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-8/1 Ground and Roll Control Spoilers 11/88 Applicability: Model DHC-8 with serial numbers 003 and subsequent. Requirement: 1. Modify the landing gear proximity switch electronic unit (PSEU) in accordance with De Havilland SB No. 8-32-54 Revision B. 2. Modify the electrical power phase supply for the PSEU BITE power circuit in accordance with De Havilland SB No. 8-32-55 Revision A. 3. Remove the placard, and reinstate the equipment previously deactivated by Transport Canada AD CF-86-11 R2 Para 1, 2 and 3, in accordance with the instructions of De Havilland SB No. 8-27-34 Revision C. Note: Transport Canada AD CF-86-11 R2 and FAA AD 86-14-51 R1 refer. It should be noted however that compliance with either of these documents does not ensure compliance with this AD, unless specific reference is made to the terminating action of the above referenced Service Bulletins. Compliance: Before issue of a Certificate of Airworthiness. Background: Deactivation of the ground spoilers and roll control spoilers was necessary to prevent an uncommanded deployment in the ground mode, and to preclude a hazardous loss of lift in a critical phase of flight. Incorporation of the specified modifications permits removal of the operating limitations and re-establishes normal use of all spoilers in the ground mode.