Flap Ribs 101 and 103 misalignment

Two issues were found when doing a test assembly of the flaps.

About 1.6mm misalignment between the skin holes and flange holes of Ribs 101 and 103 observed. Also a gap of about 1mm and 0.5mm respectively between the flange and skin surfaces for respectively Ribs 101 and 103.

After discussion with TAF the following remedy will be adopted:

Shim the gaps with 1.02mm and 0.64mm 6061-T6 sheet

Match drill enlarged holes of 4.9mm (#11 drill) centred on the lozenge shaped opening formed by the misaligned holes. The resultant holes will be circular. A drilling template should be used. The distance between the new hole centres will be about 8.8mm, less than the ideal 2D=9.6mm rule when 4.8mm rivets are used. TAF have confirmed a relaxed 1.5D=7.2mm is acceptable in this instance. Total thickness is 1.15mm (0.64mm flange + 0.51mm skin), greater than the 0.5mm minimum grip range of Gesipa 4.8mm x 10mm polygrip rivets

After further consideration, I will not be performing the above modifications owing to the risk of fouling the skins with the required re-centering and enlarging of holes. Instead I have requested replacements from TAF.