Working On Flap Controls

Spent some time working on components that make up the flap controls. The flap handle is a hollow tubular shaft that internally receives a thumb knob, a spring and fork assembly.  These parts allow the flap handle to be raised or lowered then locked in three preset positions. The fork assembly has a pin through it which locks into groves cut into the F-1266A flap detent bracket. The fork assembly has three spacers sandwiched between the two forks this is typically done with pop rivets … but AN470AD4 solid rivets were used in the place of the pop rivets.

Using a rivet gage to determine the correct rivet length that will hold together the fork assembly.

After the flap handle fork assembly was riveted together, it was clamped onto the F-1260A flap handle tube, carefully aligned, then the F-1260A tube was match drilled to the rivet holes in the fork assembly. The assembly was disassembled, deburred, then riveted with LP4-3 pop rivets.

Riveting the flap handle fork onto the F-1260A flap handle tube with LP4-3 pop rivets.

Completed flap handle fork assembly with the locking pin installed.

The next flap control component to be riveted was the F-1266A flap detent bracket. The flap detent bracket becomes sandwiched between two F-1266C flap detent angles then attached onto the F-1266B detent bracket plate.

Riveting the two F-1266C flap detent angles onto the F-1266A flap detent bracket.

One of the two F-1266C angles only has holes on one flange … the other flange becomes match drilled to the F-1266B flap detent bracket plate after the angles are riveted to the F-1266A flap detent bracket.

Flap detent assembly secured onto the F-1266B flap detent bracket plate with Clecos. Note how the nearest F-1266C flap detent angle has no rivet holes … there are holes in the F-1266B bracket plate below which will be used to match drill the angle.

Using the rivet holes in the F-1266B bracket plate to match drill the one F-1266C flap detent angle that had no rivet holes.

After match drilling the F-1266C flap detent angle the assembly disassembled and deburred. Next the six rivet holes in the F-1266B bracket plate are machine countersunk on the bottom side of the plate for AN426AD4-6 flush rivets.

Machine countersinking the six rivet holes in the F-1266B bracket plate with a #30 100 degree countersink bit.

Riveting the flap detent assembly onto the F-1266B bracket plate with AN426AD4-6 flush solid rivets.

Completed flap detent bracket assembly.