AD/JT15D/7 Amdt 2 - Fan Blade Rub

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, address various safety and operational standards within the aviation sector. Part 39 of these regulations, specifically, pertains to airworthiness directives, which are regulatory mandates that compel aircraft operators to comply with safety standards. One such airworthiness directive, AD/JT15D/7Amdt 2, pertains to Pratt and Whitney Canada Turbine Engines of the JT15D Series, focusing on the issue of fan blade rub. This directive was introduced to mitigate the risk of damage to the low pressure compressor case due to fan blade rub, which could compromise engine safety and performance. The policy objective behind this legislation is to ensure the continued airworthiness of the specified engines through regular inspections and necessary corrective actions, thereby maintaining the highest safety standards within civil aviation. The relevant authority for these regulations is the Civil Aviation Safety Authority, which is responsible for enforcing compliance with the airworthiness directives. AD/JT15D/7Amdt 2 requires that engines not incorporating Pratt and Whitney Canada Service Bulletin No. 7268 or 7300 undergo an inspection of the low pressure compressor case inner diameter for evidence of fan blade rub. If such evidence is found, specific corrective actions must be taken, including a fan blade tip clearance check and a fluorescent penetrant inspection of the affected area. In cases where cracking is detected, the low compressor case must be replaced. This directive became effective on 4 March 1993 and requires compliance within 25 hours of time in service and thereafter at intervals not exceeding 300 hours.

Scope and Application

The Civil Aviation Regulations 1998, under Part 39 - 106, addresses the airworthiness directives specifically for Pratt and Whitney Canada Turbine Engines of the JT15D Series, with a focus on the issue of fan blade rub. This legislation applies to JT15D-4, -4B, and -4D engines that do not incorporate Pratt and Whitney Canada Service Bulletin No. 7268 or 7300. The directive mandates that these engines must undergo an inspection of the low pressure compressor case inner diameter to detect any signs of fan blade rub. If such evidence is found, a fan blade tip clearance check must be performed according to Pratt and Whitney Canada Maintenance Manual P/N 3017542, chapter 72-30-53, with adjustments made as necessary. Additionally, a fluorescent penetrant inspection of the affected area is required, which must be conducted by a holder of a valid Non-Destructive Testing Authority. If any cracking of the low compressor case is detected, the case must be replaced. This directive applies nationally across Australia, aligning with the overarching Civil Aviation Regulations, and must be adhered to by all relevant operators within the specified timeframes.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39, Section 106, address the safety of Pratt and Whitney Canada's JT15D Series turbine engines. Specifically, Amendment 2 to Airworthiness Directive (AD)/JT15D/7 pertains to the issue of fan blade rub on JT15D-4, -4B, and -4D engines that do not incorporate Pratt and Whitney Canada Service Bulletin No. 7268 or 7300. According to Section 106 of these Regulations, the main requirement is to inspect the low pressure compressor case inner diameter for evidence of fan blade rub. If such evidence is found, several corrective actions must be undertaken. First, a fan blade tip clearance check should be carried out following Pratt and Whitney Canada's Maintenance Manual (PWC M/M P/N 3017542, chapter 72-30-53), with necessary adjustments made as required. Second, a fluorescent penetrant inspection of the rub area must be performed, which must be conducted by an individual holding a valid Non-Destructive Testing (NDT) Authority. If the inspection reveals cracking in the low compressor case, the case must be replaced. The Act imposes several obligations on the parties involved. It mandates that the inspection and subsequent actions be completed within specific timeframes. The initial inspection must occur unless it has already been performed, within 25 hours of the engine's time in service. Following this initial inspection, subsequent inspections must be carried out at intervals not exceeding 300 hours of time in service. The individuals conducting the fluorescent penetrant inspection must hold a valid NDT Authority, ensuring that they are qualified to perform this critical task. Failure to comply with the requirements outlined in the AD/JT15D/7 could lead to serious consequences. Although the specific penalties are not detailed within the text, non-compliance with Civil Aviation Regulations generally can result in both civil and criminal penalties. Civil penalties may include fines, and in more severe cases, criminal penalties could apply, potentially leading to imprisonment. The severity of the penalties often depends on the nature and extent of the breach, as well as any resulting harm or risk to aviation safety.