{"id":"F2006B05717","name":"AD/PA-31/129 Amdt 1 - Elevator Structure","slug":"ad-pa-31-129-amdt-1-elevator-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135516,"registerId":"commonwealth-F2006B05717-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/129 Amdt 1 - Elevator Structure","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/PA-31/129 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nPiper PA-31 Series Aeroplanes\n\nAD/PA-31/129\n\nAmdt 1\n\n  \n\nElevator Structure 12/2001 DM\n\nApplicability: Aircraft applicable to Requirements 1, 2, or 3 as specified below: For Requirement 1:\n\nModel PA-31 and PA-31-300, serial numbers 31-2 through 31-694 For Requirement 2:\n\nModels Serial numbers\n\nPA-31P 31P-1 through 31P-7730012\n\nPA-31T 31T-7400002 through 31T-8120104\n\nPA-31T1 31T-7804001 through 31T-8304003 and 31T-1104004 through 31T-1104017\n\nPA-31T2 31T-8166001 through 31T-8166076 and 31T-1166001 through 31T-1166008\n\nPA-31T3 31T-8275001 through 31T-8475001 and 31T-5575001\n\nFor Requirement 3:\n\nModel PA-31, PA-31-300, and PA-31-325, serial numbers 31-2 through 31-8312019 Model PA-31-350, serial numbers 31-5001 through 31-8452021 and 31-8253001\n\nthrough 31-8553002.\n\nPA-31P-350, serial numbers 31P-8414001 through 31P-8414050.\n\nRequirement: 1.a. Inspect the rudder and elevator spars and elevator butt ribs for cracks in accordance with the instructions contained in Piper Service Bulletin (SB) No. 323, dated 21 September 1970.\n\n    1.b. If cracks are found in the rudder or elevator structure during any inspection, replace the cracked part, and either continue to re-inspect in accordance with SB No. 323, or incorporate Elevator and Rudder Hinge Replacement Kit No. 760- 465 in accordance with the instructions contained in the kit, revised 25 October 1989.\n\n    1.c. Incorporate Elevator and Rudder Hinge Replacement Kit No. 760-465 in accordance with the instructions contained in the kit, revised 25 October 1989.\n\n    2.a. Modify the elevator trim tab system and elevator control tube in accordance with the instructions contained in Elevator Trim System Modification Kit No. 760-989, as referenced in Piper SB No. 477A, dated 3 November 1975.\n\nNote 1: This modification is retained from AD 76-03-01, and applies to certain Model PA-31T aircraft. If complied with before issue of an Australian Certificate of Airworthiness, no further action is required.\n\n    2.b. Incorporate Elevator Butt Rib Refinement Kit, part number 766-219, in accordance with the instructions contained in the kit; as referenced in Piper SB No. 897B, dated 15 July 1997.\n\nNote 2: This refinement kit may have been incorporated as specified in Piper SB 897A; in which case, no further action is required.\n\n3. Incorporate Elevator Butt Rib Reinforcement Kit, part number 766-642, in accordance with instructions contained in the kit; as specified in Piper SB No. 1008, dated 30 September 1997.\n\nNote 3: If AD/PA-31/126 Amdt 3 is applicable to an aircraft affected by Requirement 3, then the spar replacement required by AD/PA-31/126 Amdt 3 should, if possible, be accomplished before incorporating Kit 766-642. No credit is given for accomplishing Piper SB 864.\n\nNote 4: FAA AD 2001-06-01 Amdt 39-12148 refers.\n\nCompliance: 1.a. Within 100 hours time in service after the last inspection previously\n\nrequired by AD/PA-31/13 (AD 70-26-06), and thereafter at intervals not to exceed 100 hours time in service; until Piper Kit No. 760-465 is incorporated.\n\n    1.b. Before further flight.\n\n    1.c. Upon accumulating 2,000 hours total time in service or within 100 hours time in service after 9 August 2001, whichever occurs later.\n\n2.a. and 2.b. Upon accumulating 2.000 hours total time in service or within 100 hours time in service after 9 August 2001, whichever occurs later.\n\n3. Upon accumulating 2,000 hours time in service or within 100 hours time in service after 9 August 2001, whichever occurs later.\n\nThe compliance times of the original issue of this Directive remain unchanged by this issue.\n\nThis amendment becomes effective on 10 October 2001.\n\nBackground: The FAA policy of incorporating modifications, when available, that will terminate the need for repetitive inspections, prompted the issue of FAA AD 2001-06-01, which superseded three existing FAA ADs; and were reflected in CASA Directives. This Directive consolidates the inspection requirements of the previously issued Directives, and requires terminating action for the inspections.\n\nAmendment 1 is issued to clarify, as Note 3, the installation interrelationship between the elevator spar and the butt rib reinforcement kit, following information received from the manufacturer.\n\nThe original issue of this Airworthiness Directive became effective on 9 August 2001.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 4 October 2001\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 10 October 2001.