AD/RB211/38 - Engine - High Pressure Turbine Disc

Applicability: The AD is limited to Rolls‑Royce RB211‑524, RB211‑535C and RB211‑535E4 series engines that have HP turbine discs listed by part and serial number in NMSB 72‑AF996 Revision 1 (Applicability). The SB identifies the affected part and serial numbers; the AD does not itself list part or serial numbers, it points readers to the SB for that detail.

Action cycle: The AD sets a three‑step compliance regime: (1) remove affected HP turbine discs from aircraft and replace with a serviceable disc, (2) inspect each HP turbine disc prior to any reinstallation in accordance with the SB, and (3) prohibit installation of any listed disc unless it has been inspected and passed the inspection (Requirements 1-3). Discs failing inspection must be returned to Rolls‑Royce for further investigation (Requirement 2).

Compliance timing: For the removal/replacement obligation (Requirement 1) the compliance window is not set in the AD text itself but is cross‑referred to Section 1.C “Compliance” of the SB; the AD instructs operators to follow that time period (Compliance). Requirements 2 and 3 are effective from the AD’s effective date (Compliance). The AD’s effective date is 20 November 2008 (Compliance).

Risk mechanism: The technical risk identified in the Background is that a maintenance eddy‑current inspection technique may have been performed incorrectly, with the consequence that cracks in HP turbine discs could remain undetected. The technical failure mode the AD aims to prevent is disc fracture and subsequent high‑energy debris release (Background). The AD delegates the inspection method and identification of affected serials to the manufacturer SB (Background; Applicability).

Inter‑instrument references: The AD relies on two external documents: Rolls‑Royce Alert NMSB 72‑AF996 Revision 1 (the manufacturer service bulletin that lists affected part/serial numbers and provides inspection instructions and the Section 1.C compliance windows) and EASA AD 2008‑0176 (referenced in the Requirements notes). The AD therefore functions as a regulatory overlay that makes compliance with the manufacturer SB mandatory for the listed parts.

Scope examples: The AD notes that the affected engines are known to be installed on, but not limited to, Lockheed Martin L‑1011, Boeing 747, 757 and 767 series aircraft, and Tupolev Tu204 aircraft (Applicability). The AD wording “known to be installed on, but not limited to” signals that the list is illustrative, and applicability is determined by the engine/part/serial checklist in the SB, not by airframe model alone.

Delegation and signature: The AD is signed by “Charles Lenarcic, Delegate of the Civil Aviation Safety Authority” and dated 3 October 2008, with an explicit effective date later (20 November 2008) (signature and Compliance). The AD label is AD/RB211/38 dated 12/2008.

Aircraft operators: Any operator of aircraft fitted with Rolls‑Royce RB211‑524, RB211‑535C or RB211‑535E4 engines must determine whether their installed HP turbine discs are among those listed by part and serial number in NMSB 72‑AF996 Revision 1 (Applicability). The AD’s obligations , removal and replacement, inspection prior to reinstallation, and prohibition on installing uninspected or failed parts , fall on operators and their maintenance organisations insofar as they are responsible for the airworthiness of the aircraft and the parts installed.

Maintenance organisations and technicians: Maintenance organisations and maintenance personnel performing inspections and parts replacement must follow the instructions in Rolls‑Royce Alert NMSB 72‑AF996 Revision 1 when conducting the inspections required before any reinstallation (Requirements 1-3). The AD makes the SB’s inspection procedure the mandated standard for these HP discs.

Parts suppliers and stock managers: Entities responsible for supply chains and parts inventory must ensure that serviceable replacement HP turbine discs are sourced and that any disc identified in the SB is not installed unless it has been inspected and passed as required by the AD (Requirement 3). For affected discs that fail inspection, the AD requires return to Rolls‑Royce, imposing logistical and inventory tracking responsibilities (Requirement 2).

Rolls‑Royce plc: The manufacturer is named as the recipient of failed discs for “further investigation” (Requirement 2) and is the author of the NMSB that both identifies affected serials and prescribes the inspection method. The AD therefore compels operator/manufacturer interaction: failed units must be returned to Rolls‑Royce.

