Overview

The Airworthiness Directive (AD) issued under the Civil Aviation Safety Regulations 1998 (CASR) addresses potential safety issues related to the Honeywell T5508D Series turbine engines, specifically those equipped with first stage turbine disk part number 2-120-030-43. This directive was enacted to mitigate the risk of uncontained engine failure due to potential fretting of the turbine disk caused by incorrect torque applied to the turbine disk clamping bolts, possibly as a result of thread lubricant application. The AD was issued by the Civil Aviation Safety Authority (CASA) delegate, Jim Coyne, on 29 May 2003, and became effective on 10 July 2003. It requires a visual and fluorescent penetrant inspection of the first turbine rotor assembly, replacement of specific bolts and their associated locking plates, and the removal and replacement of any turbine disks showing signs of fretting or cracks. Compliance with this directive must be achieved within 50 hours of its effective date, during inspections, and before further flight to ensure the airworthiness of affected aircraft.

Scope and Application

The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) pertains specifically to Honeywell T5508D engines equipped with a first stage turbine disk identified by part number (P/N) 2-120-030-43. This directive applies to all such engines in service within the Australian jurisdiction. The primary objective of this AD is to mitigate the risk of unsafe conditions that may arise from incorrect torque application to the turbine disk clamping bolts, potentially leading to fretting and disk failure. The AD mandates the execution of a visual and fluorescent penetrant inspection of the first turbine rotor assembly, as well as the replacement of specific bolts and locking plates as per the instructions outlined in Avco Lycoming Service Bulletin 5508-0031, Revision 1. Additionally, any first turbine disks exhibiting fretting or crack indications during inspection must be removed and replaced with serviceable parts. The directive requires these actions to be completed within 50 hours of the AD's effective date of 10 July 2003, and before further flight. The directive also references FAA AD 86-19-13 Amdt. 39-5374 for additional context. This legislative instrument is applicable across the Commonwealth of Australia and was published in the Commonwealth of Australia Gazette on 18 June 2003.

Key Provisions

The Airworthiness Directive (AD) outlined in the legislation is specifically directed towards Honeywell T5508D engines equipped with a first stage turbine disk bearing the part number 2-120-030-43. The directive, as stated in section 1, mandates a series of actions to be taken unless they have already been completed. These actions include conducting a visual and fluorescent penetrant inspection of the first turbine rotor assembly in line with the Accomplishment Instructions provided in Avco Lycoming Service Bulletin (SB) 5508-0031, Revision 1. Furthermore, it requires the removal and replacement of certain bolts and their associated locking plates, also following the instructions in the same service bulletin. Lastly, any first turbine disks that show signs of fretting on the disk to shaft mating face or any crack indication during inspection must be removed from service and replaced with a serviceable part. The AD is clear in its requirement that these actions must be carried out within a specified timeframe and prior to further flight. The obligations imposed by the AD on the parties or entities it governs are stringent and specific. Owners or operators of Honeywell T5508D engines must ensure that the inspections and replacements are performed meticulously according to the outlined procedures in the service bulletin. This includes not only the technical execution of the inspections and replacements but also the scheduling of these actions in compliance with the timeframes stipulated in the AD. Additionally, the directive necessitates that any affected turbine disks are promptly replaced to maintain the airworthiness of the aircraft. Breaches of the AD can lead to severe consequences, both civil and criminal. While the legislation does not explicitly state the maximum penalties, it is understood that non-compliance with an AD can result in significant fines, enforcement actions by the Civil Aviation Safety Authority (CASA), and potential grounding of the aircraft until the required actions are completed. Furthermore, the risk of an unsafe condition leading to an accident or incident can have dire implications, including legal liability for any resulting damage or injuries. It is imperative that all obligations under this AD are met to avoid these serious repercussions.