What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(.4)The captain overflew the field to assess winds conditions and the windsock indicated a quartering headwind for runway 12. During rollout the airplane veered immediately right when the power levers were brought into beta. The captain corrected with rudder and braking but was unable to maintain directional control. The aircraft ran off the right side of the runway and collided with a ditch and an embankment. After deplaning, the crew found that the winds were a 60-degree tailwind on runway 12. The windsock's pivot point on the pole was rusted and would not rotate. The aircraft with the same landing weight and a 60-degree 10-knot tailwind would require a 1,600-foot landing roll on the 2,350-foot runway without the assistance of both props in beta. The beta pin had backed out of position on the left engine's beta control linkage. The beta pin, cotter pin, and washer were found in the bottom of the engine cowling. The left engine had been changed 2 days prior to the accident. As the mechanics finished the beta pin area during engine installation, the inspector checked the area and found that the pin was in place and properly safety wired. Following the inspector's signoff of the area, the mechanics discovered that the teleflex cable was too short for the beta valve to be flushed and subsequently had to be adjusted. The director of maintenance readjusted the cable, which required disturbing the safety wire on the beta pin. One of the two mechanics that had been instructed to re-safety the connections after the adjustment thought that the rear portion had already been safetied and did not recheck the area. The inspector believed the area had already been checked and did not re-examine the beta pin. (-23)during a left engine change two days prior to the accident mechanics failed to install a cotter pin (p/n MS9245-23) in the aft propeller control cam straight pin (p/n 3008971) on the aft end of the beta control cable (wire rope) after rigging the cable. After the straight pin fell out sometime during the first flight of the day (the accident occurred on the first flight) when thrust was applied it was asymmetrical. The right engine achieved beta the left did not. This caused the aircraft to veer off the runway to the right where it impacted into a ditch.
As the FAA filed it
(.4)THE CAPTAIN OVERFLEW THE FIELD TO ASSESS WINDS CONDITIONS AND THE WINDSOCK INDICATED A QUARTERING HEADWIND FOR RUNWAY 12. DURING ROLLOUT THE AIRPLANE VEERED IMMEDIATELY RIGHT WHEN THE POWER LEVERS WERE BROUGHT INTO BETA. THE CAPTAIN CORRECTED WITH RUDDER AND BRAKING BUT WAS UNABLE TO MAINTAIN DIRECTIONAL CONTROL. THE AIRCRAFT RAN OFF THE RIGHT SIDE OF THE RUNWAY AND COLLIDED WITH A DITCH AND AN EMBANKMENT. AFTER DEPLANING, THE CREW FOUND THAT THE WINDS WERE A 60-DEGREE TAILWIND ON RUNWAY 12. THE WINDSOCK'S PIVOT POINT ON THE POLE WAS RUSTED AND WOULD NOT ROTATE. THE AIRCRAFT WITH THE SAME LANDING WEIGHT AND A 60-DEGREE 10-KNOT TAILWIND WOULD REQUIRE A 1,600-FOOT LANDING ROLL ON THE 2,350-FOOT RUNWAY WITHOUT THE ASSISTANCE OF BOTH PROPS IN BETA. THE BETA PIN HAD BACKED OUT OF POSITION ON THE LEFT ENGINE'S BETA CONTROL LINKAGE. THE BETA PIN, COTTER PIN, AND WASHER WERE FOUND IN THE BOTTOM OF THE ENGINE COWLING. THE LEFT ENGINE HAD BEEN CHANGED 2 DAYS PRIOR TO THE ACCIDENT. AS THE MECHANICS FINISHED THE BETA PIN AREA DURING ENGINE INSTALLATION, THE INSPECTOR CHECKED THE AREA AND FOUND THAT THE PIN WAS IN PLACE AND PROPERLY SAFETY WIRED. FOLLOWING THE INSPECTOR'S SIGNOFF OF THE AREA, THE MECHANICS DISCOVERED THAT THE TELEFLEX CABLE WAS TOO SHORT FOR THE BETA VALVE TO BE FLUSHED AND SUBSEQUENTLY HAD TO BE ADJUSTED. THE DIRECTOR OF MAINTENANCE READJUSTED THE CABLE, WHICH REQUIRED DISTURBING THE SAFETY WIRE ON THE BETA PIN. ONE OF THE TWO MECHANICS THAT HAD BEEN INSTRUCTED TO RE-SAFETY THE CONNECTIONS AFTER THE ADJUSTMENT THOUGHT THAT THE REAR PORTION HAD ALREADY BEEN SAFETIED AND DID NOT RECHECK THE AREA. THE INSPECTOR BELIEVED THE AREA HAD ALREADY BEEN CHECKED AND DID NOT RE-EXAMINE THE BETA PIN. (-23)DURING A LEFT ENGINE CHANGE TWO DAYS PRIOR TO THE ACCIDENT MECHANICS FAILED TO INSTALL A COTTER PIN (P/N MS9245-23) IN THE AFT PROPELLER CONTROL CAM STRAIGHT PIN (P/N 3008971) ON THE AFT END OF THE BETA CONTROL CABLE (WIRE ROPE) AFTER RIGGING THE CABLE. AFTER THE STRAIGHT PIN FELL OUT SOMETIME DURING THE FIRST FLIGHT OF THE DAY (THE ACCIDENT OCCURRED ON THE FIRST FLIGHT) WHEN THRUST WAS APPLIED IT WAS ASYMMETRICAL. THE RIGHT ENGINE ACHIEVED BETA THE LEFT DID NOT. THIS CAUSED THE AIRCRAFT TO VEER OFF THE RUNWAY TO THE RIGHT WHERE IT IMPACTED INTO A DITCH.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.