{"id":"F2006B06501","name":"AD/RAD/44 - Collins DME-42 Distance Measuring Equipment","slug":"ad-rad-44-collins-dme-42-distance-measuring-equipment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48063,"registerId":"commonwealth-F2006B06501-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/RAD/44 - Collins DME-42 Distance Measuring Equipment","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Radio Communication and Navigation Equipment\n\n \n\nAD/RAD/44 Collins DME-42 Distance Measuring Equipment 3/87\n\nApplicability: Collins Model DME-42 part number 622-6263-002 Distance Measuring Equipment. Requirement:               Modify in accordance with Rockwell Collins Service Bulletin DME 42 No. 6, dated\n\n15 October 1986.\n\n \n\nNote: FAA AD 86-22-10 refers.\n\n \n\nCompliance: If fitted to an aircraft - within 25 hours time in service after 12 March 1987 or prior to 12 May 1987, whichever occurs first. Otherwise - before fitment to an aircraft.\n\n \n\nBackground: The software incorporated in -002 units can cause erroneous display of DME information because of tuning errors.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope remains the same as stated in the source text: it targets only Collins Model DME-42 units with part number 622-6263-002 and mandates a specific modification per Rockwell Collins Service Bulletin DME 42 No. 6. The instrument does not expand to other models, alternative remedies, or wider operational rules in the text provided. (Applicability / Requirement)"},"complexity_factors":["Narrow applicability: applies to a single model and part number (Collins Model DME-42 part 622-6263-002). (Applicability)","Single prescriptive remedy: modification must follow a single service bulletin (Rockwell Collins Service Bulletin DME 42 No. 6). (Requirement)","Short, fixed compliance window for units already fitted (25 hours TIS after 12 March 1987 or before 12 May 1987). (Compliance)","Obligation before fitment: units not yet fitted must be modified before installation, which affects procurement and installation workflows. (Compliance)","Dependence on external technical document (the service bulletin) for implementation details creates operational dependencies (Requirement)","Reference to FAA AD introduces potential cross-jurisdictional alignment considerations. (Note)"],"plain_english_summary":"What this instrument does (mechanically)\n\n- Requires a specific retrofit to Collins Model DME-42 distance measuring equipment, part number 622-6263-002. (Requirement)\n- The retrofit must be carried out by following Rockwell Collins Service Bulletin DME 42 No. 6, dated 15 October 1986. (Requirement)\n- Sets mandatory timing: if a unit is already fitted to an aircraft it must be modified within 25 hours time in service after 12 March 1987 or before 12 May 1987, whichever comes first; units not yet fitted must be modified before being fitted to any aircraft. (Compliance)\n- Notes a related FAA airworthiness directive. (Note)\n\nOfficial stated reason\n\n- The instrument states the software in the -002 units can cause erroneous display of DME information because of tuning errors. (Background)\n- The modification is presented as a corrective measure to address those software/tuning errors. (Background / Requirement)\n\nWho this affects and who pays\n\n- Aircraft operators and owners who have Collins DME-42 units of part number 622-6263-002 fitted to, or intended for fitting to, their aircraft are directly affected. (Applicability / Compliance)\n- The operator/owner must arrange and bear the cost and scheduling of the modification to comply with this directive because compliance is tied to the unit being fitted to the aircraft or fitted in future. (Requirement / Compliance)\n\nWhat decisions this instrument forces and what behaviour changes\n\n- Operators must decide whether to schedule the mandated modification promptly to meet the 25-hour / date deadline or refrain from fitting affected units until they are modified. (Compliance)\n- Maintenance providers must perform the modification according to the specified Rockwell Collins service bulletin. (Requirement)\n- Some operators may choose to remove or replace affected units rather than modifying them; others will accept downtime to carry out the prescribed update. (Compliance / Requirement)\n\nCosts, incentives and trade-offs (mechanics, not judgments)\n\n- Direct costs: parts, labour and aircraft downtime to perform the modification according to the service bulletin. (Requirement)\n- Time constraint: the compliance window (25 hours TIS after 12 March 1987 or before 12 May 1987) concentrates demand for maintenance in a short period, which can increase scheduling pressure and short-term maintenance costs. (Compliance)\n- Opportunity cost: aircraft availability is reduced while units are modified; operators balance that against the legal requirement to comply. (Compliance)\n- Substitution effect: because unmodified -002 units must not be fitted, operators planning new installations must either perform the modification before fitment or select alternative equipment. (Compliance)\n\nImplementation risk and compliance burden\n\n- The directive relies on operators and maintenance organisations to obtain and correctly apply Rockwell Collins Service Bulletin DME 42 No. 6; incorrect or incomplete implementation would leave the underlying software/tuning issue unaddressed. (Requirement)\n- The AD references an FAA directive, so operators that operate internationally may need to consider corresponding foreign requirements when planning compliance. (Note)\n\nDiscretion and enforcement\n\n- The instrument prescribes the exact corrective action and specific timing; there is little regulatory discretion for alternative means of compliance in the text provided. (Requirement / Compliance)\n\nNet effect (mechanical summary)\n\n- Affected Collins DME-42 -002 units must be modified according to Rockwell Collins Service Bulletin DME 42 No. 6 within the stated time limits to address a software/tuning error that can cause erroneous DME displays. (Requirement / Background / Compliance)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific technical defect in a single aircraft component. It has not expanded beyond its original purpose of mandating a specific hardware/software modification."},"complexity_factors":["Extremely short document (under 200 words)","Only one defined term implicitly referenced (the part number)","Single, unambiguous compliance pathway with clear deadline structure","No cross-references to other legislation beyond a non-binding note about a related FAA directive","No conditional logic beyond the simple 'if fitted/not fitted' binary","No exceptions, exemptions, or nested provisions"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft equipment rather than cars.\n\n**What it does:** It requires owners and operators to fix a software bug in a specific navigation device — the **Collins DME-42 Distance Measuring Equipment** (part number 622-6263-002). This device tells pilots how far they are from a ground-based navigation beacon.\n\n**The problem:** The software in these units can display **wrong distance information** due to \"tuning errors\" — basically, the device might show you're closer or further from a beacon than you actually are. That's dangerous when pilots rely on this data for navigation, especially in bad weather or busy airspace.\n\n**What must happen:**\n- **If already installed on an aircraft:** Fix it within 25 flight hours after 12 March 1987, or before 12 May 1987 — whichever comes first.\n- **If sitting in a warehouse:** Fix it before installing it on any aircraft.\n\n**The fix:** Follow the manufacturer's service bulletin (Rockwell Collins Service Bulletin DME 42 No. 6, dated 15 October 1986).\n\n**Who it affects:** Anyone operating an Australian-registered aircraft with this specific Collins DME-42 unit installed.\n\n**Why it matters:** Incorrect distance readings can lead to navigation errors, mid-air proximity issues, or controlled flight into terrain — all potentially fatal. This AD ensures the faulty software gets corrected before it causes an accident."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rad-44-collins-dme-42-distance-measuring-equipment","history":"/api/acts/ad-rad-44-collins-dme-42-distance-measuring-equipment/history","analysis":"/api/acts/ad-rad-44-collins-dme-42-distance-measuring-equipment/analysis","conflicts":"/api/acts/ad-rad-44-collins-dme-42-distance-measuring-equipment/conflicts","importantCases":"/api/acts/ad-rad-44-collins-dme-42-distance-measuring-equipment/important-cases","documents":"/api/acts/ad-rad-44-collins-dme-42-distance-measuring-equipment/documents"}}