{"id":"F2025L00556","name":"AD/BEECH 36/43 Amdt 6 Wing Bolt, Nut and Fitting 9/2025","slug":"ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":106358,"registerId":"commonwealth-F2025L00556-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Textron Aviation (Beechcraft) 36 (Bonanz","sectionType":"part","heading":"Textron Aviation (Beechcraft) 36 (Bonanza) Series Aeroplanes","content":"# Textron Aviation (Beechcraft) 36 (Bonanza) Series Aeroplanes\n\n| AD/BEECH 36/43 Amdt 6 | Wing Bolt, Nut and Fitting | 9/2025 |\n| --------------------- | -------------------------- | ------ |\n\n| Applicability: | All models of Textron Aviation (formerly Beechcraft) 36 series aeroplanes, all serial numbers |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Remove inspection covers from wing attach fitting recesses and inspect for corrosion or loss of inhibitor. Also inspect drain holes for any blockage that would cause water or debris to accumulate.Note 1: It may be necessary to use a bright light and mirror/magnifying glass to see hard to view areas of the bolt or fittings for signs of corrosion on accessible areas of the bolt. Non accessible areas like the bolt thread encapsulated by the nut will be inhibited, so it is highly unlikely they will experience corrosion unless the general surrounding area is corroded.2. Remove and inspect wing bolts, washers, nuts and fittings in accordance with Beechcraft Maintenance Manual 36-590001-9D Revision D2 May 29, 2024 Chapter 57, as in force on the date of commencement of this AD.Note 2: The bolt torque should be checked before removal for inspection or replacement to confirm the bolt has been torqued to correct value. If the torque value is incorrect, other maintenance action may be required.Note 3: Amendment 5 of this AD referred, and this Amendment also refers, to all serial numbers within its Applicability as the type certificate holder has not updated the Beechcraft Shop manual which includes other serial number ranges. The maintenance listed above at Requirement 2 is to be utilised for all serial numbers with reference to the wing bolt, nut and fitting requirements.3. Retire wing bolts, washers and nuts from service and replace with new hardware in accordance Beechcraft Maintenance Manual 36-590001-9D Revision D2 May 29, 2024 Chapter 57, as in force on the date of commencement of this AD. Render unserviceable all hardware retired. Alternatively, as per the above aircraft maintenance manual the bolts may be maintained on condition IAW Table 201 Beechcraft Maintenance Manual 36-590001-9D Revision D2 May 29, 2024, Chapter 57, as in force on the date of commencement of this AD. |\n| Compliance: | For Requirement 1:Every 12 calendar months for all aircraft. If visible corrosion is found within the recess or on visible portion of the bolt or nuts, washers or fittings, then Requirement 2 must be accomplished before further flight. |\n\n| | For Requirement 2:a. For aircraft operating only in private operations:i. unless the inspection has already been accomplished in accordance with either of the requirement documents within 10 years from the initial installation of the wing bolts, inspect within 100 hours’ time in service (TIS) or 12 months from the commencement date of this AD, whichever occurs first. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | Note 4: Installation of the wing bolts includes where they are removed for inspection purposes and re-installed.ii. re-inspect at intervals not to exceed 10 years from the previous inspection.b. For all other operational categories:i. unless the inspection has already been accomplished in accordance with either of the requirement documents within 5 years from the installation of the wing bolts, inspect within 100 hours’ TIS or 12 months from the commencement date of this AD, whichever occurs first.Note 5: Installation of the wing bolts includes where they are removed for inspection purposes and re-installed.ii. re-inspect at intervals not to exceed 5 years from the previous inspection.For Requirement 3:Before 20 years TIS after the first installation of new zero time wing bolts. Alternatively, as per the maintenance manual the bolts may be maintained on condition IAW table 201 of the Beechcraft Maintenance Manual 36-590001-9D Revision D2 May 29, 2024, Chapter 57, as in force on the date of commencement of this AD.Note 6: Always replace wing attach nuts with new items when removing the wing attach bolts for inspection.Mandatory reporting requirements:Both NIL findings of defects and confirmed defects for Requirement 2 inspection must be reported via CASA’s Defect Reporting Service, either through the online portal at:https://www.casa.gov.au/resources-and-education/our-systems/defect-report-serviceor by using Form 404 available from:https://www.casa.gov.au/defect-report |\n| | Commencement date:This AD commences on 01 June 2025. |\n| Background: | The