{"id":"F2006B04998","name":"AD/CESSNA 170/69 - Main Landing Gear Pivot Assembly","slug":"ad-cessna-170-69-main-landing-gear-pivot-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44907,"registerId":"commonwealth-F2006B04998-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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\nCessna 170, 172, F172, FR172, &175 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/CESSNA 170/69 Main Landing Gear Pivot","sectionType":"part","heading":"AD/CESSNA 170/69 Main Landing Gear Pivot Assembly 7/2001","content":"# AD/CESSNA 170/69 Main Landing Gear Pivot Assembly 7/2001\n\nApplicability: Model 172RG aircraft, with serial numbers 691 and 172RG0001 through 172RG1191.\n\nRequirement: Inspect the main landing gear pivot assemblies for cracks in accordance with the Accomplishment Instructions in Cessna Service Bulletin (SB) SEB90-1 Revision 3, dated 15 March 1999, and the Model 172RG Series Service Manual.\n\nIf cracks are found, before further flight, replace the affected main landing gear pivot assembly with the part referenced in SB SEB90-1 Revision 3.\n\nBefore further flight after the inspection, install new bushings on both main landing gear pivot assemblies using the applicable kit referenced in SB SEB90-1 Revision 3.\n\nNote: FAA AD 2001-06-06 Amdt 39-12153 refers.\n\nCompliance: Within 100 hours time in service after 12 July 2001.\n\nThis Airworthiness Directive becomes effective on 12 July 2001.\n\nBackground: The FAA received many service difficulty reports of failures of main landing gear pivot assemblies on Model 172RG aircraft. Failure of the pivot assemblies has resulted in gear-up landings or loss of braking. Investigation revealed the end of the pivot experiences overload stress because of improper bushing clearance, and can produce fatigue cracks that spread until the pivot fitting fails, preventing the landing gear from extending.\n\n![](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 22 May 2001\n\n![](image.001.png)","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD stays on scope with its original safety‑fix purpose: it addresses reported failures of the main landing gear pivot assemblies on specified Model 172RG aircraft by requiring inspection, replacement of cracked parts, and installation of corrective bushings. It does not broaden the affected fleet beyond the listed serial numbers, nor does it add unrelated obligations; therefore it has not grown significantly beyond its original safety‑correction intent."},"complexity_factors":["Narrow applicability limited to specific serial numbers (small scope)","Short requirement section with two clear mandatory actions (inspect; replace if cracked)","Mandatory preventive action (install new bushings on both pivots) regardless of inspection result","Single, modest compliance window (100 hours time in service)","Cross‑references to external documents: Cessna Service Bulletin SEB90-1 Revision 3 and Model 172RG Series Service Manual","Reference to an FAA AD (2001-06-06) for background — creates an external authority link but no additional procedural complexity"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires owners/operators of specified Cessna 172RG aeroplanes to inspect the main landing gear pivot assemblies for cracks using the procedures in Cessna Service Bulletin SEB90-1 Revision 3 and the Model 172RG Series Service Manual. (Requirement)\n- If a crack is found, the affected pivot assembly must be replaced with the part referenced in the service bulletin before the aircraft is flown again. (Requirement)\n- Regardless of whether cracks are found, new bushings must be installed on both main landing gear pivot assemblies using the applicable kit referenced in the service bulletin before further flight after the inspection. (Requirement)\n- Applies only to Model 172RG aircraft with serial numbers 691 and 172RG0001 through 172RG1191. (Applicability)\n- Compliance window: the inspection and bushing installation must be done within 100 hours time in service after 12 July 2001. The AD took effect on 12 July 2001. (Compliance / Effective date)\n\n**Why the rule exists (claimed purpose) and what that implies in practice**\n\n- The AD cites multiple service difficulty reports of main landing gear pivot assembly failures that have produced gear‑up landings or loss of braking. The investigative finding reported is that improper bushing clearance led to overload stress and fatigue cracks in the pivot end, eventually allowing the fitting to