The pilot was conducting a flight to check the output of the spray system fitted to the aircraft. During the take-off he heard a noise from the rear of the aircraft and noticed something moving away from the aircraft. He continued with the take-off and two spray runs before positioning the aircraft on a downwind leg for landing. As the aircraft was turned onto the base leg the pilot realised that he could not apply left rudder. The pilot stated that he then intended landing the aircraft on the base leg but found that cone markers blocked the path. The aircraft was then lined up with and landed on runway 22. An inspection determined that the leaf-spring mounting that retains the tailwheel had failed due to fatigue. The loss of rudder control experienced by the pilot resulted from the bending of the left rudder to tailwheel control arm so that adequate left rudder could not be applied. It is considered that the leaf-spring failure should have been detected during routine maintenance or pre-flight inspection.
