Vintage aircraft often have vintage owners. Familiarity being a source of contempt, long-time owners of aircraft seeing little activity may also see little need to perform preventive maintenance or conduct regular inspections. It was just fine when I parked it; what could possibly have broken while it was sitting in a hangar? can be a familiar refrain to pilots who have owned the same airplane for a significant time. After a while, the pilot/owner is so familiar with the aircraft, he or she can tell somethings wrong just by the slipstream noise.