{"id":"F2006B09610","name":"AD/F100/10 - Engine Mount Shear Shelf Web","slug":"ad-f100-10-engine-mount-shear-shelf-web","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54365,"registerId":"commonwealth-F2006B09610-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F100/10 - Engine Mount Shear Shelf Web","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)  \nFokker F100 (F28 Mk 100) Series Aeroplanes\n\nAD/F100/10 Engine Mount Shear Shelf Web 4/99\n\nApplicability: F.28 Mk.0100 aircraft, serial numbers, 11244 through 11308, 11310, 11312 through\n\n11314, 11316, 11321, 11328 and 11329.\n\nRequirement: 1. Inspect the engine mount shear shelf webs around the areas of the fixed cowl aft hook centreline and the fixed cowl mid hook centreline for cracks and damage, and reinforce the engine mount shear shelf webs in accordance with the Accomplishment Instructions Part 1 or Part 2, as applicable, of Fokker Service Bulletin (SB) F100-71-012 dated 7 February 1992.\n\n2. Repair cracks in accordance with Fokker F.28 Mk.0100 Structural Repair Manual (SRM).\n\nNote: RLD BLA 92-032 refers.\n\nCompliance: 1. Unless previously accomplished, before accumulating 12,000 flight hours since new.\n\n2. If cracks are found during the inspection in accordance with Requirement 1, repair before further flight.\n\nThis Airworthiness Directive becomes effective on 22 April 1999.\n\nBackground: Interference has been found to be possible between the fixed cowl mid and aft hooks and the engine mount shear shelf web. Aside from a noticeable increase in vibration and noise, this interference can cause cracks and other damage to the shear shelf web. This in turn affects fatigue life. This AD requires the affected areas to be inspected and subsequently reinforced.","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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive targeting a specific structural defect in specific aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear applicability (specific aircraft serial numbers)","Only two compliance conditions: time-based (12,000 flight hours) and condition-based (if cracks found)","No defined terms section — technical terms reference external documents (Service Bulletin, Structural Repair Manual)","Minimal conditional logic (only 'unless previously accomplished' and 'if cracks are found')","Short document (approximately 200 words) with straightforward structure","Single cross-reference to external technical document (RLD BLA 92-032) in a non-binding note"],"plain_english_summary":"Safety order requires owners/operators of specified Fokker F100 serial-numbered aircraft to inspect and reinforce the engine‑mount “shear shelf web” where cowling hooks contact it, and to repair any cracks before the airplane may fly. Actions must be completed before 12,000 total flight hours (unless already done). This prevents fatigue damage that could reduce structural life or lead to failure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope is unchanged from its stated purpose: it targets specified Fokker F100 serial numbers and mandates inspection, reinforcement, and repair per the cited manufacturer documents (Applicability; Requirement 1–2). No expansion or narrowing of applicability or actions is indicated in the text."},"complexity_factors":["Limited applicability to specified serial numbers increases administrative tracking for operators (Applicability).","Prescriptive technical actions require following external manufacturer documents: Fokker SB F100-71-012 and the F.28 Mk.0100 SRM (Requirement 1 and 2).","Compliance measured in flight hours (before 12,000 hours) imposes scheduling constraints on maintenance planning (Compliance 1).","Immediate grounding risk for aircraft with detected cracks because repairs must be done before further flight (Compliance 2).","Inspection scope is anatomically specific (mid and aft hook centrelines), which may require specialized inspection procedures or skilled technicians (Requirement 1).","Regulatory enforceability is clear but relies on operators' accurate hours-recording and adherence to the SB/SRM; few discretionary options are provided in the AD text."],"plain_english_summary":"This Airworthiness Directive requires operators of listed Fokker F100 (F28 Mk.100) aeroplanes to inspect the engine-mount shear shelf webs near the fixed-cowl mid and aft hook centrelines, reinforce those areas per Fokker Service Bulletin F100-71-012, and repair any cracks per the Structural Repair Manual. Operators must complete the inspection/reinforcement before the aeroplane reaches 12,000 flight hours; any cracks found must be repaired before further flight. The operator bears the cost and schedules maintenance to meet the flight-hour deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-10-engine-mount-shear-shelf-web","history":"/api/acts/ad-f100-10-engine-mount-shear-shelf-web/history","analysis":"/api/acts/ad-f100-10-engine-mount-shear-shelf-web/analysis","conflicts":"/api/acts/ad-f100-10-engine-mount-shear-shelf-web/conflicts","importantCases":"/api/acts/ad-f100-10-engine-mount-shear-shelf-web/important-cases","documents":"/api/acts/ad-f100-10-engine-mount-shear-shelf-web/documents"}}