{"id":"F2006L00356","name":"AD/F100/74 - Fire Protection - Engine Fire Extinguishing Line Shuttle Valve","slug":"ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116965,"registerId":"commonwealth-F2006L00356-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Fokker F100 (F28 Mk 100) Series Aeroplan","sectionType":"division","heading":"Fokker F100 (F28 Mk 100) Series Aeroplanes","content":"### Fokker F100 (F28 Mk 100) Series Aeroplanes\n\n| AD/F100/74 | Fire Protection - Engine FireExtinguishing Line Shuttle Valve | 3/2006 |\n| ---------- | ------------------------------------------------------------- | ------ |\n\n| Applicability: | Fokker Aircraft B.V. Model F28 Mark 0070 and Mark 0100 aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Inspect the nuts on the affected shuttle valves in accordance with Section 3. Accomplishment Instructions of Fokker Service Bulletin SBF100-26-019 dated6 January 2006 or later CAA-NL approved revision.If no discrepancies are found no further action is required by this AD.2. When discrepancies are found during the inspection, detailed in Requirement 1 of this AD, tighten or replace the affected nuts, or replace the shuttle valves in accordance with Section 3. Accomplishment Instructions of FokkerSBF100-26-019 or later CAA-NL approved revision.3. Report all discrepancies, if any have been found, to the TC-holder as detailed in SBF100-26-019 or later CAA-NL approved revision.Note 1: Fokker 70/100 Maintenance Manual Task 26-21-03-400-814A also pertains to this subject.Note 2: CAA AD Netherlands NL-2006-002 EASA approval 2006-018 dated23 January 2006 refers. |\n| Compliance:    | 1. Within 6 months after the effective date of this AD.2. Before further flight.3. Within 7 days after the inspection is completed.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n|                | This Airworthiness Directive becomes effective on 16 March 2006.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n\n| Background: | One Fokker 100 (F28 Mark 0100) operator reported that during maintenance in the APU compartment, a disconnected nut was discovered on one of the shuttle valves in the deployment lines of the engine fire-extinguishing system. An additional check by the operator revealed that on more aircraft in its fleet, the nuts of the shuttle valves were incorrectly tightened. This condition, if not corrected, could result in failure or reduced efficiency of the engine fire-extinguishing system in case of an engine fire. Since a potentially unsafe condition has been identified that is likely to exist or develop on other aircraft of this type design, this AD requires a one-time inspection of the nuts and shuttle valves in the deployment lines of the engine fire-extinguishing system in the APU compartment and corrective actions, as necessary. |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n1 February 2006","sortOrder":0},{"sectionNumber":"AD/F100/74","sectionType":"part","heading":"AD/F100/74","content":"## AD/F100/74","sortOrder":1},{"sectionNumber":"Fire Protection - Engine Fire Extinguish","sectionType":"part","heading":"Fire Protection - Engine Fire Extinguishing Line Shuttle Valve","content":"## Fire Protection - Engine Fire  \nExtinguishing Line Shuttle Valve","sortOrder":2},{"sectionNumber":"3/2006","sectionType":"part","heading":"3/2006","content":"## 3/2006","sortOrder":3}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD remains tightly scoped to its original safety purpose. It addresses a specific mechanical defect identified in the Fokker 70/100 fleet (loose shuttle valve nuts in the engine fire-extinguishing system) and imposes targeted inspection and reporting requirements. There is no evidence of scope creep — the instrument does not expand into unrelated systems, aircraft types, or operational requirements beyond what is necessary to mitigate the identified unsafe condition."},"complexity_factors":["Single-issue directive focused on one mechanical component (shuttle valve nuts)","Only 3 compliance requirements with clear conditional logic (if-then structure)","References external technical documents (Fokker Service Bulletin SBF100-26-019) rather than embedding full instructions","Minimal defined terms — only standard aviation acronyms (APU, AD, TC-holder)","No nested exceptions or complex cross-referencing within the instrument itself","Straightforward timeline: 6 months / before flight / 7 days"],"plain_english_summary":"This CASA Airworthiness Directive mandates operators of Fokker F70 and F100 aircraft in Australia to inspect shuttle-valve nuts in the APU/engine fire-extinguishing system within six months, and to tighten, replace, or replace the valve before flight if faults are found. Findings must be reported to Fokker within seven days. It addresses a safety risk where loose/disconnected nuts could prevent fire suppression during an engine fire."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive stays within the original, targeted scope: it applies only to Fokker F28 Mark 0070 and 0100 aircraft and mandates a one‑time inspection and corrective action of the shuttle valves as identified in the Background and Applicability sections. It does not expand obligations beyond those aircraft or impose recurring inspections."},"complexity_factors":["Narrow technical task but safety‑critical: inspection of shuttle‑valve nuts in the APU compartment requires qualified maintenance access and precision (Requirement; Background).","Dependency on an external service bulletin and regulator approvals: mandated work must follow Fokker Service Bulletin SBF100‑26‑019 or a later CAA‑NL approved revision, creating reliance on that document's content and revisions (Requirement).","Multiple corrective options increase operational judgement: AD allows tightening, replacing nuts, or replacing shuttle valves per the service bulletin, leaving maintenance engineers to choose actions that affect cost and downtime (Requirement 2).","Fixed and tight compliance windows: inspection within 6 months, corrective action required before next flight if discrepancies found, and reporting within 7 days — scheduling and operational disruption risks for operators (Compliance 1–3).","Administrative reporting to the type‑certificate holder creates coordination and recordkeeping burden (Requirement 3; Compliance 3).","Applicability limited to specified models concentrates compliance burden on specific operators but reduces general applicability (Applicability).","References to maintenance manual Task 26‑21‑03‑400‑814A and to CAA/NL approvals imply cross‑document consistency checks and possible parts/logistics coordination (Note 1; Requirement).","One‑time mandatory action (not recurring) lowers ongoing regulatory complexity but concentrates short‑term resource impact (Background; Requirement)."],"plain_english_summary":"This Airworthiness Directive requires operators of Fokker F28 Mark 0070 and Mark 0100 aeroplanes to inspect shuttle‑valve nuts in the APU‑compartment engine fire‑extinguishing deployment lines, correct any loose or incorrect nuts or replace shuttle valves, and report findings to the type‑certificate holder. Deadlines are set for inspection, corrective action before further flight, and reporting; the measure addresses a discovered risk to the engine fire‑extinguishing system's effectiveness."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve","history":"/api/acts/ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve/history","analysis":"/api/acts/ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve/analysis","conflicts":"/api/acts/ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve/conflicts","importantCases":"/api/acts/ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve/important-cases","documents":"/api/acts/ad-f100-74-fire-protection-engine-fire-extinguishing-line-shuttle-valve/documents"}}