AD/PA-22/18 - Horizontal Stabiliser Trim Control Screw Mechanism - Stop Installation

Overview

The Civil Aviation Regulations 1998, as amended, address safety and operational standards for civil aviation within Australia. Specifically, Part 39 - 105 within this legislative framework pertains to the Civil Aviation Safety Authority's (CASA) schedule of airworthiness directives, which are mandatory orders to ensure the continued airworthiness of aircraft. The directive AD/PA-22/18, enacted to address safety concerns associated with the Piper PA-22 (Tri-Pacer and Colt) series aeroplanes, focuses on rectifying an issue with the horizontal stabiliser trim control screw mechanism. This directive mandates that a stop be installed to prevent the yoke assembly from binding against the pulley when the mechanism is adjusted to its extreme nose-down position, thereby mitigating the risk of operational complications and ensuring the safe performance of these aircraft. Compliance with this directive is required forthwith, underscoring its critical importance for maintaining airworthiness standards.

Scope and Application

The Civil Aviation Safety Authority (CASA) has issued Airworthiness Directive AD/PA-22/18, which applies to all models of Piper PA-22 (Tri-Pacer and Colt) series aeroplanes under the Civil Aviation Regulations 1998. The directive mandates that operators and owners of these aircraft must modify the horizontal stabiliser trim control screw mechanism by installing a stop to prevent the yoke assembly from binding against the pulley when the mechanism is adjusted to the extreme nose-down position. This requirement is aimed at enhancing safety by mitigating potential operational hazards associated with the described mechanism. Compliance with AD/PA-22/18 must be achieved forthwith, and the directive references W.E. James Aircraft Pty. Ltd. Drawing No. WEJ-65 as an approved means of achieving compliance. The directive applies to all relevant aircraft irrespective of their registration or location within the Commonwealth of Australia, ensuring a consistent approach to safety across the national airspace. This legislative instrument extends its reach to all Piper PA-22 series aeroplanes, irrespective of whether they are used for commercial, charter, or private purposes. The directive is applicable to any entity or individual who holds or operates such aircraft within Australian jurisdiction, ensuring a comprehensive safety measure is enforced. There are no stated exclusions or exemptions within the directive, and it does not specify particular thresholds related to aircraft age or flight hours. However, the scope of the directive may be further elaborated or restricted through subordinate instruments issued by CASA, providing additional guidance or specific conditions under which the directive applies.

Key Provisions

The Civil Aviation Regulations 1998, particularly in Part 39, outlines a series of directives aimed at ensuring the safety and airworthiness of various aircraft, including the Piper PA-22 (Tri-Pacer and Colt) Series Aeroplanes. Section AD/PA-22/18 of this regulation mandates the installation of a stop on the horizontal stabiliser trim control screw mechanism. Specifically, it requires that a modification be made to prevent the yoke assembly (P/N 42692-00) from binding against the pulley (P/N 12982-00) when the mechanism is fully wound to the nose-down position. This modification is to be carried out on all models of the Piper PA-22 series to avoid potential safety hazards. The regulation references W.E. James Aircraft Pty. Ltd. Drawing No. WEJ-65 as an approved method for achieving this compliance. Entities and parties governed by these regulations are obligated to ensure that the specified modifications to the horizontal stabiliser trim control screw mechanism are implemented without delay. This means that the modification must be carried out as soon as possible, and the directive specifies "forthwith" to emphasise the urgency of the compliance requirement. These obligations extend to aircraft owners, operators, and maintenance providers who must ensure that the necessary adjustments are made and documented appropriately. Compliance with this directive is crucial for maintaining the airworthiness of the aircraft, and failure to adhere to the prescribed modifications could result in the aircraft being deemed unfit for operation. Failure to comply with the provisions outlined in the Civil Aviation Regulations 1998, particularly AD/PA-22/18, can lead to significant consequences. The regulations do not explicitly state the penalties for non-compliance in this specific directive, but generally, breaches of Civil Aviation Regulations can result in enforcement actions by the Civil Aviation Safety Authority (CASA). These actions can include fines, suspension or revocation of aircraft certificates, and other administrative penalties. In more severe cases, criminal charges may be brought against individuals or entities responsible for the non-compliance, leading to potential imprisonment. The exact penalties depend on the nature and severity of the breach, but the overarching goal is to ensure that all safety directives are strictly followed to maintain the highest standards of aviation safety.