{"id":"F2010L02202","name":"AD/PW4000/15 - 14th and 15th Stage Rubstrips","slug":"ad-pw4000-15-14th-and-15th-stage-rubstrips","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":124825,"registerId":"commonwealth-F2010L02202-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/PW4000/15 | 14th and 15th Stage Rubstrips | 15/2010 |\n| ------------ | ----------------------------- | ------- |\n\n```html\n

Applicability:

Pratt and Whitney (PW) models PW4164, PW4168, and PW4168A turbofan engines, serial numbers P733301 through P733500, that have HPC inner case assembly part number (P/N) 53H272-01 installed.

Note 1: These engines are installed on, but not limited to Airbus Industrie A330 aeroplanes.

Requirement:

Unless previously accomplished, to prevent engine power loss during takeoff due to high pressure compressor (HPC) surge, perform the following:

1. Borescope-inspect in accordance with paragraphs 1.A. through 1.I of the Accomplishment Instructions, Borescope Inspection of Pratt & Whitney (PW) Alert Service Bulletin (ASB) PW4G-100-A72-170, Revision 3, dated
31 January 2003, using schedules in Table 1 of this AD:

Table 1. - Installed-Engine Initial Borescope Inspection Schedule

Accumulated engine cycles on
the effective date of this AD:

Initial borescope-inspect 14th
and 15th stage rubstrips:

(1) Fewer than 900 cycles-since-new (CSN) or cycles-since-refurbishment (CSR) of the HPC inner rear case assembly.

Before accumulating 1,500 CSN or CSR, whichever occurs later.

(2) 900 or more CSN or CSR

Within 600 cycles-in-service (CIS) after the effective date of this AD.

2. Perform the applicable action as specified in the following Table 2:

Table 2. - Borescope Inspection Results and Required Action

Results observed at last borescope inspection:

Action:

(1) 14th stage rubstrip shows wear through to the parent material of the stator, with the circumferential length of the wear being 1.0\" or more.

Remove engine from service within 250 CIS.

\n```\n\n```html\n

(2) 15th stage rubstrip shows wear through to the parent material of the stator, with the circumferential length of the wear being 2.0\" or more.

Remove engine from service within 250 CIS.

(3) 14th stage rubstrip shows wear through to the parent material of the stator, with the circumferential length of the wear being less than 1.0\".

Reinspect every 300 CIS.

(4) 15th stage rubstrip shows wear through to the parent material of the stator, with the circumferential length of the wear being less than 2.0\".

Reinspect every 300 CIS.

(5) Both 14th and 15th stage rubstrips show no wear through to the parent material of the stator.

Reinspect every 600 CIS.

3. For aeroplanes with two affected engines installed, perform the actions as specified in following Table 3:

Table 3. - Borescope Inspection Results and
Required Actions for Two Affected Engines

First engine borescope results:

Second engine borescope schedule:

Second engine borescope results:

Action:

(1) Wear as specified in Table 2, Steps (1) through (4).

Within 10 CIS since borescope inspection of first engine.

Wear as specified in Table 2, Steps (1) through (4).

Remove either the first or second engine from service within 25 CIS since borescope inspection of the second engine and replace with a serviceable engine. Remove or re-inspect in accordance with Table 2 for remaining engine and if still applicable perform actions as specified in Requirement 3 of this AD.

(2) Wear as specified in Table 2, Steps (1) through (4).

Within 10 CIS since borescope inspection of first engine.

Wear as specified in Table 2, Step (5).

For both engines, remove or re-inspect in accordance with Table 2 and, if still applicable, perform actions as specified in Requirement 3 of this AD.

(3) Wear as specified in Table 2, Step (5).

Inspect as specified in Table 1.

Wear as specified in Table 2.

For both engines, remove or inspect in accordance with Table 2 and, if still applicable, perform actions as specified in Requirement 3 of this AD.

Definition of Serviceable Engine.

For the purposes of this AD, a serviceable engine is:

a. An engine that incorporates an HPC with zero CSN; or

b. An engine covered by the Terminating Action detailed in this AD; or

c. An engine inspected as specified in Requirements 1 through 3 of this AD, and is following the 600 CIS re-inspection interval as specified in Table 2 of this AD.

Engines borescope-inspected before the effective date of this AD in accordance with PW ASB PW4G-100-A72-170, Revision 1, or Revision 2, must follow Requirements 1 through 3 of this AD, after the effective date of this AD.

Later revisions of the above ASB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2003-09-02, are considered acceptable for compliance with the equivalent Requirements of this AD.

Terminating Action.

Replacement of HPC inner rear case assembly with an HPC inner rear case assembly containing a Haynes 242 rear hook, including assemblies modified or replaced by PW SB No. PW4G-100-72-159, PW SB No. PW4G-100-72-187, or Chromalloy Repair Procedure 00-CFL-039-0, constitutes terminating action for the repetitive engine borescope inspections of this AD.

