{"id":"F2006B09796","name":"AD/F28/61 - Wings - Rear Spar Web Plate","slug":"ad-f28-61-wings-rear-spar-web-plate","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54717,"registerId":"commonwealth-F2006B09796-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/61 - Wings - Rear Spar Web Plate","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Fokker F28 Series Aeroplanes\n\n \n\nAD/F28/61 Wings - Rear Spar Web Plate 7/89\n\nApplicability: All F28 aircraft with serial numbers 11003 to 11241 inclusive, 11991 and 11992. Requirement:               Action in accordance with Fokker F28 Service Bulletin F28/57-84.\n\nNote: RLD AD 89-46 refers.\n\n \n\nCompliance: Prior to exceeding 35000 flight cycles.\n\n \n\nAircraft which have exceeded 35000 but not 45000 flight cycles as at 7 April 1989: Prior to 30 September 1989.\n\n \n\nAircraft which have exceeded 45000 but not 55000 flight cycles as at 7 April 1989: Prior to 30 June 1989.\n\n \n\nAircraft which have exceeded 55000 flight cycles as at 7 April 1989: Prior to 15 May 1989.\n\n \n\nBackground: Fatigue tests have shown that cracks may develop in the rear spar web plate between STA. 4790 and STA. 5280.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on rear spar web plate fatigue cracking in Fokker F28 aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, clearly defined applicability (specific serial number ranges)","Straightforward compliance structure with four tiered deadlines based on flight cycles","No defined terms section or interpretation provisions","Single cross-reference to Fokker Service Bulletin F28/57-84 for technical requirements","Minimal conditional logic (only flight cycle thresholds)","No nested exceptions or complex procedural requirements","Short document (approximately 200 words of substantive content)"],"plain_english_summary":"CASA orders owners/operators of certain Fokker F28 aeroplanes (S/N 11003–11241, 11991–11992) to inspect and repair the wing rear spar web plate identified by Fokker Service Bulletin F28/57-84 after fatigue testing revealed crack risk.\n\nDeadlines are staggered by accumulated flight cycles (heavier-used aircraft must comply sooner). The measure prevents wing‑spar cracking and potential structural failure."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"No change evident in scope from the text: the AD specifies applicability by serial number, mandates following Service Bulletin F28/57-84, and sets tiered deadlines tied to flight-cycle bands to address identified fatigue cracking. The instrument itself does not indicate any amendment or narrowing/expansion of that stated scope."},"complexity_factors":["Applicability tied to specific serial-number set (F28 aircraft with serials 11003–11241, 11991, 11992) — requires operators to verify affected airframes (Applicability).","Tiered compliance schedule based on flight-cycle bands as at 7 April 1989 (general action before 35,000 cycles; separate deadlines for >35,000–45,000; >45,000–55,000; >55,000) — necessitates accurate cycle accounting and staggered work planning (Compliance).","Mandated action is to follow an external technical document (Fokker Service Bulletin F28/57-84) — the AD depends on that bulletin for procedure, scope and technical criteria (Requirement).","Technical subject is fatigue cracking in a defined structural area (rear spar web plate between STA.4790 and STA.5280) — requires structural inspection/repair expertise and possible parts or engineering disposition (Background).","Cross-reference to another directive (RLD AD 89-46) creates a need to check related regulatory material for complete compliance obligations (Note).","Deadlines are historical and specific (dates in 1989) which concentrates scheduling pressures for higher-cycle aircraft and may complicate retrospective compliance tracking (Compliance).","Compliance costs and operational disruption fall on the aircraft owners/operators because the AD prescribes mandatory corrective action (Requirement/Compliance)."],"plain_english_summary":"Mandates that owners/operators of certain Fokker F28 aircraft must carry out the inspection and corrective actions set out in Fokker Service Bulletin F28/57-84 for the rear spar web plate. Compliance deadlines vary by each aircraft's flight-cycle total as at 7 April 1989, with earlier deadlines for higher-cycle aircraft. The directive follows fatigue tests that showed possible cracking between wing stations STA.4790 and STA.5280 and therefore requires structural inspection/repair within fixed time limits."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-61-wings-rear-spar-web-plate","history":"/api/acts/ad-f28-61-wings-rear-spar-web-plate/history","analysis":"/api/acts/ad-f28-61-wings-rear-spar-web-plate/analysis","conflicts":"/api/acts/ad-f28-61-wings-rear-spar-web-plate/conflicts","importantCases":"/api/acts/ad-f28-61-wings-rear-spar-web-plate/important-cases","documents":"/api/acts/ad-f28-61-wings-rear-spar-web-plate/documents"}}