AD/BN-2/65 - NLG Leg Cylinder Bearing Surfaces

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, address the need for maintaining airworthiness standards and ensuring the safety of aircraft operations within Australian airspace. Part 39 of these regulations specifically pertains to the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, which are imperative in mitigating risks associated with aircraft operations. These directives are critical in maintaining the safety and reliability of aircraft, particularly in instances where specific design or manufacturing flaws could compromise the integrity of flight operations. The policy objective of such regulations is to mandate safety standards that prevent potential failures and ensure the ongoing airworthiness of aircraft, thereby protecting passengers, crew, and the general public. One such directive, AD/BN-2/65, pertains to the Pilatus Britten-Norman BN-2 Series Aeroplanes and specifically addresses issues related to the NLG Leg Cylinder Bearing Surfaces. This directive was introduced in response to occurrences where the chrome plating on the cylinder assembly part number 61757 had delaminated, leading to stiffness in the rudder and nose wheel steering systems. The requirement under this directive mandates action in accordance with Britten Norman Mandatory Service Bulletin BN2/SB.249, necessitating compliance before further flight or at the next 100-hour inspection, whichever comes first. This directive became effective on 20 May 1999, aiming to ensure the continued safe operation of BN2, BN2A, BN2B, and BN2T Islander aircraft by addressing identified safety concerns.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all persons and entities involved with the operation, maintenance, and certification of Pilatus Britten-Norman BN-2 Series Aeroplanes, namely the BN2, BN2A, BN2B, and BN2T Islander aircraft. This regulatory directive is enforced by the Civil Aviation Safety Authority (CASA) and pertains to the maintenance and operational standards of these aircraft within the Commonwealth of Australia. The directive mandates compliance with Britten Norman Mandatory Service Bulletin BN2/SB.249, requiring specific action concerning the NLG leg cylinder bearing surfaces, to address instances where the chrome plating has delaminated, which may lead to operational stiffness in the rudder and nose wheel steering systems. The directive requires compliance before further flight if any stiffness is detected or at the next 100-hour inspection, whichever event occurs first, and became effective on 20 May 1999. This regulation does not explicitly outline any exclusions or thresholds, and its application may be further detailed or modified through subordinate instruments or additional service bulletins issued by CASA.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105 (paragraphs 5/99) and Schedule of Airworthiness Directives, mandate specific action concerning the Pilatus Britten-Norman BN-2 Series Aeroplanes, particularly models BN2, BN2A, BN2B, and BN2T Islander. This directive, referred to as AD/BN-2/65, addresses the issue of NLG leg cylinder bearing surfaces. The primary requirement is for the action outlined in Britten Norman Mandatory Service Bulletin BN2/SB.249, with reference to FHL Service Bulletin 32-19 Issue 1. The directive requires compliance before further flight if any stiffness or restriction is detected in the rudder or nose wheel steering system, or during the next 100-hour inspection, whichever occurs first. The directive was made effective on 20 May 1999. In terms of obligations, operators of the affected aircraft models must ensure that the maintenance and inspection procedures as specified in the service bulletins are strictly followed. This includes addressing any identified issues with the chrome plating on the bearing surfaces of the cylinder assembly Part No 61757. The directive highlights that the chrome plating can delaminate, leading to operational stiffness, and thus, timely and thorough inspections and actions are necessary to maintain airworthiness. Failure to comply with the requirements outlined in the Airworthiness Directive may result in serious safety implications. The Civil Aviation Safety Authority (CASA) may take enforcement actions against non-compliance, which could lead to operational restrictions or grounding of the aircraft until the necessary actions are taken. While specific penalties are not detailed in the directive, non-compliance with CASA regulations generally can result in significant financial penalties, legal action, and potential criminal charges if safety is compromised. Under the Civil Aviation Act 1988, operators are required to adhere to all applicable Airworthiness Directives and service bulletins. Non-compliance not only risks the safety of the aircraft and its occupants but also subjects the operator to potential civil and criminal penalties. The severity of these penalties can include substantial fines and imprisonment, reflecting the high priority placed on aviation safety by regulatory authorities.