AD/ENST 28/36 - Lamiflex Bearings

Overview

The Civil Aviation Regulations 1998 (Cth), particularly in PART 39, mandate strict safety measures to ensure the airworthiness of aircraft, including helicopters. The legislation was enacted to address the critical need for ensuring the safety of civil aviation operations by imposing stringent compliance and inspection requirements on aircraft components. One such directive, AD/ENST 28/36, pertains specifically to the Enstrom F-28 Series Helicopters, targeting the safety issue of Lamiflex bearings used in these models. The policy objective behind this regulation is to mitigate the risk of catastrophic failure due to bearing delamination, which could lead to loss of control and severe accidents. The Australian Civil Aviation Safety Authority (CASA) enforces these regulations to uphold high safety standards in the aviation industry. The directive requires immediate removal from service of Lamiflex bearings that are either illegible or manufactured more than five years prior to inspection, underscoring the urgency and importance of adhering to the stipulated safety measures. Compliance with these directives is mandatory within specific time frames following the enactment, ensuring that safety protocols are rigorously followed to prevent potential accidents. This regulation exemplifies the commitment to safeguarding aviation safety by addressing specific mechanical failures and setting clear, actionable guidelines for maintaining aircraft airworthiness.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to the Enstrom F-28 Series helicopters with models F28A, C, C2, F; 280, 280C, F, and FX that are equipped with main rotor feathering elastomeric Lamiflex bearings P/N 28-14320-12 or 28-14320-15. The geographic and jurisdictional reach of this legislation is national, as it is issued under the authority of the Commonwealth of Australia and pertains to civil aviation safety within Australia. The legislation mandates actions in compliance with Enstrom Service Directive Bulletin No. 0081 Rev. A, requiring the removal from service of any Lamiflex bearing where the date of manufacture is not visible or illegible, or where it is marked as being manufactured five years prior to any inspection. The compliance requirements include adhering to these regulations within five hours of service after 26 September 1994 and at intervals not exceeding 100 hours of service thereafter, as well as addressing any symptoms specified in the Requirement Document. This directive is integral to mitigating the risk of bearing failure, which could result in the delamination and extrusion of rubber and brass, potentially leading to loss of control of the helicopter.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39, specifically address airworthiness directives for various aircraft models, including the Enstrom F-28 Series Helicopters. Section 105 of this part details the airworthiness directives, with AD/ENST 28/36 being a crucial directive concerning the Lamiflex bearings in certain Enstrom F-28 models. This directive applies to models F28A, C, C2, F; 280, 280C, F and FX equipped with main rotor feathering elastomeric Lamiflex bearings with part numbers 28-14320-12 or 28-14320-15. Under section 105, the directive requires operators of the specified Enstrom F-28 models to follow Enstrom Service Directive Bulletin No. 0081 Rev. A. This entails removing any Lamiflex bearing from service if the date of manufacture is not visible or illegible, or if the bearing was manufactured more than five years prior to any inspection performed in accordance with this directive. This requirement aims to ensure that bearings are replaced before they reach a potentially unsafe condition, as evidenced by previous reports of bearing failures due to delamination and extrusion of rubber and brass. Operators must comply with these requirements within five hours of the directive's issuance, dated 26 September 1994, and thereafter at intervals not exceeding 100 hours of time in service. The directive also mandates action if specific symptoms outlined in the requirement document are experienced. Operators and entities governed by this directive are obligated to ensure that inspections are conducted regularly and bearings are replaced as per the specified intervals and conditions. This includes maintaining records of inspections and replacements to demonstrate compliance. Failure to adhere to these requirements can result in serious safety hazards, such as complete bearing failure and potential loss of control of the helicopter. The directive emphasises the importance of traceability of the manufacturing date to ensure the bearings are within their designated service life. Non-compliance with these airworthiness directives can lead to severe consequences. The regulations outline potential civil and criminal penalties for breaches. Civil penalties can include substantial fines, while criminal penalties may involve imprisonment. The exact penalties are not specified in the given text but are typically detailed in other sections of the Civil Aviation Regulations or related legislation. It is essential for operators to adhere to these directives to maintain the safety and airworthiness of the aircraft.