COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-42 (Cheyenne III) Series Aeroplanes AD/PA-42/11 Hydraulic Hose 6/86 DM Applicability: All model PA-42 Cheyenne III with S/Nos 42-7800001, 42-7800002, 42-7801003, 42-7801004 and 42-8001001 to 42-8001106. All model PA-42 Cheyenne IIIA with S/Nos 42-8301001, 42-8301002, 42-5501003 to 42-5501023, 42-5501025. Requirement: Action in accordance with Piper Service Bulletin No. 822. Compliance: Within 25 hours time in service after 19 May 1986. Background: A group of hydraulic hoses were manufactured using material that does not meet the pressure requirements for operation in the aircraft hydraulic system.