{"id":"F2006B10875","name":"AD/JBK 117/8 Amdt 2 - Engine Mount Sidewards Link","slug":"ad-jbk-117-8-amdt-2-engine-mount-sidewards-link","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56381,"registerId":"commonwealth-F2006B10875-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JBK 117/8 Amdt 2 - Engine Mount Sidewards Link","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/JBK117/8 Amdt 1 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nKawasaki BK117 Series Helicopters\n\nAD/JBK 117/8\n\nAmdt 2\n\n  \nEngine Mount Sidewards Link 10/2002\n\nApplicability: Models BK 117, BK 117A-3, BK117A-4, BK 117B-1 and BK 117B-2 helicopters without Kawasaki Service Bulletin KSB-117-121 incorporated.\n\nRequirement: Action in accordance with Kawasaki Service Bulletin KSB-117-120A.\n\nNote: JCAB AD TCD-4358A-98 refers.\n\nCompliance: For helicopters that have accumulated more than 1200 hours time in service:\n\nInitially inspect in accordance with paragraphs 9.(1) and 9.(3) of Service Bulletin KSB-117-120A within 50 hours time in service after 5 November 1998, unless already accomplished in accordance with Kawasaki Service Bulletin KSB-117-120 or\n\n\\-120A.\n\nFor all other compliance requirements: As specified in the requirement document with an effective date of 5 November 1998.\n\nNote: Compliance with Kawasaki Service Bulletin KSB-117-121 dated 19 June 1997, constitutes terminating action for the requirements of this AD.\n\nThis Amendment becomes effective on 3 October 2002.\n\nBackground: This Airworthiness Directive was issued in order to prevent failure of the engine mount sidewards link due to excessive wear of the sidewards link tail cone side lug bore.\n\nAmendment 1 was issued in response to a revision of the requirement document, which added an inspection and changed the compliance requirements.\n\nKawasaki BK117 Series Helicopters\n\nAD/JBK 117/8 Amdt 2 (continued)\n\nAmendment 2 is issued to add a specific note for terminating action. There are no changes to the requirements or compliance.\n\nThe original issue of this Airworthiness Directive became effective on 23 May 1998.\n\n![Signature of David Alan Villiers Delegate of the Civil Aviation Safety Authority](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 20 August 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 September 2002.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 2 did not broaden or add substantive requirements; it only added a specific note clarifying that incorporation of Kawasaki Service Bulletin KSB-117-121 constitutes terminating action. The AD's original purpose—preventing failure of the engine mount sidewards link by requiring inspections/corrective action per KSB-117-120A—remains unchanged."},"complexity_factors":["Short document with a single, focused safety directive","One primary external technical document to follow: Kawasaki Service Bulletin KSB-117-120A","Single terminating-action reference to Kawasaki Service Bulletin KSB-117-121","One conditional compliance timeline (helicopters >1200 hours TIS require inspection within 50 hours after specified date)","Minor cross-reference to a foreign AD (JCAB AD TCD-4358A-98)","Amendment history limited to adding a terminating-action note; no nested exceptions or multilayered conditions"],"plain_english_summary":"**What this directive does (mechanics)**\n\n- This is an Airworthiness Directive (AD) that applies to Kawasaki BK117 family helicopters (models BK 117, BK 117A-3, BK117A-4, BK 117B-1 and BK 117B-2) that have not had Kawasaki Service Bulletin KSB-117-121 installed (Applicability).\n- It requires operators to carry out the actions specified in Kawasaki Service Bulletin KSB-117-120A (Requirement). Those actions are inspection and any corrective work described in that service bulletin.\n- For helicopters with more than 1200 hours total time in service, an initial inspection must be done in accordance with paragraphs 9.(1) and 9.(3) of KSB-117-120A within 50 hours time in service after 5 November 1998, unless that inspection has already been done to the earlier bulletin KSB-117-120 or -120A (Compliance).\n- Following the initial inspection the other compliance intervals and tasks are as set out in the requirement document with an effective date of 5 November 1998 (Compliance).\n- Installing Kawasaki Service Bulletin KSB-117-121 (dated 19 June 1997) counts as terminating action for this AD (Note / terminating action).\n- The AD is issued under the Civil Aviation Regulations authority and is legally binding on operators of affected helicopters (pursuant to subregulation 39.1(1) CAR 1998 as stated in the preamble).\n\n**Who is affected**\n\n- Owners and operators of the listed Kawasaki BK117 helicopter models that have not incorporated Service Bulletin KSB-117-121. Maintenance organisations that perform inspections and modifications on those helicopters are also affected.