AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/DART/28 and issues the following AD under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Rolls Royce Turbine Engines - Dart Series
AD/DART/28
Amdt 1
HP Turbine Blades - Inspection and Rework 10/2003
DM
Applicability: Rolls Royce Dart 500 series engines as detailed in Rolls Royce Service Bulletin Da72-543 dated 11 July 2003.
Requirement: 1. For engines NOT reworked to repair scheme DRS611 standards in accordance with the original issue of this Directive, carry out the requirements of Rolls Royce Service Bulletin Da72-530 dated May 1998.
2. For engines reworked to repair scheme DRS611 standards in accordance with Rolls Royce Service Bulletin Da72-530 dated May 1998:
(a) Inspect the HP turbine blade platforms and shrouds in accordance with the applicable Rolls Royce Dart Overhaul Manual; and
(b) Carry out repeat inspections of the HP turbine blade platforms and shrouds in accordance with applicable Rolls Royce Dart Overhaul Manual.
Note 1: For further information, including references and accomplishment instructions, Rolls Royce Service Bulletin Da72-543 dated 11 July 2003 refers.
3. If excessive gaps between blade shrouds and platforms are found in compliance with Requirement 2(a) or (b), the engine may not be returned to service unless reworked in accordance with applicable Rolls Royce Dart Overhaul Manual.
Note 2: German LBA AD 2003-217 dated 7 August 2003 refers.
Compliance: For Requirement 1: Before further flight.
For Requirement 2(a):
- Prior to exceeding 7400 flight hours since the last inspection of the blades in accordance with the Overhaul Manual; or
- Prior to exceeding 7400 flight hours since new blades were installed; or
- Prior to exceeding 1500 flight hours from the effective date of this Directive which ever comes later.
Rolls Royce Turbine Engines - Dart Series
AD/DART/28 Amdt 1 (continued)
For Requirement 2(b): At intervals not exceeding 7400 flight hours. For Requirement 3: Before further flight.
This Amendment becomes effective on 27 August 2003.
Background: The original issue of this Directive required a one time inspection and rework of all HP turbine blades was after an investigation found that a number of HP turbine disc rim failures since 1972, resulting in HP turbine disc release, was due to high stress levels in the HP turbine disc bucket groove due to blade vibration. This blade vibration can occur as a result of excessive gaps between blade shrouds and platforms. This amendment re-writes the requirements, in consideration of the German LBA AD, by introducing an initial inspection followed by repeat inspections in order to prevent further uncontained disc rim failures.
The original issue of this Airworthiness Directive became effective on 10 September 1998.
Jim Coyne
Delegate of the Civil Aviation Safety Authority 22 August 2003
The above AD is notified in the Commonwealth of Australia Gazette on 27 August 2003.
Overview
The Civil Aviation Safety Authority (CASA) has issued the Airworthiness Directive (AD) AD/DART/28 Amdt 1 to address the issue of excessive gaps between blade shrouds and platforms in Rolls Royce Dart 500 series engines, which can lead to high stress levels and disc rim failures. This directive was enacted to ensure the ongoing airworthiness of these aircraft engines by mandating specific inspections and rework procedures to mitigate the risk of blade vibration and subsequent failures. The directive revokes the previous AD/DART/28 and incorporates considerations from the German LBA AD 2003-217 to improve safety measures. The policy objective is to prevent uncontained disc rim failures and ensure the safety of aircraft operations by enforcing mandatory inspections and rework where necessary.
Scope and Application
This Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) pertains to Rolls Royce Dart 500 series engines as detailed in Rolls Royce Service Bulletin Da72-543 dated 11 July 2003. It applies to all operators of these engines and mandates specific inspection and rework requirements to address safety concerns identified in the original issue of the Directive. The AD is effective in the Commonwealth of Australia and requires compliance with the outlined inspection and rework procedures before further flight. For engines that have not yet been reworked to the repair scheme DRS611, the AD mandates adherence to Rolls Royce Service Bulletin Da72-530 dated May 1998. For engines already reworked to DRS611 standards, it requires initial and repeat inspections of the high-pressure (HP) turbine blade platforms and shrouds, with rework required if excessive gaps are detected. Compliance is contingent on specific flight hour thresholds, with inspections mandated before further flight under certain conditions. This AD revises and replaces the previous AD/DART/28, reflecting updated safety protocols in collaboration with the German LBA AD 2003-217 dated 7 August 2003.
Key Provisions
The Airworthiness Directive (AD) AD/DART/28 Amdt 1, issued under the Civil Aviation Safety Regulations (CASR) 1998, pertains specifically to Rolls Royce Dart 500 series engines. The directive mandates specific actions to ensure the airworthiness of these engines. The applicability of the directive (Section 1) is limited to the engines detailed in Rolls Royce Service Bulletin Da72-543 dated 11 July 2003. The requirement section (Section 2) outlines specific actions depending on whether the engine has been reworked to meet DRS611 standards as per the original AD/DART/28. For engines not reworked to these standards, the original inspection and rework requirements outlined in Rolls Royce Service Bulletin Da72-530 dated May 1998 must be followed. For engines that have been reworked, the HP turbine blade platforms and shrouds must be inspected according to the Rolls Royce Dart Overhaul Manual. A repeat inspection is also required after the first one. If excessive gaps between blade shrouds and platforms are detected, the engine must be reworked in accordance with the Overhaul Manual before it can be returned to service.
The obligations imposed on the entities governed by this AD include conducting inspections and reworks as specified. For engines that have not been reworked to DRS611 standards, the inspection and rework must occur before further flight. For engines that have been reworked, the initial inspection must be conducted before the engine accrues 7400 flight hours since the last blade inspection or 1500 flight hours since the effective date of this AD, whichever is later. The repeat inspections must occur at intervals not exceeding 7400 flight hours. Any rework due to detected excessive gaps must be completed before the engine returns to service. These obligations are detailed in the compliance section (Section 3) of the AD.
Any failure to comply with the requirements of this Airworthiness Directive can lead to severe consequences. The directive does not explicitly state the penalties for non-compliance, but violations of airworthiness directives generally can result in significant legal and financial repercussions. Non-compliance may lead to the grounding of affected aircraft, which can incur substantial costs and operational disruptions. Additionally, the directive's provisions are enforced under the Civil Aviation Safety Regulations 1998, and breaches could potentially lead to penalties under those regulations, which may include fines and other enforcement actions. The exact penalties would depend on the specific circumstances and the discretion of the Civil Aviation Safety Authority.