AD/DHC-3/32 Amdt 1 - Utility Seat Forward Leg Positive Lock Installation

Overview

The Civil Aviation Regulations 1998, under Part 39 - 105, address safety concerns in civil aviation by issuing Airworthiness Directives (ADs) to ensure that aircraft meet specific safety standards. One such AD, AD/DHC-3/32 Amendment 1, pertains to DHC-3 (Otter) Series aeroplanes, specifically addressing an issue with utility seats that could disengage under certain conditions. This legislation was introduced to rectify a safety gap identified in side folding cabin utility seats where a sideways force could cause the forward leg to disengage from the keyhole slot in the seat rail. The Civil Aviation Safety Authority, as the enacting body, mandates compliance with the De Havilland Canada Service Bulletin 3/42 Revision A to mitigate the risk of such disengagement, thereby enhancing overall flight safety. The policy objective of this AD is to ensure that the specified models of utility seats are maintained and inspected rigorously to prevent any potential disengagement that could compromise flight safety. Compliance requires that inspections be conducted prior to the issue of the next Maintenance Release after 31 December 1987, and subsequently at each inspection for Maintenance Release until the seats are modified as detailed in the referenced service bulletin. This measure underscores the commitment of the Civil Aviation Safety Authority to maintaining high safety standards in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, as amended, apply to all DHC-3 (Otter) Series Aeroplanes with side folding cabin utility seats, mandating compliance with Airworthiness Directive (AD) DHC-3/32 Amendment 1, which requires the installation of a utility seat forward leg positive lock. This regulation applies to aircraft operators and maintenance personnel across Australia, enforcing adherence to the specified maintenance requirements and inspections to ensure the safety of the aircraft. The regulation’s geographic reach is nationwide, ensuring consistent safety standards are met throughout the Commonwealth. The directive applies to all models of DHC-3 (Otter) Series Aeroplanes equipped with side folding cabin utility seats, necessitating specific actions in accordance with De Havilland Canada Service Bulletin (SB) 3/42 Rev A. Compliance must be achieved before the issue of the next Maintenance Release after 31 December 1987 and subsequently at each inspection for Maintenance Release issue until the modification is completed. Additionally, after each deployment of the seats, a compliance inspection must be conducted until the modification is in place. This directive extends its application through subordinate instruments, ensuring the safety of air travel within the Commonwealth of Australia.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, include specific airworthiness directives for aircraft such as the DHC-3 (Otter) series aeroplanes. One such directive, AD/DHC-3/32 Amendment 1, pertains to the installation of a utility seat forward leg positive lock to address safety concerns (section 11/88). This directive applies to all models equipped with side folding cabin utility seats. The requirement is for action to be taken in accordance with De Havilland Canada Service Bulletin (SB) 3/42 Revision A, which details the necessary modifications to ensure the seat's structural integrity. Compliance with this directive is mandatory and involves two key steps. First, the inspection and compliance must be completed prior to the issuance of the next Maintenance Release after 31 December 1987, and subsequently at each inspection for a Maintenance Release until the aircraft is modified as specified in SB 3/42 Rev A (section 1). Second, the directive requires an inspection each time the seats are moved from the stowed to the deployed position, continuing until the modifications are made (section 2). Additionally, this inspection can be performed by the Pilot-In-Command, provided the precise AD reference is entered in a certification made on the Maintenance Release (Note 1). The regulations impose clear obligations on the parties involved, such as aircraft operators and maintenance personnel, to ensure that the required modifications are implemented and that the specified inspections are carried out. Failure to comply with these directives could result in significant safety risks, such as the utility seat forward leg disengaging from the keyhole slot in the seat rail under sideways force. Operators must adhere to these compliance requirements to maintain the airworthiness of the aircraft. Failure to comply with these airworthiness directives can lead to serious consequences. While the specific civil or criminal penalties are not detailed within the directive itself, non-compliance with Civil Aviation Regulations can result in enforcement actions by the Civil Aviation Safety Authority (CASA). Potential consequences may include fines, grounding of the aircraft, or other regulatory actions deemed necessary to ensure compliance and safety. The exact penalties would be determined based on the severity of the breach and the specific regulations involved.