Swearingen SA-226T, Wheeling, Ill., April 11, 2007-A partial failure of the left engine propeller governor made directional control impossible, and the airplane ran into an airport sign, according to the NTSB. The pilot reported that at 75 knots during the takeoff roll, he felt a surge from the left engine, which “continued and positive directional control could not be regained.” The pilot aborted the takeoff and attempted to regain directional control by using differential braking and rudder inputs. The airplane subsequently departed the left side of the runway and hit an airport sign; the pilot
and the four passengers were uninjured.

Inspection of the governor revealed that the flyweight toe extensions were worn, altering flyweight position and reducing pressure gain. Recommended TBO of the unit is 3,500 hours, the subject governor had 913 hours at the time of the accident. The flyweights are not normally replaced during overhaul unless wear is found.