{"id":"F2010L00098","name":"AD/BEECH 18/17 Amdt 5 - Aircraft Modification, Inspection and Retirement","slug":"ad-beech-18-17-amdt-5-aircraft-modification-inspection-and-retirement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":122807,"registerId":"commonwealth-F2010L00098-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Beechcraft 18 Series Aeroplanes","sectionType":"division","heading":"Beechcraft 18 Series Aeroplanes","content":"### Beechcraft 18 Series Aeroplanes\n\n| AD/BEECH 18/17 Amdt 5 | Aircraft Modification, Inspectionand Retirement | 1/2010 |\n| --------------------- | ----------------------------------------------- | ------ |\n\n| Applicability: | All Model Beech 18 Series. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Modify the wing by installing an external strap modification in accordance with FAA AD 75-27-09 R2 paragraph F.2. Inspect wing structure and strap components in accordance with FAA AD75-27-09 R2 paragraphs A through C.3. a. For aeroplanes incorporating the Dee Howard Company STCs SA832SW and SA895SW in combination visually inspect in situ the external strap modification for cracks and/or corrosion, using appropriate optical aids. Pay particular attention to welds at end fittings, bends in the strap, forward and aft edges and the strap sections normally covered by the locating clips.3. b. For aeroplanes incorporating all other external strap modification STC’s, visually inspect in situ for cracks and/or corrosion.4. Retire aircraft from service.Note: This Directive is aimed at modifying and inspecting the wing so that a measure of main spar fail-safe capability is achieved. In order to maintain the necessary full limit load residual strength in the event of a spar truss tube failure it should be noted that the maximum gross weight of any Beech 18 variant is limited to4490 Kg (9900 lb.). This does not endorse weight increases for aircraft certificated below this figure. |\n| Compliance: | 1. Before issue of Certificate of Airworthiness.2. a. For spar trusses with welded repair or modifications:Within 300 hrs from the date of last inspection carry out the intent of requirement 2 and thereafter at 750 hour intervals.b. For spar trusses without welded repair or modifications:Within 300 hrs from the date of last inspection carry out the intent of requirement 2 and thereafter at 1500 hour intervals.3. a. At intervals not exceeding 100 hours time in service.b. At intervals not exceeding 300 hours time in service.4. Before exceeding 10000 hours time in service after strap modification or before 20000 hours time in service after manufacture, whichever occurs first. |\n| | This Amendment becomes effective on 21 January 2010. |\n| Background: | The original issue of this directive mandated inspections of the most likely locations for cracking and damage, included a strap modification to provide fail-safe ability and introduced a fatigue life limitation.Amendment 1. Added additional wing stations to the inspection to improve fail safe capability and included all possible locations instead of the most likely locations.Amendment 2. Required an additional inspection of the strap installation. Also added a note on the Maximum weight of a Beech 18 variant.Amendment 3. Following the cracking of some strap installations with foreign operators the threshold for strap inspections was amended. Calendar life limit was removed.Amendment 4. Reduced the intervals for the strap inspection following the failure of a strap from an operator.This Amendment refers to the State of Design directive for inspection requirements with the halving of intervals for welded repairs/modifications to the truss. |\n\n![](image.001.png)\n\nPeter Boyd \nDelegate of the Civil Aviation Safety Authority\n\n7 January 2010","sortOrder":0},{"sectionNumber":"AD/BEECH 18/17 Amdt 5","sectionType":"part","heading":"AD/BEECH 18/17 Amdt 5","content":"## AD/BEECH 18/17 Amdt 5","sortOrder":1},{"sectionNumber":"Aircraft Modification, Inspectionand Ret","sectionType":"part","heading":"Aircraft Modification, Inspectionand Retirement","content":"## Aircraft Modification, Inspection \nand Retirement","sortOrder":2},{"sectionNumber":"1/2010","sectionType":"part","heading":"1/2010","content":"## 1/2010","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original directive focused on basic wing inspections and strap installation. Through five amendments, it has expanded significantly: added inspection locations (Amendment 1), added strap-specific inspections (Amendment 2), removed calendar life limits and added STC-specific requirements (Amendment 3), halved inspection intervals after strap failures (Amendment 4), and now incorporates US FAA directives by reference while adding differentiated inspection schedules for repaired vs. unmodified spars (Amendment 5). The scope has evolved from simple modification mandate to a comprehensive fatigue management regime with multiple conditional tracks."