Regulator: The Civil Aviation Safety Authority (through its delegate) is the issuing authority of the AD; the signature block identifies the CASA delegate and records the AD as an instrument with an effective date (signature; Compliance). CASA is the body issuing the requirement and thus the regulator charged with promulgation of the AD, although the AD text itself does not enumerate enforcement mechanisms or penalties.

Aircraft types and fleets: The AD lists illustrative airframes on which affected engines are known to be installed (Lockheed Martin L‑1011, Boeing 747/757/767, Tupolev Tu204). Operators of these airframes should prioritise checking the SB serial list, but applicability depends on the actual engine and part serials installed rather than airframe model alone (Applicability).

Other aviation authorities and oversight bodies: The AD explicitly refers to EASA AD 2008‑0176 dated 18 September 2008 (Requirements Note 2), which indicates a cross‑jurisdictional recognition of the issue. The AD therefore affects how overseas‑based parts or engines covered by EASA action are managed within the CASA regulatory matrix.

Key duties established by the AD are directly stated in the Requirements and in the Compliance paragraph:

• Removal and replacement duty: Operators must remove from aircraft the HP turbine discs identified in Rolls‑Royce Alert NMSB 72‑AF996 Revision 1 and replace them with a serviceable disc. The timing for this removal is determined by the SB’s Section 1.C “Compliance” schedule, which the AD adopts by reference (Requirement 1; Compliance).

• Inspection prior to reinstallation duty: Prior to reinstallation on an engine, each HP turbine disc must be inspected in accordance with the instructions of the SB. The AD mandates the SB’s inspection procedure as the normative method for assessing whether a disc can be reinstalled (Requirement 1).

• Non‑reinstallation and return duty for failed parts: Any HP turbine disc that fails the inspection required by the AD “shall not be reinstalled on an engine and must be returned to Rolls‑Royce for further investigation” (Requirement 2). This is an affirmative logistical duty placed on the person or organisation handling the failed disc.

• Installation prohibition unless inspected and passed: The AD prohibits the installation of any HP turbine disc identified in the SB on any engine unless it has been inspected in accordance with the SB and has passed that inspection (Requirement 3). This creates an ongoing operational constraint: even after the immediate removal/replacement operation, identified discs remain subject to the inspection‑and‑pass gate before installation.

Rights and procedural notes implied by the AD text:

• Right to rely on the SB for technical instructions: The AD directs operators and maintenance organisations to the Rolls‑Royce Alert NMSB for part/serial identification and for the inspection method and compliance times. The SB is therefore the source of technical detail and the AD makes compliance with it mandatory (Applicability; Requirements; Compliance).

• Right to return failed parts to the manufacturer: The AD expressly requires that discs failing inspection be returned to Rolls‑Royce for investigation, which entails that Rolls‑Royce is the designated recipient for such units and must accept them for that purpose. The AD does not elaborate how Rolls‑Royce will process or remediate returned parts; it only requires the return (Requirement 2).

• No express mitigation procedures in the AD: The AD does not itself provide an alternative compliance route, a deferment mechanism, or explicit provision for credit for previous work. The AD defers technical detail and compliance timing to the SB, and elsewhere references EASA AD 2008‑0176 (Requirements Note 2; Compliance). The AD does not set out a process in its text for seeking deviations or exemptions; it simply sets mandatory duties.

Administrative and temporal duties:

• The AD becomes effective on 20 November 2008; from that date Requirements 2 and 3 are immediately operative, while Requirement 1 must be satisfied within the time windows set out in the SB’s Section 1.C (Compliance). Operators therefore have a split set of timing duties: some immediate (do not install any listed disc unless inspected and passed) and some subject to the SB compliance schedule (removal/replacement).

What the AD does not state as rights or duties:

• The AD does not specify penalties, fines, or enforcement procedures in its text. It is silent on appeals processes, directions for recordkeeping beyond the inspection, or on who pays for replacement parts, inspections, or shipping of failed discs. Those operational and legal consequences are not addressed in the AD text provided.

The AD text supplied does not include a penalty schedule, civil or criminal sanctions, or a procedural enforcement framework. The document is an instruction from the Civil Aviation Safety Authority (signed by the authority’s delegate), and it sets mandatory actions and compliance timings, but it does not itself specify the mechanisms by which non‑compliance will be detected, administratively addressed, or sanctioned.

