{"id":"F2007L00643","name":"AD/CESSNA 206/63 - Crew Seat Back Cylinder Lock Modification","slug":"ad-cessna-206-63-crew-seat-back-cylinder-lock-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":64127,"registerId":"commonwealth-F2007L00643-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 206 Series Aeroplanes","sectionType":"division","heading":"Cessna 206 Series Aeroplanes","content":"### Cessna 206 Series Aeroplanes\n\n| AD/CESSNA 206/63 | Crew Seat Back Cylinder Lock Modification | 5/2007 DM |\n| ---------------- | ----------------------------------------- | --------- |\n\n| Applicability: | Cessna 206H (Serial Numbers 20608001 through 20608250) and Cessna T206H (Serial Numbers T20608001 through T20608570). |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1) Aeroplanes that do not have Modification Kit MK172-25-10A or Modification Kit MK172-25-10B installed, for each crew seat (pilot and copilot), install Modification Kit MK172-25-10C or fabricate and install a steel lock rod/bar. Follow Cessna Single Engine Service Bulletin SB04-25-01, Revision 4, dated December 26, 2006, for installing Modification Kit MK172-25-l0C, or, follow Cessna Single Engine Service Bulletin SB04-25-02, Revision 1, dated October 17, 2005, or Revision 2, dated June 5, 2006, for fabricating and installing a steel lock rod/bar.2) Aeroplanes that have Modification Kit MK172-25-10A or Modification Kit MK172-25-10B installed:(i) For each crew seat (pilot and co-pilot), perform an installation inspection in accordance with Cessna Single Engine Service Bulletin SB04-25-01, Revision 4, dated 26 December 2006.(ii) If you do not find any discrepancies during the inspection required in paragraph (2)(i) of this AD, make a log book entry showing compliance with this AD and no further action is required.(iii) If you find discrepancies during the inspection required in paragraph (2)(i) of this AD, make all necessary corrective actions in accordance with Cessna Single Engine Service Bulletin SB04-25-01, Revision 4, dated 26 December 2006.Note: FAA AD 2007-05-10 Amdt 39-14971 and Cessna Service Bulletins SB04-25-01 and SB04-25-02 refer. |\n| Compliance: | 1) For aeroplanes over 1,000 hours time-in-service (TIS) on the effective date of this AD, perform the action within the next 4 months after the effective date of this AD; orFor aeroplanes from 501 to 1,000 hours TIS on the effective date of this AD, perform the action within the next 8 months after the effective date of this AD; or |\n\n| | For aeroplanes from 0 to 500 hours TIS on the effective date of this AD, perform the action within the next 12 months after the effective date of this AD.2) For aeroplanes meeting Requirement 2:(i) Within the next 30 days after the effective date of this AD.(ii) Before further flight after the inspection required in paragraph 2(i) of this AD.(iii) Before further flight after the inspection required in paragraph 2(i) of this AD. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | This Airworthiness Directive becomes effective on 11 April 2007. |\n| Background: | This AD results from reports of the crew seat back cylinder lock assembly failing at the aft end area and other cylinder lock assemblies found cracked. The actions specified in this AD are intended to prevent the crew seat cylinder lock assembly from bending, cracking, or failing. This failure could cause uncontrolled movement of the seat back, resulting in possible backward collapse during flight. Backward collapse of either crew seat back could result in an abrupt pitch-up if the affected crew member continues to hold on to the control yoke during this failure and could cause difficulty in exiting the airplane from an aft passenger seat after landing. |\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n9 March 2007","sortOrder":0},{"sectionNumber":"AD/CESSNA 206/63","sectionType":"part","heading":"AD/CESSNA 206/63","content":"## AD/CESSNA 206/63","sortOrder":1},{"sectionNumber":"Crew Seat Back Cylinder Lock Modificatio","sectionType":"part","heading":"Crew Seat Back Cylinder Lock Modification","content":"## Crew Seat Back Cylinder Lock Modification","sortOrder":2},{"sectionNumber":"5/2007 DM","sectionType":"part","heading":"5/2007 DM","content":"## 5/2007 DM","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains focused scope on the specific safety defect (crew seat back cylinder lock failure) for the identified aircraft models. The tiered compliance schedule and dual-path requirements (modification vs inspection) represent standard aviation safety regulatory practice for addressing in-service defects, not scope creep."