initial issue of this Airworthiness Directive became effective on 1 February 1996 and made mandatory the inspection and replacement periods for the wing attachment hardware as detailed in the requirement document.Amendment 1 of this AD added the Note 1 to Requirement 2 and added the fittings as an item to be inspected when the wing bolts, washers and nuts are removed and inspected.Amendment 2 of this AD removed the alternative means of compliance that had been issued to allow in-situ inspection of the wing attachment bolts and nuts rather than conduct the manufacturer’s required MPI.Amendment 3 of this AD was issued to extend the compliance time for Requirement 1 by two months whilst the proposed airworthiness directive process was conducted for AD/BEECH 36/43 Amdt 4.Amendment 4 of this AD allowed for aircraft used in private operations to be visually inspected for corrosion in the exposed areas of the wing attach bolts and wing fitting recess with the inspection interval increased from 5 to 10 years, in lieu of using the manufacturer’s maintenance instructions. For all other types of operations, the inspection requirements remained unchanged, requiring inspection of the wing attach hardware and fitting recess per the manufacturer’s maintenance data.Amendment 5 of this AD was issued following a change to the Instructions for Continued Airworthiness (ICA) by the type certificate holder, increasing the life limit of the wing bolts to 20 years and only requiring a removal and visual inspection at the five-year interval.Amendment 6 of this AD follows the amendment of the Beechcraft Maintenance Manual allowing for the wing attach bolts to be maintained on condition following their 20 year in service life as an option to replacing the bolts. |\n\n![Delegate signature](image.001.jpeg)\n\nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n01 May 2025","sortOrder":0},{"sectionNumber":"AD/BEECH 36/43 Amdt 6","sectionType":"part","heading":"AD/BEECH 36/43 Amdt 6","content":"## AD/BEECH 36/43 Amdt 6","sortOrder":1},{"sectionNumber":"Wing Bolt, Nut and Fitting","sectionType":"part","heading":"Wing Bolt, Nut and Fitting","content":"## Wing Bolt, Nut and Fitting","sortOrder":2},{"sectionNumber":"9/2025","sectionType":"part","heading":"9/2025","content":"## 9/2025","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":true,"description":"The original 1996 AD required mandatory replacement of wing bolts at set intervals. Amendment 6 significantly expands the scope by introducing an 'on condition' maintenance alternative that allows bolts to remain in service indefinitely if they continue to pass inspections, rather than requiring automatic retirement at 20 years. This represents a shift from prescriptive time-based replacement to a condition-based maintenance philosophy, effectively extending the operational life of hardware and reducing costs for operators while maintaining safety through enhanced inspection regimes."},"complexity_factors":["Multiple nested compliance pathways based on aircraft operational category (private vs. all other operations)","Cross-references to external manufacturer maintenance manual (Beechcraft Maintenance Manual 36-590001-9D Revision D2) with specific chapter and table citations","Conditional logic: 'unless already accomplished', 'whichever occurs first', 'if visible corrosion found then...'","Alternative compliance options (replacement at 20 years OR on-condition maintenance per Table 201)","Six amendment history references creating layered regulatory context","Multiple defined time measurement methods (calendar months, hours time in service (TIS), years from installation)","Mandatory reporting requirements with specific CASA portal and form references","Notes that modify or clarify requirements (6 notes total) interspersed throughout requirements"],"plain_english_summary":"This AD requires owners/operators and maintenance organisations of Beechcraft 36 (Bonanza) aeroplanes to inspect and ultimately replace wing attachment hardware (bolts, nuts, washers, fittings) to prevent catastrophic wing separation. It mandates annual visual checks for corrosion/drain blockages, regular detailed hardware inspections (first within 100 flight hours or 12 months; repeat intervals: 10 years for private use, 5 years for commercial/charter/training), and replacement by 20 years unless maintained on-condition. All inspection results must be reported to CASA."