{"id":"F2006L01693","name":"AD/CF34/11 - Lufthansa A.E.R.O. - Undertorqued LP Turbine Rotors","slug":"ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":59450,"registerId":"commonwealth-F2006L01693-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"General Electric Turbine Engines - CF34 ","sectionType":"division","heading":"General Electric Turbine Engines - CF34 Series","content":"### General Electric Turbine Engines - CF34 Series\n\n| AD/CF34/11 | Lufthansa A.E.R.O. - UndertorquedLP Turbine Rotors | 7/2006 |\n| ---------- | -------------------------------------------------- | ------ |\n\n| Applicability: | General Electric Engine model CF34-3 serial numbers (S/N) 872579, 807566, 807346C, 872278, 872334, 873070 last overhauled by Lufthansa A.E.R.O., Germany.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the requirements of German LBA Airworthiness Directive D-2006-139 at any revision status.Note 1: Lufthansa A.E.R.O. Shop Information Letter (SIL) CF34-3 SIL 06-001 pertains to the subject of this AD.Note 2: German LBA Airworthiness Directive D-2006-139 dated 18 May 2006 refers.                                                                                                                                                                                                                                                                                                                                                                                            |\n| Compliance:    | For engine serial numbers 872579, 807566 and 807346C - Within 500 hours since last shop visit.For engine serial numbers 872278, 872334 and 873070 - At the next aircraft letter-check or scheduled or unscheduled engine shop visit, whichever occurs first.                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n|                | This Airworthiness Directive becomes effective on 6 July 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| Background:    | During routine tool calibration in February 2006, Lufthansa A.E.R.O. detected a malfunctioning torque wrench. The deviation of the malfunctioning torque wrench was 38% below the target value (e.g. at 40 lb-in setting, the actual torque value was 24.8 lb-in). The subject torque wrench was last calibrated in February 2005.On review of all internal work orders since February 2005, Lufthansa A.E.R.O. identified six engines on which this torque wrench was used for final assembly. The defective torque wrench was used for assembling rotating LP Turbine hardware on three engines while on the other three engines, the wrench was used for assembly of the stationary LP Turbine hardware. |\n\n|     | Actions specified in this AD are aimed at preventing uncontained turbine wheel failure, loss of engine power and probable damage to and/or loss of the aircraft. |\n| --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n24 May 2006","sortOrder":0},{"sectionNumber":"AD/CF34/11","sectionType":"part","heading":"AD/CF34/11","content":"## AD/CF34/11","sortOrder":1},{"sectionNumber":"Lufthansa A.E.R.O. - UndertorquedLP Turb","sectionType":"part","heading":"Lufthansa A.E.R.O. - UndertorquedLP Turbine Rotors","content":"## Lufthansa A.E.R.O. - Undertorqued  \nLP Turbine Rotors","sortOrder":2},{"sectionNumber":"7/2006","sectionType":"part","heading":"7/2006","content":"## 7/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument confines corrective action to the six engines identified as having been assembled with the defective torque wrench. That scope matches the stated purpose of addressing undertorqued LP turbine hardware and does not expand beyond the affected serial numbers (Applicability; Background)."},"complexity_factors":["Very narrow applicability: only six CF34‑3 engine serial numbers listed (Applicability).","Delegation to foreign directive: requires compliance with German LBA AD D‑2006‑139 at any revision status (Requirement), creating dependence on another authority's text.","Two-tier compliance timing: different deadlines for two engine groups (Compliance).","Technical root cause identified (defective torque wrench) but remedial actions follow external AD (Background and Requirement).","Low regulatory discretion: mandatory actions and fixed effective date limit interpretive flexibility (Requirement; Compliance)."],"plain_english_summary":"This Airworthiness Directive orders owners/operators of six specific GE CF34‑3 engines overhauled by Lufthansa A.E.R.O. to perform the inspections and corrective work set out in German LBA AD D‑2006‑139 because a miscalibrated torque wrench produced undertorqued LP turbine hardware. Three serials must be addressed within 500 flight hours; the other three at the next letter‑check or engine shop visit. Operators and maintenance organisations pay for inspections/repairs; the regulator prescribes the work and timing."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow, targeted purpose: addressing a specific maintenance error affecting six identified engines. There is no evidence of scope creep — it does not expand to other engine models, other maintenance facilities, or broader operational requirements beyond the immediate safety issue."},"complexity_factors":["Very short document — approximately 300 words of substantive content","Only 6 specific serial numbers affected — extremely narrow scope","Single requirement: comply with an external German directive (LBA D-2006-139)","Two simple compliance timeframes based on engine serial number grouping","No defined terms section, no cross-references to other Australian legislation","No conditional logic or nested exceptions — straightforward 'if your engine is on this list, do this' structure","Background narrative explains the technical issue in plain language"],"plain_english_summary":"This AD mandates urgent inspection and repair of six specific General Electric CF34-3 engines (SN 872579, 807566, 807346C, 872278, 872334, 873070) overhauled by Lufthansa A.E.R.O. A torque wrench used during assembly delivered ~38% less torque, risking undertorqued turbine rotors that could cause uncontained engine failure, loss of power, or aircraft damage. Operators of these engines must comply: three engines fixed within 500 flight hours, the other three at the next maintenance check, following the German LBA directive (D-2006-139)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors","history":"/api/acts/ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors/history","analysis":"/api/acts/ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors/analysis","conflicts":"/api/acts/ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors/conflicts","importantCases":"/api/acts/ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors/important-cases","documents":"/api/acts/ad-cf34-11-lufthansa-a-e-r-o-undertorqued-lp-turbine-rotors/documents"}}