{"id":"F2006B05109","name":"AD/CESSNA 185/19 - Nose Wheel Pivot Bolt","slug":"ad-cessna-185-19-nose-wheel-pivot-bolt","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45094,"registerId":"commonwealth-F2006B05109-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 185/19 - Nose Wheel Pivot Bolt","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Cessna 185 Series Aeroplanes\n\n \n\nAD/CESSNA 185/19 Nose Wheel Pivot Bolt 12/73\n\nApplicability: All amphibian models with Scott nose wheel assemblies. Requirement:  Retire the nose wheel pivot bolt from service.\n\nCompliance: a. Within 100 hours time in service after 31 January 1974 for those nose wheel pivot bolts which have achieved 500 hours time in service, and thereafter at intervals not exceeding 600 hours time in service.\n\n \n\nb. All other nose wheel pivot bolts before achieving 600 hours time in service and thereafter at intervals not exceeding 600 hours time in service.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The provided text sets a specific, hours-based retirement schedule for nose wheel pivot bolts on the named aircraft and does not indicate any broadening or narrowing of applicability beyond the stated group (all amphibian models with Scott nose wheel assemblies). There is no indication in the text that the directive’s scope has been changed from an earlier or different intent."},"complexity_factors":["Narrow applicability: limited to Cessna 185 amphibian models fitted with Scott nose wheel assemblies (straightforward to identify).","Two-tier hours-based compliance schedule: different initial action for bolts at or above 500 hours on a specified date, then identical recurring intervals (requires tracking historic hours and ongoing hours).","Administrative requirement to track time-in-service for individual bolts (record-keeping burden).","Lack of technical detail in the text about replacement parts or procedure creates practical implementation steps outside the directive (maintenance organisations must supply procedural detail).","No conditional inspection or alternative compliance path described in the text (binary retire/replace requirement reduces interpretive complexity)."],"plain_english_summary":"What the rule does (mechanics)\n\n- This airworthiness directive applies to Cessna 185 amphibian aeroplanes that have Scott nose wheel assemblies (Applicability).\n- It requires the nose wheel pivot bolt to be removed from service (retired) rather than remaining in operational use (Requirement).\n- The retirement schedule depends on the bolt's accumulated time in service (Compliance a and b):\n  - For pivot bolts that had already reached 500 hours time in service by 31 January 1974: retire that bolt within the next 100 hours time in service after 31 January 1974, and then replace/retire them at intervals not exceeding 600 hours time in service thereafter (Compliance a).\n  - For all other pivot bolts: retire them before they reach 600 hours time in service and thereafter at intervals not exceeding 600 hours time in service (Compliance b).\n\nWho this affects\n\n- Aircraft owners and operators of Cessna 185 amphibian models fitted with Scott nose wheel assemblies.\n- Maintenance organisations and technicians who perform scheduled inspections and bolt replacement.\n- The regulator that enforces compliance with airworthiness directives.\n\nWho pays and who decides\n\n- The aircraft owner/operator bears the direct costs: tracking hours, removing and replacing the pivot bolt, paying labour and parts, and any associated aircraft downtime.\n- The Civil Aviation Safety Authority (through this directive) sets the mandatory requirement and the timing; operators must follow the intervals specified in the Compliance paragraphs.\n\nWhy it matters (stated and implied)\n\n- The directive’s text requires retiring the pivot bolt on a set schedule. The AD itself does not include an explicit statement of the underlying technical rationale in the provided text. Airworthiness directives are issued to manage component life or failure risk; that purpose is an implied rationale but is not described in this document.\n\nCosts, incentives and trade-offs (mechanisms rather than judgements)\n\n- Immediate and recurring direct cost: owners/operators must replace pivot bolts according to the hours-based schedule. The requirement creates a recurring maintenance expense at most every 600 hours time in service (Compliance a and b).\n- Administrative burden: operators must track each pivot bolt’s accumulated time in service and schedule retirements before or at the required hour-limits (Compliance a and b). Time-in-service accounting is the compliance metric in the text.\n- Operational effect: aircraft may be unavailable while the bolt is retired and replaced; timing of replacements will affect maintenance planning and utilisation.\n- Regulatory discretion: the directive prescribes mandatory times and does not show discretionary alternatives or conditional inspection options in the provided text; compliance must follow the stated intervals.\n\nImplementation risks and practical notes\n\n- The AD does not specify replacement part specification, inspection technique, or corrective action beyond “retire the nose wheel pivot bolt,” so maintenance organisations will need to determine the appropriate replacement part and procedure consistent with aircraft maintenance standards and any additional manufacturer guidance.\n- Because the compliance measure is hours-based, there is a risk of missed compliance if time-in-service records are incomplete or inaccurate; accurate record-keeping is therefore necessary (Compliance a and b).\n\nSource citations\n\n- Applicability, Requirement, and the two compliance paragraphs are taken directly from the directive’s text: Applicability; Requirement; Compliance a; Compliance b."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on nose wheel pivot bolt replacement intervals. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (amphibian models + Scott nose wheel assemblies)","Simple binary compliance structure (two paths based on existing hours)","Single mechanical component addressed with straightforward time-in-service thresholds","No cross-references to other legislation or technical standards","No nested exceptions or conditional sub-clauses"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Cessna 185 series aeroplanes** that are **amphibian models** (planes that can land on water and land) fitted with **Scott nose wheel assemblies**.\n\n**What it does:**\n- **Requires removal and replacement** of a specific part called the \"nose wheel pivot bolt\" — a critical component that allows the front wheel to steer.\n- **Sets strict time limits** for when this bolt must be retired from service based on how many hours the aircraft has flown.\n\n**Who it affects:**\n- Owners and operators of amphibious Cessna 185 aircraft with Scott nose wheel assemblies.\n- Maintenance engineers responsible for inspecting and servicing these aircraft.\n\n**Why it matters:**\n- This directive was issued to prevent **mechanical failure of the nose wheel steering system**, which could cause loss of control during taxiing, take-off, or landing. The mandatory replacement intervals ensure the bolt is changed before it can fail due to metal fatigue or wear.\n\n**The two compliance paths:**\n- **Path A:** If your bolt already has 500+ hours of use — replace it within 100 hours of 31 January 1974, then every 600 hours after that.\n- **Path B:** For all other bolts — replace before they hit 600 hours of use, then every 600 hours thereafter."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-185-19-nose-wheel-pivot-bolt","history":"/api/acts/ad-cessna-185-19-nose-wheel-pivot-bolt/history","analysis":"/api/acts/ad-cessna-185-19-nose-wheel-pivot-bolt/analysis","conflicts":"/api/acts/ad-cessna-185-19-nose-wheel-pivot-bolt/conflicts","importantCases":"/api/acts/ad-cessna-185-19-nose-wheel-pivot-bolt/important-cases","documents":"/api/acts/ad-cessna-185-19-nose-wheel-pivot-bolt/documents"}}