{"id":"F2005L02395","name":"AD/B737/130 Amdt 2 - Rudder PCU - Displacement Tests","slug":"ad-b737-130-amdt-2-rudder-pcu-displacement-tests","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":36840,"registerId":"commonwealth-F2005L02395-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/130 Amdt 2 | Rudder PCU - Displacement Tests | 10/2005 |\n| ------------------ | ------------------------------- | ------- |\n\n| Applicability: | All Model B737 series aircraft. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Perform a displacement test on the secondary slide in the dual servo valve in the rudder PCU in accordance with Boeing Alert Service Bulletin 737-27A1221 Revision 1 dated January 28, 1999 (Model 737-100, -200, -300, -400 and -500 series) or in accordance with Boeing Alert Service Bulletin 737-27A1222, Revision 1, dated January 28, 1999 (Model 737-600, -700 and -800 series).2. Subject to the test in Requirement 1 proving negative (valve fails test), replace the valve assembly in accordance with Boeing Alert Service Bulletin737-27A1221 Revision 1 dated January 28, 1999 (Model 737-100, -200, -300,-400 and -500 series) or in accordance with Boeing Alert Service Bulletin737-27A1222, Revision 1, dated January 28, 1999 (Model 737-600, -700 and-800 series), and repeat test.3. Do not install on any aircraft any main rudder PCU having P/N 65-44861-12 and serial number 3509A or lower or, any PCU having P/N 65C37053-(XX) (Model 737-100, -200, -300, -400 and -500 series) or PCU having P/N 251A301-(XX) and serial number 0299 or lower (Model 737-600, -700 and -800 series) unless the PCU nameplate has been vibro-engraved with the letter “C” following the serial number.Accomplishment of the requirements of AD/B737/201 (FAA AD 2002-20-07) constitutes terminating action for the requirements of this Directive.Note 1: Subsequent serial numbers greater than those listed in Requirement 3 are displacement tested as part of the certified production process and do not require the letter “C” to be vibro-engraved.Note 2: FAA AD 99-11-05 Amendment 39-11175 issued December 7, 1999 refers and corrects FAA AD 99-11-05 dated 24 May 1999. |\n| Compliance: | 1. Initial Test.a. Model 737-100, -200, -300, -400 and -500 series aeroplanes the test must be completed within 16 months time in service from 12 August 1999. Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours. |\n| | b. For aeroplanes equipped with a PCU having P/N 65-44861-12 and serial number 3509A or lower or P/N 65C37053-(XX), the test must be completed within 16 months time in service from 12 August 1999. Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.c. For Model 737-600, -700 and -800 aeroplanes having line numbers 1 through 222 inclusive that are equipped with PCU’s having P/N 251A301-(XX) and serial number 299 or lower, conduct the test within 16 months time in service from 12 August 1999. Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.d. For all other aeroplanes, conduct the test prior to the accumulation of 24,000 total flight hours or within 30 days from the effective date of this Directive, whichever is the later. Thereafter, repeat the displacement test at intervals not exceeding 24,000 flight hours.2. Prior to further flight.3. After 30 November 2000.The compliance times remain unchanged by this issue. |\n| | This Amendment becomes effective on 29 September 2005. |\n| Background: | As part of the rudder system improvement programme, this Directive was introduced to detect cracks in the secondary slide in the dual concentric servo valve of the rudder PCU. This Directive reflects a Country of Origin Airworthiness Directive.Amendment 1 reflected a number of corrections to the original directive mandated by the Country of Origin AD.Amendment 2 is issued in response to FAA AD 2002-20-07, which requires incorporation of a new rudder control system; which when incorporated, supersedes the requirements of AD 99-11-05, the Requirement document of this Directive.The original issue of this Airworthiness Directive became effective on 12 August 1999. |\n\n![](image.001.