Summary
The pilot completed the refuelling of the aircraft and pushed it back to a position approximately half way across
the 100 feet wide apron. He applied the parking brake, carried out a pre-flight check and commenced the
starting up procedure. He made two unsuccessful attempts to start the engine and then adopted the flooded
start technique by setting the throttle to 3/4 open and the mixture control to "Idle Cut Off". When the engine
fired on this attempt the pilot moved the mixture control to "Rich" but then found that he was unable to close
the throttle, which had apparently jammed. The aircraft moved forward under high power, overcoming the
parking brake, which was weak. Before the pilot was able to move his feet from their position on the floor and
place them on the brake pedals, or take any of the other courses of action which were indicated, the aircraft
had travelled forward some 60 feet to a position at which it struck a heavy wooden post and a steel stake on the
fence line of the apron. Examination of the throttle control assembly did not disclose any defect which would
have accounted for the inability of the pilot to control the engine power output, however, misuse of the throttle
locking button could have led to a situation in which the throttle control jammed.