What the AD does state about enforceability is implicit rather than explicit:

• The AD is presented as an authoritative airworthiness requirement and is signed by a CASA delegate with an effective date recorded (3 October 2008 signature, effective 20 November 2008) (signature; Compliance). That signature establishes the AD as a formal regulatory instrument; however, the AD text does not set out how failure to comply will be dealt with procedurally or what penalties might follow.

• The AD requires the return of failed HP turbine discs to Rolls‑Royce for further investigation (Requirement 2). That requirement creates an obligation on operators or maintenance organisations to ship or transfer the failed parts to the manufacturer, but the AD does not specify timelines for that return beyond the requirement nor any sanctions for failing to return a part.

• The AD cross‑references Rolls‑Royce NMSB 72‑AF996 Revision 1 and EASA AD 2008‑0176 (Requirements Note 2; Compliance), which may indicate alignment with overseas regulatory action. The AD text itself, however, does not specify enforcement mechanisms such as audits, mandatory reporting to CASA, grounded status for non‑compliant aircraft, or administrative penalties.

Consequences for practitioners reading the AD:

• Because the AD contains mandatory duties with clear objectives (removal, inspection, prohibition of installation unless inspected and passed), operators and maintenance organisations should treat the AD as binding and implement systems to evidence compliance. The AD does not provide the recordkeeping regime; the absence of such detail in the AD text implies that responsible parties will need to rely on usual maintenance record practices and any recordkeeping details in the Rolls‑Royce SB.

• The AD’s silence on penalties means the AD itself does not instruct how CASA will enforce compliance in practice. Practitioners should not assume no enforcement; rather, they should note that the AD creates mandatory obligations and that industry practice would be to expect regulatory oversight, but such oversight mechanisms are not specified in the AD text supplied.

• For returned failed discs, the AD mandates return to the manufacturer but does not specify who bears transport costs, who bears liability for handling, or what remedial actions Rolls‑Royce will take , these operational details are outside the AD text.

In short, the AD imposes mandatory duties, but the precise enforcement and penalty framework is not specified in the text provided. The AD must therefore be treated as a compliance imperative whose administrative and disciplinary enforcement details are to be found outside the AD text (for example, in broader regulatory instruments or organisational procedures), but those instruments are not included in the supplied material.

The AD expressly integrates and relies upon external aviation safety instruments and a manufacturer service bulletin for technical content. The document’s explicit cross‑references are the only inter‑instrument interactions stated in the text:

• Rolls‑Royce Alert Non‑Modification Service Bulletin 72‑AF996 Revision 1: The AD identifies affected part and serial numbers in this SB and makes the SB the authoritative technical guide for inspection and the compliance timing for Requirement 1 (Applicability; Requirements; Compliance). The AD therefore functions as a regulatory instrument that compels compliance with the SB’s content for the listed parts. Practically, the SB provides the technical inspection method and the compliance intervals in Section 1.C that the AD adopts as binding for operators.

• EASA AD 2008‑0176 (dated 18 September 2008): The AD explicitly refers to an EASA airworthiness directive and records that EASA AD 2008‑0176 is relevant (Requirements Note 2). The AD does not elaborate on the legal effect of the EASA AD within the Australian regulatory framework; it merely references it. The cross‑reference indicates coordination or recognition of similar regulatory action by another authority but the AD text does not provide details on harmonisation, whether compliance with EASA AD 2008‑0176 will be accepted as compliance with this AD, or whether further actions consistent with EASA’s directive are required.

• Manufacturer/Operator relationship: By mandating that discs failing inspection be “returned to Rolls‑Royce for further investigation” (Requirement 2) and by directing operators to the Rolls‑Royce SB for technical instructions, the AD formalises a procedural interaction between operators and the manufacturer. The AD makes compliance dependent on the SB for technical steps and Section 1.C for timing, so the manufacturer’s documentation is embedded in the regulatory obligation.

What is not stated in the AD:

• The AD does not list or identify any broader statutory provisions, administrative codes, or civil aviation act sections that provide the CASA delegate’s authority to issue the AD. The instrument does not itself set out how it will be enforced against certificates, how it affects continuing airworthiness certification, or how it integrates with inspection authorisation schemes; none of those cross‑references appear in the AD text presented.