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This amendment consolidates prior AD requirements and replaces repetitive inspections with mandatory terminating modifications where kits are available (Background). It adds a clarification about sequencing between elevator spar replacement and installation of Butt Rib Reinforcement Kit 766‑642 (Note 3). It does not change the original compliance times (Compliance)."},"complexity_factors":["Multiple aircraft models and many serial‑number ranges listed under Applicability, requiring careful applicability checks (Applicability).","Several distinct corrective options and mandatory kit installations (Kit No. 760‑465, 760‑989, 766‑219, 766‑642) across Requirements 1–3, increasing parts and procedure variation (Requirements 1–3).","Combination of repetitive inspection regime plus terminating modifications: inspections remain until a terminating kit is incorporated, creating tracking and maintenance‑planning burdens (Requirement 1.a; Compliance).","Compliance timing tied to total time‑in‑service or fixed hour windows after a date, producing dual triggers operators must monitor (Compliance).","Cross‑references to multiple Piper Service Bulletins and kit instructions mean procedures are defined outside the AD, requiring operators to obtain and follow external technical documents (Requirements referencing SBs and kits).","Interactions with other ADs and manufacturer guidance (references to AD/PA‑31/126 Amdt 3, FAA AD 2001‑06‑01) introduce sequencing rules and conditional credits that affect work scope (Note 3; Background).","Notes limiting credit for earlier Service Bulletins and specifying sequencing (Note 2 and Note 3) create conditional exceptions that must be interpreted case‑by‑case.","Legal basis and effect are regulatory (issued under subregulation 39.1(1) of CAR 1998), so non‑compliance has regulatory consequences and requires administrative oversight (introductory paragraph)."],"plain_english_summary":"This Airworthiness Directive obliges owners/operators of the listed Piper PA‑31 series aircraft and serial ranges to inspect elevator and rudder spars, butt ribs and related components, and to either repair/replace cracked parts or incorporate specified Piper modification kits that terminate repetitive inspections. It consolidates earlier ADs by requiring particular kit installations (see Requirements) and sets exact compliance windows (see Compliance). Owners/operators pay for inspections, parts and labour; the amendment clarifies sequencing between spar replacement and kit 766‑642 (Note 3) and leaves original compliance times unchanged."},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive. The original directive consolidated three previous FAA ADs into one CASA directive. Amendment 1 adds only a clarifying note (Note 3) about installation sequencing. The scope remains focused on elevator and rudder structural safety for the specified Piper aircraft, which was the original intent. No mission creep or expansion beyond aviation safety maintenance requirements."},"complexity_factors":["Multiple overlapping applicability sections requiring serial number cross-referencing (three separate requirement categories with different aircraft models and serial ranges)","Interdependent requirements where compliance with one affects another (Note 3 specifies sequencing between this AD and AD/PA-31/126 Amdt 3)","Conditional logic throughout: 'if cracks found...', 'if complied with before...', 'if possible...', 'whichever occurs later' calculations","Cross-references to external documents: 4 Piper Service Bulletins, 3 specific modification kits with part numbers, and 1 other Airworthiness Directive","Nested exceptions and credits: Note 2 provides exemption if SB 897A already done; Note 3 denies credit for SB 864; Note 1 exempts if done pre-Certificate of Airworthiness","Dual compliance time calculations involving both flight hour thresholds (100 hours, 2,000 hours) and calendar dates (9 August 2001, 10 October 2001)","Technical aviation terminology requiring domain knowledge (spar, butt rib, time in service, terminating action)"],"plain_english_summary":"This AD requires owners/operators of specified Piper PA‑31 series aeroplanes to inspect and repair cracks in elevator and rudder spars and elevator butt ribs, and to install prescribed modification/reinforcement kits. Cracks must be repaired before flight; inspections recur until the permanent kits are fitted.\n\nThe amendment consolidates earlier orders and clarifies the sequencing when multiple ADs apply. The aim is to prevent catastrophic control failure by eliminating the underlying structural issue and ending repetitive inspections."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-129-amdt-1-elevator-structure","history":"/api/acts/ad-pa-31-129-amdt-1-elevator-structure/history","analysis":"/api/acts/ad-pa-31-129-amdt-1-elevator-structure/analysis","conflicts":"/api/acts/ad-pa-31-129-amdt-1-elevator-structure/conflicts","importantCases":"/api/acts/ad-pa-31-129-amdt-1-elevator-structure/important-cases","documents":"/api/acts/ad-pa-31-129-amdt-1-elevator-structure/documents"}}