{"id":"F2007L04224","name":"AD/TAY/12 Amdt 6 - Low Pressure Compressor Ice Impact Panels","slug":"ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70429,"registerId":"commonwealth-F2007L04224-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rolls Royce Turbine Engines - Tay Series","sectionType":"division","heading":"Rolls Royce Turbine Engines - Tay Series","content":"### Rolls Royce Turbine Engines - Tay Series\n\n| AD/TAY/12 Amdt 6 | Low Pressure Compressor Ice Impact Panels | 12/2007 |\n| ---------------- | ----------------------------------------- | ------- |\n\n| Applicability: | Tay 611-8, Tay 611-8C, Tay 620-15, Tay 650-15 and Tay 651-54 series engines with Low Pressure (LP) compressor ice impact panels of Rolls-Royce Deutschland (RRD) Service Bulletin (SB) TAY-72-1326 standard.Note 1: These engines are known to be installed on, but not limited to, Boeing 727 series, Fokker F28 Mark 0070 and Mark 0100, and Gulfstream G-IV and GIV-X aircraft. |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Repetitively inspect the low pressure compressor ice impact panels in accordance with the instructions of, RRD NMSB TAY-72-1638 Revision 3 or later approved revisions, or Non-Modification Service Bulletin (NMSB) TAY-72-1639 Revision 2 or later approved revisions, as applicable to engine model.2. If more than one engine on an aircraft is equipped with epoxy bonded ice impact panels, rework the epoxy bonded ice impact panels on one engine using polysulphide bonding in accordance with RRD NMSB TAY-72-1638 Revision 3 or later approved revisions, or NMSB TAY-72-1639 Revision 2 or later approved revisions, as applicable to engine model.3. Install modified ice impact panels with additional retention features and rework the LP Compressor case assembly in accordance with RRD SB TAY-72-A1643 Revision 1 or later approved revisions, or SB TAY-72-A1650 Revision 1 or later approved revisions, as applicable to engine model.Note 2: The instructions for the repetitive inspection requirements for theTay 611-8C engines are included in the Time Limits Manual Chapter 05-20-02.After accomplishment of the modification as required by Requirement 3 of this AD, the repetitive inspections of Requirement 1 and the rework detailed in Requirement 2 are no longer required.Note 3: EASA AD 2007-0258 dated 25 September 2007 refers. |\n\n| Compliance: | 1. As per the intervals detailed in the applicable document or manual.2. Before further flight after the effective date of this AD, unless previously accomplished.3. No later than 31 December 2011. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | This Amendment becomes effective on 22 November 2007. |\n| Background: | An event has occurred on a Tay 620-15/20 powered aircraft where all the Low Pressure (LP) compressor case ice impact panels of Rolls-Royce Service Bulletin TAY-72-1326 standard on both engines were released in flight. The released LP compressor case ice impact panels were caught in front of the fan outlet guide vanes, resulting in bypass duct blockage and significant thrust loss. The actions specified by this Airworthiness Directive are intended to make sure that the bonding of these LP compressor ice impact panels complies with the design intent.Amendment 6 reflects that RRD has revised NMSB TAY-72-A1650 Revision 1 to introduce new production LP compressor cases for the Tay 611-8 engines to allow replacement of the complete LP compressor case instead of the ice impact panels only. This amendment adds a reference to the latest RRD Service Bulletin (SB) revision.Amendment 5 included the TAY 611-8C engine.Amendment 4 included a new replacement panel which has a new retention system and layer structure which is designed to prevent failure of the panel.Amendment 3 updated the reference document to the last revision and changed the compliance period for some models of engine for replacement of the ice impact panels.Amendment 2 updated the reference documents to reflect the latest revision.Amendment 1 of this Directive superseded those requirements detailed in AD/TAY/10 Amdt 1 and AD/TAY/11.Amendment 5 of this Directive became effective on 19 January 2006.Amendment 4 of this Directive became effective on 27 October 2005.Amendment 3 of this Directive became effective on 12 May 2005.Amendment 2 of this Directive became effective on 23 December 2004. |\n\n| | Amendment 1 of this Directive became effective on 28 October 2004. |\n| --- | ------------------------------------------------------------------ |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n2 October 2007","sortOrder":0},{"sectionNumber":"AD/TAY/12 Amdt 6","sectionType":"part","heading":"AD/TAY/12 Amdt 6","content":"## AD/TAY/12 Amdt 6","sortOrder":1},{"sectionNumber":"Low Pressure Compressor Ice Impact Panel","sectionType":"part","heading":"Low Pressure Compressor Ice Impact Panels","content":"## Low Pressure Compressor Ice Impact Panels","sortOrder":2},{"sectionNumber":"12/2007","sectionType":"part","heading":"12/2007","content":"## 12/2007","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"Originally addressed ice impact panel bonding issues for specific Tay engine models. The scope has expanded through 6 amendments to: (1) add new engine models (Tay 611-8C in Amendment 5), (2) introduce new replacement panel designs with retention systems (Amendment 4), (3) allow complete LP compressor case replacement rather than just panel replacement (Amendment 6), and (4) incorporate updated technical documentation revisions. The directive has evolved from a simple inspection/rework order to a comprehensive modification program with multiple technical pathways."