{"id":"F2006B04214","name":"AD/BEECH 90/22 Amdt 3 - Wing Structural Fatigue Limitation","slug":"ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43970,"registerId":"commonwealth-F2006B04214-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 90/22 Amdt 3 - Wing Structural Fatigue Limitation","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BEECH 90/22 Amdt 2 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nBeechcraft 90 & 65-90 (King Air) Series Aeroplanes\n\nAD/BEECH 90/22\n\nAmdt 3\n\n  \nWing Structural Fatigue Limitation 2/2002\n\nApplicability: Model 65-A90, B90, & C90 aircraft with centre section and outer wing main spar lower caps exceeding 10,000 hours’ time in service.\n\nRequirement: Retire from service the centre section and outer wing main spar lower caps, including the centre-section to outer wing attachment fittings.\n\nThis life limitation assumes an average mean flight cruise weight of 9050 pounds and one landing per hour. Should the mean cruise weights, averaged over the life of the aircraft be greater than 9100 pounds or should landings occur on average at or greater frequency than one every 45 minutes, the Authority must be advised.\n\nOperators of Model 65-A90 aircraft which was originally certificated at a maximum gross weight of 9300 pounds may apply to the Authority for a revised spar life.\n\nNote: On the basis of the currently available fatigue substantiation for the aircraft, only one spar cap replacement is permitted. Any proposal for a further extension in life incorporating a second spar change must be supported by a substantiation covering all the remaining primary structure including empennage, control surface hinge arms etc. This substantiation must incorporate a safe life assessment, or a sufficiently rigorous revised inspection schedule to ensure that any fatigue cracking which could occur in service will be detected before the aircraft is endangered. A third spar change will not be permitted.\n\nThis amendment becomes effective on 21 February 2002.\n\nBackground Amdt 3 - The model designations in the applicability section have been corrected to reflect those given on the FAA Type Certificate.\n\nBeechcraft 90 & 65-90 (King Air) Series Aeroplanes\n\nAD/BEECH 90/22 Amdt 3 (continued)\n\nAmendment 2 of this Airworthiness Directive became effective on 30 June 1977.\n\n![](image.002.png)  \n\nDelegate of the Civil Aviation Safety Authority 3 January 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 30 January 2002.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This amendment corrects the model designations in the Applicability section (Background) but does not expand the substantive regulatory scope. The core requirement — retire specified spar caps after 10,000 hours TIS, allow one spar-cap replacement, and require substantiation for any further life extension — remains the operative limitation. The change is therefore a technical correction rather than a material expansion of the AD’s original purpose."},"complexity_factors":["Single short AD document (limited length) but multiple conditional rules","One clear defined numeric threshold (10,000 hours’ time in service) in the Applicability section","Operational assumptions and two alternative notification triggers (mean cruise weight and landing frequency) in Requirement","Permit for one spar-cap replacement, conditional and requiring extensive substantiation for any second replacement (nested requirement for substantiation)","Cross-authority process: operators may apply to the Authority for a revised spar life (adds administrative pathway and regulatory discretion)","Reference to an external regulatory provision (subregulation 39.1(1) of CAR 1998) and to FAA Type Certificate model designations (Background), creating modest cross-referencing","Prohibits further (third) spar change — a hard limit combined with conditional approval paths increases implementation complexity"],"plain_english_summary":"**What this instrument does (mechanically)\n\n- Revokes the earlier AD/BEECH 90/22 Amdt 2 and replaces it with AD/BEECH 90/22 Amdt 3. (See header and Background.)\n- Requires retirement from service of the centre section and outer wing main spar lower caps, including the centre-section to outer wing attachment fittings, on certain Beechcraft 65-A90, B90 and C90 (King Air) aeroplanes when those parts have exceeded 10,000 hours’ time in service. (Applicability & Requirement.)\n- Sets the assumptions used to calculate that life limit: an average mean cruise weight of 9,050 pounds and an assumed rate of one landing per hour. If the aircraft’s long-term average cruise weight exceeds 9,100 pounds, or landings happen more frequently than one every 45 minutes on average, the operator must advise the aviation Authority. (Requirement.)\n- Allows operators of Model 65-A90 aeroplanes originally certificated at a maximum gross weight of 9,300 pounds to apply to the Authority for a revised spar life. (Requirement.)\n- Limits life-extension options: only one spar-cap replacement/change is permitted on the basis of currently available fatigue substantiation. Any proposal for a second spar-cap change requires a full substantiation (safe-life assessment or a sufficiently rigorous revised inspection schedule) covering the remaining primary structure; a third spar change is not permitted. (Note.)\n- Becomes effective 21 February 2002. (Compliance/effective date.)\n\nWho this affects\n\n- Aircraft owners/operators of Beechcraft Model 65-A90, B90 and C90 (King Air) series aeroplanes that have centre-section and outer wing main spar lower caps with more than 10,000 hours’ time in service. (Applicability.)