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/CA21/9 Carburettor Heat Modification Number 7/97 12/98 TX Applicability: All Skyfox CA22A aircraft fitted with ROTAX 912 engines. Requirement: Embody Skyfox modification Number 7/97 in accordance with the manufacturer's instructions. Compliance: Within 10 flying hours or 30 days, whichever is the sooner, of the effective date of this directive. This directive becomes effective on 18 September 1998. Background: ROTAX powered Skyfox CA22A aircraft suffer from excessive RPM drop when carburettor heat is selected. Skyfox modification 7/97 was released in October 1997 to correct this unsatisfactory characteristic. This is considered to be a safety of flight issue and this Directive is issued to ensure that all Skyfox CA22A aircraft are modified expediently.