AD/DHC-6/54 Amdt 2 - Side Folding Cabin Utility Seats - Inspection and Modification

Overview

The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B09142, address safety concerns associated with the side folding cabin utility seats of DHC-6 (Twin Otter) Series Aeroplanes. Enacted by the Australian Government, the objective of this regulation is to ensure that the aircraft maintain airworthiness standards and mitigate risks to passengers and crew. The regulation applies to all DHC-6 aircraft fitted with the specified seats and mandates inspections and modifications to prevent the disengagement of the front legs of the seats from the floor's keyhole slots, which poses a safety hazard. Compliance with this directive is necessary to ensure continued safe operation of the affected aircraft. The regulation requires an initial inspection within 10 hours after 27 March 1984 and subsequent inspections at intervals not exceeding 50 hours until a specific modification is implemented. Once the modification is complete, inspections must adhere to the De Havilland Inspection Requirement Manual. This legislative update aligns with Transport Canada's Airworthiness Directive CF-83-25 R1, Revision 1, to harmonise safety standards and enhance the overall safety of civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, applies to all DHC-6 (Twin Otter) series aeroplanes fitted with side folding cabin utility seats. This legislation is designed to address a specific safety concern identified in the aircraft's design, namely the potential for the front legs of the cabin utility seats to disengage from the keyhole slots in the floor, which poses a risk to the occupants. The scope of this regulation encompasses all relevant aircraft, mandating compliance with the detailed inspection and modification requirements outlined in the referenced De Havilland Inspection Requirement Manual Revision 6, chapter 25, Item 5, as amended by the Transport Canada AD CF-83-25 R1. The application of this directive is not limited by geographic or jurisdictional boundaries within the Commonwealth of Australia, ensuring uniform safety standards are upheld across all regions. There are no stated exclusions or exemptions within the text, and compliance is mandatory for all applicable aircraft operators. The Act’s application may be extended or further detailed through subordinate instruments, ensuring that the regulations remain current with any developments in aviation safety standards.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contains the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, including AD/DHC-6/54 Amendment 2 concerning the side folding cabin utility seats on DHC-6 (Twin Otter) series aeroplanes. This directive applies to all DHC-6 aircraft fitted with side folding cabin utility seats (Section 1). The primary requirement is to conduct an inspection within 10 hours of service after 27 March 1984, as detailed in the referenced document De Havilland of Canada S.B. No. 6/447 Rev. A, and Transport Canada AD CF-83-25 R1 (Section 1.1). Subsequent inspections must occur at intervals not exceeding 50 hours of service until the modification No. 6/1828 is implemented on all side folding utility seats (Section 1.2). Following the incorporation of the specified modification, inspections must comply with the De Havilland Inspection Requirement Manual Revision 6, chapter 25, Item 5 (Section 1.3). The obligations under this directive require operators of DHC-6 aircraft to ensure that the specified inspections and modifications are carried out in a timely manner. Operators must adhere to the inspection intervals and the requirements outlined in the De Havilland Inspection Requirement Manual post-modification. This includes ensuring that the aircraft is grounded or restricted from service until the modifications are completed and subsequent inspections are satisfactorily conducted. It is also the responsibility of the operators to maintain accurate records of all inspections and modifications performed in compliance with the directive. Failure to comply with the requirements of this airworthiness directive can result in significant consequences. Although specific penalties are not detailed in the text provided, non-compliance with CASA directives generally can lead to enforcement actions. These may include fines, penalties, and in severe cases, the grounding of the aircraft. The exact penalties can vary depending on the severity and frequency of the non-compliance. It is important for operators to adhere strictly to the directive to avoid any legal repercussions and to ensure the continued airworthiness of the aircraft.