{"id":"F2006B08148","name":"AD/CESSNA 310/21 Amdt 1 - Turbocharger","slug":"ad-cessna-310-21-amdt-1-turbocharger","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115310,"registerId":"commonwealth-F2006B08148-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 310/21 Amdt 1 - Turbocharger","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)  \nCessna 310 Series Aeroplanes\n\nAD/CESSNA 310/21\n\nAmdt 1\n\n  \nTurbocharger 9/87\n\nApplicability: All models T310P and T310Q fitted with Continental model TSIO-520-B engines.\n\nRequirement: Remove the turbosupercharger turbine insulation blanket or stainless steel heat shields and visually inspect the complete surface of the TCM turbosupercharger assembly P/N 632729 (AID P/N 406610) for cracks, bulges, or burnt areas.\n\nNote: Turbine housings exhibiting any cracks, bulges, or burnt areas shall be replaced before further flight.\n\nCompliance: Prior to accumulating 425 hours total time in service and thereafter at each issue of a new Maintenance Release.\n\nBackground: This Airworthiness Directive was originally raised to reflect the requirement of FAA AD 70-3-4, effective 31 January 1970. This Amendment is raised to clarify the Requirement, and include reference to stainless steel heat shields, that were fitted beginning with 1972 models.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment clarifies the existing inspection requirement and explicitly expands the set of components to be removed and inspected to include stainless steel heat shields that were fitted beginning with 1972 models. It does not broaden applicability beyond the specified T310P and T310Q models with Continental TSIO-520-B engines, nor does it add alternative inspection methods or additional aircraft types. (Background, Applicability, Requirement)"},"complexity_factors":["Narrow technical applicability limited to T310P and T310Q with Continental TSIO-520-B engines (Applicability)","Requirement tied to a specific part number (TCM turbosupercharger assembly P/N 632729), increasing the need for accurate parts identification (Requirement)","Action requires removal of insulation blanket or stainless steel heat shields prior to inspection, adding a discrete labour task (Requirement)","Inspection standard is a simple visual check for specific defects (cracks, bulges, burnt areas) — low technical diagnostic complexity but binary replacement trigger (Requirement, Note)","Compliance timing is tied to hours-in-service and to each new Maintenance Release, creating recurring administrative tracking (Compliance)","Amendment purpose is clarification and inclusion of stainless steel shields fitted from 1972 models, a narrow scope change that nonetheless affects some airframes (Background)"],"plain_english_summary":"What this rule changes mechanically\n\n- This Airworthiness Directive (AD) tells owners/operators of certain Cessna 310 aeroplanes to take specific maintenance steps concerning the turbosupercharger. (Applicability, Requirement)\n- It requires removal of the turbine insulation blanket or stainless steel heat shields and a visual inspection of the entire Continental turbosupercharger assembly P/N 632729 for cracks, bulges, or burnt areas. Turbine housings that show any of those defects must be replaced before the aircraft flies again. (Requirement, Note)\n- The inspection must be done before the aeroplane accumulates 425 hours total time in service and then again at each issue of a new Maintenance Release. (Compliance)\n- The amendment clarifies the original directive and explicitly references stainless steel heat shields that began to be fitted from 1972 models. (Background)\n\nWho is affected and who decides\n\n- Affected parties: owners/operators of Cessna 310 models T310P and T310Q fitted with Continental TSIO-520-B engines. They are the ones who must carry out the removal and inspection and, where applicable, arrange replacement. (Applicability, Requirement, Note)\n- Decision rule: the AD sets a binary visual standard — if cracks, bulges, or burnt areas are present the turbine housing must be replaced before further flight; otherwise continued operation subject to the stated inspection intervals is permitted. (Requirement, Note, Compliance)\n\nWhat this requires them to do and the incentives/costs created\n\n- Immediate actions: remove the turbine insulation blanket or stainless steel heat shields, conduct a full visual inspection of the specified turbosupercharger assembly, and replace turbine housings that show the listed defects. (Requirement, Note)\n- Timing obligation: complete the first inspection before 425 