Aileron cables

I decided to drill the holes to run the aileron cables through the wing ribs today and immediately ran into some issues understanding the instructions. After speaking with Mark and researching the forum it became apparent that the instruction manual was wrong, and the photos in the manual were incorrect also.

In addition, the factory had added a fairlead mount on rib #2 instead of rib #6, and the holes were not centred. Also the two pulley retainers that mount above the wing strut had been welded incorrectly so that the guards blocked the cable.

I removed the rivets holding the fairlead in place, and eventually riveted it into the correct place on rib #6. Then I removed the weld on the pulley guards and got a friend to weld them correctly. I also corrected the holes that were off center.

Then I made a card template and used it to mark the holes for the first 6 ribs, these holes keep the cable close to the top skin in order to clear the flap mechanism when the flaps are lowered. I also used a steel rod to estimate the position of the remaining ribs out to the aileron bellcrank. These holes gradually slope down from just below the top skin, to the bell crank at mid position. The bellcrank also moves the cable fore and aft as it moves, so the holes closer to the bellcrank need to be elongated.

Finally I threaded a galvanized cable into position, and it all lined up correctly.

Next, I marked out the position to cut the hole for the forward cable through the bottom skin where it exits to run down the strut. The position didn’t look correct even after checking it again against the instructions. The correct position differs from the instructions by nearly an inch. I’ll drill this tomorrow.