• The AD does not state whether compliance with the SB or EASA AD will be accepted as proof of compliance with Australian regulatory requirements beyond the AD; practitioners must therefore treat the AD as the binding Australian obligation and follow it in conjunction with the SB.

• The AD does not specify whether any actions performed prior to the AD effective date that meet the SB’s requirements will be credited towards compliance; the text does not provide retroactive credit instructions.

In summary, within the provided text the AD interacts with other instruments only by reference to the Rolls‑Royce NMSB (for part identification, inspection method and Section 1.C timing) and to EASA AD 2008‑0176. The AD does not elaborate further on its statutory foundation or on enforcement interplay with other legislative instruments in the supplied content.

The AD as presented carries the following dated elements and revision references, and contains no indication of subsequent amendments within the supplied material:

• Rolls‑Royce Alert Non‑Modification Service Bulletin 72‑AF996 Revision 1 dated 17 July 2008 is the manufacturer document referenced throughout the AD for both part/serial identification and inspection instructions (Applicability; Requirements). The SB is identified specifically as Revision 1 and dated 17 July 2008.

• The AD is labelled AD/RB211/38 and dated 12/2008 in its header information (title block), which suggests it was prepared in the 12/2008 AD series. The signature page is dated 3 October 2008 and the AD states an effective date of 20 November 2008 (signature; Compliance).

• The AD text references EASA AD 2008‑0176 dated 18 September 2008 (Requirements Note 2), indicating contemporaneous international action.

The supplied AD text does not record any later revisions, rescissions, or amendments to AD/RB211/38 itself. The absence of an amendment history in the supplied document means the reader should treat the AD as effective as of 20 November 2008 and governed by the content shown unless a later instrument explicitly varies it. If operators require information about subsequent ADS, superseding ADs, or revised SBs, that information is not contained in the document supplied and must be sought from the regulator or the manufacturer.

Two points in the AD suggest versioning to be tracked externally:

• The AD’s reliance on NMSB 72‑AF996 Revision 1 indicates that technical content and compliance timing are subject to the SB’s revision history. Subsequent revisions of the SB could adjust compliance times, inspection techniques, or parts identified; however, such changes are not recorded in this AD text.

• The reference to EASA AD 2008‑0176 suggests that international airworthiness directives may present parallel or amended obligations that could affect operators in multiple jurisdictions; the AD does not indicate whether it will be amended to maintain alignment.

In short, the supplied instrument contains a snapshot of regulatory action (AD/RB211/38, effective 20 November 2008) that incorporates Rolls‑Royce NMSB 72‑AF996 Revision 1 (17 July 2008) and acknowledges EASA AD 2008‑0176 (18 September 2008). No later amendment history is recorded in the provided text.

The supplied AD contains no litigation history, no references to judicial decisions, and no record of legal challenges or contested enforcement actions. The document is an administrative airworthiness directive and includes only the regulatory requirements, the technical reference to the Rolls‑Royce SB, and the effective date.

What the AD does record relevant to dispute potential is limited to procedural facts:

• The AD is issued by the Civil Aviation Safety Authority delegate and is signed and dated (3 October 2008) with an effective date of 20 November 2008 (signature; Compliance). No appeal routes, review provisions, or dispute resolution mechanisms are specified within the AD text.

• The AD requires return of failed discs to Rolls‑Royce for further investigation (Requirement 2). That instruction creates potential factual bases for future manufacturer investigations and possibly further regulatory action, but the AD text supplies no information about how those investigations will be managed, what remedial actions may follow, or whether there will be formal findings subject to legal review.

Because the document does not recount litigation, appeals or judicial proceedings, readers seeking history of disputes or court decisions related to RB211 HP turbine discs, the SB, or the AD would not find that information in the AD text provided. Any such litigation history , if it exists , is outside the supplied material.

The AD contains several operational and compliance‑risk features that practitioners should note carefully; these are stated or directly implied in the AD text and its references.

Reliance on the manufacturer SB for critical detail

• The AD delegates core technical and timing content to Rolls‑Royce Alert NMSB 72‑AF996 Revision 1 (Applicability; Requirements; Compliance). The AD does not itself include the part/serial list, the inspection procedure, or the Section 1.C compliance periods. Operators must obtain and rely on the SB to identify affected serial numbers and to follow the mandated inspection technique. Failure to possess, understand, or correctly apply the SB could result in non‑compliance with the AD despite adherence to what the operator believed were appropriate procedures.

