AD/DC4/31 - Propeller Feathering System - Modification

Overview

The Civil Aviation Regulations 1998, as amended by F2006B08838, were enacted to ensure the safe operation of aircraft within Australian airspace. This particular legislative instrument, under PART 39 - 105, addresses the safety of Douglas DC4 Series aeroplanes by issuing an Airworthiness Directive concerning the propeller feathering system. The primary objective of this directive is to mitigate fire hazards associated with the flexible hose components of the propeller feathering lines by mandating their replacement with hose assemblies that have greater fire resistance. This directive aims to enhance the overall safety and reliability of the aircraft, ensuring compliance with international safety standards set forth by the Federal Aviation Administration (FAA) and the Australian Civil Aviation Safety Authority (CASA). The enforcement of these regulations falls under the jurisdiction of the relevant legislature, ensuring that all modifications are performed in adherence to the specified requirements.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Airworthiness Directives issued by the Civil Aviation Safety Authority (CASA) and applies to all Douglas DC4 Series aeroplanes. This particular directive, AD/DC4/31, mandates that the flexible hose components of the propeller feathering lines located forward of the firewall be replaced with hose assemblies that offer enhanced fire resistance. The acceptable hose assemblies for this purpose include Resistoflex P/N SSFR-3800-10, Aeroquip P/N 304000 (680-10S with 304 sleeves over end fittings), Aeroquip P/N 309009-10S or -8S, FAA AD 55-15-3, or ANO 105.1.16.2.5.31. It is important to note that the directive does not affect flexible hose assemblies situated forward of the cylinders and connecting to the governor. This regulation applies nationally and is enforced by CASA, with potential extensions or restrictions via subordinate instruments.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contains a schedule of airworthiness directives for various aircraft types, including the Douglas DC4 Series Aeroplanes (section 105). One such directive, AD/DC4/31, addresses modifications to the propeller feathering system. This directive applies to all models of the Douglas DC4 series (section 1). The requirement is to replace the existing flexible hose components of the propeller feathering lines that are located forward of the firewall with hose assemblies that exhibit greater fire resistance (section 2). Acceptable hose assemblies for this purpose include Resistoflex P/N SSFR-3800-10, Aeroquip P/N 304000 (specifically 680-10S with 304 sleeves over end fittings), and Aeroquip P/N 309009-10S or -8S (section 2). It is important to note that the flexible hose assemblies located forward of the cylinders and connecting to the governor are not subject to this directive (section 2). The Civil Aviation Regulations impose specific obligations on the parties and entities it governs. Aircraft owners and operators must ensure that the modifications specified in AD/DC4/31 are carried out before any further flight operations. This includes sourcing the approved hose assemblies and replacing the existing flexible hose components as required (section 1). Maintenance personnel and engineers responsible for the aircraft must be aware of the directive and perform the necessary modifications in accordance with the specified standards and procedures. Additionally, the directive references FAA AD 55-15-3 and ANO 105.1.16.2.5.31, indicating that compliance with these related regulations is also necessary (section 2). Failure to comply with the requirements of AD/DC4/31 can lead to significant consequences. The Civil Aviation Regulations outline various offences and penalties for non-compliance with airworthiness directives. In this case, if an aircraft is operated without the required modifications to the propeller feathering system, it may be deemed unairworthy (section 3). This can result in enforcement actions by the Civil Aviation Safety Authority, including the imposition of fines and potential grounding of the aircraft. The specific penalties for non-compliance are not detailed within the text of AD/DC4/31, but they are likely to be in line with the broader provisions of the Civil Aviation Regulations and related legislation.