{"id":"F2006B05532","name":"AD/PA-24/33 Amdt 3 - Stabilator Torque Tube Bearing Block Attachment Fitting","slug":"ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46434,"registerId":"commonwealth-F2006B05532-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-24/33 Amdt 3 - Stabilator Torque Tube Bearing Block Attachment Fitting","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPiper PA-24 (Comanche) Series Aeroplanes\n\nAD/PA-24/33\n\nAmdt 3\n\n  \n\nStabilator Torque Tube Bearing Block Attachment Fitting\n\n  \n10/94\n\nApplicability: Model Serial Numbers\n\nPA24-180, PA24-250, and PA24-260 24-1 through 24-5047 PA24-400 26-2 through 26-148\n\nRequirement: 1. Inspect the stabilator torque tube bearing support fittings for looseness by accomplishing the following:\n\n    Remove the tailcone and rear aft fuselage access door.\n\n    b. Grasp the stabilator tip and exert a fore and aft force and then an up and down force.\n\n    c. If looseness is found during the inspection specified above, incorporate Piper Part No. 760 835 (Hi-Shear Rivet Replacement Kit) on the affected fitting.\n\n    d. Reinstall the tailcone and right rear aft fuselage access door.\n\n2. Reinspect all stabilator torque tube bearing support fittings on which Piper Kit Part No 760 835 has not been incorporated; in accordance with Requirement 1 of this Directive.\n\nNote 1: Incorporating Piper Kit Part No. 760 835 on all four stabilator torque tube bearing support fittings constitutes terminating action for the inspection requirements of this Directive.\n\nNote 2: FAA AD 94-13-10 Amdt 39-8951 and Piper SB 411A refer.\n\nCompliance: 1. Within 100 hours time in service after 15 September 1994, unless Piper Kit Part No. 760 835 is incorporated on all four stabilator torque tube bearing support fittings.\n\n2. At intervals not to exceed 100 hours time in service, until Piper Kit Part No. 760 835 is incorporated on all four stabilator torque tube bearing support fittings.\n\nThe compliance of the previous issue of this Directive was “at intervals not exceeding 300 hours time in service”.\n\nThis amendment is effective from 15 September 1994.\n\nBackground: Incidents of looseness of the stabilator torque tube bearing support fittings prompted the issue of this Directive. The actions specified are intended to prevent the loss of pitch control because of looseness of the fittings. Amendment 3 is issued to align this Directive with the issue of a new FAA AD which specifies reinspection and terminating action criteria.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 3 to an existing Airworthiness Directive. The amendment narrows the inspection interval from 300 hours to 100 hours and aligns with updated FAA guidance, but does not expand beyond the original safety purpose of addressing stabilator torque tube bearing fitting looseness on Piper PA-24 series aircraft. The scope remains tightly focused on the specific mechanical defect identified in the original 1994 directive."},"complexity_factors":["Single discrete subject matter (one specific mechanical component on one aircraft family)","Only 2 defined terms implicitly used ('time in service' and 'stabilator')","Linear procedural structure with clear sequential steps (remove, inspect, repair if needed, reinstall)","Minimal cross-referencing (only 2 external references in notes: FAA AD and Piper Service Bulletin)","Clear compliance deadlines with simple alternative paths (100 hours or permanent fix)","No nested exceptions or conditional logic beyond the basic 'if found loose, then repair' structure","Short document length (approximately 300 words of substantive content)"],"plain_english_summary":"This directive orders owners/operators of certain Piper PA‑24 Comanche aircraft to inspect and, if needed, repair the stabilator torque tube bearing support fittings to prevent loosening that can cause loss of pitch control.  \n\nLicensed mechanics must perform the checks, repeat inspections every 100 flight hours until all affected fittings are fixed with the specified repair kit (Piper Part No. 760‑835)."},"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":3,"scope_assessment":{"changed":false,"description":"Amendment 3 tightened and clarified the original directive but did not broaden its subject matter beyond its original safety purpose. Changes are procedural: it shortens the inspection interval (from 300 to 100 hours), mandates reinspection intervals until a specified corrective kit is fitted to all four fittings, and specifies the kit as terminating action. These are refinements to achieve the same safety objective rather than an expansion into new areas."