{"id":"F2006B05137","name":"AD/CESSNA 185/45 - Wing Lower Spar Cap Angle Stiffener","slug":"ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45195,"registerId":"commonwealth-F2006B05137-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 185/45 - 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 185 Series Aeroplanes\n\nAD/CESSNA 185/45 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 185, 185A, 185B, 185C, 185D, 185E, A185E, and A185F.\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 this 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":"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":3,"scope_assessment":{"changed":false,"description":"The AD's scope aligns with its stated purpose: it targets Cessna 185-series aeroplanes that have the specified wing-extension STC/STA and requires inspection and retrofit where the angle stiffener is absent to restore design compliance. There is no indication in the instrument text that the applicability or remedial objective was broadened beyond that original intent."},"complexity_factors":["Applicability limited to Cessna 185-series aircraft that have the specific wing-extension STC (SA00276NY) or STA (SA93-136) incorporated — requires operators to check modification status.","Technical inspection location specified by wing stations (WS 90–110) and precise installation point (WS 100.50), requiring familiarity with aircraft station references.","Work and remedy are physical: inspect inside wing aft of spar and, if absent, install a stainless-steel reinforcement strap per ART Service Bulletin SB-1-96 Parts A & B (Issue 1, 11 April 1996).","Directive cross-references an external service bulletin (ART SB-1-96) for accomplishment instructions, so compliance requires access to and interpretation of that document.","Compliance timing: must be done within 50 hours time-in-service after 5 November 1998 or before further flight if stiffener is missing — creates a short operational window and potential scheduling/grounding impacts.","Terminology difference (STC vs STA) may create administrative ambiguity for operators about whether the modification on an airframe is covered."],"plain_english_summary":"This Airworthiness Directive requires operators of Cessna 185-series aeroplanes fitted with the specific wing-extension STC (SA00276NY) or STA (SA93-136) to inspect inside each wing (between wing stations 90 and 110) for a lower spar cap angle stiffener, and to fit a stainless-steel reinforcement strap at WS 100.50 before further flight if the stiffener is missing. Testing showed the modified wings may not meet design requirements without the stiffener; the AD mandates inspection and retrofit within 50 hours time-in-service to prevent possible in-flight wing failure."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: addressing a specific structural deficiency in specific modified Cessna 185 aircraft. The scope has not expanded beyond the original safety issue identified in 1998."},"complexity_factors":["Very short document (approximately 250 words)","Only 2 defined technical terms (WS for Wing Station, STA explained in a note)","Single clear applicability test (specific aircraft models + specific modification)","Binary compliance path: inspect → if missing, install (no nested conditions)","Single cross-reference to FAA AD 98-16-04 (informational only)","No sub-delegations, no exemptions, no conditional exceptions"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection of the wing spar area on certain Cessna 185 variants that have a specific wing‑extension STC/STA to check for a missing angle stiffener. If the stiffener is absent, operators must install a stainless‑steel reinforcement strap before further flight.\n\nIt targets owners/operators of the affected Cessna 185s because missing stiffeners can lead to wing structural failure; compliance was required within 50 flight hours after 5 November 1998."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener","history":"/api/acts/ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener/history","analysis":"/api/acts/ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener/analysis","conflicts":"/api/acts/ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener/conflicts","importantCases":"/api/acts/ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener/important-cases","documents":"/api/acts/ad-cessna-185-45-wing-lower-spar-cap-angle-stiffener/documents"}}