AD/B747/203 - Lavatory Drain System Leak Tests

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, includes a directive aimed at addressing the issue of "blue ice" formation and detachment on Boeing 747 Series aeroplanes. This problem arises from the design features of the 747 toilet flush system, which has led to increased incidences of leaks that cause blue ice to form on the airframe, subsequently detaching in flight and causing damage to both the aircraft and property on the ground. The Airworthiness Directive, identified as AD/B747/203, mandates that the inspection and maintenance requirements outlined in US Federal Aviation Administration (FAA) AD 99-08-10 be implemented. The objective is to enhance the reliability of the lavatory drain system, thereby reducing the risk of leaks and the formation of "blue ice." Enacted by the Civil Aviation Safety Authority, the policy objective behind this directive is to ensure the safety and airworthiness of Boeing 747 Series aeroplanes by mitigating the risk associated with lavatory drain system leaks. The directive became effective on 17 June 1999, requiring compliance with the specified inspection and maintenance actions as detailed in FAA AD 99-08-10, with an initial and subsequent repetitive actions timeline as outlined in FAA AD 99-08-10 Amendment 39-11116.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the authority of the Civil Aviation Safety Authority, includes the Airworthiness Directive AD/B747/203, which mandates inspection and maintenance of the lavatory drain system for Boeing 747 Series Aeroplanes. This directive applies to all Model 747-100, -200, -300, -SP, and -400F series aeroplanes that are certificated in any category. The requirement for inspection and maintenance follows the guidelines set forth by the US Federal Aviation Administration's AD 99-08-10, which includes specific actions to be taken to mitigate the risk of leaks in the lavatory drain system, a problem that has led to incidents of "blue ice" forming on the airframe and causing damage. Compliance with this directive is mandated for both initial and subsequent repetitive actions as detailed in the US FAA AD 99-08-10 Amendment 39-11116, with an effective date of 17 June 1999. This directive is applicable nationwide within Australia, encompassing all states and territories, and applies to all operators and owners of the specified Boeing 747 models operating under Australian jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contain the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives (AD). Among these, AD/B747/203 pertains to the Boeing 747 series aeroplanes, particularly focusing on the lavatory drain system leak tests (section 6/99). This directive applies to all 747-100, -200, -300, -SP, and -400F series aeroplanes that are certificated in any category (section 6/99). It mandates that the inspection and maintenance requirements outlined in the US Federal Aviation Administration (FAA) AD 99-08-10 must be performed (section 6/99). For reference, the FAA AD 99-08-10 amendment 39-11116 is noted as providing further details (section 6/99). Compliance with this directive requires that the initial action and subsequent repetitive actions, as defined in the FAA AD 99-08-10 Amendment 39-11116, are implemented with a revised effective date of 17 June 1999 (section 6/99). This Airworthiness Directive becomes effective on 17 June 1999. The AD/B747/203 mandates specific obligations and requirements for the operators of Boeing 747 series aeroplanes. Operators must ensure that the inspection and maintenance actions specified in the FAA AD 99-08-10 are performed. This includes following the detailed procedures and guidelines set out in FAA AD 99-08-10 Amendment 39-11116. Operators are also required to comply with the revised effective date of 17 June 1999 for these actions. The directive ensures that the lavatory drain system is thoroughly inspected and maintained to prevent leaks, thereby reducing the formation of “blue ice” which can cause damage to the airframe and property on the ground. Breach of the requirements stipulated in AD/B747/203 can lead to significant consequences. Under the Civil Aviation Act 1988, operators who fail to comply with an Airworthiness Directive may be subject to civil penalties. The maximum penalty for non-compliance can be substantial, reflecting the importance of adhering to these safety directives. Additionally, failure to meet these requirements can result in the aircraft being deemed unairworthy, which could lead to grounding of the aeroplane until the necessary inspections and maintenance are completed. This not only poses a safety risk but also incurs operational and financial costs for the operator. In summary, AD/B747/203 mandates specific inspection and maintenance procedures for the lavatory drain systems of Boeing 747 series aeroplanes to prevent the formation of “blue ice” and subsequent damage. Operators must ensure compliance with the FAA AD 99-08-10 and its amendments, with the directive becoming effective from 17 June 1999. Failure to comply with these requirements can lead to severe civil penalties and the grounding of the aircraft, highlighting the critical nature of adhering to these safety measures.