The door flanges are skip welded to the fuselage tubes to prevent warping.
The welds are about 3/8" long and are on 1 1/2" centers. Here
is the passenger side forward door flange welded in place:
The aft door flanges were made next. Here is the pilot's side aft door
flange blank ready for the 9/16" flanges to be bent:
Here are the flanges being formed using a couple of straight pieces of 3/4"
plywood (again, like on the wing ribs):
Here is the piece after forming. Note that the 9/16" flange was notched
at the bend and welded back together after the flanges were formed:
The aft door flange was fitted to the fuselage frame at station D/N. Again
a straight edge was used to assure that the flange was properly aligned:
Here it is after skip welding:
The next piece to be fitted was the bottom door flanges. The bottom
door flanges are made from .040 steel and have a 1 1/8" flange on the them.
The piece that goes between station B/P and station C/S is a constant width
that matches the width of the forward door flange.
In the above photo you can see that a piece of aluminum angle and a straightedge
are used to properly align the piece and to hold it in place for welding.
Again, the piece was skip welded in place, this time the welds were about 1/2" long and on 1 1/2" centers.
The final door flange for the front doors of the airplane is the other bottom
piece that goes from station C/S to station D/N. This piece tapers
from the width of the aft door flange to the width of the other bottom door
flange. Here it is fitted and skip welded in place:
That completes the pilot's side for now.
Click here to go Door Flanges page 3