},"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"},"flash_summary":{"complexity_score":7,"scope_assessment":{"changed":true,"description":"Yes. The AD has evolved substantially from the original 1996 directive. Subsequent amendments progressively broadened compliance options and extended allowable service life: Amendment 4 introduced a relaxed visual inspection pathway and longer intervals for private operations; Amendment 5 raised the life limit of wing bolts to 20 years and relaxed mandatory replacement; Amendment 6 adds the option to maintain bolts \"on condition\" per the Beechcraft Maintenance Manual rather than mandatory retirement at 20 years. These changes move the instrument from a single prescriptive inspection/replacement regime toward multiple, operation‑category‑dependent pathways that rely more on manufacturer maintenance data and condition monitoring. That shift reduces immediate replacement costs for some operators but increases reliance on maintenance judgement, recordkeeping and the specific manual revision cited."},"complexity_factors":["Cross-reference to an external normative document: Beechcraft Maintenance Manual 36-590001-9D Revision D2 (Chapter 57 and Table 201) — the AD relies on that manual as authoritative for procedures and the \"maintain on condition\" option","Different inspection regimes depending on operational category (private operations versus all other operations) with differing intervals (10 years v 5 years) and differing initial inspection triggers","Multiple compliance options for hardware end-of-life: mandatory replacement before 20 years TIS OR maintain-on-condition per the maintenance manual","Several conditional linkages: visible corrosion in Requirement 1 triggers Requirement 2 before further flight; incorrect bolt torque may require additional maintenance (Note 2)","Numerous specific procedural details increasing operational complexity (remove inspection covers, inspect drain holes, use bright light/mirror/magnifier to view recesses, torque checks, replace nuts when bolts removed)","Mandatory reporting of both NIL findings and defects to CASA — creates non-technical compliance and administrative burden","Historical layering: six amendments with changing requirements (Notes and Background) — operators must track which amendment created the current options and why","Timing rules with mixed units (calendar months, flight hours TIS, years from installation) and differing starting points (from AD commencement date or from initial installation) — increases potential for calculation errors","References to interpretations about inaccessible areas (e.g., encapsulated threads unlikely to corrode) add judgment calls for inspectors","Specific commencement date and repeated phraseology requiring adherence to the manual \"as in force on the date of commencement\" — creates a fixed point for normative documents that may differ from later revisions"],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Applies to: all Textron Aviation (Beechcraft) 36 (Bonanza) series aeroplanes, every serial number (Applicability).\n\n- Requires three linked actions:\n - Requirement 1: Once every 12 calendar months remove the inspection covers over the wing-attach fitting recesses and visually check for corrosion or loss of corrosion inhibitor, and check drain holes are clear (Compliance: every 12 months).\n - Requirement 2: Remove the wing bolts, washers, nuts and fittings and inspect them in accordance with the Beechcraft Maintenance Manual 36-590001-9D Revision D2 (Chapter 57). Check bolt torque before removal; if torque is incorrect other work may be needed. If corrosion is visible in Requirement 1, the removal inspection (Requirement 2) must be done before further flight.\n - Requirement 3: Retire (permanently remove from service) and replace wing bolts, washers and nuts with new hardware before they reach 20 years time-in-service (TIS) after first installation. Alternatively, the maintenance manual allows these bolts to be \"maintained on condition\" per its Table 201 (i.e. inspected and retained if satisfactory rather than mandatorily replaced).\n\n- Timing differences by operation type (Requirement 2):\n - Private operations: unless already inspected within 10 years of first installation, perform the removal inspection within 100 flight hours or 12 months from the AD start date (whichever comes first); thereafter re‑inspect at intervals not exceeding 10 years.\n - All other operations (commercial, charter, training, etc.): unless already inspected within 5 years of installation, inspect within 100 flight hours or 12 months from the AD start date; thereafter re‑inspect at intervals not exceeding 5 years.\n\n- Other specifics:\n - When wing attach bolts are removed for inspection, replace nuts with new items (Note 6).\n - Mandatory reporting to CASA: both NIL findings (no defect) and any confirmed defects found during the Requirement 2 inspection must be reported through CASA’s Defect Reporting Service (online portal or Form 404).\n - Commencement date: 1 June 2025.\n\n**Who it affects\n\n- Aircraft owners and operators of Beechcraft 36 series aeroplanes (private and commercial).\n- Maintenance organisations and mechanics who conduct the inspections and replacements.\n- Parts suppliers (who sell replacement bolts, nuts and washers).\n- CASA (regulator) — receives mandatory reports and enforces compliance.