AD/JETSTREAM/67 - Wing - Fuselage Forward Attachment Spigot Bushes Migration

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, encompasses the Civil Aviation Safety Authority's schedule of airworthiness directives, including AD/JETSTREAM/67 which pertains to the British Aerospace BAe 3100 (Jetstream) Series Aeroplanes. This legislative instrument was enacted to address a critical safety issue concerning the wing-fuselage forward attachment spigot bushes on certain Jetstream aircraft. The problem identified was that the outboard bush in the spigot post assembly could migrate inboard, potentially leading to a redistribution of loads in the wing and a reduction in fatigue life, which could compromise the overall airworthiness of the aircraft. The regulations were enacted by the Commonwealth of Australia and are overseen by the Civil Aviation Safety Authority, with the policy objective of ensuring that all affected aircraft meet the specified safety standards to mitigate risks associated with bush migration. Compliance with AD/JETSTREAM/67 requires a visual inspection of the outboard bush in the spigot post assembly to ascertain any inboard migration, followed by the installation of a modified one-piece bush if the migration exceeds a specified threshold. This directive applies to all HP137 Mk1 aircraft and Jetstream series 3100 aircraft with constructor’s numbers ranging from 601 to 702 inclusive. Inspections are mandated within a defined timeline post the directive’s issuance, with subsequent inspections scheduled at specific intervals based on the findings of the initial inspection. The installation of the modified bush cancels the need for further inspections, underscoring the importance of timely compliance to ensure continued airworthiness.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertain to the safety of aircraft and their operation within Australian airspace. This legislation applies to all HP137 Mk1 aircraft and Jetstream series 3100 aeroplanes with constructor’s numbers ranging from 601 to 702 inclusive. The regulation mandates specific actions concerning the spigot bushes in the wing-fuselage forward attachment of these aircraft to ensure airworthiness. The requirement includes a visual inspection of the outboard bush in the spigot post assembly to determine any migration inboard, followed by the installation of a modified one-piece bush if necessary. Compliance with this directive involves inspecting the aircraft within 1200 landings after 15 September 1994 and repeating inspections at intervals based on the extent of bush migration, while modifications must be undertaken within 200 landings if the migration exceeds 0.5 inches. This regulation ensures that these aircraft maintain the necessary safety standards to mitigate potential risks such as load redistribution in the wing and reduced fatigue life.

Key Provisions

The Civil Aviation Regulations 1998, under PART 39 - 105, specifically address the airworthiness directives for British Aerospace BAe 3100 (Jetstream) series aeroplanes. AD/JETSTREAM/67 pertains to the wing-fuselage forward attachment spigot bushes migration (section 10/94). This directive applies to all HP137 Mk1 aircraft and Jetstream series 3100 aircraft with constructor's numbers ranging from 601 to 702 inclusive. The primary requirement of this directive is to visually inspect the outboard bush in the spigot post assembly on both the left and right sides to determine if the bush has migrated inboard, as per British Aerospace SB 57-A-JA 920640 Fig 1 and Part 1. If bush migration is detected, the installation of a modified one-piece bush is mandated, in accordance with British Aerospace SB 57-A-JA 920640 Part 2. Operators and owners of the affected aircraft must ensure compliance with these inspection and modification requirements. The initial inspection must be carried out within 1200 landings after 15 September 1994, and subsequent inspections are required at intervals of 6000 landings if no bush migration is detected, or at intervals of 1200 landings if bush migration is less than 0.5 inches. If bush migration is more than 0.5 inches, the modification must be completed within 200 landings. Once the one-piece bush is installed, it negates the requirement for further inspections under this directive. Failure to adhere to the requirements set forth in AD/JETSTREAM/67 may result in serious safety issues, including the redistribution of loads in the wing and a reduction in fatigue life, which can compromise the overall airworthiness of the aircraft. The regulations do not explicitly outline specific penalties or consequences for non-compliance; however, non-compliance with airworthiness directives is generally considered a breach of the Civil Aviation Act 1988 and may lead to enforcement actions by the Civil Aviation Safety Authority (CASA). These actions can include fines, suspension or revocation of airworthiness certificates, or other regulatory measures deemed necessary to ensure compliance and maintain safety standards.