I made the jig in photo one. It is actually the jig i used for the slat brackets but I added one more hole. I set the flapperon brackets as per the instructions and they seemed to fit nice and tight to the skin. Drilled with #20 and clecoed. Checked my distances between and they are bang on. Important to get the brackets on the correct side of the supports from the ribs. Two on one side two on the other. If not your distances will be off.
Template jig
Drilled and clecoed
Finished ready for L angle supports at the base of each bracket