Variable compliance windows

• Requirement 1’s compliance timing is determined by Section 1.C “Compliance” of the SB, not by a single date in the AD (Compliance). This produces potential variability: the applicable time period can differ depending on serial numbers or other factors in the SB. Practitioners must read Section 1.C carefully to determine the exact compliance window that applies to each affected part. Treat the absence of a single AD‑level deadline as an administrative risk: it requires part‑by‑part analysis.

Immediate prohibition affecting operations

• Requirements 2 and 3 are effective from the AD’s effective date and state that discs failing inspection “shall not be reinstalled” and that no HP turbine disc identified in the SB may be installed “unless it has been inspected … and has passed that inspection” (Requirements 2-3; Compliance). This immediate prohibition can affect operational scheduling: even if an operator has a spare disc listed in the SB, it cannot lawfully be installed unless and until the SB inspection is carried out and passed.

Logistics and supply implications

• The AD mandates removal of affected discs and replacement with a serviceable disc (Requirement 1). Practitioners must plan for supply of serviceable discs. The AD is silent on whether the manufacturer will provide replacements, their cost, or priority. The AD also requires the return of failed discs to Rolls‑Royce (Requirement 2), which means operators must manage transport, export/import (if international), and tracking. These logistics may create aircraft downtime, potential out‑of‑service costs, and inventory pressure.

Inspection technique sensitivity

• The Background states the problem may arise from an error in an eddy‑current inspection technique carried out during maintenance (Background). The AD therefore mandates inspection per the SB. If operators previously relied on an incorrect eddy‑current method, they face the risk that historic inspections did not reveal cracks and that parts currently in service may be compromised. This raises an implicit need to re‑assess prior inspection records against the SB method.

Recordkeeping and proof of compliance gaps

• The AD does not specify recordkeeping procedures or the format for demonstrating compliance with the inspection requirement. Practitioners should not assume any particular form of evidence is sufficient; they must rely on normal maintenance record practices and any record requirements that appear in the SB. The lack of explicit recordkeeping rules in the AD text is a procedural gap that operators must close administratively (for example, by retaining SB inspection reports and shipping documentation for returned parts).

Return to manufacturer may trigger further actions

• Requirement 2 states that failed discs must be returned to Rolls‑Royce for “further investigation” but does not indicate subsequent steps such as repair, replacement credit, or remedial measures. Operators should expect Rolls‑Royce to follow up but should not assume the nature, timing or cost allocation of any remediation; these operational consequences are not defined in the AD.

Cross‑jurisdictional implications

• The AD references EASA AD 2008‑0176 (Requirements Note 2), which suggests parallel action by another regulator. Operators with internationally registered aircraft or parts crossing jurisdictions should confirm whether compliance with the EASA AD or the SB will satisfy all applicable regulatory obligations in each jurisdiction. The AD text itself does not resolve jurisdictional coordination or credit for compliance.

No penalties or enforcement detail in the AD text

• The AD text contains no explicit sanctions or enforcement process (Penalties and enforcement). That absence means operators should not assume lenience; instead, they should treat the AD as a binding requirement and prepare evidence and procedures to demonstrate compliance in the event of regulator queries.

In short, the primary operational “gotchas” are dependence on the Rolls‑Royce SB for the critical technical and timing information, the need to check Section 1.C for part‑specific deadlines, the immediate installation prohibition from the AD effective date, logistical burdens associated with replacement and returns, and the lack of explicit enforcement and recordkeeping detail in the AD text. Each of those items is grounded in the AD’s wording and its cross‑references.

The AD’s instructions are concise and largely procedural. To comply with the AD as written, follow these steps and operational actions, each grounded in the AD text and its cross‑references.

1. Obtain the authoritative materials

• Acquire Rolls‑Royce Alert Non‑Modification Service Bulletin 72‑AF996 Revision 1 dated 17 July 2008. The AD’s applicability and actions refer directly to that SB for part/serial identification, the inspection procedure, and the compliance time schedule (Applicability; Requirements; Compliance). Also obtain a copy of EASA AD 2008‑0176 (18 September 2008) for reference because the AD notes it (Requirements Note 2).

