AD/PFP/16 - Ken Brock Propeller Hub Extension

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 107, includes Airworthiness Directives (ADs) issued by the Civil Aviation Safety Authority (CASA). One such directive, AD/PFP/16, addresses a safety issue concerning Ken Brock propeller hub extensions fitted to Lycoming 0-320 or 0-360 powered amateur-built aircraft. This directive was enacted to address a problem where insufficient wall thickness in certain propeller hub extenders led to fatigue failures. The policy objective of this AD is to ensure the airworthiness and safety of affected aircraft by requiring either the replacement or refitting of the propeller hub extenders based on their wall thickness. The directive mandates compliance by the next scheduled aircraft inspection or by 31 July 1991, whichever is earlier. The Civil Aviation Safety Authority issued this directive to mitigate potential safety risks associated with the identified manufacturing defect.

Scope and Application

The Civil Aviation Regulations 1998, as amended, include specific safety directives aimed at ensuring the airworthiness of aircraft within Australia, with the Civil Aviation Safety Authority overseeing compliance. The particular directive AD/PFP/16 focuses on propeller hub extensions supplied by Ken Brock for Lycoming 0-320 or 0-360 powered amateur-built aircraft. This regulation applies to any aircraft owner or operator who uses such hub extenders, ensuring they adhere to the prescribed safety standards. The directive mandates that the wall thickness of the hub extender be measured, with specific instructions to replace the hub extender if the thickness is found to be approximately 7 mm (.25 inches), and to refit the propeller if the thickness is approximately 12 mm (.50 inches). Compliance with this directive must be achieved at the next scheduled aircraft inspection or by 31 July 1991, whichever comes first, addressing the identified safety concern of potential fatigue failure due to insufficient wall thickness. The scope of this regulation is limited to the specified hub extenders and aircraft engines, and does not extend to other types of aircraft or propeller systems.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 107, mandates Airworthiness Directives that ensure the safety of aircraft in Australia. One such directive, AD/PFP/16, pertains to Ken Brock Propeller Hub Extensions for Lycoming 0-320 or 0-360 powered amateur-built aircraft. This directive applies to any propeller hub extender supplied by Ken Brock that has been fitted to these aircraft (Section 1). The primary requirement outlined in this directive is the inspection and subsequent action based on the wall thickness of the hub extender. Specifically, the propeller must be removed from the hub extender, and the wall thickness must be measured (Section 2.1). If the measured wall thickness is approximately 12 mm (0.50 inches), the propeller should be refitted without further action (Section 2.1). However, if the wall thickness is approximately 7 mm (0.25 inches), the hub extender must be replaced before further flight (Section 2.2). Compliance with these requirements must be achieved by the next scheduled aircraft inspection or by 31 July 1991, whichever comes first (Section 3). The Civil Aviation Regulations 1998 impose specific obligations on the owners and operators of amateur-built aircraft fitted with Ken Brock propeller hub extenders. These obligations include conducting a thorough inspection of the hub extender's wall thickness as per the directive. Owners and operators must ensure that the propeller is removed and the wall thickness is accurately measured. Based on the measurement, they must either refit the propeller if the wall thickness is adequate or replace the hub extender if it is insufficient. The directive mandates that these actions be taken by the next scheduled inspection or by the specified deadline, ensuring that the aircraft remains airworthy and compliant with safety standards. Failure to comply with the requirements set out in AD/PFP/16 can lead to significant consequences. The Civil Aviation Regulations 1998 do not explicitly detail the penalties for non-compliance in this specific directive, but general aviation safety regulations may impose fines or other penalties for operating an aircraft that does not meet airworthiness standards. Additionally, the continued operation of an aircraft with a non-compliant hub extender could result in severe safety risks, potentially leading to criminal charges or civil liabilities if an incident occurs due to the non-compliance. It is crucial for owners and operators to adhere strictly to the directive to avoid these potential repercussions.