Talking of oversize holes, I used to work for a helicopter manufacturer who designed and embodied a flotation bag modification for the British Army. They used the forward undercarriage mountings as the main attachment points for the flotation bags. Unfortunately they carried out the modification at a time when the aircraft was stripped down and jacked up for heavy maintenance. When the aircraft was rebuilt, lowered off jacks and fuelled up, The 8mm holes didn't even come close to lining up. The solution was to drill out one set of holes to 12mm and the other set of holes to 13mm then use the original 8mm bolts with very big washers to clamp the thing up. Cringeworthy
