{"id":"F2009L03770","name":"AD/PW4000/14 - Low Pressure Turbine Disks","slug":"ad-pw4000-14-low-pressure-turbine-disks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":141659,"registerId":"commonwealth-F2009L03770-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pratt and Whitney Turbine Engines - PW40","sectionType":"division","heading":"Pratt and Whitney Turbine Engines - PW4000 Series","content":"### Pratt and Whitney Turbine Engines - PW4000 Series\n\n| AD/PW4000/14 | Low Pressure Turbine Disks | 11/2009 |\n| ------------ | -------------------------- | ------- |\n\n```html\n

Applicability:

Pratt & Whitney PW4164, PW4168, and PW4168A turbofan engines with certain low pressure turbine (LPT) stage 4 disks, part number (P/N) 51N404, that have a serial number (S/N) listed in Table 1 of this AD, installed.

Note 1: These engines are installed on, but not limited to, Airbus A330-200 and A330-300 series aeroplanes.

Table 1. - Affected LPT Stage 4 Disks by Serial Number

LPT Stage 4 Disk Serial Nos.

CLDLC01142

CLDLC01151

CLDLC01143

CLDLC01152

CLDLC01144

CLDLC01181

CLDLC01145

CLDLC01182

CLDLC01146

CLDLC01183

CLDLC01148

CLDLC01185

CLDLC01149

CLDLC01186

CLDLC01150

CLDLC01187

Requirement:

1. Remove from service any LPT stage 4 disk that has an S/N listed in Table 1 of this AD.

2. Do not install any disk, P/N 51N404, that has an S/N listed in Table 1 of this AD or any disk removed as specified in paragraph (f) of this AD except as allowed by paragraph (h) of this AD.

Note 2: FAA AD 2007-26-20 Amdt 39-15322 dated 20 December 2007 refers.

\n```\n\n| Compliance: | For Requirement 1 - At the next piece-part exposure after the effective date of this AD or within 7,500 cycles-since-new, unless the actions have already been done.For Requirement 2 - After the effective date of this AD. |\n| ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | This Airworthiness Directive becomes effective on 22 October 2009. |\n| Background: | This AD results from a report of improperly manufactured LPT stage 4 disks. The issuing of this AD is intended to prevent an uncontained engine failure due to low-cycle fatigue, which could result in damage to the aeroplane. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n2 September 2009","sortOrder":0},{"sectionNumber":"AD/PW4000/14","sectionType":"part","heading":"AD/PW4000/14","content":"## AD/PW4000/14","sortOrder":1},{"sectionNumber":"Low Pressure Turbine Disks","sectionType":"part","heading":"Low Pressure Turbine Disks","content":"## Low Pressure Turbine Disks","sortOrder":2},{"sectionNumber":"11/2009","sectionType":"part","heading":"11/2009","content":"## 11/2009","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific manufacturing defect in a single engine component. It has not expanded beyond its initial safety purpose of preventing uncontained engine failures from defective LPT stage 4 disks."},"complexity_factors":["Short, single-purpose directive with only 2 substantive requirements","Limited applicability: 3 engine models, 1 part number, 15 specific serial numbers in a defined table","Simple conditional logic: 'remove by X date OR Y cycles' — no nested exceptions","Cross-reference to one FAA AD (Note 2) but no complex legislative interdependencies","No defined terms section — technical terms (LPT, P/N, S/N) are standard aviation shorthand","Single compliance timeline with straightforward alternatives (next maintenance vs. cycle limit)"],"plain_english_summary":"This CASA Airworthiness Directive mandates removal and prohibition of reinstallation of specific Pratt & Whitney PW4164/68/68A low-pressure turbine stage-4 disks (P/N 51N404, listed serials) because of improper manufacture causing low-cycle fatigue and risk of uncontained engine failure. It affects operators and maintenance organisations of A330-200/-300 aircraft (and any other aircraft with these engines). The AD took effect 22 October 2009; affected disks must be removed by the next opportunity or within 7,500 flight cycles."},"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":3,"scope_assessment":{"changed":false,"description":"The AD's scope remains focused and targeted: it covers only specific LPT stage 4 disks by part and serial number on named engine models. It mandates removal and a ban on reinstallation, with no expansion of parts, models, or new inspection regimes beyond what the AD lists (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow, part-specific scope limited to a fixed list of serial numbers (Table 1) (Applicability; Table 1).","Two clear, simple mandates: remove listed disks from service and prohibit installing listed or removed disks (Requirement paragraphs 1–2).","Compliance timing uses a mixed trigger: 'next piece-part exposure' or a discrete cycles threshold (7,500 cycles‑since‑new) for removal, creating scheduling choices for operators (Compliance).","Cross-reference to an external FAA AD (FAA AD 2007-26-20) introduces reliance on related regulatory material (Note 2).","Reference to an exception mechanism (paragraph (h)) creates limited discretionary relief not detailed in the excerpt (Requirement 2)."],"plain_english_summary":"This Airworthiness Directive requires operators to remove from service and prohibits reinstalling certain Pratt & Whitney PW4000 low-pressure turbine (LPT) stage 4 disks (P/N 51N404) identified by serial number. It applies to PW4164, PW4168 and PW4168A engines (used on A330-200/300 among others). CASA states the action responds to improperly manufactured disks to prevent low-cycle fatigue and possible uncontained engine failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw4000-14-low-pressure-turbine-disks","history":"/api/acts/ad-pw4000-14-low-pressure-turbine-disks/history","analysis":"/api/acts/ad-pw4000-14-low-pressure-turbine-disks/analysis","conflicts":"/api/acts/ad-pw4000-14-low-pressure-turbine-disks/conflicts","importantCases":"/api/acts/ad-pw4000-14-low-pressure-turbine-disks/important-cases","documents":"/api/acts/ad-pw4000-14-low-pressure-turbine-disks/documents"}}