\n\n**Why it matters (official rationale and practical effects)**\n\n- Officially, the AD exists to prevent failure of the engine mount sidewards link caused by excessive wear of the tail cone side lug bore (Background). Mechanically, that means aircraft operators must inspect and, if required by the bulletin, repair or replace worn components to prevent a structural failure between the engine mount and airframe.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: the helicopter owner/operator pays for inspections, any repairs, parts and labour, and for incorporation of Service Bulletin KSB-117-121 if they choose the terminating action.\n- Who decides: the Civil Aviation Safety Authority (CASA) delegate issued the AD; compliance timing and methods are determined by the instruction in Kawasaki Service Bulletin KSB-117-120A and by the operator/maintenance organisation executing that bulletin.\n- Behaviour change: affected operators must schedule and perform inspections per the service bulletin and the AD timetable; operators may choose to incorporate KSB-117-121 to remove recurring inspection obligations (terminating action).\n\n**Costs, incentives and trade-offs (mechanical analysis)**\n\n- Direct costs: inspections and any corrective maintenance incur technician hours and possible replacement parts; aircraft may be grounded for the work, imposing opportunity cost (lost flight hours/revenue).\n- Incentive structure: by naming KSB-117-121 as terminating action, the AD creates a clear financial trade-off — pay once to incorporate the terminating modification, or continue periodic inspections and potential repeated repairs. This concentrates a clear benefit (ending recurring inspections) for those who can afford the modification.\n- Compliance burden: the AD is specific about when the initial inspection must occur for aircraft >1200 hours TIS (within 50 hours after 5-Nov-1998) and otherwise defers to the service bulletin schedule; operators must track hours and ensure timely action to remain airworthy.\n- Implementation risk: effective compliance depends on access to the Kawasaki service bulletins, qualified maintenance personnel, and parts availability. Delay or inadequate inspections increase the risk the unsafe condition remains uncorrected.\n\n**Other procedural notes**\n\n- The AD cross-references a Japanese authority AD (JCAB AD TCD-4358A-98) and Kawasaki service documents; these references guide the technical method but do not change the legal requirement that the operator comply with the CASA AD sections cited.\n- Amendment 2 only added a specific note making KSB-117-121 terminating action and did not change inspection requirements or compliance times (Background / Amendment notes).\n\n(References: Applicability, Requirement, Compliance, Note and Background paragraphs of AD/JBK 117/8 Amdt 2.)"},"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":3,"scope_assessment":{"changed":false,"description":"This amendment is purely technical and clarifying. The original 1998 AD addressed engine mount wear safety. Amendment 1 expanded requirements with additional inspections. Amendment 2 adds only a clarifying note about terminating action without changing substantive requirements or compliance obligations. The scope remains tightly focused on the original safety issue."},"complexity_factors":["Multiple cross-references to external documents (Kawasaki Service Bulletins KSB-117-120, KSB-117-120A, KSB-117-121, and JCAB AD TCD-4358A-98)","Layered applicability criteria (specific helicopter models plus exclusion for those with KSB-117-121 incorporated)","Tiered compliance deadlines based on flight hours accumulated (1200 hours threshold)","Nested effective dates (original 1998, Amendment 1 unspecified, Amendment 2 effective 3 October 2002)","Conditional terminating action provision (compliance with KSB-117-121 ends the obligation)"],"plain_english_summary":"This CASA safety notice (Amendment 2) replaces an earlier notice and requires owners/operators of certain Kawasaki BK117 models (unless factory-modified by SB KSB-117-121) to inspect the engine mount sidewards link per manufacturer Service Bulletin KSB-117-120A, checking for wear at the tail cone side lug bore. \n\nIt matters because worn links can allow engine shift or detachment in flight; installing the factory modification is terminating action. The notice took effect 3 October 2002."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jbk-117-8-amdt-2-engine-mount-sidewards-link","history":"/api/acts/ad-jbk-117-8-amdt-2-engine-mount-sidewards-link/history","analysis":"/api/acts/ad-jbk-117-8-amdt-2-engine-mount-sidewards-link/analysis","conflicts":"/api/acts/ad-jbk-117-8-amdt-2-engine-mount-sidewards-link/conflicts","importantCases":"/api/acts/ad-jbk-117-8-amdt-2-engine-mount-sidewards-link/important-cases","documents":"/api/acts/ad-jbk-117-8-amdt-2-engine-mount-sidewards-link/documents"}}