The Cessna 550 Citation Bravo corporate jet taxied at Lismore Airport for a flight to Baryulgil, New South Wales. The flight crew consisted of a captain and copilot, who were the only occupants of the aircraft. The flight crew did not detect anything abnormal during the taxi and take-off roll, until the captain attempted to rotate the aircraft to the take-off pitch attitude. When the aircraft had achieved the required rotate speed, the captain applied the normal backpressure on the control column to achieve a standard rate of rotation, and the aircraft did not rotate. The captain then applied full backpressure and reported that the controls felt very heavy. Neither the captain nor the copilot detected any change in the aircraft’s pitch attitude or any indication of pitch-up on the attitude direction indicator. The captain rejected the take-off, applied full braking and reverse thrust, but the aircraft overran the runway. The nose landing gear detached from the aircraft about 50 m beyond the end of the sealed runway, and the aircraft came to rest in long grass and mud. The aircraft sustained substantial damage, and the captain and copilot were uninjured. The aircraft did not accelerate normally as the acceleration was retarded by drag associated with rolling friction. This was indicative of partial brake pressure remaining during the take-off run. The partial brake pressure was possibly due to the parking brake being selected on at the holding point with enough pressure to retard aircraft acceleration during the take-off, but not sufficient to prevent the aircraft reaching rotate speed. Furthermore, the nose-down moment generated by the partial brake pressure probably prevented the aircraft rotating sufficiently to become airborne, despite normal nose-up elevator deflection. Heat in the brakes due to partial pressure during the take-off run may have reduced their effectiveness when the captain rejected the take-off, contributing to the runway overrun. Contributing factors – There was probably residual braking pressure in the wheel brakes during the take-off run. – The aircraft’s parking brake was probably applied while at the holding point and not disengaged before taxing onto the runway for take-off. – The Citation aircraft did not have an annunciator light to show that the parking brake is engaged, and the manufacturer’s before take-off checklist did not include a check to ensure the parking brake is disengaged. – The aircraft experienced a retarded acceleration during the take-off run, and did not rotate as normal when the appropriate rotate speed was reached, resulting in a critical rejected take-off and a runway overrun.