},"complexity_factors":["Multiple conditional pathways based on existing modification status (Requirement 1 vs Requirement 2)","Time-in-service (TIS) tiered compliance schedule (three brackets: 0-500, 501-1000, 1000+ hours)","Cross-references to external technical documents (Cessna Service Bulletins SB04-25-01 Rev 4 and SB04-25-02 Rev 1/2)","Specific serial number applicability ranges requiring verification","Nested sub-requirements with conditional logic (2(i), 2(ii), 2(iii) — inspect, then act based on findings)","Reference to parallel FAA AD (2007-05-10) for context but not binding in Australia"],"plain_english_summary":"This CASA Airworthiness Directive mandates corrective action on specific Cessna 206H/T206H serials because the pilot/co‑pilot seat back cylinder lock can crack and suddenly collapse. That failure risks unexpected pitch changes in flight and blocked exits on the ground. Owners/operators must install an approved lock kit (or fabricate/install a steel lock rod per Cessna) or inspect and rectify earlier kits, with compliance deadlines tied to total airframe hours."},"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"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The directive enforces the originally stated safety objective: prevent crew seat back cylinder lock bending, cracking or failure for the listed Cessna 206/T206 serial numbers. It does not expand applicability beyond those serial ranges and sets specific corrective/inspection actions and deadlines consistent with the background safety concern."},"complexity_factors":["Applicability limited to narrow serial-number ranges (Cessna 206H 20608001–20608250; T206H T20608001–T20608570) — requires precise operator identification.","Multiple compliance paths: install MK172-25-10C OR fabricate/install a steel lock rod/bar OR inspect/correct earlier kits MK172-25-10A/B, increasing decision complexity (Requirement).","References to multiple external documents (Cessna Single Engine Service Bulletins SB04-25-01 Rev 4, SB04-25-02 Rev 1/2, and FAA AD 2007-05-10) require operators to follow detailed external procedures.","Tiered compliance timeline based on time-in-service (TIS) brackets: 0–500, 501–1,000, >1,000 hours, each with different deadlines — scheduling and maintenance planning burden (Compliance).","Mandatory inspection timing for aircraft with earlier kits: 30-day inspection window and corrective action required before further flight if discrepancies are found — creates immediate operational impacts.","Recordkeeping requirement: if no discrepancies, a log book entry must be made showing compliance; otherwise corrective actions must be logged (Requirement 2(ii)).","Technical implementation options include either purchase/installation of a supplied kit or fabrication to the service bulletin specification — variable cost and skill/resource requirements for operators.","Safety-risk linkage is explicit (Background): failure modes described inform urgency, but enforcement depends on operators executing technical inspections and repairs to a service-bulletin standard."],"plain_english_summary":"This directive requires owners/operators of specified Cessna 206H and T206H aeroplanes to secure the crew seat back cylinder lock by installing Modification Kit MK172-25-10C or fabricating and installing a steel lock rod/bar, or by inspecting and correcting earlier MK172-25-10A/B installations per Cessna service bulletins. It is intended to prevent seat-back lock bending, cracking or failure that could allow uncontrolled seat movement. Compliance deadlines vary by aircraft time-in-service and some inspections must be completed before further flight."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-206-63-crew-seat-back-cylinder-lock-modification","history":"/api/acts/ad-cessna-206-63-crew-seat-back-cylinder-lock-modification/history","analysis":"/api/acts/ad-cessna-206-63-crew-seat-back-cylinder-lock-modification/analysis","conflicts":"/api/acts/ad-cessna-206-63-crew-seat-back-cylinder-lock-modification/conflicts","importantCases":"/api/acts/ad-cessna-206-63-crew-seat-back-cylinder-lock-modification/important-cases","documents":"/api/acts/ad-cessna-206-63-crew-seat-back-cylinder-lock-modification/documents"}}