AD/CESSNA 185/36 - Aileron Balance Weight Installation

Overview

The Civil Aviation Regulations 1998, specifically within Part 39 - 105, address the issue of ensuring the airworthiness of aircraft through various directives, including AD/CESSNA 185/36. Enacted by the Commonwealth of Australia, this legislation aims to safeguard the integrity and safety of civil aviation by providing clear directives for aircraft maintenance and modifications. This particular directive, issued by the Civil Aviation Safety Authority, targets the Cessna 185 series aeroplanes to mitigate the risk of aileron flutter, which could otherwise lead to destructive outcomes. The policy objective is to enforce stringent checks and compliance to maintain the safety standards of the aircraft, particularly focusing on the installation of aileron balance weights. Ensuring adherence to these regulations within the stipulated timeframe is critical to prevent potential hazards during flight.

Scope and Application

The Civil Aviation Safety Authority's Schedule of Airworthiness Directives under the Civil Aviation Regulations 1998 specifically addresses the installation and inspection of aileron balance weights for Cessna 185 series aeroplanes, as outlined in AD/CESSNA 185/36. This directive applies to all models 185, 185A through 185E, and A185E and A185F aircraft that have been modified in accordance with the Robertson STC SA 1441WE. The primary requirement is to ensure that these aircraft, if modified by Robertson Aircraft Corporation Repair Station No. 415-23 prior to 1 August 1983, undergo an inspection of their aileron balance weights. If the height of all the balance weights is approximately 3/4 inch, the aircraft is deemed correctly installed and no further action is required. However, if any weight measures approximately 1/2 inch, it must be replaced with the correct part number as per the applicable STC data or Robertson S.B. No. 20. Following replacement, the ailerons must be rebalanced within the limits specified by the Cessna Aircraft Company Service Manual for the specific aircraft. Compliance with this directive is mandatory within 50 hours of time in service after 31 January 1983, and failure to adhere to the directive could result in destructive aileron flutter.

Key Provisions

The Civil Aviation Regulations 1998, particularly under Part 39, specifically address the airworthiness directives for aircraft, including the Cessna 185 Series Aeroplanes. Section AD/CESSNA 185/36 outlines the requirements for aileron balance weight installation. This directive applies to all models of the Cessna 185 series, specifically those that have been modified in accordance with the Robertson STC SA 1441WE (Section 1). The directive mandates that operators determine whether the aircraft in question has undergone the specified modifications by the Robertson Aircraft Corporation Repair Station No 415-23 prior to 1 August 1983 (Section 1). If the aircraft has been so modified, the directive requires an inspection of the aileron balance weights (Section 2). This inspection entails measuring the height of all aileron balance weights. If all weights measure approximately 3/4 inch, they are correctly installed, and no further action is necessary (Section 2). However, if any weight measures approximately 1/2 inch, it must be replaced with a balance weight of the appropriate part number, as specified by the applicable STC data or Robertson S.B. No. 20. Additionally, the ailerons must be rebalanced within the limits specified by the Cessna Aircraft Company Service Manual for the particular aircraft model (Section 2). The regulations impose specific obligations on the operators of the affected aircraft. They must ensure that the aircraft has been modified as per the Robertson STC SA 1441WE and carry out the necessary inspection of the aileron balance weights. If the weights are found to be incorrectly installed, the operators must replace them and rebalance the ailerons accordingly. This must be completed within 50 hours of the aircraft being in service after 31 January 1983 (Section 3). Compliance with these requirements is critical to maintaining the airworthiness of the aircraft and ensuring safe flight operations. Failure to comply with the provisions of AD/CESSNA 185/36 could result in serious safety issues, such as destructive aileron flutter, which could compromise the integrity and safety of the aircraft during flight. The Civil Aviation Safety Authority (CASA) enforces these regulations rigorously, and non-compliance may lead to various penalties and consequences. These could include fines, suspension or revocation of the aircraft's airworthiness certificate, or other enforcement actions deemed necessary by CASA. The exact penalties are not specified within the text of the directive but are generally aligned with the broader regulatory framework governing civil aviation in Australia.