CE-550 flight crew reported a loss of directional control while initiating the take-off roll. The aircraft came to a stop as the nose wheel exited the right edge of the runway with the nose wheel on the grass area with no damage.
Synopsis
CE-550 flight crew reported a loss of directional control while initiating the take-off roll. The aircraft came to a stop as the nose wheel exited the right edge of the runway with the nose wheel on the grass area with no damage.
Narrative
I was pilot flying from the left seat and PIC. We were in a slow taxi on taxiway approaching Runway XXL on the center line. The taxi checklist had been completed. Approaching Runway XXL; ZZZ Tower cleared us for take-off. I advanced the power slightly to continue the taxi onto the runway and called for the runway items checklist. The aircraft then suddenly veered to the right uncommanded; at a 45 degree angle. I immediately reduced the thrust to idle and applied full left rudder and brake. There was no command authority to the left and we continued to the right. I then applied full braking on both brakes at which time the aircraft came to a stop as the nose wheel exited the taxiway and came to rest in the grass. ZZZ Tower queried us as to what we were doing; and we responded that we had a directional control issue. We then requested that the FBO send a tug out to extricate us from the grass and tow us back to the FBO. Engines were shut down; and we advised medical of our situation. All pre-flight items were completed prior to departure.
Second reporter narrative
After our routine post-flight inside and outside the plane; I was the Second in Command (SIC) of the flight and did not observe any issues on the plane. After receiving clearance from Ground; we exited the ramp at the taxiway with a left turn. I performed the proper taxi checklist during the straight taxiway with no issues. On the next right turn; we continued to taxi in slow motion on the last segment of the taxiway; and we received clearance for take-off. The PIC moved the throttle slightly to compensate for the slight up slope and lost speed. Before reaching the holding short line; I was preparing the before-take-off checklist; the PIC was in control of the airplane; and I suddenly noticed a right turn toward the grass. I noticed that the PIC was surprised and struggling with the left pedal to correct the turn with no response observed. I decided to push both brake pedals at that moment; and we stopped the airplane with the front wheel positioned by the edge of the concrete taxiway on the grass border.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.