AD/ENST 28/15 Amdt 2 - Tail Rotor Spindle and Drive Shaft - Inspection and Retirement

Overview

The Civil Aviation Regulations 1998, amended by the Civil Aviation (Airworthiness) Regulations 2006, include Part 39 which pertains to the airworthiness directives issued by the Civil Aviation Safety Authority (CASA). The purpose of this legislation is to ensure the safety of civil aviation by enforcing compliance with airworthiness standards and mandates, particularly concerning specific aircraft models. One such directive, AD/ENST 28/15 Amendment 2, focuses on Enstrom F-28 Series Helicopters, addressing the critical issue of tail rotor spindle failure. This directive was introduced to mitigate the risk of catastrophic failure that could result from a tail rotor spindle issue, thereby safeguarding flight safety. CASA, as the enacting body, aims to uphold stringent safety standards through these airworthiness directives, ensuring that all relevant aircraft meet the required safety benchmarks to prevent accidents and protect the lives of those onboard and on the ground.

Scope and Application

The Civil Aviation Regulations 1998, as detailed in Part 39 - 105 of the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, specifically address the Enstrom F-28 Series Helicopters, with the directive AD/ENST 28/15 Amendment 2 concerning the tail rotor spindle and drive shaft. This directive applies to all models F-28 and 280, mandating specific actions to ensure safety and compliance. The directive requires the removal of tail rotor spindles P/N 28-15202 from service and their replacement with new or re-worked spindles, installation of tail rotor strike tabs, and inspections of both the tail rotor spindle and drive shaft according to specified guidelines. Compliance timelines are set, with the replacement and inspection of the tail rotor spindle needing to be completed within 10 hours of time in service after 17 August 1977, while the installation of strike tabs and inspections before further flight following any tail rotor strike must be carried out forthwith. The geographic and jurisdictional reach of this directive is national, applying across the Commonwealth of Australia under the regulatory oversight of the Civil Aviation Safety Authority. This legislation does not specify exclusions or exemptions, and any further clarification or extension of its application may be found in subordinate instruments issued by the relevant authorities.

Key Provisions

The Civil Aviation Regulations 1998 (CAR) set forth specific directives in Part 39 - 105, particularly under the Civil Aviation Safety Authority (CASA) schedule of airworthiness directives for Enstrom F-28 series helicopters. One such directive is AD/ENST 28/15 Amendment 2, which addresses the tail rotor spindle and drive shaft. Section 1 of the directive mandates the removal of tail rotor spindles P/N 28-15202 from service, replacing them with either a new spindle P/N 28-15202-13 or a reworked spindle identified by an 8-character serial number acid etched on the spindle centre section (Section 1). Additionally, tail rotor strike tabs must be installed as per Enstrom Service Directive Bulletin No. 0037 Revision A or FAA AD 77-04-04 Amendment 39-2839 (Section 2). Operators are required to inspect the tail rotor spindle and the tail rotor drive shaft following the procedures outlined in the aforementioned bulletins and FAA AD (Sections 3 and 4). These requirements impose specific obligations on helicopter operators and maintenance personnel. Operators must ensure that the identified tail rotor spindles are removed and replaced within a specified timeline, with a particular focus on adhering to the 10-hour limit for the new or reworked spindles to be in service after 17 August 1977 (Section 1). The installation of tail rotor strike tabs must be completed immediately (Section 2), while inspections of the tail rotor spindle and drive shaft must be conducted before any further flight following a tail rotor strike (Sections 3 and 4). Failure to comply with these directives may result in significant safety risks and potential legal ramifications. Non-compliance with the provisions of AD/ENST 28/15 Amendment 2 could lead to serious consequences. The regulations do not explicitly outline specific offences or penalties in the provided text, but non-compliance with CASA directives generally results in regulatory enforcement actions, including the potential for CASA to issue compliance orders, fines, or even grounding of the affected aircraft. The severity of penalties may vary based on the nature and extent of non-compliance, with potential maximum penalties being determined by relevant aviation safety legislation. Operators must therefore ensure strict adherence to the mandated timelines and procedures to avoid adverse outcomes.