KeithB
Well Known Member
This is a cautionary post for RV-14 builders completing the wing kit and incorporating Service Bulletin 16-03-28 for aileron hinge brackets. It might also apply to the RV-10 as the hinges and SB kit are the same.
When the service bulletin came out for the aileron hinge brackets, I had largely completed the wings, but had not riveted on the bottom skins (to allow for avionics decisions such as auto pilot servo, magnetometer, etc. to be incorporated later). With the bottom skins still open, I felt it was an opportunity to incorporate the revised aileron hinges with limited difficulty (compared to after the wings are closed up), and opted to order and install the retrofit kit.
I drilled out the spar rivets to remove the old hinge, disassembled the hinge to recover the bearing, reassembled the new hinge and riveted it to the spar per the provided instructions. However, when I went to install the aileron back on the wing, the inboard edge of the aileron now contacted the heads of the AN470AD4 rivets used to join the two halves of the new hinge bracket. In retrospect, of course the new hinge is thicker with the addition of a pair of .125 angles. This increased thickness comes out of the distance between the base of the hinge brackets, and out of the clearance between the leading edge of the aileron and the base of the hinge bracket.
I talked to mothership tech support and the fixes proposed were 1) file/bend the aileron skin to clear the rivet heads, 2) swap or substitute washers and/or spacers on the hinge bolts to move the aileron outboard or 3) drill out AN470 rivets in favor of AN426 ones where the heads interfered. After a limited amount of filing, I abandoned 1) as insufficient and unsatisfactory. 2) turned out to be inadequate by itself. So, for 3) I drilled out the two bottom-most AN470AD4 rivets of the 5 joining the hinge bracket halves, then countersunk the angle and replaced with AN426AD4-11 rivets (yes, they are that long). The upper 3 rivets were okay. In addition, on one aileron, I also needed to reposition washers and modify the spacer to better center the aileron between the two hinge brackets. It ends up a tighter fit than before the hinge bracket replacement, but it works.
I would recommend all 5 AN470AD4 rivets be replaced with AN426AD4 rivets when joining the halves of the new inboard aileron hinge brackets. Some adjustment of spacer/washers may still be required.
I apologize for the quality of the photos.
When the service bulletin came out for the aileron hinge brackets, I had largely completed the wings, but had not riveted on the bottom skins (to allow for avionics decisions such as auto pilot servo, magnetometer, etc. to be incorporated later). With the bottom skins still open, I felt it was an opportunity to incorporate the revised aileron hinges with limited difficulty (compared to after the wings are closed up), and opted to order and install the retrofit kit.
I drilled out the spar rivets to remove the old hinge, disassembled the hinge to recover the bearing, reassembled the new hinge and riveted it to the spar per the provided instructions. However, when I went to install the aileron back on the wing, the inboard edge of the aileron now contacted the heads of the AN470AD4 rivets used to join the two halves of the new hinge bracket. In retrospect, of course the new hinge is thicker with the addition of a pair of .125 angles. This increased thickness comes out of the distance between the base of the hinge brackets, and out of the clearance between the leading edge of the aileron and the base of the hinge bracket.
I talked to mothership tech support and the fixes proposed were 1) file/bend the aileron skin to clear the rivet heads, 2) swap or substitute washers and/or spacers on the hinge bolts to move the aileron outboard or 3) drill out AN470 rivets in favor of AN426 ones where the heads interfered. After a limited amount of filing, I abandoned 1) as insufficient and unsatisfactory. 2) turned out to be inadequate by itself. So, for 3) I drilled out the two bottom-most AN470AD4 rivets of the 5 joining the hinge bracket halves, then countersunk the angle and replaced with AN426AD4-11 rivets (yes, they are that long). The upper 3 rivets were okay. In addition, on one aileron, I also needed to reposition washers and modify the spacer to better center the aileron between the two hinge brackets. It ends up a tighter fit than before the hinge bracket replacement, but it works.
I would recommend all 5 AN470AD4 rivets be replaced with AN426AD4 rivets when joining the halves of the new inboard aileron hinge brackets. Some adjustment of spacer/washers may still be required.
I apologize for the quality of the photos.