fail. (Background)\n- The AD’s stated purpose is to detect and correct those fatigue cracks and to replace the bushings to correct the clearance that caused overload stress. Mechanically, that means: inspect, replace cracked fittings, and fit new bushings even if no crack is present. (Requirement)\n\n**Who pays and who decides**\n\n- Aircraft owners/operators bear the cost and downtime: they must schedule the inspection, buy any replacement pivot assemblies or bushing kits referenced in the service bulletin, and have the work performed to an acceptable maintenance standard. (Requirement)\n- The Civil Aviation Safety Authority (via its delegate) issued the directive and set the compliance timeline; the technical instructions to carry out the work come from the Cessna service bulletin and the model service manual, which maintenance personnel must follow. (Applicability / Requirement)\n\n**Trade‑offs, implementation risks and likely effects on behaviour**\n\n- Costs and downtime: operators will incur inspection labour and parts costs and aircraft may be temporarily grounded for inspection and any required replacement. If cracked pivots are found, replacement is required before further flight, increasing immediate costs. (Requirement / Compliance)\n- Preventive element: installing new bushings on both pivots is mandatory even where no crack is detected. That raises upfront cost for all affected aircraft in the applicability range but reduces the risk of future fatigue failure attributed to improper clearance. (Requirement)\n- Parts and workmanship reliance: the AD relies on the specific parts and procedures in Cessna SB SEB90-1 Rev 3 and the Model 172RG Service Manual. Availability of the referenced kits/parts and competent maintenance support affects how quickly owners can comply. (Requirement)\n- Enforcement and substitution: non‑compliance increases continued operational risk for affected aeroplanes; compliance shifts behaviour toward preventive maintenance steps prescribed by the manufacturer/authority. The AD is narrowly targeted (specified serial numbers), so only a defined subset of operators is affected. (Applicability)\n\n**Concrete mechanics by citation**\n\n- Applicability: Model 172RG, serial numbers 691 and 172RG0001–172RG1191. (Applicability)\n- Requirement: Inspect per Cessna SB SEB90-1 Rev 3 and the Model 172RG Series Service Manual; replace cracked assemblies with the SB referenced part before further flight; install new bushings on both pivots before further flight after inspection. (Requirement)\n- Compliance: Complete within 100 hours time in service after 12 July 2001. (Compliance)\n- Background: Reports of pivot failures, fatigue from improper bushing clearance leading to gear‑up landings or loss of braking. (Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It targets a specific safety defect in a specific aircraft model (Cessna 172RG) with defined serial numbers. The directive has not expanded beyond its original purpose of addressing main landing gear pivot assembly failures."},"complexity_factors":["Single, specific aircraft model and serial number range (narrow applicability)","Clear, linear requirement structure (inspect → if cracked, replace → install bushings)","References external technical documents (Cessna Service Bulletin and Service Manual) rather than embedding all instructions","Single compliance deadline (100 hours time in service)","No nested exceptions or conditional logic beyond the 'if cracks found' branch","Short document (approximately 300 words of substantive text)"],"plain_english_summary":"CASA requires owners/operators of certain Cessna 172RGs (S/N 691 and 172RG0001–172RG1191) to inspect main landing gear pivot assemblies for cracks, replace any cracked parts before further flight, and install new bushings. This addresses reported pivot failures and gear‑up/brake risks from improper bushing clearance; comply within 100 flight hours after 12 July 2001 per Cessna SB SEB90‑1 Rev 3 and the 172RG service manual."},"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-cessna-170-69-main-landing-gear-pivot-assembly","history":"/api/acts/ad-cessna-170-69-main-landing-gear-pivot-assembly/history","analysis":"/api/acts/ad-cessna-170-69-main-landing-gear-pivot-assembly/analysis","conflicts":"/api/acts/ad-cessna-170-69-main-landing-gear-pivot-assembly/conflicts","importantCases":"/api/acts/ad-cessna-170-69-main-landing-gear-pivot-assembly/important-cases","documents":"/api/acts/ad-cessna-170-69-main-landing-gear-pivot-assembly/documents"}}