Door & Window Latches

Started July 28, 2006

The latches for the main cabin doors are shown in the Bear-Tracks newsletter as being back near the rear of the door.  When I sat in Proto II, I decided that I didn't like having to reach behind my shoulder to open the door.  Therefore, I came up with a design that is similar to the original plan, but moves the mechanism more toward the middle of the door where it's easier to reach.

Here is my set-up:

I also have decided to only have the handle on the inside of the door and not prodruding on the outside.  Since the window must be in the up position to open the door anyway, why not just reach inside to open the door?  Also it makes locking the airplane simple.  I will lock the window in the closed position and you can't open the door.

Here is a close-up of the handle assembly:

The spring pushes against a washer and cotter pin, which pushes the latch rod aft.

ADDENDUM

May 19, 2007

After covering and during final installation of the doors, I decided to modify this system to allow the doors to be closed without pulling the latch handle forward.  To accomplish this I made a striker for the door flange. This was made from 4130N steel plate:

The 3/8" tube used for the door latch was then tapered to 45 degrees and shortened enough to allow it to hit the edge of the striker and slide across it and into the hole:

Now the front doors close just like a car door.  

Next we will work on the Window latch.

Here are the parts needed for the window latch:

The latch is screwed into the window frame and the hook and nut is screwed onto the other side.  Here is the outside of the window latch in the closed position.

Here is the inside of the window latch:

After covering the inside of the door with fabric, I will make a stainless steel striker plate for this hook to ride against.

Door & Window Latches

Completed: August 13, 2006

Total Time: 12 hours

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