{"id":"F2006B04053","name":"AD/BEECH 56/22 Amdt 2 - Wing Main Spar Centre Section","slug":"ad-beech-56-22-amdt-2-wing-main-spar-centre-section","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43675,"registerId":"commonwealth-F2006B04053-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 56/22 Amdt 2 - Wing Main Spar Centre Section","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)  \nBeechcraft 56TC (Turbo Baron) Series Aeroplanes\n\nAD/BEECH 56/22\n\nAmdt 2\n\n  \nWing Main Spar Centre Section 11/90\n\nApplicability: Model 56TC and A56TC, Serial Number TG-1 to TG-94 inclusive.\n\nRequirement: Inspect the wing forward spar carry through structure forward and aft frames, in accordance with Beechcraft Service Bulletin No 2269 Rev 1, dated March 1990.\n\nNote: FAA AD 90-08-14, Amendment 39-6563 refers.\n\nCompliance: Within 100 hours’ time in service after 1 November 1990, or prior to the accumulation of 1500 hours total time in service, whichever occurs later. Where no cracks are found, repeat the inspections at intervals not to exceed 500 hours’ time in service.\n\nWhere cracks are found, repeat the inspections at intervals as detailed in the Requirement Document.\n\nCrack limits must not be exceeded. Specific locations repaired or reinforced by the installation of the applicable Beech P/N 58-4008 kit, or other approved scheme, need not be inspected before 1500 hours’ time in service after installation of that kit, however affected areas adjacent to repair doublers remain subject to the above compliance. Aircraft inspected in accordance with the previous issue of this Directive shall be considered to have been inspected in accordance with this amendment.\n\nBackground: There have been numerous reports of cracking at various locations in the wing carry though structure. This problem was first found in Australia in 1981. The cracking is caused by fatigue in the corners of the fuselage frame webs, around and between huckbolts and in areas where stringers are attached. To date there have been no reports of cracks having progressed to failure, however uncorrected this condition could lead to eventual catastrophic failure.\n\nEngineering analysis has determined, however, that cracking within defined limits is not an immediate threat to safe flight, if assessed and monitored in accordance with this amendment. Compliance threshold has been adjusted to align it with manufacturers recommendations.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"Originally issued to address urgent safety concerns about wing spar cracking, this directive has evolved through two amendments. Amendment 2 specifically adjusts compliance thresholds and inspection intervals based on new engineering analysis showing that limited cracking is manageable with monitoring. The scope has shifted from 'inspect immediately due to imminent danger' to a more nuanced risk-managed approach with tiered inspection schedules based on findings."},"complexity_factors":["Multiple conditional compliance pathways (no cracks vs. cracks found vs. repaired with kit)","Time-based calculations involving 'whichever occurs later' logic","Cross-reference to external technical document (Beechcraft Service Bulletin No 2269 Rev 1)","Cross-reference to US FAA Airworthiness Directive (90-08-14)","Specific serial number applicability range (TG-1 to TG-94)","Exception to exception logic regarding repaired areas vs. adjacent areas"],"plain_english_summary":"This Airworthiness Directive mandates inspections of the wing main spar centre section on Beechcraft 56TC and A56TC Turbo Baron aircraft (S/N TG‑1 to TG‑94) to detect fatigue cracks in frames and bolt holes. It aims to prevent possible catastrophic structural failure by enforcing recurring checks and tighter follow-up if cracks are found. Amendment 2 revises the compliance deadline to align with the manufacturer; inspections done under the previous AD remain compliant."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment does not materially expand the population of affected aircraft or introduce new types of mandatory work; it refines compliance timing and clarifies inspection/deferral treatment for repaired areas to align with manufacturer recommendations. In other words, it adjusts thresholds and procedural alignment rather than broadening the AD’s original safety scope."},"complexity_factors":["Narrow applicability by serial number (TG-1 to TG-94) but requires referencing external documents (Beechcraft Service Bulletin No. 2269 Rev 1)","Conditional compliance timing: two-part initial threshold (within 100 hours after a calendar date OR before reaching 1,500 total hours, whichever is later)","Different repetition rules depending on detection outcome (500-hour interval if no cracks; alternative intervals if cracks are found)","Exception/deferment rule for repaired locations using kit P/N 58-4008 or approved scheme (1,500-hour inspection deferral), plus requirement to still inspect adjacent areas","Reference to undefined ‘‘crack limits’’, and delegation of exact intervals/limits to the Requirement Document/service bulletin","Cross-reference to FAA AD 90-08-14 (external regulatory document)","Statement that prior inspections under earlier issue satisfy compliance (backwards-compatibility clause)"],"plain_english_summary":"**What this instrument does (mechanical change)**\n\n- Requires specific Beechcraft aeroplanes (Model 56TC and A56TC, serial numbers TG-1 to TG-94) to have the wing forward spar carry-through structure inspected according to Beechcraft Service Bulletin No. 2269 Rev 1 (March 1990). (See “Applicability” and “Requirement”.)