Not jammed, but associated problem. Southern UK S&R helo Flt Cdr was large and muscular (known as 'Punch-up' P.....) Helos were Whirlwind 10s with floor mounted rotary friction adjusters for the control column. Punch-up used to insist on flying with these frictions fully tightened - "gives it a bit of 'feel' . He was duty First standby one day when the 'trapper' arrived unexpectedly. Said 'trapper' was authorised for a bit of 'hands-on' around the airfield in the standby aircraft. All was well until lift-off!! The subsequent manouevres were unusual as franfic attempts were made to translate, maintain yaw control and reduce frictions by applying feet to rotary knobs. Control and calm was eventually restored but blood pressure probably remained high for a while!!