COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Fokker F27 Series Aeroplanes AD/F27/137 Rudder Horn Assembly and Control Rod 11/94 Applicability: Model F27 Mk 100 through Mk 700 series, all serial numbers, if in pre-SB F27/27- 131 configuration. Requirement: Action in accordance with Fokker SB F27/27-131. Note: RLD AD 94-105 (A) refers. Compliance: Prior to 1 March 1996. Background: A number of cracked or broken rudder horns have been reported to the manufacturer. An investigation revealed that impact overload, caused by heavy gust conditions while parked, had caused the initial fracture. The RLD has determined that an unsafe condition has been identified that may exist or develop in other aircraft of the same type design, and therefore requires fitment of an improved rudder horn assembly and control rod.