hours total time in service and repeat at every new Maintenance Release. This creates a scheduled compliance point and recurring inspection duty. (Compliance)\n- Who pays and who bears disruptions: operators will bear the labour and parts cost of removing shields/blankets and conducting inspections; where defects are found, operators must bear the cost and operational downtime of replacing turbine housings before flying again. (Requirement, Note)\n\nCompliance burden and discretion\n\n- Burden: the work is a mechanical inspection and potential replacement tied to a clear time threshold and to maintenance releases, which imposes predictable recurring maintenance work on affected aircraft. (Requirement, Compliance)\n- Discretion: the AD prescribes what to look for (cracks, bulges, burnt areas) and mandates replacement where those defects exist; it leaves no discretion to defer replacement where defects are found. The AD specifies only a visual inspection method — it does not require additional testing or laboratory analysis. (Requirement, Note)\n\nTrade-offs and implementation risks\n\n- The AD’s stated background links it to an earlier FAA directive and says the amendment’s purpose is clarification and to include stainless steel heat shields. That change mechanically expands the parts to be removed and inspected where those shields were fitted. (Background)\n- Implementation risks are limited to practical issues of performing the removal and inspection and meeting the replacement-before-flight requirement when defects are found; the AD does not specify alternatives or temporary measures. (Requirement, Note, Compliance)\n\nNet effect in plain terms\n\n- Operators of the specified Cessna 310 models must add a specific inspection step (removal of blankets or heat shields and a visual inspection of turbosupercharger P/N 632729) before 425 hours TIS and at each Maintenance Release, and must replace any turbine housings that show cracking, bulging, or burn damage before further flight. The amendment clarifies the requirement and explicitly covers stainless steel heat shields fitted from 1972 models. (Applicability, Requirement, Note, Compliance, Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original safety purpose. The only change from the original 1970 FAA directive is the addition of 'stainless steel heat shields' to cover 1972+ models — a minor technical clarification that does not expand the substantive scope beyond turbocharger inspection requirements for the specified aircraft."},"complexity_factors":["Single, specific aircraft type and engine combination (narrow applicability)","One clear inspection requirement with three specific defect indicators (cracks, bulges, burnt areas)","Simple binary compliance trigger (425 hours OR new Maintenance Release)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Only one defined term requiring clarification (P/N = Part Number, AID = Aircraft Installation Drawing)","Background section provides helpful context without creating additional legal obligations"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft owners and operators. It applies to specific **Cessna 310 twin-engine aircraft** (models T310P and T310Q) that have **Continental TSIO-520-B engines** with turbochargers.\n\n**What it requires:**\n- **Remove** the insulation blanket or heat shield covering the turbocharger turbine\n- **Visually inspect** the entire turbocharger assembly for:\n  - Cracks\n  - Bulges  \n  - Burnt/discoloured areas\n- **Replace** the turbine housing immediately if any damage is found — the aircraft cannot fly until this is done\n\n**When to do it:**\n- Before the turbocharger reaches **425 hours of total operating time**\n- **Every time** the aircraft gets a new Maintenance Release (a periodic safety certificate, typically every 100 hours or 12 months)\n\n**Why it matters:**\nTurbocharger turbine housings can fail catastrophically if cracked or overheated. This could cause engine failure, fire, or loss of aircraft control. The directive was updated to include newer aircraft models that have stainless steel heat shields (introduced in 1972), not just the older insulation blankets."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-310-21-amdt-1-turbocharger","history":"/api/acts/ad-cessna-310-21-amdt-1-turbocharger/history","analysis":"/api/acts/ad-cessna-310-21-amdt-1-turbocharger/analysis","conflicts":"/api/acts/ad-cessna-310-21-amdt-1-turbocharger/conflicts","importantCases":"/api/acts/ad-cessna-310-21-amdt-1-turbocharger/important-cases","documents":"/api/acts/ad-cessna-310-21-amdt-1-turbocharger/documents"}}