{"id":"F2006B10825","name":"AD/INST/23 Amdt 1 - Edo-Aire Mitchell NSD-360 Compass System - Addition of Nav Flag Adapter","slug":"ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56303,"registerId":"commonwealth-F2006B10825-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/INST/23 Amdt 1 - Edo-Aire Mitchell NSD-360 Compass System - Addition of Nav Flag Adapter","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nInstruments and Automatic Pilots\n\nAD/INST/23\n\nAmdt 1\n\n  \n\nEdo-Aire Mitchell NSD-360 Compass System \\- Addition of Nav Flag Adapter\n\n  \n1/78\n\nApplicability: NSD-360 Compass Systems using VOR/Localiser Converters other than Edo-Aire Mitchell types AK423, IC707 or IC707-1, and using navigation instruments P/N 52D136- 0020, 52D136-0120, 52D136-0220, 52D136-1020, 52D136-1120, 52D136-\n\n1220, 52D137-1020, 52D137-1120, 52D137-1220.\n\nDocument: 1. Edo-Aire Mitchell SB No. MB-13; or\n\n2. Piper SB No. 565, 566 or 600-63; or\n\n3. Aircraft Manufacturer SBs which refer to Edo-Aire Mitchell SB No. MB-13. Compliance: Within 100 hours time in service after 31 January 1978.\n\nNote: Compliance with previous issue of this Directive, satisfies compliance with this issue.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The amendment appears to maintain the original scope — adding a Nav Flag Adapter to the NSD-360 compass system. The note confirming that compliance with the previous issue satisfies this issue suggests this is a minor technical update or clarification rather than a scope expansion. The applicability criteria and compliance requirements remain tightly focused on the original safety issue."},"complexity_factors":["Single, specific technical modification required","Only 6 defined part numbers for navigation instruments in applicability section","Clear compliance pathway with 3 alternative document references","Simple time-based compliance deadline (100 hours after fixed date)","No nested exceptions or conditional logic — straightforward applicability test","Single note clarifying grandfathering of previous compliance","Highly targeted scope: one specific compass system with specific converter exclusions"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) that requires aircraft owners and operators to fix a specific safety problem.\n\n**What it does:** It orders modifications to a particular aircraft compass system (the **Edo-Aire Mitchell NSD-360**) to add a \"Nav Flag Adapter.\" This adapter is a safety device that shows pilots when navigation signals are unreliable or invalid — basically a warning flag that says \"don't trust this reading.\"\n\n**Who it affects:** Owners and operators of aircraft using the NSD-360 compass system **with specific navigation instruments** (listed by part numbers like 52D136-0020, etc.) **AND** using VOR/Localiser converters (devices that translate navigation signals) that are **not** the Edo-Aire Mitchell types AK423, IC707, or IC707-1.\n\n**What must be done:** Aircraft operators must install the Nav Flag Adapter by following one of these technical documents:\n- Edo-Aire Mitchell Service Bulletin MB-13, **or**\n- Piper Service Bulletins 565, 566, or 600-63, **or**\n- Their aircraft manufacturer's service bulletin that references Edo-Aire Mitchell SB MB-13\n\n**When:** Within 100 hours of flight time after 31 January 1978.\n\n**Why it matters:** Without this adapter, pilots might not know when navigation signals are faulty, potentially leading to dangerous navigation errors. The \"nav flag\" is a critical safety indicator.\n\n**Good news for compliant operators:** If you already followed the previous version of this directive, you're still compliant — you don't need to do it again."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD amends the NSD-360 requirement to include the navigation-flag adapter and specifies how to comply (Document and Compliance). The AD’s own Note states that compliance with the previous issue satisfies this issue, indicating no expansion of obligations for operators who already complied and therefore no substantive change in the population required to comply (Note)."},"complexity_factors":["Technical specificity of applicability (specific converter exclusions and multiple navigation instrument part numbers).","Cross-referencing of multiple external service bulletins rather than including installation instructions in the AD.","Short, fixed compliance window tied to hours-in-service after a historical date (requires operational tracking).","Administrative step of confirming applicability per part numbers and converter types.","Simple amendment form with limited procedural variation (lower legal complexity despite technical specifics)."],"plain_english_summary":"This AD requires operators to install a navigation‑flag adapter on aircraft with Edo‑Aire Mitchell NSD‑360 compass systems that use VOR/localiser converters other than AK423, IC707 or IC707‑1 and the listed instrument part numbers, by following one of the referenced service bulletins (Edo‑Aire or Piper/manufacturer SBs).  \n\nAffected owners/operators must obtain the applicable SB, pay for and fit the adapter within 100 hours TIS after 31 Jan 1978; prior compliance under the earlier issue is accepted."}},"importantCases":[],"_links":{"self":"/api/acts/ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter","history":"/api/acts/ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter/history","analysis":"/api/acts/ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter/analysis","conflicts":"/api/acts/ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter/conflicts","importantCases":"/api/acts/ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter/important-cases","documents":"/api/acts/ad-inst-23-amdt-1-edo-aire-mitchell-nsd-360-compass-system-addition-of-nav-flag-adapter/documents"}}