{"id":"F2006B04608","name":"AD/BELL 222/17 - Drive Train Overheat Temperature Indicators","slug":"ad-bell-222-17-drive-train-overheat-temperature-indicators","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44360,"registerId":"commonwealth-F2006B04608-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 222/17 - Drive Train Overheat Temperature Indicators","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)  \nBell Helicopter Textron Canada (BHTC) 222 Series Helicopters\n\nAD/BELL 222/17 Drive Train Overheat Temperature Indicators 6/94\n\nApplicability: Models 222, 222B and 222U, all serial numbers.\n\nRequirement: On all appropriate grease lubricated couplings, replace the zinc chromate type stripes with TEMP-PLATES in accordance with Part I of Bell ASB 222-93-67 Rev.A or 222U-93-40 Rev.A, as applicable.\n\nNote: Canadian AD CF-94-06 BELL refers.\n\nCompliance: At the next scheduled lubrication interval after 26 May 1994, and prior to installation of replacement couplings and/or driveshaft assemblies.\n\nBackground: Following an accident with a Bell 212 it was determined that the colour change in the chromate based primers applied to couplings, was not sufficiently distinct to warn of an overheated condition and subsequent impending failure.\n\nFederal Register of Legislative Instruments F2006B04608","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect identified through accident investigation. The scope remains precisely limited to the identified safety issue with temperature indication on drive train couplings."},"complexity_factors":["Single, specific technical requirement (replace one component with another)","Only 3 defined models in applicability","Clear compliance deadline with simple alternative timing","No nested exceptions or conditional logic","Short document (approximately 150 words)","Single cross-reference to Canadian AD for context only"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order for aircraft. It applies to **Bell 222 series helicopters** (models 222, 222B, and 222U).\n\n**What it does:**\n- Requires helicopter operators to replace old **zinc chromate temperature indicator stripes** on grease-lubricated couplings with new **TEMP-PLATES** (special temperature-sensitive plates that show when parts have overheated).\n\n**Why it matters:**\n- After a Bell 212 helicopter accident, investigators found the old colour-changing paint wasn't clear enough to warn pilots when drive train parts were dangerously hot. If you can't see overheating, the coupling can fail catastrophically — potentially causing the helicopter to crash.\n\n**Who must comply:**\n- Anyone operating these specific Bell helicopter models.\n\n**When:**\n- By the next scheduled lubrication after 26 May 1994, or before installing any replacement parts.\n\n**The bottom line:** This is a straightforward safety fix — swapping out a bad warning system for a better one to prevent mechanical failures."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive, as supplied, sets a narrowly defined technical change for Bell 222 series helicopters: replace zinc chromate colour stripes with TEMP-PLATES on appropriate grease-lubricated couplings, at the next scheduled lubrication after 26 May 1994 and before installing replacement couplings/driveshaft assemblies (Applicability; Requirement; Compliance). The source text provides no evidence that the scope has been broadened or narrowed from an earlier intent within this instrument; therefore no change in scope is identifiable from the supplied text."},"complexity_factors":["Narrow technical scope limited to specific helicopter models and a specific component (Applicability; Requirement).","Action is prescriptive and simple: replacing chromate stripes with TEMP-PLATES following a Bell ASB (Requirement).","Compliance timing is tied to scheduled lubrication intervals rather than immediate grounding, reducing scheduling disruption but requiring coordination (Compliance).","Reliance on external documents (Bell ASBs and a referenced Canadian AD) adds an administrative step to obtain and follow those instructions (Requirement; Note).","Interpretive ambiguity in the phrase \"appropriate grease lubricated couplings\" may require judgement to identify affected parts (Requirement)."],"plain_english_summary":"This AD requires operators of Bell 222-series helicopters to replace zinc‑chromate colour‑stripe overheat indicators on grease‑lubricated couplings with TEMP‑PLATES per the cited Bell Alert Service Bulletin, at the next scheduled lubrication after 26 May 1994 and before installing replacement couplings/driveshafts. It responds to findings that the chromate stripes failed to show overheating clearly; operators/maintenance organisations bear costs, must follow the ASB, and record compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-222-17-drive-train-overheat-temperature-indicators","history":"/api/acts/ad-bell-222-17-drive-train-overheat-temperature-indicators/history","analysis":"/api/acts/ad-bell-222-17-drive-train-overheat-temperature-indicators/analysis","conflicts":"/api/acts/ad-bell-222-17-drive-train-overheat-temperature-indicators/conflicts","importantCases":"/api/acts/ad-bell-222-17-drive-train-overheat-temperature-indicators/important-cases","documents":"/api/acts/ad-bell-222-17-drive-train-overheat-temperature-indicators/documents"}}