\n- Maintenance organisations and parts suppliers who perform spar removals, replacements or inspections for these models. (Implicit in the retirement and replacement requirement.)\n- The Civil Aviation Safety Authority (the “Authority”), because operators must notify it in specified circumstances and may apply to it for revised life limits. (Requirement & application clause.)\n\nWhy it matters (purpose claimed by the instrument, then practical effects)\n\n- The AD’s stated purpose is to address an unsafe condition caused by structural fatigue in the wing spars (centre section and outer wing main spar lower caps). The mechanical effect is to impose a mandatory life limit and to constrain how many times a spar cap may be replaced before the aircraft’s primary structure needs a wider safety substantiation. (Header; Requirement; Note.)\n\nPractical consequences, incentives and trade-offs\n\n- Who pays: owners/operators pay for removing and replacing retired spar caps and associated fittings, any inspections required, aircraft downtime, and costs to prepare and submit an application for a revised life if they seek an extension. (Requirement & Note.)\n- Behaviour changes: operators may alter aircraft usage to stay within the assumed operational profile (e.g. reduce mean cruise weight or reduce flight frequency) to avoid triggering notifications or to preserve remaining life; alternatively they may apply for a revised life limit and invest in structural substantiation. (Requirement & Note.)\n- Market effects: maintenance shops and parts suppliers face increased demand for spar replacement work; older aircraft owners bear concentrated replacement costs, which may reduce operation or resale options for these airframes. Small operators with limited cash reserves face proportionally larger burdens. (Requirement & Note.)\n- Compliance burden and discretion: operators must track hours on the specified parts, count landings and cruise-weight averages, notify the Authority if thresholds are exceeded, and can seek authority approval for alternate life limits — creating administrative and documentation workloads. The Authority has discretion to grant revised spar lives upon application. (Requirement.)\n- Risk and implementation costs: replacement parts availability, certified repair/overhaul capacity, and the need for rigorous fatigue substantiation for any further life extension create practical hurdles; lack of substantiation means further life extensions are limited. (Note.)\n- Substitution effects: operators may respond by changing mission profiles (lighter loads, fewer takeoffs/landings), retiring affected aircraft, or investing in the required substantiation to permit further spar changes. (Requirement & Note.)\n\nConcrete limits and procedural points to note\n\n- Threshold for mandatory retirement: greater than 10,000 hours’ time in service on the specified spar caps. (Applicability.)\n- Notification triggers: if mean cruise weight averaged over the aircraft life is >9,100 lb, or average landings are more frequent than one every 45 minutes, the Authority must be advised. The life limit calculation itself uses an assumed mean cruise weight of 9,050 lb and one landing per hour. (Requirement.)\n- Life-extension policy: one spar-cap replacement is permitted; any second replacement requires a comprehensive substantiation covering all remaining primary structure or a revised inspection regime; a third replacement is forbidden. (Note.)\n\nSource sections cited: Applicability; Requirement; Note; Background.**"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: establishing safe life limits for wing spar components on specific Beechcraft King Air models. Amendment 3 makes only technical corrections to model designations to align with FAA Type Certificate data, without expanding the substantive scope or adding new requirements beyond the original fatigue limitation intent."},"complexity_factors":["Short, single-purpose directive with clear applicability criteria","Only 3 defined model variants in scope (65-A90, B90, C90)","Single primary requirement with two conditional reporting triggers (weight and landing frequency)","One substantive exception process for lighter-weight 65-A90 variants","Contains one nested limitation (one replacement permitted, second requires extensive substantiation, third prohibited)","Minimal cross-referencing (only references CAR 1998 subregulation 39.1(1) for issuing authority)","Background section is brief and limited to explaining the amendment reason"],"plain_english_summary":"This safety order requires permanent retirement of the centre section and outer wing main spar lower caps on Beechcraft King Air Models 65‑A90, B90 and C90 once those parts reach 10,000 flight hours, to prevent metal‑fatigue wing failures. It affects owners/operators of high‑hour aircraft and mandates notification if aircraft are flown heavier or with more frequent landings (which accelerate fatigue). One spar‑cap replacement is allowed (no third replacement); lighter A90s may seek a longer life limit from CASA."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation","history":"/api/acts/ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation/history","analysis":"/api/acts/ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation/analysis","conflicts":"/api/acts/ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation/conflicts","importantCases":"/api/acts/ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation/important-cases","documents":"/api/acts/ad-beech-90-22-amdt-3-wing-structural-fatigue-limitation/documents"}}