\n\n- Sets when and how often the inspections must be carried out: within 100 hours’ time in service after 1 November 1990, or before the aircraft reaches 1,500 hours total time in service, whichever is later. If no cracks are found, inspections must be repeated at intervals not exceeding 500 hours’ time in service. If cracks are found, inspection frequency follows the intervals set out in the referenced service document. (See “Compliance”.)\n\n- States that repaired or reinforced locations where the approved Beech kit P/N 58-4008 (or another approved repair scheme) has been installed need not be inspected for 1,500 hours after that installation; but areas adjacent to those repairs still require inspection at the stated intervals. (See “Requirement”.)\n\n- Confirms that aircraft previously inspected under the earlier version of this directive are treated as having complied. (See final paragraph of the Requirement section.)\n\n**Who is affected**\n\n- Owners and operators of Beechcraft Model 56TC and A56TC aeroplanes with serial numbers TG-1 through TG-94. They must organise and pay for the inspections and any follow-up repairs or reinforcements.\n\n- Maintenance organisations and certificated mechanics who carry out the inspections and repairs, because they must follow the methods and intervals in Beechcraft Service Bulletin No. 2269 Rev 1 (or an approved alternative repair scheme).\n\n- The Civil Aviation Safety Authority (CASA) as the enforcing regulator: it sets the mandatory directive and approves any alternative repair schemes.\n\n**Why it matters (stated rationale and operational effect)**\n\n- The directive responds to repeated reports of fatigue cracking in the wing carry-through structure (corners of fuselage frame webs, around and between huckbolts, and at stringer attachments). The background notes the cracking was first found in Australia in 1981 and, if uncorrected, could eventually lead to catastrophic failure. The AD nevertheless states that cracking within defined limits is not an immediate threat if monitored per this amendment. (See “Background”.)\n\n**Practical implications, costs and incentives**\n\n- Who pays: aircraft owners/operators are responsible for the cost of inspections, any increased maintenance downtime, and for repairs or reinforcement kits (for example, P/N 58-4008) where required.\n\n- Who decides: the inspection methods and intervals are determined by the mandatory service bulletin referenced in the directive; alternatives must be an approved repair scheme (i.e., approved by the regulator or an acceptable authority). Maintenance organisations decide operationally when and how to perform the inspections, consistent with the service bulletin and regulatory approval.\n\n- Behaviour changes required: operators must schedule an initial inspection within the stated time window, perform recurring inspections (every 500 hours if no cracks; more frequently if cracks are found per the service document), and install approved reinforcement kits or repairs where cracking or limits require it. Some operators may elect to install the reinforcement kit pre-emptively to defer inspections on the repaired locations for 1,500 hours.\n\n**Trade-offs, risks and implementation points**\n\n- Concentrated costs: the financial and operational burden falls on the relatively small group of aircraft owners covered by the serial-numbered applicability. The directive does not spread costs across a broader fleet.\n\n- Incentive to repair vs inspect: because installing the approved reinforcement kit defers inspection of that repaired location for 1,500 hours, operators face a trade-off between paying once for reinforcement (and gaining inspection relief for that area) versus recurring inspection costs and potential downtime.\n\n- Dependence on external documents: the AD delegates procedural detail (inspection methods, crack-size limits, intervals when cracks are found) to Beechcraft Service Bulletin No. 2269 Rev 1 and the ‘‘Requirement Document.’’ That creates implementation risk if the bulletin is ambiguous, unavailable, or requires technical interpretation.\n\n- Regulatory discretion: the AD permits \"other approved scheme(s)\" for repair. That leaves the regulator discretion to accept alternative methods, which requires administrative oversight and creates potential variability across approvals.\n\n- Operational downtime and safety benefit: inspections and repairs impose aircraft downtime and maintenance costs but are intended to detect and arrest fatigue cracking before it progresses to an unsafe condition. The AD states engineers consider cracking within defined limits manageable if monitored as required.\n\n**Key text anchors**\n\n- Applicability: Model 56TC/A56TC, S/N TG-1 to TG-94.\n- Requirement: inspect forward spar carry-through per Beechcraft Service Bulletin No. 2269 Rev 1.\n- Compliance: initial timing (100 hours after 1 Nov 1990 or before 1,500 total hours, whichever later); repeat intervals (500 hours if no cracks; as specified in Requirement Document if cracks are found).\n- Repair/deferral: installation of P/N 58-4008 (or approved scheme) defers inspection of repaired locations for 1,500 hours; adjacent areas still require inspection.\n- Background: fatigue cracking reported; risk of eventual catastrophic failure if uncorrected.\n\n"},"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-beech-56-22-amdt-2-wing-main-spar-centre-section","history":"/api/acts/ad-beech-56-22-amdt-2-wing-main-spar-centre-section/history","analysis":"/api/acts/ad-beech-56-22-amdt-2-wing-main-spar-centre-section/analysis","conflicts":"/api/acts/ad-beech-56-22-amdt-2-wing-main-spar-centre-section/conflicts","importantCases":"/api/acts/ad-beech-56-22-amdt-2-wing-main-spar-centre-section/important-cases","documents":"/api/acts/ad-beech-56-22-amdt-2-wing-main-spar-centre-section/documents"}}