Note: This is a reprint from ThorpList edited by Richard Eklund.
- Look for wing skin creases on either side (fore and aft) of the main spar. Creases are evidence of excessive g-loads, usually due to high-speed pull-ups.
- Check the nose rib rivets for looseness or evidence of working loose. The original plans called for 12 rivets on the upper surface of the nose ribs and 12 on the lower surface. A number of builders later found that these rivets were overloaded and would work themselves loose. Thorp later revised his plans to add additional rivets. DWG A-???
- Check for cracks in the landing gear A-frame, particularly where the cross-member is welded to the gear legs. Also, some aircraft have been found w/o heat-treated landing gear. These can be retrofitted with the gear-leg extensions from Classic Sport Aircraft.
- Check for the rudder pedals hitting on the fuel tank.
- Check for chafing on the fuel tank. At least one builder found his tank worn thin where something was rubbing.
- Check for stall strips on the original T-18 wing. These are typically made from