[bruceh]

I started fitting the flaps now that the wings are on temporarily. The instructions on this process are pretty sparse.

After the flap was put back on the wing, I pulled it up by hand to be flush with the underside of the fuselage and could tell that there was some resistance. Moving the flap back down I could see that the inboard edge of the nose of the flap was hitting the F-705B attachment for the rear wing spar. I was able to poke a pencil in there with the flap up and draw a line to see how much overlapped with the nose of the flap.

There is a note on DWG 38, Section G-G, about trimming of the F-705B and F-605C to eliminate interference with the nose of the flap assembly. It also cautions about the critical 5/8" edge distance requirement for the rear wing spar attach bolt.

I don't want to trim this critical attach point just to eliminate the interference with the nose of the flap. It looks like it would be a much better idea to trim the nose of the flap (marked in blue ink in this photo). There is just the flap leading edge skin under the blue mark, so there is nothing structural going on there.

Any one else have this issue? Searching of the forums and web came up blank on this.

 

[Ironflight]

Trim the nose of the flap - you wont' ever notice that it is gone!

 

[flion]

+1 what Paul said. As I recall, on my -6A I had to trim at both ends; the inboard aileron attachment also caused some interference. It's covered when the flaps are retracted and it isn't critical to the airflow over the wing when the flaps are down.

 

[bruceh]

I figured that was the right thing to do here, but I have never heard of any one else having to trim this.

If there is one thing I have learned in building this project, it is never cut/drill aluminum until you are really sure about what you are doing.

On to the left flap!

 

[rjcthree]

Trimming flap

Just had to do the same thing. The interference was about 1/32", but real. Rick 90432