Substantially damaged in ground running incident prior to take-off (see video below). The explanation is approximately as follows:- Nose wheel is locked (should have unlocked in pre-taxi check list). Pilot then tries to taxi and turn left but the aircraft doesn’t respond as expected. After a pause, the nose wheel is unlocked, but without first re-centering the pedals. As soon as the nose wheel unlocks, the aircraft turns violently as commanded by the pedal position – the trim motors hold the pedal input at the last set position. 2 POB, not seriously injured