Aunt Donna, Uncle Richard and Liz had just finished a scenic tour of the lava flow on the Big Island of Hawaii. When I got out of the plane, oil was all over the fuselage. Investigation revealed I had not put the oil cap on after adding oil before the flight. We had lost one quart of oil. It was embarrassing and messy but no harm was done. Two days later I ran up the engine on the ground and flew over the airport, each time inspecting afterward for any oil leaks. All was OK.