AD/B747/146 - Engine Strut Wing Seal

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, are a comprehensive set of rules designed to ensure the safety and regulation of civil aviation in Australia. One specific aspect of these regulations is the Schedule of Airworthiness Directives, which includes AD/B747/146, relating to Boeing 747 Series Aeroplanes. This directive was introduced to address the problem of fuel leakage in the engine strut area, which posed a significant risk of fire, particularly on the ground after engine shutdown. The policy objective is to mitigate this risk by mandating the installation of a seal on the wing front spar at each engine strut, in accordance with specified Boeing service bulletins. The Civil Aviation Safety Authority (CASA) enforces compliance with these directives to uphold the highest safety standards in civil aviation.

Scope and Application

The Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, specifically AD/B747/146 concerning the Boeing 747 series aeroplanes, applies to aircraft models equipped with either General Electric CF6-45 or CF6-50 engines, or Pratt & Whitney JT9D series engines, as detailed in Boeing Service Bulletin 747-28-2160, Revision 1. The directive mandates the installation of a seal on the wing front spar at each engine strut, following the guidelines set out in the aforementioned service bulletin. This regulatory requirement aims to prevent fuel leakage in the engine strut area, a concern raised following a reported fire incident on the ground after engine shutdown. The directive must be complied with prior to 16 September 1996, aligning with the Federal Aviation Administration (FAA) AD 95-02-07 Amendment 39-9126. The scope of this legislation is geographically confined to the Commonwealth of Australia, as it is a part of the Civil Aviation Regulations 1998, enforcing safety standards across the national airspace.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 - 105, include specific Airworthiness Directives (AD) that govern the safety and maintenance standards of aircraft. One such directive, AD/B747/146, pertains to Boeing 747 series aeroplanes and mandates the installation of a seal on the wing front spar at each engine strut to address potential fuel leakage issues (Section 6/95). This directive applies to model 747 series aircraft equipped with either General Electric CF6-45 or CF6-50 engines, or Pratt & Whitney JT9D series engines, as listed in Boeing Service Bulletin 747-28-2160, Revision 1. These requirements are intended to prevent fires caused by fuel leakage in the engine strut area along the wing front spar. Operators of affected aircraft must ensure compliance with the directive by installing the specified seal according to Boeing's detailed instructions. This involves meticulous adherence to the guidance provided in Boeing Service Bulletin 747-28-2160 or its revision, which includes specific procedures for seal installation. Failure to comply with this directive could result in serious safety hazards, as evidenced by a reported incident where a fire occurred due to fuel leakage in this area. The obligations imposed on the operators include conducting a thorough inspection of the engine strut area and ensuring the seal is installed correctly to contain any potential fuel leakage. This directive also references FAA AD 95-02-07 Amdt 39-9126, which further underscores the importance of these safety measures. Operators must ensure that all necessary actions are completed before the specified compliance date, which is 16 September 1996, to avoid any regulatory non-compliance or safety risks. Failure to adhere to the requirements set out in AD/B747/146 could result in severe consequences. The primary risk is the potential for fuel leakage leading to fires, which not only endangers the aircraft and its occupants but also poses a significant threat to ground personnel and surrounding infrastructure. From a regulatory standpoint, non-compliance with this directive may result in enforcement actions by the Civil Aviation Safety Authority (CASA). These actions could include fines, operational restrictions, or even the grounding of non-compliant aircraft until the required modifications are made. The specific penalties for breaches of the Civil Aviation Regulations are detailed in other sections of the Act, with potential civil and criminal sanctions that could include substantial fines and imprisonment.