{"id":"F2006B09615","name":"AD/F100/15 - Centre Section Frame Strips","slug":"ad-f100-15-centre-section-frame-strips","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54371,"registerId":"commonwealth-F2006B09615-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F100/15 - Centre Section Frame Strips","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 F100 (F28 Mk 100) Series Aeroplanes\n\n \n\nAD/F100/15 Centre Section Frame Strips 4/99\n\nApplicability: F.28 Mk.0100 aircraft, serial numbers 11244 through 11371.\n\n \n\nRequirement: Install two reinforcement plates each at fuselage STA.14911 and STA.17011 in accordance with Fokker Service Bulletin (SB) F100-53-072 dated 12 March 1993.\n\n \n\nNote: RLD BLA 93-037(A) refers.\n\n \n\nCompliance: Unless previously accomplished, before accumulating 24,000 flight cycles since new.\n\n \n\nThis Airworthiness Directive becomes effective on 22 April 1999.\n\n \n\nBackground:   During fatigue tests on the F.28 Mk.0100, cracks were discovered in the frame strips at fuselage STA.14911 and STA.17011. This AD requires a modification to increase the crack initiation threshold beyond 90,000 flight cycles.\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\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 on a specific structural modification for a defined aircraft type. It has not expanded beyond its original purpose of addressing the discovered fatigue cracking issue."},"complexity_factors":["Single, specific technical requirement with clear reference to manufacturer documentation","Limited applicability (defined by precise aircraft model and serial number range)","Simple compliance condition (flight cycle threshold with 'unless previously accomplished' exception)","No nested definitions, cross-references to other legislation, or conditional logic beyond the basic applicability and compliance clauses","Background explanation provided in plain language","Total length: approximately 150 words of substantive content"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires operators of Fokker F100 aircraft (S/N 11244–11371) to install reinforcement plates at two fuselage locations to prevent fatigue cracking of frame strips.  \n\nThe change, per Fokker service instructions, restores structural life (beyond ~90,000 cycles) after testing revealed crack risk. Compliance is required before the aircraft reaches 24,000 flight cycles. Effective date: 22 April 1999."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive's scope—specific serial-number applicability, the required reinforcement plates at STA.14911 and STA.17011, the reference to the manufacturer service bulletin, and the 24,000 flight‑cycle compliance threshold—matches the stated background objective of addressing fatigue cracks and raising the crack‑initiation threshold beyond 90,000 cycles. The AD does not expand or narrow that stated objective beyond its explicit requirements."},"complexity_factors":["Targeted applicability: limited to F.28 Mk.0100 aircraft, serial numbers 11244 through 11371 (Applicability).","Technical structural work: installation of two reinforcement plates at fuselage STA.14911 and STA.17011 (Requirement).","Prescriptive compliance method: work must follow Fokker Service Bulletin F100-53-072 dated 12 March 1993 (Requirement).","Time-bound mandate: compliance required before accumulating 24,000 flight cycles since new (Compliance).","Safety-performance benchmark: modification intended to increase crack-initiation threshold beyond 90,000 flight cycles (Background).","Operational and cost burden: operators bear procurement, maintenance labour and aircraft downtime costs (implied by Requirement/Compliance).","Regulatory enforceability and scheduling pressure: AD has an effective date (22 April 1999) that fixes when the mandate applies (Effectivity)."],"plain_english_summary":"Requires specified Fokker F100 (F28 Mk.100) aeroplanes (serials 11244–11371) to have two reinforcement plates fitted at two fuselage stations per Fokker Service Bulletin F100‑53‑072, to be done before 24,000 flight cycles; effective 22 April 1999. The directive responds to fatigue-test discoveries of cracks at those frame strips and seeks to raise the crack-initiation threshold beyond 90,000 cycles. Affected operators must arrange the structural modification, pay for parts and labour, and plan for aircraft downtime to comply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-15-centre-section-frame-strips","history":"/api/acts/ad-f100-15-centre-section-frame-strips/history","analysis":"/api/acts/ad-f100-15-centre-section-frame-strips/analysis","conflicts":"/api/acts/ad-f100-15-centre-section-frame-strips/conflicts","importantCases":"/api/acts/ad-f100-15-centre-section-frame-strips/important-cases","documents":"/api/acts/ad-f100-15-centre-section-frame-strips/documents"}}