{"id":"F2006B05092","name":"AD/CESSNA 180/79 - Wing Lower Spar Cap Angle Stiffener","slug":"ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45073,"registerId":"commonwealth-F2006B05092-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 180/79 - Wing Lower Spar Cap Angle Stiffener","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 180, 182 and Wren 460 Series Aeroplanes\n\nAD/CESSNA 180/79 Wing Lower Spar Cap Angle Stiffener 12/98\n\nApplicability: The following aircraft models, all serial numbers, that have wing extension supplemental type certificate (STC) SA00276NY or supplemental type approval (STA) SA93-136 incorporated.\n\nModels 180, 180A, 180B, 180C, 180D, 180E, 180F, 180G, 180H, 180J, 180K, 182, 182A, 182B, 182C, 182D, 182E, 182F, 182G, 182H, 182J, 182K, 182L, 182M, 182N,\n\n182P, 182Q, 182R, 182S, R182, T182, and TR182.\n\nNote: The STA is the Canadian version of the U.S. STC.\n\nRequirement: 1. Inspect inside the left and right wings, aft of the spar, closest to where the strut connects to the wing, for an angle stiffener along the lower spar cap between Wing Station (WS) 90 and WS 110, in accordance with Part A of the Accomplishment Instructions of Air Research Technology Inc. (ART) Service Bulletin No. SB-1-96, Issue 1, dated 11 April 1996.\n\n2. If an angle stiffener is not installed, before further flight, install a stainless steel reinforcement strap on the underside of each wing, along the spar at WS 100.50 in accordance with Part B of the Accomplishment Instructions of ART Service Bulletin No. SB-1-96, Issue 1.\n\nNote: FAA AD 98-16-04 Amdt 39-10679 refers.\n\nCompliance: Unless already accomplished, within 50 hours time in service after 5 November 1998.\n\nThis Airworthiness Directive becomes effective on 5 November 1998.\n\nBackground: Test results have revealed that the wings of affected Cessna aircraft, without the angle stiffener, do not meet the applicable design requirements after being modified by above referenced STC or STA. The actions specified by Directive are intended to prevent wing failure during flight caused by the absence of an angle stiffener, which could cause loss of control of the aircraft.","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":"The directive’s scope is confined to the affected aircraft modified by the identified STC/STA and requires inspection and retrofit where the angle stiffener is absent. The instrument addresses the specific deficiency identified by test results and does not broaden applicability beyond the stated modified aircraft."},"complexity_factors":["Technical precision required: inspection location and installation use specific wing stations (WS 90–110; install at WS 100.50).","Narrow applicability: applies only to listed Cessna models that have STC SA00276NY or STA SA93-136 incorporated.","Safety‑critical timing: missing stiffener must be rectified \"before further flight,\" with overall compliance within 50 hours TIS.","External dependencies: compliance depends on following ART Service Bulletin SB-1-96 (Part A/B) and cross‑references FAA AD 98‑16‑04.","Operational burden: internal wing inspection and stainless‑steel strap installation likely require certified maintenance facilities, parts procurement and downtime.","Enforcement and cost allocation: owner/operator bears costs and scheduling; directive creates a de facto grounding risk until rectified."],"plain_english_summary":"This directive requires owners/operators of certain Cessna 180/182 (and related) aeroplanes fitted with a specific wing‑extension STC/STA to inspect the lower wing spar between wing stations 90 and 110 for an angle stiffener and, if none is found, fit a stainless‑steel reinforcement strap at about WS 100.50.\n\nThe aircraft owner/operator must pay for and arrange the inspection and any installation, complying within 50 hours time‑in‑service of the effective date; the measure is intended to restore the wing’s design strength after modification and reduce the risk of in‑flight wing failure."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: addressing a specific structural safety defect in specific Cessna aircraft with a specific wing modification. There is no evidence of scope creep; the directive targets exactly the problem identified in the background (missing angle stiffeners after wing extension STC/STA installation)."},"complexity_factors":["Single, specific technical requirement with clear alternative action path","Only 2 defined technical terms (STC and STA) explained in a note","No nested exceptions or conditional logic beyond the binary 'if not installed, then install' structure","Straightforward compliance deadline with single condition ('unless already accomplished')","References only one external technical document (ART Service Bulletin SB-1-96) with specific issue date","Short length (approximately 250 words)"],"plain_english_summary":"This mandatory Airworthiness Directive requires operators of Cessna 180/182 series and Wren 460 aeroplanes with the specific wing‑extension STC to inspect inside both wings near the strut for an angle stiffener between Wing Stations 90–110. If the stiffener is missing, install a stainless steel reinforcement strap on each wing before next flight. It addresses a failure risk from the wing extension; compliance was required within 50 flight hours after 5 Nov 1998."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener","history":"/api/acts/ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener/history","analysis":"/api/acts/ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener/analysis","conflicts":"/api/acts/ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener/conflicts","importantCases":"/api/acts/ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener/important-cases","documents":"/api/acts/ad-cessna-180-79-wing-lower-spar-cap-angle-stiffener/documents"}}