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n19 August 2005","sortOrder":0},{"sectionNumber":"AD/B737/130 Amdt 2","sectionType":"part","heading":"AD/B737/130 Amdt 2","content":"## AD/B737/130 Amdt 2","sortOrder":1},{"sectionNumber":"Rudder PCU - Displacement Tests","sectionType":"part","heading":"Rudder PCU - Displacement Tests","content":"## Rudder PCU - Displacement Tests","sortOrder":2},{"sectionNumber":"10/2005","sectionType":"part","heading":"10/2005","content":"## 10/2005","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":true,"description":"Amendment 2 modifies the Directive by recognising FAA AD 2002‑20‑07: incorporation of the FAA‑mandated rudder control system serves as terminating action for these testing requirements. The Amendment therefore adds an alternative compliance pathway and updates the Directive to reflect the Country of Origin AD while preserving the displacement‑test regime and serial/part restrictions (Background; Requirement note)."},"complexity_factors":["Multiple model-specific service instructions: two different Boeing Alert Service Bulletins are mandated depending on aircraft model series (Requirement 1).","Serial-number and part-number specific installation prohibition: certain PCU P/Ns and serial ranges are barred from installation unless vibro‑engraved with “C” (Requirement 3).","Multiple compliance paths and a terminating action: compliance can be ended by incorporation of the FAA AD 2002‑20‑07 rudder control system (Requirement note; Background).","Staggered and conditional compliance times: initial-test deadlines vary by model, line number and part/serial status, with recurring intervals specified (Compliance 1a–1d).","Reactive replacement obligation: failed displacement tests must lead to valve replacement and a repeat test, creating immediate operational and parts‑cost consequences (Requirement 2).","Cross-references to other directives and FAA AD corrections add interpretive burden (Note 1 and Note 2; Background)."],"plain_english_summary":"This Directive requires operators of all Boeing 737 models to perform displacement tests on the rudder PCU dual-servo valve, replace valves that fail the test, and prohibits installing certain PCU part/serial numbers unless the unit is vibro‑engraved “C”. Tests must follow Boeing Alert Service Bulletins and are repeated on a recurring schedule. The Directive also recognises that installing the FAA‑mandated new rudder control system (FAA AD 2002‑20‑07) can terminate these testing requirements."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original directive (August 1999) was a standalone safety measure requiring repetitive testing of rudder PCUs. Amendment 2 (2005) significantly expanded the scope by incorporating a 'terminating action' pathway — allowing operators to escape the repetitive testing regime entirely by installing a redesigned rudder control system. This transformed the directive from a permanent maintenance burden into a transitional measure, effectively scheduling its own obsolescence for compliant operators."},"complexity_factors":["Multiple aircraft model groupings with different part numbers and serial number cutoffs (737-100/-200/-300/-400/-500 vs -600/-700/-800)","Four distinct compliance timelines depending on aircraft model, line number, and PCU part/serial number","Cross-reference to terminating action from another directive (AD/B737/201 / FAA AD 2002-20-07)","Specific technical references to Boeing Alert Service Bulletins with revision dates and different bulletins for different model groups","Conditional logic: \"Subject to the test in Requirement 1 proving negative\" creates a dependency chain","Nested serial number and part number exceptions in Requirement 3 with specific engraving requirements","Reference to foreign (FAA) regulatory instruments and their amendment numbers"],"plain_english_summary":"This AD requires operators of Boeing 737 Classic and Next‑Generation series in Australia to inspect the rudder PCU’s dual‑servo valve (secondary slide) via a displacement test, replace faulty valves, and ensure certain older units are vibro‑engraved “C.” Tests recur every 24,000 flight hours. Issued after fatal rudder‑control accidents, it prevents loss of rudder control; installing the new rudder control system later can terminate the repetitive tests."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-130-amdt-2-rudder-pcu-displacement-tests","history":"/api/acts/ad-b737-130-amdt-2-rudder-pcu-displacement-tests/history","analysis":"/api/acts/ad-b737-130-amdt-2-rudder-pcu-displacement-tests/analysis","conflicts":"/api/acts/ad-b737-130-amdt-2-rudder-pcu-displacement-tests/conflicts","importantCases":"/api/acts/ad-b737-130-amdt-2-rudder-pcu-displacement-tests/important-cases","documents":"/api/acts/ad-b737-130-amdt-2-rudder-pcu-displacement-tests/documents"}}