CIVIL AVIATION ACT 1988
CIVIL AVIATION SAFETY REGULATIONS 1998
ISSUE OF AIRWORTHINESS DIRECTIVE
Under section 98 of the Civil Aviation Act 1988, the Governor-General may make regulations for the purposes of the Act and in the interests of the safety of air navigation. Under regulation 39.001 of the Civil Aviation Safety Regulations 1998, CASA may issue airworthiness directives (ADs) for kinds of aircraft or aeronautical products. Subregulation 39.001(5) of the Civil Aviation Safety Regulations 1998 provides that an AD is a disallowable instrument for the purposes of section 46A of the Acts Interpretation Act 1901. Therefore, in accordance with section 6 of the Legislative Instruments Act 2003, an AD is a legislative instrument.
Under Annex 8 to the Convention on International Civil Aviation, the State of Design has overall responsibility for continuing airworthiness of an aircraft type, and must provide any information necessary to ensure the continuing airworthiness of a type to appropriate States of Registry. ADs (and their equivalents) are the most common form of continuing airworthiness information, and are issued by most ICAO Contracting States.
The State of Registry of an individual aircraft is responsible for its continuing airworthiness. Under Annex 8, the State of Registry must develop or adopt requirements to ensure the continuing airworthiness of aircraft. When a State of Design issues an AD against a type of aircraft on the Australian Register, CASA, as Australia’s national airworthiness authority, must assess that information and, if appropriate, issue an Australian AD to mandate the requirements of the State of Design.
CASA has raised AD/DHC-1/22 Amendment 4 to correct an unsafe situation on de Havilland DHC-1 aircraft. CASA raised the original issue of this AD to mandate the inspection of the tailplane structure on DHC-1 aircraft. A recent review of de Havilland technical documents has shown that the inspection is also applicable to Portuguese manufactured T Mk 20 aircraft. Due to the imminent entry onto the Australian register of a Portuguese manufactured DHC-1 T Mk 20, CASA has amended the AD to include this model in the applicability of the AD. The amended AD, AD/DHC-1/22 Amendment 4, becomes effective on 22 June 2011. This AD cancels and replaces the previous issue.
CASA has not consulted with the Australian industry and public because this amendment does not alter the AD requirements or compliance.
The AD has been made by the Manager, Continuing Airworthiness, in the Airworthiness and Engineering Branch, Standards Development and Future Technology Division, on behalf of CASA, in accordance with subsection 94 (1) of the Act.