2. Identify affected parts

• Cross‑check the installed HP turbine discs on each RB211‑524, RB211‑535C or RB211‑535E4 engine in your fleet against the part and serial numbers listed in NMSB 72‑AF996 Revision 1. The AD makes the SB the determinant of applicability; the AD itself does not list serials (Applicability).

3. Determine compliance deadlines

• For each affected disc identified in the SB determine the applicable compliance time under Section 1.C “Compliance” of the SB. Requirement 1’s removal and replacement deadline is governed by that SB section (Compliance). Record the deadline for each part/serial and schedule the required maintenance slot accordingly.

4. Schedule removal and replacement

• Plan and execute removal from aircraft of any HP turbine discs identified in the SB and replace them with a serviceable disc within the SB’s specified time period (Requirement 1). Ensure the replacement disc itself meets airworthiness and serviceability requirements and is not one of the SB‑identified discs unless it has been inspected and passed the SB method (Requirement 3).

5. Perform inspection per the SB before any reinstallation

• Prior to any reinstallation of a HP turbine disc (including those removed for the AD and any spares that might otherwise be installed), carry out the inspection procedure precisely as instructed in the Rolls‑Royce SB (Requirement 1). The AD makes compliance with the SB’s inspection method mandatory.

6. Manage failed inspections

• If any disc fails the SB inspection, do not reinstall it on any engine; instead, return the disc to Rolls‑Royce for further investigation as required by the AD (Requirement 2). Ensure the physical tracking and shipping of the failed disc is documented, including chain of custody and any export/import paperwork needed if returning across borders. The AD commands the return but does not specify timelines beyond the inspection outcome.

7. Enforce the installation prohibition

• From the effective date of the AD (20 November 2008) no HP turbine disc identified in the SB may be installed on any engine unless it has been inspected in accordance with the SB and has passed that inspection (Requirement 3; Compliance). Update your maintenance release and parts control procedures to block installation of SB‑identified discs unless there is a clear, recorded inspection pass per the SB.

8. Document and retain evidence of compliance

• Although the AD does not specify a recordkeeping format, keep detailed records of part identification checks, SB inspection reports, dates and locations of removal/replacement, serial numbers of serviceable replacement discs, and evidence of return shipments for failed parts. Maintain correspondence with Rolls‑Royce regarding returned parts and any follow‑up investigation results. These records will be the practical proof of compliance given the AD’s silence on recordkeeping procedure.

9. Coordinate with supply chain and operations

• Because the AD requires physical replacement with serviceable discs, coordinate with parts suppliers, other operators, and the manufacturer to source serviceable discs in time to meet SB Section 1.C deadlines. Factor likely aircraft downtime into operational scheduling.

10. Monitor manufacturer and regulator updates

• Track any revisions to NMSB 72‑AF996 and any further ADs from CASA or other authorities (for example, the referenced EASA AD) that might extend, clarify or vary the AD obligations. The AD in the supplied text references NMSB Revision 1 and EASA AD 2008‑0176; any subsequent revisions could alter compliance details.

Operational responsibilities and allocation of costs

• The AD assigns operational duties (removal/replacement, inspection, returns) to the operator/maintenance organisation and assigns Rolls‑Royce as the recipient for failed parts (Requirements 1-2). The AD does not state who pays for replacement parts, inspections, or shipping of failed discs. Practitioners should therefore treat cost allocation as a commercial matter to be managed through existing supplier, operator and manufacturer arrangements unless otherwise directed by subsequent communications from the regulator or manufacturer.

Practical checklist itemisation

• Make an immediate checklist entry for each affected engine: (a) verify whether the engine contains an SB‑listed disc; (b) note the SB Section 1.C compliance date for that disc; (c) book maintenance slots for removal/replacement in accordance with the deadline; (d) arrange inspection according to SB prior to any reinstallation; (e) prepare logistics for returning any failed parts to Rolls‑Royce; (f) ensure installation prohibition is enforced administratively from 20 November 2008.

By following these steps, an operator or maintenance organisation will satisfy the AD’s explicit requirements as articulated in the supplied text: removal and replacement within SB Section 1.C timeframes, SB‑compliant inspection prior to reinstall, non‑reinstallation and return of failed parts to Rolls‑Royce, and prohibition on installation of SB‑identified discs unless inspected and passed (Requirements 1-3; Compliance; Applicability).