AD/APU/14 - TSCP700 First Stage LPC Disc

Overview

The Civil Aviation Regulations 1998, as part of Part 39 concerning the Civil Aviation Safety Authority, were enacted to ensure the safety and airworthiness of aircraft within Australian airspace. Specifically, the regulation addresses the safety concerns associated with auxiliary power units (APUs), particularly the AlliedSignal Inc. TSCP700 series APUs. The identified issue pertains to the stage one low pressure compressor (LPC1) disc, which has been subject to rim separation events. This prompted a requirement to remove affected LPC1 discs from service, as specified in AlliedSignal Service Bulletin TSCP700-49-7266. The policy objective is to mitigate safety risks by enforcing these airworthiness directives, ensuring that the revised effective date aligns with the manufacturer's recommendations. This directive became effective on 26 February 1998, following notification from the manufacturer and subsequent investigations that led to a reduction in the LPC1 life limit.

Scope and Application

The Civil Aviation Regulations 1998, under the Civil Aviation Safety Authority, specifically address the issue of airworthiness directives for aircraft components, with Part 39 focusing on these directives. AD/APU/14 pertains to AlliedSignal Inc.'s TSCP700 series auxiliary power units (APUs) that incorporate a stage one low pressure compressor (LPC1) disc, identified by part number 3606429-1. The directive applies to all such units in service, mandating their removal in accordance with AlliedSignal Service Bulletin TSCP700-49-7266 to address issues of LPC1 disc rim separation, which has led to a reduction in the LPC1's life limit. This directive, which became effective on 26 February 1998, is part of a broader regulatory framework aimed at ensuring the safety and airworthiness of aircraft operating within Australia, with the requirement to comply strictly as outlined in the directive and the service bulletin. This directive extends to the entire fleet of aircraft incorporating the specified APUs, and its compliance is mandatory for all operators within the Australian jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 107, pertains to the Australian Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives. Under this regulation, AD/APU/14 addresses the issue of the TSCP700 First Stage LPC Disc for AlliedSignal Inc.'s TSCP700 series auxiliary power units (APUs). The directive applies to all units that incorporate the stage one low pressure compressor (LPC1) disc, with part number 3606429-1. According to section 3 of the directive, these units must be removed from service in accordance with AlliedSignal's Service Bulletin TSCP700-49-7266 (section 3). The directive also references FAA AD 97-19-18 for additional context (section 3). Compliance with this directive is mandatory and must follow the specifications outlined in the requirement document, with the directive becoming effective from 26 February 1998 (section 4). The background of this directive (section 5) notes that the manufacturer reported incidents of LPC1 disc rim separation, which prompted further investigation and resulted in a reduced life limit for the LPC1. The obligations imposed by this directive are clear and specific. Operators of AlliedSignal Inc.'s TSCP700 series APUs must remove the affected LPC1 discs from service and comply with the instructions provided in AlliedSignal's Service Bulletin TSCP700-49-7266. This involves a thorough inspection and potentially the replacement of the discs, as mandated by the directive to ensure airworthiness and safety. Failure to comply with this directive could result in significant safety risks, potentially leading to operational downtime and additional costs associated with addressing non-compliance. Under the Civil Aviation Regulations 1998, non-compliance with airworthiness directives can lead to serious consequences. Section 39.107 of the regulations provides for both civil and criminal penalties for breaches. Civil penalties can include fines up to a specified amount, while criminal penalties can result in imprisonment. The exact penalties depend on the severity of the breach and the potential impact on aviation safety. Operators found in breach of this directive may face enforcement actions by CASA, which can include fines, operational restrictions, or even grounding of the affected aircraft until compliance is achieved. The potential for these penalties underscores the importance of adhering to the directive to maintain safety standards within the aviation industry.