COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
De Havilland DHC-1 (Chipmunk) Series Aeroplanes
AD/DHC-1/9 Rudder Torque Tube Flange - Inspection 9/57
Applicability: All models.
Requirement: 1. Remove the rudder, clean the Rudder Torque Flange P/N C1-TR-91, and inspect for cracks in the area of the shoulders on the semi- circular flange and the rivets securing the flange to the rudder torque tube. This inspection shall be made by either the dye penetrant method or visually with the aid of a 10X lens.
2. If cracking has occurred replace the flange before further flight; or 3. ANO 105.1.14.15.6.3.
Compliance: At intervals not exceeding 250 hours time in service.