COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F100 (F28 Mk 100) Series Aeroplanes AD/F100/1 Flight Controls - Horizontal Stabiliser Dual Actuator - Periodic Inspection 1/99 Applicability: F28 Mk100 aircraft serial numbers 11244 to 11356 (incl) which do not have modified Horizontal Stabiliser Dual Hydraulic Control Actuators in accordance with Fokker Service Bulletin F100-27-032 dated 20 September 1991. Requirement: 1. Perform an initial inspection in accordance with Fokker Service Bulletin F100-27- 029 dated 29 January 1991. 2. Repeat the inspection at 1. Above. Note: RLD Airworthiness Directive 91-015 Issue 2 dated 18 October 1991 refers. Compliance: 1. Aircraft which have accumulated more than 2000 flight hours or 12 months time in service at the effective date of this Directive shall be inspected within the next 400 flight hours or two months time in service. 2. Every 2000 flight hours or twelve months time in service. This Airworthiness Directive becomes effective on 28 January 1999. Background: A number of operators reported faults with the horizontal stabiliser system which were attributed to water ingress into the dual actuator servo valve manifold end cap. This directive introduces an inspection to check for such contamination pending modification of the system. Modification of the system in accordance with manufacturer's instructions cancels this requirement.