WPR15IA046 · Embraer EMB-505

The airline transport pilot was preparing to take off for a personal cross-country flight. He reported that the preflight preparations were normal, including the removal of the rudder gust lock pin. He stated that the taxi out for takeoff was normal but that he "detected an abnormal 'feel' to the rudders." He added that all of the turns to the runway were right turns and that he "easily executed" the turns. Following rotation on takeoff, the pilot noticed a significant right yaw and roll, which he initially countered with left aileron. As the airplane continued to climb, the airplane's flight was uncoordinated, and the pilot had to continuously apply left rudder to counter the right yaw; he also attempted to apply left yaw trim, but neither action resolved the issue. At this time, the pilot advised air traffic control (ATC) that he needed to return to the departure airport, and ATC cleared the pilot for a visual approach. The pilot landed the airplane; only minor damage to the left wing tip was incurred as the pilot tried to unsuccessfully correct (with the right rudder and aileron) a drift to the right after landing.

The initial examination of the airplane revealed that the rudder gust lock had failed in the locked position. Upon further examination, it was determined that the gust lock actuator had likely begun to retract as commanded by the pilot when he removed the rudder gust lock pin during the preflight/startup checks. However, the solenoid located within the gust lock actuator failed, which resulted in the pin no longer being held in the retracted position. Once the pin released from its retracted position, it engaged the ball nut, which then stopped the rotation of the actuator shaft. The failure occurred at a time when the gust lock bellcrank had not fully disengaged from the rudder quadrant, which likely resulted in the rudder being locked throughout the taxi, takeoff, climb, descent, approach and landing, and landing roll segments of the flight.

Although it is possible that a momentary power interruption could have caused the solenoid pin to release, which would have then resulted in the pin moving to the extended position and interfering with the ball nut, no conclusive evidence was found during the investigation that supported this possibility. The reason for the failure of the gust lock actuator solenoid could not be determined.

Verbatim NTSB analysis and probable cause from the NTSB dataset