},"complexity_factors":["Multiple cross-references to FAA AD 75-27-09 R2 (US aviation safety rules) for technical procedures","Conditional inspection intervals based on two different aircraft histories (welded repairs vs. no repairs)","Dual retirement criteria (10,000 hours post-modification OR 20,000 hours total — whichever is first)","Different inspection requirements for different Supplemental Type Certificates (STCs — aftermarket modifications)","Nested compliance timelines with multiple triggers (hours in service, calendar dates, modification dates)","Amendment history references five previous versions with cumulative changes"],"plain_english_summary":"This CASA Airworthiness Directive mandates safety action for all Beechcraft Model 18 series: install an external fail‑safe metal wing strap, adopt recurring wing inspections for cracks/corrosion (with schedules keyed to repair history), and retire aircraft at specified hour limits to limit fatigue risk. It affects owners, operators, maintenance personnel and certifiers, and caps maximum weight to 4,490 kg to ensure the strap can carry loads if the main spar fails."},"flash_summary":{"complexity_score":7,"scope_assessment":{"changed":true,"description":"The directive's scope has expanded since the original issue. The original mandated targeted inspections, a strap modification and a fatigue life limit; subsequent amendments added more inspection locations, introduced strap installation inspections, removed a calendar life limit, imposed a maximum gross weight note (4490 kg), tightened thresholds and inspection intervals after strap failures, and this Amendment halves inspection intervals for welded truss repairs/modifications by referencing the State of Design (FAA) directive (Background; Requirement; Compliance)."},"complexity_factors":["Multiple conditional inspection intervals depending on whether spar trusses have welded repairs/modifications (300 hr then 750 hr) or not (300 hr then 1500 hr) (Compliance).","Different inspection frequencies for strap installations (100 hr vs 300 hr) and a defined retirement time (before 10,000 hrs after strap mod or 20,000 hrs after manufacture) (Compliance, Requirement).","STC‑specific inspection detail: Dee Howard STCs SA832SW/SA895SW require focused visual checks (welds, bends, clip areas) while other STCs have broader requirements (Requirement).","Cross‑reference to FAA AD 75‑27‑09 R2 for modification and inspection procedures, creating dependency on a foreign State of Design directive (Requirement, Background).","A mandatory maximum gross weight note (4490 kg) tied to structural residual strength, affecting operational limits (Requirement).","Cumulative amendment history: successive changes have added inspection stations, new checks, removed calendar life limits, and halved intervals for welded repairs—requiring operators to track evolving obligations (Background).","Compliance timing includes prerequisite before issue of Certificate of Airworthiness, imposing scheduling and administrative burdens on owners/operators (Compliance)."],"plain_english_summary":"This Airworthiness Directive (AD) requires all Beech 18 series owners/operators to install an external wing strap modification, perform recurring inspections of wing structure and strap components (with inspection detail varying by STC and repair history), and retire aircraft after specified hours. It also caps maximum gross weight at 4490 kg to preserve residual strength. Operators fund and schedule the work; CASA enforces compliance. The AD cross‑references FAA AD 75‑27‑09 R2 and shortens inspection intervals for welded spar repairs, increasing recurring maintenance obligations."},"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-18-17-amdt-5-aircraft-modification-inspection-and-retirement","history":"/api/acts/ad-beech-18-17-amdt-5-aircraft-modification-inspection-and-retirement/history","analysis":"/api/acts/ad-beech-18-17-amdt-5-aircraft-modification-inspection-and-retirement/analysis","conflicts":"/api/acts/ad-beech-18-17-amdt-5-aircraft-modification-inspection-and-retirement/conflicts","importantCases":"/api/acts/ad-beech-18-17-amdt-5-aircraft-modification-inspection-and-retirement/important-cases","documents":"/api/acts/ad-beech-18-17-amdt-5-aircraft-modification-inspection-and-retirement/documents"}}