COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Skyfox Aviation (Calair/Hedaro) CA21 and CA22A Series Aeroplanes AD/CA21/3 Rudder Actuator Horn 1/96 Applicability: CA21 aircraft, serial numbers CA21004 through CA21035. Requirement: Inspect the rudder actuator horn for drain hole in accordance with Skyfox Aviation Service Bulletin No.4. Compliance: At the next inspection for issue of a Maintenance Release or within 100 hours time in service, from 4 January 1996 whichever occurs first. Background: Skyfox advise that a number of rudder actuator horns may not have had a drain hole installed at manufacture. This AD requires a drain hole to be drilled if not already fitted.