What was found
UPON EXITING THE AIRCRAFT, THE WEIGHT OF THE PILOT STANDING ON THE RT FLAP, TORE THE ACTUATOR ATTACH BRACKET, RIPPED THE SKIN AND PULLED THE RIB ATTACHMENT OUT OF THE FLAP. THIS CONDITION ALLOWED THE FLAP TO GO TO THE EXTENDED POSTION. IN-FLIGHT, AN UNNOTICED CRACK IN THE AREA COULD RESULT IN FLAP RETRACTION UNDER THE EXTREME AIR LOADS IN THIS AREA. SUSPECT CAUSE, OVER-STRESS OF ACTUATOR ATTACH AREA. WEAK AREA. PREVENTION, MODIFY, BEEF-UP, MORE FREQUENT INSPECTIONS.