and clamped in place with 1/8' spacers, the center portion of the hinge was welded to the fuselage frame.  Here is the completed hinge with a clevis pin:

At this point the remaining tubes for the window frame can be fabricated, clamped in place with 1/8" spacers and tack welded. the window is competed using the same technique as for the door frame.

That was the 4-place bearhawk.  

Click here for the Patrol Door and Window installation