{"id":"F2006B05708","name":"AD/PA-31/120 Amdt 1 - MLG Actuator Reinforcement Bracket","slug":"ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135507,"registerId":"commonwealth-F2006B05708-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/120 Amdt 1 - MLG Actuator Reinforcement Bracket","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-31 Series Aeroplanes\n\nAD/PA-31/120\n\nAmdt 1\n\n  \nMLG Actuator Reinforcement Bracket 6/97\n\n| Applicability: | Models                        | Serial Numbers                                                   |\n| -------------- | ----------------------------- | ---------------------------------------------------------------- |\n|                | PA-31, PA-31-300 & PA-31-325. | 31-2 through 31-8312019                                          |\n|                | PA-31-350                     | 31-5001 through 31-8553002                                       |\n|                | PA-31P                        | 31P-1 through 31P-7730012                                        |\n|                | PA-31P-350                    | 31P-8414001 through 31P-8414050                                  |\n|                | PA-31T                        | 31T-7400001 through 31T-8120104                                  |\n|                | PA-31T1                       | 31T-7804001 through 31T-8304003 &31T-1104004 through 31T-1104017 |\n|                | PA-31T2                       | 31T-8166001 through 31T-8166076 &31T-1166001 through 31T-1166008 |\n|                | PA-31T3                       | 31T-8275001 through 31T-8475001 &31T-5575001                     |\n\nRequirement: Replace any main landing gear actuator reinforcement bracket having part number 40776-00 with a new main landing gear actuator reinforcement bracket, part number 73786-02, in accordance with the Instructions section of Piper Service Bulletin 923.\n\nNote: FAA AD 96-21-11 Amdt 39-9788 refers.\n\nCompliance: Unless already accomplished, within 100 hours time in service after 22 May 1997.\n\nThe compliance of the initial issue of this Directive was,” before 3 September 1994”. This Amendment becomes effective on 22 May 1997.\n\nBackground: The FAA received reports of cracked main landing gear actuator reinforcement brackets on several of the affected aircraft, including a report of the main landing gear extending when not selected, while the aircraft was in flight.\n\nAmendment 1 is issued in response to a new FAA AD which corrects an incorrect applicability designation of Piper Model PA-31 aircraft as Piper Model PA-31-310, and changes the serial number range of other models.\n\nThe original issue of this Airworthiness Directive became effective on 3 September 1994.","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope — mandating replacement of a specific faulty aircraft part. The changes are purely technical corrections to aircraft model designations and serial number ranges, not an expansion of regulatory scope or purpose."},"complexity_factors":["Single, specific mechanical requirement with clear part numbers","Straightforward applicability table with 8 aircraft models and defined serial number ranges","Simple compliance deadline (100 hours time in service from effective date)","No nested exceptions, conditional logic, or cross-references to other legislation beyond a single FAA AD reference","Short document (approximately 250 words) with minimal defined terms"],"plain_english_summary":"This CASA Airworthiness Directive mandates replacement of a potentially cracking main landing‑gear actuator reinforcement bracket (P/N 40776‑00) with the improved part (P/N 73786‑02) on specified Piper PA‑31 series aircraft (affected serial numbers listed in the AD) to prevent uncommanded gear extension. Owners, operators and maintenance organisations must comply within 100 flight hours after 22 May 1997. Amendment 1 corrects a model designation and updates serial‑number ranges to match the FAA."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Yes. Amendment 1 corrects an incorrect model designation (PA‑31 vs PA‑31‑310) and alters serial‑number ranges for affected models, thereby changing which aircraft are captured by the Directive (Amendment 1; Applicability). The core technical requirement (replace P/N 40776‑00 with P/N 73786‑02 per Service Bulletin 923) remains the same (Requirement), but the set of affected aircraft was revised."},"complexity_factors":["Detailed applicability across multiple Piper PA‑31 variants and numerous serial‑number ranges (Applicability) increases identification work for operators.","Requirement mandates a specific parts swap (P/N 40776‑00 → 73786‑02) and refers to Piper Service Bulletin 923 for installation instructions (Requirement), creating a dependency on manufacturer documentation.","Short compliance window tied to aircraft hours (100 hours TIS after 22 May 1997) imposes scheduling and operational disruption risk (Compliance).","Inter-jurisdictional reference to an FAA AD (FAA AD 96-21-11 / Amdt 39-9788) introduces cross-regulatory coordination considerations (Note).","Amendment corrects a prior mis-specified model designation and adjusts serial-number ranges, meaning affected population changed and records must be rechecked (Amendment 1 / Background).","Costs and procurement: operators bear replacement cost and potential downtime; availability of replacement part may affect timing (implied by Requirement and Compliance)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of the listed Piper PA‑31 series aeroplanes that have main landing gear actuator reinforcement bracket part number 40776‑00 to replace it with part number 73786‑02 in accordance with Piper Service Bulletin 923. Compliance must be completed within 100 hours time in service after 22 May 1997. The amendment corrects model and serial-number applicability errors in the original directive."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket","history":"/api/acts/ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket/history","analysis":"/api/acts/ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket/analysis","conflicts":"/api/acts/ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket/conflicts","importantCases":"/api/acts/ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket/important-cases","documents":"/api/acts/ad-pa-31-120-amdt-1-mlg-actuator-reinforcement-bracket/documents"}}