\n```\n\n| | Note 2: FAA AD 2003-09-02 Amdt 39-13131 date 21 April 2003 refers. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Compliance: | For Requirement 1 - As detailed in Table 1 of this AD.For Requirement 2 - As detailed in Table 2 of this AD.For Requirement 3 - As detailed in Table 3 of this AD. |\n| | This Airworthiness Directive becomes effective on 14 August 2010. |\n| Background: | This AD requires operators to initially and repetitively borescope-inspect 14th and 15th stage rubstrips located on the 13th and 14th stage stator set for wear. This AD is prompted by reports of high pressure compressor (HPC) surges during the takeoff phase of flight that have been attributed to increased stage 14 and stage 15 HPC blade tip clearances caused by excessive wear on the HPC inner rear case rear hook. The actions specified by this AD are intended to prevent engine power loss during takeoff due to HPC surge.From a review of State of Design ADs, CASA has determined that this AD may be applicable to Australian aircraft. |\n\n![](image.001.png)\n\nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n28 July 2010","sortOrder":0},{"sectionNumber":"AD/PW4000/15","sectionType":"part","heading":"AD/PW4000/15","content":"## AD/PW4000/15","sortOrder":1},{"sectionNumber":"14th","sectionType":"part","heading":"and 15th Stage Rubstrips","content":"## 14th and 15th Stage Rubstrips","sortOrder":2},{"sectionNumber":"15/2010","sectionType":"part","heading":"15/2010","content":"## 15/2010","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The directive follows the FAA AD it references and keeps applicability narrowly tied to specific PW4000 engine models, serial numbers and HPC inner case P/N. It preserves the original inspection/threshold approach and adds an explicit terminating action; it does not broaden applicability beyond the engines and parts identified."},"complexity_factors":["Technical specificity: measures wear on 14th/15th stage rubstrips and requires interpretation of borescope images","Multiple conditional inspection intervals and thresholds (Table 1 and Table 2) that depend on CSN/CSR and measured circumferential wear lengths","Twin‑engine interdependence: paired‑engine rules require short follow‑up inspections and coordinated removals/replacements (Table 3)","Defined terminating action with several acceptable modification/repair routes (Haynes 242 rear hook, specific SBs, or repair procedure)","Limited applicability by engine model, serial number range and part number, requiring fleet identification","References to external documents (PW Alert SB revisions, FAA AD) for compliance detail and AMOC acceptance","Operational burden: tight short‑notice intervals (e.g. 10 CIS, 25 CIS, 250 CIS) creating potential aircraft downtime","Measurement precision requirement (wear circumferential length in inches) creates potential for borderline compliance decisions"],"plain_english_summary":"This Airworthiness Directive requires borescope inspections of the 14th and 15th stage rubstrips on certain Pratt & Whitney PW4164/4168/4168A engines (HPC inner case P/N 53H272-01, serials P733301–P733500), sets wear thresholds triggering re‑inspection or engine removal, and makes replacing the HPC inner rear case with a Haynes 242 rear hook a terminating action. It affects operators of aircraft using those engines (notably A330s). Operators pay for inspections, potential engine removals and replacements, and must follow tighter scheduling and twin‑engine coordination to avoid takeoff power‑loss risk."},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This AD appears to maintain its original scope as a targeted safety directive addressing a specific mechanical wear issue in a defined engine population. The document references the original FAA AD 2003-09-02 and follows the standard format for Australian airworthiness directives adopting foreign design authority requirements. There is no evidence of scope creep beyond the original safety purpose of preventing HPC surge in PW4000 engines."},"complexity_factors":["Multiple interdependent tables (Tables 1, 2, and 3) with cross-referenced conditions that must be read together to determine compliance actions","Nested conditional logic: inspection schedules depend on engine cycle counts (CSN/CSR), which then trigger different action tables based on wear measurements","Bifurcated requirements for single-engine versus twin-engine aircraft configurations (Requirement 3 creates a complex decision tree for two-engine scenarios)","Technical aviation terminology requiring specialised knowledge (borescope inspection, HPC surge, rubstrips, parent material, cycles-since-new)","Reference to external documents (Pratt & Whitney Alert Service Bulletin PW4G-100-A72-170, Revision 3) that contain the actual inspection procedures — compliance requires accessing these external standards","Definition of \"serviceable engine\" with three alternative conditions (zero CSN, terminating action completed, or following 600 CIS interval)","Grandfathering clause for engines previously inspected under earlier revisions of the service bulletin, requiring transition to new requirements","Cross-reference to FAA AD 2003-09-02 and acceptance of later FAA-approved AMOCs as equivalent compliance methods"],"plain_english_summary":"This AD mandates borescope inspections of the 14th–15th stage HPC rubstrips on certain Pratt & Whitney PW4164/4168/4168A engines (serials P733301–P733500) to detect wear that can cause HPC surge and possible engine power loss at takeoff. It affects operators of Airbus A330s (and any aircraft with these engines) in Australia.\n\nInspections must follow specified cycle-based intervals and engines with excessive rubstrip wear must be removed from service; replacing the inner case assembly with a Haynes 242 rear hook terminates the inspections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw4000-15-14th-and-15th-stage-rubstrips","history":"/api/acts/ad-pw4000-15-14th-and-15th-stage-rubstrips/history","analysis":"/api/acts/ad-pw4000-15-14th-and-15th-stage-rubstrips/analysis","conflicts":"/api/acts/ad-pw4000-15-14th-and-15th-stage-rubstrips/conflicts","importantCases":"/api/acts/ad-pw4000-15-14th-and-15th-stage-rubstrips/important-cases","documents":"/api/acts/ad-pw4000-15-14th-and-15th-stage-rubstrips/documents"}}