{"id":"F2006B05714","name":"AD/PA-31/126 Amdt 3 - Elevator Spar","slug":"ad-pa-31-126-amdt-3-elevator-spar","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135513,"registerId":"commonwealth-F2006B05714-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/126 Amdt 3 - Elevator Spar","content":"![](image.001.png)  \n![](image.002.png)  \nPiper PA-31 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/PA-31/126 Amdt 1. 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 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\nAD/PA-31/126\n\nAmdt 3\n\n  \nElevator Spar 2/2000\n\nApplicability: Models Serial Numbers\n\nPA-31, PA-31-300, and PA-31-325 31-2 through 31-8312019 PA-31-350 31-5001 through 31-8553002\n\nPA-31P-350 31P-8414001 through 31P-8414050\n\nRequirement: Inspect in accordance with either Requirement 1 or Requirement 2 below:\n\n    a. Visually inspect the upper and lower surfaces of the elevator spar, from the outboard hinge to 9-inches (230 mm) inboard of the hinge. Inspect for cracking in the skin, loose rivets, and fretting.\n\nb. (i) Gain access as necessary and perform a detail visual inspection of the rear faces of left and right elevator spar webs at the inboard ends of the outboard hinge doublers (refer to Figure 1, item C).\n\n(ii) Gain access as necessary and perform detail visual inspections of the forward faces of the left and right elevator spar webs at their outboard ends. Pay particular attention to the spar bend radii (refer to Figure 1, items A and B).\n\nIf cracks are found, replace elevator spar assembly in accordance with Requirement 3.\n\nNote 1: Installation of access holes in accordance with a scheme approved by a CAR 35 authorised person, may facilitate access for these inspections.\n\n![](image.003.png)\n\nFigure 1: Inspect the forward face of each elevator spar web, including the upper and lower bend radii between rivets ‘A’ and ‘B’. Inspect the rear face of each elevator spar adjacent to rivet ‘C”.\n\n    2. Accomplish the following in accordance with the Instructions section of Piper Mandatory Service Bulletin (MSB) 998A, dated August 4 1997:\n\n    Install access holes for the inspection of the elevator spar.\n\n    b. Inspect the elevator spar for cracks using a boroscope.\n\n    (i) If no cracks are found in the elevator spar during the inspection, reinspect the elevator spars for cracks.\n\n    (ii) If cracks are found during the initial inspection or subsequent repetitive inspection, refer to Requirement 3 of this Directive.\n\n    3. Replace each elevator or elevator spar assembly with a part of improved design as specified in the “Replacement Elevator P/N” and “Replace Spar P/N” columns of the “Material Required Table” on page 4 of Piper MSB 998A.\n\nAccomplish these replacements in accordance with the applicable maintenance manual.\n\nIf one elevator spar assembly is replaced before further flight when a crack is found, the other elevator spar assembly must still be repetitively inspected every 100 hours time in service until replacement at 1,000 hours time in service after the initial inspection or when cracks are found, whichever occurs first.\n\n    4. Inspect the elevator ice protection boots for looseness in accordance with the Instructions section of Piper MSB 998A.\n\nIf the elevator ice protection boots are loose, reinstall or replace the boots before further flight.\n\nNote 2: FAA AD 99-12-05 Amdt 39-11189 refers.\n\nCompliance: 1. a. Within 10 hours time in service after 12 October 1995, unless previously accomplished in accordance with the previous issues of this Directive.\n\nb. Before further flight if skin cracking, loose rivets, or fretting is found during the Requirement 1.a. inspection; otherwise, before 2,500 hours component time in service or within 100 hours time in service after 20 October 1995, whichever occurs later. Thereafter at intervals not to exceed 100 hours time in service; until replaced by an elevator or elevator spar assembly of improved design.\n\nNote 3: Elevator spars repaired prior to the issue of Amendment 2 of this Directive shall be inspected at intervals not exceeding 100 hours time in service unless otherwise previously approved by the Authority.\n\n    2. a. Upon accumulating 2,500 hours time in service on each elevator spar assembly, or within 100 hours time in service after 31 December 1999, whichever occurs later.\n\nb. Reinspect at intervals not to exceed 100 hours time in service; until replaced by an elevator or elevator spar assembly of improved design.\n\n    3. Whichever of the following occurs first:\n\nBefore further flight on any elevator spar assembly where any cracks are found during inspection; or,\n\nWithin 1,000 hours time in service after the first Requirement 2 inspection performed after 31 December 1999 or within 1,000 hours time in service after the next Requirement 1 inspection after 24 February 2000, as applicable.\n\n    4. Within 100 hours time in service after 31 December 1999, unless already accomplished.\n\nThe compliance times of the previous issue of this Directive remain unchanged by this issue of the Directive, except for the Requirement 3 compliance.\n\nThis Amendment becomes effective on 24 February 2000.\n\nBackground: There have been numerous reports of cracked PA-31 elevator spars. In several instances, both left and right elevator spars were cracked. In two instances the spar was completely severed, significantly reducing the elevator stiffness and introducing a risk of tailplane flutter.\n\nAmendment 1 removed the requirement to perform X-ray inspections. The visual inspection introduced maintains equivalent safety by mandating a simpler inspection that can be performed more frequently. A threshold for the inspection is also introduced, based on a survey of major defect reports. Figure 1 was revised to provide more guidance on the inspection location.