},"complexity_factors":["Short, single‑issue airworthiness directive focused on one component (stabilator torque tube bearing support fittings)","Applicability limited to specific Piper PA‑24/P A‑24‑400 serial number ranges (several ranges listed)","Two core requirements: initial inspection and conditional corrective action (install kit) with a terminating action","Simple conditional logic: if looseness found → install kit; if kit not fitted to all four → reinspect every 100 hours","Reference to an external part number (Piper Kit Part No. 760 835) as mandatory corrective action","Cross‑references to FAA AD 94‑13‑10 and Piper SB 411A (external documents for additional detail)","Clear compliance timing rules (initial within 100 hours after a specific date; repeat interval 100 hours) and an explicit effective date","Replacement of an earlier inspection interval (previously 300 hours) — creates one amendment to prior text but does not add layered exceptions"],"plain_english_summary":"**What this directive does (mechanically):**\n\n- Requires pilots/owners/maintenance organisations of certain Piper PA‑24 (Comanche) aeroplanes to check the stabilator torque tube bearing support fittings for looseness and to fix any loose fittings by installing Piper Kit Part No. 760 835 (Hi‑Shear Rivet Replacement Kit). (Requirement 1(c), Note 1)\n- If the kit is not fitted to all four fittings, the remaining fittings must be reinspected at regular intervals until the kit is installed on every fitting. (Requirement 2, Note 1)\n- Installing the kit on all four fittings stops (terminates) the need for the repeated inspections. (Note 1)\n\n**Who is affected:**\n\n- Owners and operators of Piper PA24‑180, PA24‑250, PA24‑260 and PA24‑400 aeroplanes within the serial number ranges listed in the Applicability section.\n- Licensed maintenance organisations and mechanics who perform the inspections and the rivet‑replacement kit installation. (Requirement steps)\n\n**Key actions required (how to do it):**\n\n1. Remove the tailcone and the right rear aft fuselage access door. (Requirement 1(a))\n2. Manually check each stabilator tip for fore/aft and up/down play to detect looseness. (Requirement 1(b))\n3. If looseness is found, install Piper Kit Part No. 760 835 on the affected fitting. (Requirement 1(c))\n4. Reinstall removed panels. (Requirement 1(d))\n5. If the kit has not been fitted to all four fittings, repeat the inspection at intervals not exceeding 100 hours time in service until the kit is fitted to all four. (Requirement 2; Compliance)\n\n**When it must be done:**\n\n- The initial inspection must be completed within 100 hours time in service after 15 September 1994, unless the kit is already fitted to all four fittings. (Compliance)\n- Reinspections must be performed at intervals not exceeding 100 hours until the kit is fitted to all four fittings. (Compliance)\n\n**Why the rule exists (official rationale):**\n\n- The directive was issued after incidents of looseness in the stabilator torque tube bearing support fittings. The stated aim is to prevent loss of pitch control caused by loose fittings. (Background)\n\n**Practical implications, costs and incentives:**\n\n- Who pays: aircraft owners/operators pay for inspections, downtime and any labour/parts required to fit the rivet kit (Compliance; Requirement 1(c)).\n- Who decides and enforces: the aircraft owner/operator must ensure compliance; maintenance providers carry out the work; the Civil Aviation Safety Authority enforces the directive. (Applicability; Requirement; Compliance)\n- Behaviour changes: operators face a choice: fit the rivet kit to all four fittings (one‑time cost and effort) and stop further inspections, or defer fitting and accept recurring inspections every 100 flight hours. (Note 1; Requirement 2)\n- Market effects: demand is created for Piper's rivet kit (Piper Part No. 760 835). Independent maintenance organisations may perform the work; parts availability and authorised procedure access could affect who performs the work and at what price. (Requirement 1(c); Note 1)\n- Compliance burden and opportunity cost: recurring inspections increase maintenance workload and aircraft downtime until the terminating action (kit installation) is completed. Installing the kit is a one‑time intervention that eliminates future inspection burden. (Requirement 2; Note 1)\n- Implementation risks: access to the fittings requires removing the tailcone and an access door (Requirement 1(a),(d)), which takes time and may require a maintenance facility. Delays or parts shortages could extend the period of repeated inspections.\n- Enforcement and discretion: the directive specifies inspection and repair steps; it leaves limited technical discretion to qualified maintenance personnel about how to carry out the work, but not about whether it must be done. (Requirements)\n\n**References and interaction with other documents:**\n\n- The directive cites FAA AD 94‑13‑10 and Piper Service Bulletin 411A, which provide related guidance and the FAA's corresponding requirements. (Note 2)\n\n**Net effect in one sentence:**\nOperators of the specified Piper Comanche serial numbers must inspect stabilator torque tube bearing fittings and either fix any looseness by fitting Piper's rivet replacement kit (which ends the inspection requirement when fitted to all four fittings) or perform repeat inspections at most every 100 hours until they do so. (Requirement 1–2; Note 1; Compliance)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting","history":"/api/acts/ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting/history","analysis":"/api/acts/ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting/analysis","conflicts":"/api/acts/ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting/conflicts","importantCases":"/api/acts/ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting/important-cases","documents":"/api/acts/ad-pa-24-33-amdt-3-stabilator-torque-tube-bearing-block-attachment-fitting/documents"}}