AD/DHC-8/64 - Wing Fuel Tanks - Access Panel Sealing

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA), serve as the primary regulatory framework governing civil aviation safety in Australia. This legislation was enacted to ensure the safety of air operations within Australian airspace, addressing various aspects of aircraft operations, maintenance, and airworthiness. The regulation fills a critical gap by establishing mandatory safety standards and procedures for all civil aviation activities. Part 39, which includes Airworthiness Directives, specifically aims to ensure that aircraft meet required safety standards through specific directives that address identified safety issues. The policy objective of these regulations is to maintain the highest standards of safety in civil aviation, protecting both the public and personnel involved in air operations. One such Airworthiness Directive is AD/DHC-8/64, issued on 7 October 1999, targeting the Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes. This directive was introduced in response to a discovered sealing problem with the upper wing tank access panels of DHC-8 aircraft, which could potentially lead to significant safety hazards such as loss of lightning protection and structural integrity. The directive mandates that all affected aircraft must replace the wing tank access panel seals using specific modifications and service bulletins to ensure compliance by 9 February 2000. This intervention underscores the commitment of CASA to swiftly address and mitigate identified safety risks in the aviation sector.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning Airworthiness Directives, mandates that all Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes, from serial numbers 3 through 543, must adhere to the directive AD/DHC-8/64. This directive pertains to the modification of the wing fuel tank access panel seals to rectify a sealing issue identified during routine maintenance. The requirement involves changing the wing tank access panel seals using the specified ModSum 8Q1000797, in alignment with Bombardier Service Bulletin 8-57-41 dated 9 February 1999. The directive ensures that the sealing issue, which could potentially lead to the loss of lightning protection for the fuel tanks due to fretting and corrosion of the wing ladder plate and displacement of the adjacent channel seal, is addressed. Compliance with this directive is mandatory and must be completed prior to 9 February 2000 unless the modification has already been undertaken. The directive became effective on 7 October 1999, and references Transport Canada Airworthiness Directive CF-99-20 dated 20 July 1999 for additional context. This regulation applies nationwide across the Commonwealth of Australia and extends its jurisdiction over all entities operating DHC-8 series aeroplanes within the specified serial number range.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives for Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes. Under this section, the Airworthiness Directive (AD) AD/DHC-8/64 mandates the modification of wing fuel tank access panel seals for all DHC-8 aircraft, across all models and serial numbers from 3 through 543. This directive requires the change to be made using ModSum 8Q1000797, in compliance with Bombardier Service Bulletin 8-57-41 dated 9 February 1999 (Section 105). It is noted that this directive is consistent with Transport Canada's Airworthiness Directive CF-99-20 dated 20 July 1999. The directive stipulates that this compliance must be achieved before 9 February 2000, unless the required changes have already been completed. The directive took effect on 7 October 1999. Entities governed by this Act, particularly those involved in the maintenance, operation, or oversight of DHC-8 aircraft, are required to ensure that the specified modifications are carried out in a timely manner. This includes adherence to the Bombardier Service Bulletin 8-57-41, which outlines the technical specifications and procedures for changing the wing tank access panel seals. The directive mandates that any O-ring larger than specified, which had been incorrectly fitted during production, must be replaced. The primary objective is to prevent the eventual loss of lightning protection for the fuel tanks, which could occur due to fretting and corrosion of the wing ladder plate and displacement of the adjacent channel seal. Failure to comply with the provisions of this Airworthiness Directive can lead to significant legal and operational repercussions. The Civil Aviation Regulations 1998 impose strict obligations on aircraft operators and maintenance personnel to adhere to CASA directives to ensure the airworthiness of aircraft. Non-compliance with the specified requirements could result in the aircraft being deemed non-airworthy, potentially leading to grounding and prohibition of flight. Such violations may also attract regulatory scrutiny, including investigations by CASA, and could result in penalties. The specific consequences and penalties for non-compliance are not detailed within the text of the Airworthiness Directive itself but are governed by broader provisions within the Civil Aviation Act 1988 and the Civil Aviation Regulations 1998, which can include fines and other regulatory actions.