AD/B747/135 - Potable Water Tank Pressure Relief Valve

Overview

The Civil Aviation Regulations 1998, specifically Part 39, addresses various safety standards and requirements to ensure the safety of civil aviation in Australia. Enacted by the Parliament of the Commonwealth of Australia, this piece of legislation provides comprehensive guidelines for maintaining the airworthiness of aircraft, including directives to manage specific issues identified with certain models. One such directive, AD/B747/135, pertains to the Boeing 747 series aeroplanes and aims to rectify a problem with the potable water tank pressure relief valve. The directive was introduced to address the issue of potable water tank ruptures, which had led to incidents where the tank's upper polar cap separated and caused damage, including striking the main deck ceiling panel and PSU area. The policy objective behind this directive is to ensure compliance with Boeing's Alert Service Bulletin 747-38A2105 to mitigate such risks and enhance the safety of air travel.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all Boeing 747 aircraft within the Commonwealth of Australia, ensuring compliance with the Airworthiness Directives (AD) issued by the Civil Aviation Safety Authority. This legislation mandates that all Boeing 747 aircraft, from line number 1 to 1013 inclusive, must adhere to the action stipulated in Boeing Alert Service Bulletin 747-38A2105. This requirement mandates that the necessary action be taken unless it has already been implemented prior to 1 August 1995. This directive was issued in response to reports of potable water tank ruptures, with a notable incident involving the separation of the upper polar cap from the main body of the tank, causing damage to the cabin floor and ceiling panel. The geographic reach of this regulation is national, impacting all operators of Boeing 747 aircraft within Australia, ensuring safety standards are consistently met across the industry.

Key Provisions

The main sections of the Civil Aviation Regulations 1998, specifically Part 39 - 105, address the safety directives for Boeing 747 series aeroplanes, focusing on the potable water tank pressure relief valve (section 39-105). This directive, AD/B747/135, applies to all Boeing 747 aircraft with line numbers 1 to 1013 inclusive. The requirement is to follow the action outlined in Boeing Alert Service Bulletin 747-38A2105. Compliance must be achieved unless the action was already undertaken by 1 August 1995. This Act imposes several obligations on the operators of Boeing 747 aircraft. They must ensure that all applicable aircraft adhere to the directive concerning the potable water tank pressure relief valve. This includes performing the necessary inspections and maintenance to prevent any rupture of the potable water tanks, which has been reported in past incidents. Operators must also ensure that any required modifications or replacements are completed in accordance with the specified Boeing Alert Service Bulletin. The Act outlines potential consequences for failure to comply with these safety directives. While the specific penalties are not detailed within this directive, it is reasonable to infer that non-compliance with safety directives could result in enforcement actions by the Civil Aviation Safety Authority (CASA). Such actions could include fines, grounding of the aircraft, or other regulatory measures to ensure compliance and maintain safety standards in Australian airspace. The exact penalties would be determined based on the severity of the breach and the potential risk posed to aviation safety.