COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piaggio P166 Series Aeroplanes AD/P166/34 Landing Gear Selector Valve - Modification 11/68 Applicability: All model P166 fitted with selector valve P/N 5-5233 which does not have the suffix Rev. A on valve name plate. Document: 1. Piaggio SB No. 166-56; or 2. RAI AD 68-173/P166-31, Rev. 1. Compliance: Within 100 hours time in service after 28 November 1968.