AD/LYC/86 Amdt 2 - Propeller Governor Oil Line

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, aim to ensure the safety and airworthiness of civil aircraft. This legislation is overseen by the Civil Aviation Safety Authority (CASA) and serves to protect public safety by establishing stringent safety standards for aircraft and their operations. One specific legislative instrument, F2006B11209, addresses a critical safety concern regarding Lycoming piston engines. This instrument was introduced to tackle the issue of premature failures of propeller governor oil lines in Lycoming four-cylinder engines. The policy objective is to mandate rigorous inspection and replacement of oil lines to prevent engine failure and ensure the continued airworthiness of affected aircraft. The directive requires the inspection and, where necessary, replacement of oil lines and attachment nuts, and mandates the use of only approved flexible oil lines in place of rigid lines, ensuring compliance with safety standards and preventing potential hazards.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, which is administered by the Civil Aviation Safety Authority, includes a Schedule of Airworthiness Directives. This particular directive pertains to Lycoming piston engines with rear-mounted propeller governors and external oil lines, applicable to all such engines. The directive mandates inspections and replacements of specific components to ensure safety and compliance with airworthiness standards. For rigid oil line installations, the directive requires inspecting the external oil line for leaks, cracks, abrasion, and proper support clamp fitment, with replacements as necessary. Additionally, aluminium attachment nuts must be replaced with steel nuts (P/N AN818-6), and aluminium oil line elbows (P/N MS20822-6D) must be replaced with steel elbows (P/N MS20822-6). For flexible oil line installations, the directive requires that the hose meets TSO C53a - Type D specifications; if not, it must be replaced according to Lycoming Service Instruction No.1435, Supplement 1. Compliance with these requirements is necessary within 25 hours for engines in service and prior to installation for uninstalled engines. The amendment, which became effective on 8 October 1998, addresses issues identified with TSO C53a-Type C flexible governor lines, specifying that only TSO C53a-Type D hoses are acceptable substitutes for rigid lines.

Key Provisions

The Civil Aviation Regulations 1998, specifically PART 39 - 106, section 86, addresses the Airworthiness Directives concerning Lycoming piston engines, focusing on the propeller governor oil line. According to section (1), all Lycoming four-cylinder engines with a rear-mounted propeller governor and an external oil line must undergo a rigid oil line installation. This requires an inspection for any leaks, cracks, abrasions, and the correct fitment of support clamps. If any issues are detected, the oil line must be replaced. Furthermore, if the oil line is fitted with aluminium attachment nuts, it must be replaced with an oil line that has P/N AN818-6 steel attachment nuts. Additionally, the aluminium propeller governor oil line elbow P/N MS20822-6D must be replaced with a steel elbow P/N MS20822-6. For flexible oil line installations, the hose must be inspected to ascertain its specification. If it does not meet the TSO C53a - Type D specification, it must be replaced in accordance with Lycoming Service Instruction No. 1435, Supplement 1. This applies to both engines in service and uninstalled engines prior to installation in an aircraft. The obligations imposed by this directive include ensuring that all Lycoming four-cylinder engines comply with the specified requirements within 25 hours of service for engines already in use and prior to installation for uninstalled engines. Operators and owners must conduct thorough inspections of the propeller governor oil line and associated components, replacing any defective parts with the correct specifications. The directive also requires adherence to Lycoming Service Instructions and any referenced FAA Airworthiness Directives and Lycoming Service Bulletins. Failure to comply with this Airworthiness Directive may result in serious safety hazards, potentially leading to engine failure during operation. The Civil Aviation Safety Authority (CASA) enforces compliance with these directives, and non-compliance can result in significant penalties. Under section 91 of the Civil Aviation Act 1988, penalties for non-compliance may include fines and, in severe cases, criminal charges. The maximum penalties for breaches of the Civil Aviation Regulations can vary, but they may include substantial fines for corporations and imprisonment for individuals, depending on the severity and frequency of the breach.