\n\nAmendment 2 was issued in response to an FAA AD which introduces certain inspections and replacement of the elevators or elevator spar assemblies with parts of improved design, either at a certain time period or when cracks are found, whichever occurs first. The on-going repetitive visual inspection requirement of the previous issue of this Directive is retained as an option for operators.\n\n![](image.004.png)  \nAmendment 3 is issued to clarify the intent of Compliance 3 and Compliance Note 3. Amendment 2 of this Airworthiness Directive became effective on 31 December 1999. The original issue of this Airworthiness Directive became effective on 12 October 1995.\n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 12 January 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 27 January 2000.","sortOrder":0}],"analysis":{"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":6,"scope_assessment":{"changed":true,"description":"The Directive’s scope has evolved from the original 1995 issue: Amendment 1 removed mandatory X‑ray inspections and substituted more frequent visual inspections; Amendment 2 added a mandatory replacement option with improved‑design elevators/spars (per Piper MSB 998A) and boroscope/access‑hole inspection as an alternative; Amendment 3 clarifies compliance timing for replacements and prior repairs. Overall, the instrument shifted inspection method, introduced a parts‑replacement requirement, and clarified compliance triggers and intervals."},"complexity_factors":["Multiple aircraft models and defined serial‑number ranges in the applicability (affects fleet subset).","Two alternative inspection pathways: recurring detailed visual inspections (Requirement 1) or access‑hole installation plus boroscope inspections (Requirement 2).","Varied compliance timings and triggers (immediate 10‑hour, 100‑hour intervals, 2,500‑hour thresholds, and ‘whichever occurs first’ clauses).","Mandatory replacement with specific improved‑design part numbers referenced to Piper MSB 998A (external document dependency).","Interim measures: if one spar replaced, the opposite spar still requires repetitive inspection until replacement or threshold (creates asymmetric compliance burdens).","Need for CAR 35 authorised person approval to install access holes (delegated approval and maintenance‑work discretion).","References to prior amendments and interplay with FAA AD 99‑12‑05 (cross‑jurisdictional coordination and historical changes).","Operational impact: potential groundings ‘before further flight’ if cracks or loose ice‑boot fittings are found (urgent safety compliance)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified Piper PA‑31 series aeroplanes to inspect elevator spars for cracking, fretting and loose rivets, install inspection access where needed, and replace any cracked components with improved‑design parts. It prescribes inspection methods (visual or boroscope), repetitive inspection intervals, and deadlines for replacement. It affects aircraft operators, maintenance organisations and parts suppliers because it creates mandatory inspection, repair and replacement work to address a structural cracking risk that can reduce elevator stiffness and increase flutter risk."},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This is Amendment 3 of an existing Airworthiness Directive. The background section confirms the scope has remained consistent: addressing cracked elevator spars in PA-31 aircraft. Amendment 3 explicitly states it only clarifies the intent of Compliance 3 and Compliance Note 3 from Amendment 2. The original safety purpose (preventing elevator spar failure) has not expanded beyond its initial intent."},"complexity_factors":["Multiple compliance pathways (Requirement 1 vs Requirement 2) with different inspection methods, deadlines, and ongoing obligations","Nested conditional logic: 'if cracks found then X, otherwise Y, and then Z until replacement'","Four separate compliance sections with different triggering events (flight hours, calendar dates, conditional findings)","Cross-references to external documents (Piper Mandatory Service Bulletin 998A, FAA AD 99-12-05, CAR 1998 regulations)","Amendment history references (Amendments 1, 2, and 3) that modify previous requirements without fully restating them","Specific technical measurements (9 inches/230 mm, bend radii, rivet positions) requiring reference to Figure 1","Exception handling for previously repaired spars (Note 3) and asymmetric replacement scenarios (if one spar replaced, the other still needs inspection)","Multiple defined time-in-service thresholds (10 hours, 100 hours, 1,000 hours, 2,500 hours) that interact with calendar deadlines"],"plain_english_summary":"This AD mandates inspections of elevator spars on specified Piper PA‑31 family aeroplanes to detect cracking that has led to complete spar separation and loss of control. Operators must inspect (visually or via access/borescope), secure elevator de‑ice boots, and replace any cracked or worn elevator/spar before further flight; repetitive inspections continue until improved parts are fitted.\n\nIt affects owners/operators of listed PA‑31 variants and matters because it prevents catastrophic tail failure by catching cracks early."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-126-amdt-3-elevator-spar","history":"/api/acts/ad-pa-31-126-amdt-3-elevator-spar/history","analysis":"/api/acts/ad-pa-31-126-amdt-3-elevator-spar/analysis","conflicts":"/api/acts/ad-pa-31-126-amdt-3-elevator-spar/conflicts","importantCases":"/api/acts/ad-pa-31-126-amdt-3-elevator-spar/important-cases","documents":"/api/acts/ad-pa-31-126-amdt-3-elevator-spar/documents"}}