\n\n**Why it matters (safety and operational mechanics)\n\n- The AD addresses corrosion risk in the wing attachment area — a safety‑critical structure. Corrosion, blocked drains or loss of corrosion inhibitor can accelerate hardware deterioration and compromise the structural connection between wing and fuselage.\n\n**Source claim and practical test of trade-offs\n\n- The AD’s stated purpose is to manage corrosion risk and ensure continued airworthiness by inspection, retirement or condition‑based maintenance of wing attach hardware (Requirement sections and Background). Testing that claim against practical consequences:\n - Direct costs: owners/operators pay for inspection labour, removal/reinstallation time, tools (mirror/bright light), replacement nuts/bolts and parts, and aircraft downtime.\n - Incentives: the AD gives private operators a less frequent and more visual inspection pathway (10‑year intervals for re‑inspection, and visual checks where allowed), which reduces immediate costs compared with mandatory frequent removal inspections. Commercial operators face shorter re‑inspection intervals (5 years), raising recurring inspection costs.\n - Trade-offs: longer intervals and visual inspection increase the risk that hidden corrosion (e.g. in encapsulated threads) is missed. The AD acknowledges encapsulated threads are usually inhibited and unlikely to corrode unless the surrounding area is corroded (Note 1), shifting some reliance onto observable indicators and the operator’s inspection quality.\n - Compliance burden and monitoring: mandatory reporting of both \"no defect\" and defect findings increases regulator visibility but adds administrative cost to operators and maintenance organisations. CASA’s reliance on a specific revision of the Beechcraft Maintenance Manual (Rev D2, 29 May 2024, Chapter 57 and Table 201) creates dependence on that manual’s content and on the type certificate holder updating its documents.\n - Implementation risk: accessing recesses may be difficult (note recommending bright lights and mirrors), increasing inspection time and potential for human error. Torque checks before bolt removal can reveal additional maintenance needs and create conditional workstreams.\n - Behavioural effects: operators may elect the condition‑based alternative in the maintenance manual and extend bolt life up to/after 20 years, reducing part replacement costs but increasing reliance on ongoing inspection quality.\n\n**Who pays, who decides, and what changes\n\n- Who pays: aircraft owners/operators pay inspection labour, replacement hardware and downtime costs; maintenance organisations absorb inspection work but charge for services.\n- Who decides: operators and certified maintenance organisations decide which compliance pathway to follow (replacement at 20 years versus on‑condition maintenance) subject to the AD and the cited Beechcraft Maintenance Manual. CASA determines enforcement and receives required reports.\n- What behaviour changes: more frequent and documented inspections for commercial operators; private operators have option for longer re‑inspection intervals and more visual checks; mandatory reporting increases administrative tasks; parts replacement (nuts mandatory when bolts are removed) increases parts purchasing.\n\n**Concrete implementation notes operators should watch for\n\n- Use the specific Beechcraft Maintenance Manual revision cited (36-590001-9D Rev D2, 29 May 2024, Chapter 57 and Table 201) as the normative source for inspection and replacement procedures (Requirements 2 and 3).\n- Check torque values before removing bolts (Note 2) — an incorrect torque reading may indicate additional structural or maintenance problems.\n- Ensure drain holes are unobstructed to prevent water/debris accumulation (Requirement 1).\n- File CASA defect reports whether an inspection finds defects or not.\n\n**Bottom line**: The AD mandates regular inspection and end‑of‑life (or condition‑based) treatment of wing attach bolts, nuts and fittings on all Beechcraft 36 series aeroplanes to manage corrosion risk. It creates different inspection cadences for private versus other operations, requires removal and detailed inspection per the manufacturer’s manual in certain cases, mandates replacement (or condition‑based retention) of hardware around 20 years TIS, and imposes reporting obligations to CASA."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025","history":"/api/acts/ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025/history","analysis":"/api/acts/ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025/analysis","conflicts":"/api/acts/ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025/conflicts","importantCases":"/api/acts/ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025/important-cases","documents":"/api/acts/ad-beech-36-43-amdt-6-wing-bolt-nut-and-fitting-9-2025/documents"}}