{"id":"F2005L02831","name":"AD/PW100/12 - Propeller Shaft","slug":"ad-pw100-12-propeller-shaft","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":37793,"registerId":"commonwealth-F2005L02831-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pratt and Whitney Canada Turbine Engines","sectionType":"division","heading":"Pratt and Whitney Canada Turbine Engines - PW100 Series","content":"### Pratt and Whitney Canada Turbine Engines - PW100 Series\n\n| AD/PW100/12 | Propeller Shaft | 11/2005 |\n| ----------- | --------------- | ------- |\n\n| Applicability: | Pratt & Whitney Canada (P&WC) PW118, PW118A, PW118B, PW119C, PW120, PW120A, PW121, PW121A, PW123, PW123B, PW123C, PW123D, PW123E, PW124B, PW125B, PW127 and PW127E engines with propeller shafts listed in Tables 1 to 4.of Transport Canada AD CF-2005-29.Note 1: The above engines are installed on, but not limited to, Aerospatiale ATR 42 and ATR 72, Bombardier DHC-8-100/200/300, Domier 328-120, Embraer EMB120, and Fokker 50 aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Destroy/Discard propeller shafts identified in Table 1, 2, and 3 of Transport Canada AD CF-2005-29.2. For propeller shafts identified in Table 4 of Transport Canada AD CF-2005-29; perform a visual inspection for oil leaks as per PART A of the Accomplishment Instructions of P&WC SB 21714R2, dated 20 May 2005, or later Transport Canada approved revisions.(a) If an oil leak is found, do as follows:(i) Do an inspection of the propeller shaft seal area for leaks per the Engine Maintenance Manual - Corresponding Fault Isolation Chart (Oil leak from propeller shaft area).(ii) If the oil leak can be fixed without the propeller removed, the engine can be put back into service.(iii) If the propeller needs to be removed to fix the oil leak, do the procedure for the internal inspection of the propeller shaft in Requirement 3 of this directive.(b) If an oil leak is not found, the engine can be put back into service.3. For propeller shafts identified in Table 4 of Transport Canada AD CF-2005-29; perform an internal inspection of the propeller shafts as per PART B of the Accomplishment Instructions of P&WC SB 21714R2, or later Transport Canada approved revisions. |\n\n|             | (a) If a crack is found, remove and discard the propeller shaft, and install a new propeller shaft as per Part C of the Accomplishment Instructions of P&WC SB 21714R2 or later Transport Canada approved revisions.(b) If no crack is found, the engine can be put back into service.Note 2: (Applies to Requirement 2 and 3 inspections: Visual & Internal) Compliance using inspection methods contained in any of the previous versions of P&WC SB 21714 prior to the effective date of the directive satisfy the requirements of SB 21714, Revision 2, mandated by this directive.4. Propeller shafts listed in Table 4 of Transport Canada AD CF-2005-29 must be removed and destroyed/discarded.Note 3: Transport Canada AD CF-2005-29 refers. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | 1. Within five days after the effective date of this directive.2. Within five days after the effective date of this directive, and repeated every week afterwards until the propeller shafts are removed from service.(a)(i) Before further flight.(a)(ii) Following rectification of the oil leak.(a)(iii) Before further flight.3. Within 250 hours air time, or not more than 3 months after the effective date of this directive, whichever occurs first.(a) Before further flight.4. No later than 31 December 2007. No extensions or alternate means of compliance are permitted.                                                                                                                                                               |\n|             | This Airworthiness Directive becomes effective on 27 October 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n| Background: | There have been two reported instances of propeller shafts being found with through going cracks at the no. 19 bearing area. The root cause was positively identified as “Hydrogen Embrittlement” caused by the improper nickel-plating repair process performed at two different overhaul facilities. These two exceptional events are related to the excessive period of time that the propeller shaft spent in the nickel-plating tank.Both events were discovered following a persistent external oil leak in the propeller shaft area, as the crack had migrated past the seal runner.                                                                                                                                                           |\n\n|     | Transport Canada has issued Service Difficulty Alert AL-2005-05 in March 2005 to provide information about this issue and explain the planned corrective actions to rectify this problem. |\n| --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n16 September 2005","sortOrder":0},{"sectionNumber":"AD/PW100/12","sectionType":"part","heading":"AD/PW100/12","content":"## AD/PW100/12","sortOrder":1},{"sectionNumber":"Propeller Shaft","sectionType":"part","heading":"Propeller Shaft","content":"## Propeller Shaft","sortOrder":2},{"sectionNumber":"11/2005","sectionType":"part","heading":"11/2005","content":"## 11/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The directive's scope is focused on propeller shafts listed in Transport Canada AD CF-2005-29 and actions prescribed by P&WC SB 21714R2 (or earlier approved revisions). It confines measures to those listed shafts and to inspection/removal/replacement procedures tied to that identification, consistent with the stated cause (hydrogen embrittlement) and does not expand applicability beyond the referenced tables and SB (Applicability; Requirement; Note 3)."},"complexity_factors":["Wide applicability across many PW100 engine models and multiple aircraft types (Applicability).","Different mandatory actions depending on the table in Transport Canada AD CF-2005-29: immediate destruction (Tables 1–3), inspection then possible removal (Table 4) (Requirement).","Multiple inspection types and conditional steps: visual inspection for oil leaks, fault isolation per Engine Maintenance Manual, internal inspection, and removal if cracks are found (Requirement 2–3, 2.a.i–iii).","Cross-references to external documents: Transport Canada AD CF-2005-29 and P&WC SB 21714R2 (or earlier approved revisions) govern methods and acceptable prior compliance (Requirement; Note 2; Note 3).","Staggered, tight compliance timelines: within 5 days, weekly repeats until removal, before further flight in some cases, within 250 hours or 3 months, and a final removal deadline (Compliance).","Absolute prohibition on extensions or alternate means of compliance (Compliance: 'No extensions or alternate means of compliance are permitted'), increasing operational rigidity.","Direct economic burden on operators and maintenance providers for disposal and replacement of shafts and for repeated inspections (Requirement; Compliance).","Implementation requires coordination between operators, overhaul facilities and maintenance organisations to follow specific fault isolation and SB procedures (Requirement 2.a.i; Requirement 3).","Potential traceability and record-keeping demands to show compliance with specified SB revisions and Transport Canada tables (Requirement; Note 2)."],"plain_english_summary":"This directive requires operators of Pratt & Whitney Canada PW100-series engines to remove and destroy specified propeller shafts and to carry out visual and internal inspections on others, following P&WC Service Bulletin procedures and Transport Canada AD tables. It responds to cracks caused by hydrogen embrittlement from improper nickel‑plating. Operators and maintenance organisations pay for inspections, repairs and replacements, must meet staggered deadlines (days to months), and are not permitted alternative compliance methods."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused scope. It addresses a specific safety defect (hydrogen embrittlement in propeller shafts) with targeted requirements. The scope remains tightly constrained to the identified safety issue and affected engine models."},"complexity_factors":["Multiple nested requirements with sub-requirements (Requirements 1-4, each with sub-parts a, b, i, ii, iii)","Cross-references to external documents: Transport Canada AD CF-2005-29 (Tables 1-4), P&WC Service Bulletin 21714R2, and Engine Maintenance Manual Fault Isolation Charts","Conditional logic chains: inspection outcomes determine different compliance paths (oil leak found/not found, crack found/not found)","Multiple compliance deadlines with different triggers: immediate (5 days), recurring (weekly), flight-hour based (250 hours), calendar-based (3 months, 31 December 2007)","Four separate tables referenced but not reproduced in the directive itself","Note 2 creates an exception allowing use of earlier inspection methods under specific conditions"],"plain_english_summary":"This CASA Airworthiness Directive orders operators of PW100-powered aircraft (ATR 42/72, Bombardier Dash 8, Dornier 328, Embraer EMB120, Fokker 50) to remove and destroy specified propeller shafts, carry out weekly visual checks for oil leaks on others, perform internal crack inspections within 250 flight hours or three months, and replace any cracked shafts — with all affected shafts to be removed by 31 December 2007. It responds to cracked shafts from a faulty nickel‑plating repair process that could cause catastrophic failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pw100-12-propeller-shaft","history":"/api/acts/ad-pw100-12-propeller-shaft/history","analysis":"/api/acts/ad-pw100-12-propeller-shaft/analysis","conflicts":"/api/acts/ad-pw100-12-propeller-shaft/conflicts","importantCases":"/api/acts/ad-pw100-12-propeller-shaft/important-cases","documents":"/api/acts/ad-pw100-12-propeller-shaft/documents"}}