AD/BEECH 90/81 - Stabiliser and Fin Moisture Sealing

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes an Airworthiness Directive concerning the Beechcraft 90 and 65-90 (King Air) Series Aeroplanes. This legislative instrument, enacted by the Commonwealth of Australia, aims to address the problem of control cable freezing in certain aircraft models, which can compromise safety and operational reliability. The directive was introduced to ensure the safety and airworthiness of these aircraft by mandating specific maintenance actions to prevent moisture-related issues that could lead to control failures. The Civil Aviation Safety Authority, the body responsible for the regulations, has established these requirements to align with the manufacturer's Service Bulletin 2254, ensuring that affected aircraft are maintained to a standard that safeguards against identified hazards.

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 the Beechcraft 90 and 65-90 (King Air) Series Aeroplanes with model F90 serial numbers LA-1 to LA-236. This regulation mandates action in accordance with Beechcraft Service Bulletin 2254, which focuses on the stabilising and fin moisture sealing to prevent control cable freezing, a known issue previously addressed in other aircraft models. The directive requires compliance before the next inspection for Maintenance Release, following 10 August 1989, or within 100 hours’ time in service after that date, whichever is later. The regulation's scope is confined to these specific aircraft models and serial numbers, and it applies nationally across Australia as part of the Commonwealth's regulatory framework. The applicability of this directive extends to all aircraft falling within the specified serial numbers and model type within the Australian jurisdiction. There are no stated exclusions or exemptions in the directive itself, although broader exemptions may apply under other sections of the Civil Aviation Regulations. The regulation reinforces the importance of adhering to manufacturer guidelines to ensure aircraft safety, particularly in addressing known vulnerabilities such as control cable freezing. The scope of application is further extended or clarified through subordinate instruments that may detail specific procedures and compliance measures.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39, particularly in the Schedule of Airworthiness Directives, outlines specific requirements for maintaining the airworthiness of certain aircraft models. One such directive is AD/BEECH 90/81, which pertains to the Beechcraft 90 and 65-90 (King Air) series aeroplanes (Section 39 - 105). This directive mandates the sealing of the stabiliser and fin to prevent moisture ingress, an issue that has led to control cable freezing in similar aircraft models. This specific directive applies to model F90 with serial numbers LA-1 to LA-236 (Section 39 - 105). The action required is in accordance with Beechcraft Service Bulletin 2254, which provides the technical specifications and procedures for implementing the necessary moisture sealing. The directive requires compliance either before the next inspection for maintenance release after 10 August 1989, or within 100 hours’ time in service after the same date, whichever is later (Section 39 - 105). Entities governed by these regulations, such as aircraft operators and maintenance providers, must ensure that the specified actions are carried out on the applicable aircraft. This involves conducting the necessary inspections and applying the moisture sealing as directed by the manufacturer's service bulletin. The Civil Aviation Safety Authority (CASA) expects these entities to maintain meticulous records of compliance to demonstrate adherence to the directive. Failure to comply with AD/BEECH 90/81 could lead to significant consequences. Non-compliance could result in the aircraft being deemed unairworthy, which could lead to grounding of the aircraft until the necessary actions are completed. Additionally, operators may face regulatory enforcement actions, which could include fines or other penalties as stipulated under the Civil Aviation Act 1988. The exact penalties for non-compliance are not specified in the directive but typically can include substantial financial penalties and possible criminal charges for those responsible for oversight failures.