},"complexity_factors":["Multiple amendment history (6 versions) creating layered requirements","Cross-references to 4 different Rolls-Royce Service Bulletins (SB TAY-72-A1643, SB TAY-72-A1650, NMSB TAY-72-1638, NMSB TAY-72-1639) with specific revision numbers","Conditional logic: Requirement 2 only applies 'if more than one engine on an aircraft is equipped with epoxy bonded ice impact panels'","Termination condition: Requirements 1 and 2 cease to apply after Requirement 3 is accomplished","Multiple engine models with slightly different applicable documents (Tay 611-8, 611-8C, 620-15, 650-15, 651-54)","Three different compliance deadlines with different triggers (interval-based, immediate, calendar date)","Reference to external EASA AD 2007-0258 for context"],"plain_english_summary":"This CASA Airworthiness Directive targets certain Rolls‑Royce Tay engines (used on Boeing 727, Fokker 70/100, Gulfstream G‑IV, etc.) after failures of internally bonded ice‑impact panels that can detach, block the bypass duct and cause serious in‑flight power loss. \n\nIt mandates repeated inspections, interim bonding rework if needed, and installation of improved panels plus a compressor‑case modification by the compliance date; once the permanent modification is done, repetitive inspections are no longer required."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"The Directive’s scope expanded across amendments: Amendment 5 added the TAY 611‑8C engine; Amendment 4 introduced a new replacement panel with an altered retention system and layer structure; Amendment 6 introduced new production LP compressor cases allowing replacement of the complete LP compressor case instead of panels and updated referenced service bulletins. Other amendments updated referenced documents and adjusted compliance periods. These changes broadened repair/replacement options and added/clarified affected models and documentary references (Background; Requirements; Notes)."},"complexity_factors":["Multiple engine models and aircraft installations covered (Tay 611‑8, 611‑8C, 620‑15, 650‑15, 651‑54) increasing applicability complexity (Applicability).","Several distinct mandatory actions: repetitive inspections, rework of epoxy bonded panels, and installation or replacement of modified panels/LP compressor case (Requirements 1–3).","Cross‑references to multiple Rolls‑Royce Deutschland service/NMSB and SB documents and their later approved revisions (Requirements and Notes); compliance depends on following the correct revision for each model.","Staged and differing compliance deadlines (inspection intervals per manuals; rework before further flight after effective date unless already done; modification by 31 Dec 2011) require tracking and scheduling.","Modification terminates earlier repetitive obligations (Note: after Requirement 3, Requirements 1 and 2 no longer required) which creates dependency between actions.","Alternative technical solutions allowed (panel rework vs full LP compressor case replacement introduced in Amendment 6) add decision complexity for operators.","One model’s inspection instructions are included in the Time Limits Manual (Tay 611‑8C), adding a procedural cross‑reference (Note 2).","Safety‑critical operational consequence (in‑flight release causing thrust loss) increases regulatory urgency and potential enforcement/compliance scrutiny (Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of certain Rolls‑Royce Tay engines (Tay 611‑8, 611‑8C, 620‑15, 650‑15 and 651‑54) fitted with low‑pressure compressor ice impact panels to perform repetitive inspections, rework epoxy‑bonded panels to polysulphide where multiple engines are affected, and install modified panels or replace the LP compressor case per specified Rolls‑Royce Deutschland service bulletins. It responds to an in‑flight panel release that caused bypass duct blockage and thrust loss; operators pay for inspections, repairs and replacements and must meet staged compliance dates (final modification by 31 Dec 2011)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels","history":"/api/acts/ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels/history","analysis":"/api/acts/ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels/analysis","conflicts":"/api/acts/ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels/conflicts","importantCases":"/api/acts/ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels/important-cases","documents":"/api/acts/ad-tay-12-amdt-6-low-pressure-compressor-ice-impact-panels/documents"}}