Door Handle Stops (Cessna 0411615)

The inside door handles work in the reverse of what you would expect from opening car doors. To open the door you push the handle forward. It has to do with how the handle connects to the latch. There is a long thin strip of aluminum which is pulled forward to operate the latch. Because the handle is located just below the window the link from the handle to the strip makes the handle work in reverse. This could have been solved by placing the handle about 3 inches lower on the door but it would have put the handle in a very awkward location.

Because of all this a stop is needed to prevent buckling the long aluminum strip if someone pulls on the handle instead of pushing. The parts manual shows the stop (20) but mine were both missing. From looking at the picture in the parts manual the stop has 2 tabs which fit into 2 of the 4 holes in the inner bearing plate for the handle. The outer bearing plate is identical but without the holes for the stop. This stop looks weak, even more so if it were made from aluminum, which is probably why they were both removed. A change to the design was needed to make a stop which would work.

The material could be no thicker than 0.040" so a piece of .040" 4130 steel was used to make the stops. The original stop appears to be loaded in bending, which make it weak, so the new stop tab was designed to be loaded in shear with a welded corner for extra stiffness (see pictures below).

The process for making the stops was straight forward.  A paper pattern was made to check the fit.  The parts were laid out on the steel and as much hole punching, drilling and cutting done while the parts were still held on the sheet of steel.  The tabs were filed close to finished size but the notch for the stop was not cut to shape until all the bending was done.

Once the tabs were all bent they were filed to a snug fit in the holes of the bearing plate.

The Stop Tab was then welded.  The notch could then be cut and filed to a good fit so the handle would stop with the latch in the fully closed position.

The pictures below show the stop with the handle in the latched position and then in the unlatched (pushed forward) position. The cotter pins have not been bent for these pictures because that can only be done once all the parts are in the doors.

The left door with the latch and handle reassembled.  Next is the window latch, new glass in the window and then seals for the window and the door.  I don't plan to install the interior fabric panels until the plane is flying or I win the lottery.