AD/DHA-3/5 - Windscreen Wiper - Modification

Overview

The Civil Aviation Regulations 1998, as amended by the Legislative Instrument F2006B08988, focus on enhancing aviation safety through the implementation of Airworthiness Directives. This specific directive, AD/DHA-3/5, targets Drover Series Aeroplanes equipped with vacuum-operated windscreen wipers, particularly those identified with DH Part No. S3-533A. The directive was enacted to address the problem of insufficient windscreen wiper performance, which could potentially compromise visibility and thus flight safety. The enacting authority for these regulations is the Civil Aviation Safety Authority, under the overarching policy objective of ensuring the highest standards of airworthiness and safety within the aviation industry. Compliance with these directives is mandatory and must be achieved without delay to mitigate any safety risks associated with inadequate windscreen wiper function.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 pertaining to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, applies to all models of Drover Series aeroplanes equipped with a vacuum-operated windscreen wiper with DH Part No. S3-533A. This legislation governs the mandatory modifications or replacements of the windscreen wiper installation to ensure safety standards are met. The directive mandates that the windscreen wiper installation must provide a minimum blade pressure of 28 ounces against the windscreen, measured at the blade attachment point, and a minimum operating rate of 200 strokes per minute. Alternatively, the installation can be replaced with a De Havilland P/N S3-547A electrically-operated type or any other wiper installation approved by the Secretary. The compliance requirement is immediate, ensuring that any necessary modifications or replacements are conducted forthwith. The scope of this legislation extends nationally, applying across the Commonwealth of Australia, thereby affecting all relevant aircraft operators and maintenance entities within its jurisdiction. The regulations do not specify exclusions or exemptions, implying that all applicable aircraft must adhere to the stipulated modifications. The authority to extend or restrict the application of this directive may be exercised through subordinate instruments, thereby allowing for further clarification or adaptation to specific circumstances.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, establish the schedule of airworthiness directives, including AD/DHA-3/5 for Drover Series Aeroplanes, which mandates modifications to the windscreen wiper system (section 12/52). For all models equipped with vacuum-operated windscreen wipers with DH part number S3-533A, the directive requires that the wiper installation be modified to ensure a minimum blade pressure of 28 ounces against the windscreen, measured at the blade attachment point, and a minimum operating rate of 200 strokes per minute (section 1). Alternatively, the installation can be replaced with a De Havilland P/N S3-547A, electrically-operated type, or another wiper installation approved by the Secretary (section 2). Additionally, compliance with DH TNS CT(A3) No. 46 or ANO 105.1.14.14 is required (section 3). The obligations imposed by this directive necessitate that operators of Drover Series Aeroplanes fitted with the specified windscreen wipers must undertake the required modifications or replacements without delay. Operators are required to ensure that the windscreen wiper system meets the specified pressure and operating rate criteria or install an approved alternative. This includes verifying that any modifications or replacements are conducted in accordance with the standards set forth in the directive and any relevant technical standards or airworthiness notifications. Compliance must be achieved forthwith, indicating that the modifications must be completed promptly upon the issuance of the directive. Failure to comply with the airworthiness directive AD/DHA-3/5 may result in serious safety implications for the operation of the aircraft. Civil Aviation Safety Regulations do not specify explicit offences or penalties for non-compliance within the directive itself. However, general provisions under the Civil Aviation Act 1988 may apply, potentially leading to enforcement actions, fines, or other regulatory consequences for failing to meet airworthiness requirements. Operators are advised to ensure strict adherence to the directive to avoid any potential legal repercussions or safety hazards.