AD/B767/55 - Centre Fuel Tank Override Pumping Unit Diffuser Assembly

Overview

The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B03409, were enacted to enhance safety in civil aviation through the implementation of specific airworthiness directives. This legislation, managed by the Civil Aviation Safety Authority, addresses the risk of structural failure in Boeing 767 series aeroplanes, particularly focusing on the centre fuel tank override pumping unit diffuser assembly. The problem identified pertains to potential separation of the brazed joint in certain serial numbers, which could result in hazardous ignition sources during dry pump operations. The directive mandates compliance with Boeing Alert SB 767-28A0036 and references Sundstrand Alert SB 5006286-28-A4, aiming to ensure all affected aircraft meet safety standards prior to 31 May 1991. The overarching policy objective is to mitigate safety risks and maintain high standards of airworthiness in the operation of civil aircraft.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning Airworthiness Directives, apply to the Boeing 767 Series Aeroplanes with line numbers 1 through 359, 361, and 362, requiring adherence to Boeing Alert SB 767-28A0036 for the centre fuel tank override pumping unit diffuser assembly. This regulation is intended to address a specific safety concern involving the separation of the brazed joint that attaches the diffuser ring to the diffuser sleeve in certain serial number override pumping units, which could potentially lead to an ignition source within the centre tank during dry pump operations. The directive is applicable to all relevant aircraft that fall within the specified serial number range and mandates compliance prior to 31 May 1991, with the regulation taking effect from 7 July 1991. The scope of the regulation is explicitly defined by the Commonwealth of Australia and extends to ensuring the airworthiness and safety of the affected Boeing 767 aeroplanes.

Key Provisions

The Civil Aviation Regulations 1998, specifically under PART 39 - 105, provide detailed provisions regarding the airworthiness directives for the Boeing 767 series aeroplanes, as outlined in AD/B767/55. This directive pertains to the centre fuel tank override pumping unit diffuser assembly and applies to models 767 with line numbers ranging from 1 through 359, 361, and 362. The key requirement is that operators must follow Boeing Alert SB 767-28A0036, with a reference to Sundstrand Alert SB 5006286-28-A4. This action is necessary to address a specific issue where the brazed joint attaching the diffuser ring to the diffuser sleeve may separate, potentially leading to an ignition source within the centre tank if a dry pump operation occurs. Operators of the specified Boeing 767 models must ensure compliance with these directives. This involves taking corrective action in line with the specified Boeing Service Bulletin (SB) and Sundstrand Service Bulletin (SB). The compliance requirement must be fulfilled before 31 May 1991, as indicated by the note 7/91TX. The directive underscores the importance of maintaining the integrity of the fuel tank system to prevent hazardous situations, particularly those that could lead to fuel tank explosions or fires. Failure to adhere to these airworthiness directives can result in significant legal and safety consequences. Non-compliance with the specified airworthiness requirements can lead to enforcement actions under the Civil Aviation Act 1988. In severe cases, operators may face penalties for breaching safety regulations, which can include fines and potential grounding of the aircraft until the necessary actions are taken. Additionally, civil liability may arise if non-compliance results in an accident or incident that causes harm or damage. The potential criminal consequences for non-compliance with these airworthiness directives are severe. Under the Civil Aviation Regulations 1998, operators who fail to adhere to the specified directives may be prosecuted. The maximum penalties can include substantial fines and imprisonment, reflecting the gravity of neglecting safety measures that are designed to protect the public and aviation personnel. The regulatory framework aims to ensure that all necessary safety measures are implemented to mitigate risks associated with the operation of Boeing 767 series aeroplanes.