COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes AD/DHC-8/30 Nose Wheel Steering Potentiometer Lever Stop 1/94 Applicability: Model DHC-8 Series 100 aircraft, serial numbers 003 through 334. Requirement: Accomplish de Havilland Modification 8/1809, in accordance with de Havilland Service Bulletin 8-32-99 Revision A. Note: Transport Canada AD CF-93-24 refers. Compliance: Prior to 15 May 1994. Background: The potentiometer stops in the nose gear steering system have been found to be too short to limit excessive uncontrolled potentiometer lever movement, in the event of failure of the mechanical link between the rudder pedals and the potentiometer. Failure of the link could result in the aircraft departing the runway during take-off or landing.