Oops
Taking of with 40 degrees of flap in a 150. Went up like a lift but didn't go forwards very fast! This was because I'd been distracted by a machine gun like noise when I was doing my pre-flight which was caused by my seatbelt buckle banging on the fuselage in the prop wash.........
Taking off the other day and wondering why my steed was taking longer than normal to levitate. No need to retract the flaps on the climbout then.......
Filling up my Piper Cub wing tank and forgetting to close the valve to the wingtank. Found out just how loud Whirlybird could scream when the (already full) front tank overflowed all over her feet! Sorry Whirls!
Nearly took off with the pitot tube cover in place after deciding to go flying after test running the engine. Thanks Mike!