{"id":"F2006B06533","name":"AD/RAD/78 - Becker AR4201 VHF Transceiver","slug":"ad-rad-78-becker-ar4201-vhf-transceiver","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48194,"registerId":"commonwealth-F2006B06533-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 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\nRadio Communication and Navigation Equipment","sortOrder":0},{"sectionNumber":"AD/RAD/78 Becker AR4201 VHF Transceiver ","sectionType":"part","heading":"AD/RAD/78 Becker AR4201 VHF Transceiver 10/2003","content":"# AD/RAD/78 Becker AR4201 VHF Transceiver 10/2003\n\nApplicability: Becker Flugfunkwerk GmbH AR4201-( ) series Very High Frequency transceivers with serial numbers (S/N) 150 up to and including 9499.\n\nRequirement: 1. Inspect the Becker AR4201 transceiver to determine the S/N.\n\n    2. If, as a result of the Requirement 1 inspection, the S/N is determined to be in the range 150 to 9499 inclusive, amend the Aircraft Flight Manual (AFM) ‘Limitations Section’ by including the following limitation:\n\n“USAGE OF BECKER COMM EQUIPMENT 4201 IS RESTRICTED TO VFR OPERTIONS”\n\nThis is to be accomplished by inserting a copy of this Directive into the AFM.\n\n    3. Modify the transceiver in accordance with Becker Flugfunkwerk GmbH Service Bulletin AR4201-01/03 dated 22 July 2003.\n\n    4. Remove the Requirement 2 AFM amendment.\n\n    5. AR4201-( ) series transceivers with S/N 150 up to and including 9499 may not be installed on any aeroplane as a replacement part or new installation unless modified in accordance with Requirement 3.\n\nNote: LBA AD 2003-234 refers.\n\nCompliance: For Requirement 1 and 2 \\- Within ten days after the effective date of this Directive.\n\nFor Requirement 3 \\- At the discretion of the Certificate of Registration holder. For Requirement 4 - Following compliance with Requirement 3.\n\nFor Requirement 5 \\- As of the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 2 October 2003.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard product-specific Airworthiness Directive addressing a known safety defect in a particular avionics component. The scope remains tightly focused on the Becker AR4201 transceiver serial numbers 150-9499 throughout, with no expansion into broader operational or regulatory matters."},"complexity_factors":["Very short document (approximately 300 words)","Only 5 operational requirements with clear sequential numbering","Single defined term (S/N for serial number) in common usage","No cross-references to other legislation beyond a single note referencing a German aviation authority document (LBA AD 2003-234)","Simple conditional logic: 'If S/N in range X-Y, then do Z'","Clear compliance dates with no nested exceptions or alternative compliance paths","Single applicability criterion (specific serial number range of specific product)"],"plain_english_summary":"This CASA Airworthiness Directive orders owners/operators to check Becker AR4201 VHF transceiver serials 150–9499 and, if affected, restrict the radio’s use to VFR only until it’s modified per the manufacturer’s service bulletin. It also bans installing unmodified units. It affects aircraft owners, pilots and maintenance engineers and matters because the defect makes the radios unsafe for instrument (IFR) operations, prompting an immediate safety restriction and later mandatory repair."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope aligns with its stated safety purpose: it targets a defined set of AR4201 units (S/N 150–9499), imposes a temporary AFM operational limitation, mandates a manufacturer-specified modification, and bars use of unmodified units. The AD does not expand or narrow that population beyond the serial-number criterion and the stated corrective steps."},"complexity_factors":["Narrow equipment scope defined by serial-number range (S/N 150–9499) — applicability limits affected population.","Mixed compliance timing: Requirement 1 and AFM insertion (Requirement 2) due within 10 days of effective date; modification (Requirement 3) timing left to holder's discretion (Compliance: Requirement 3) — creates variable scheduling and operational impact.","Temporary operational restriction requires an AFM amendment (Requirement 2) and later removal after modification (Requirement 4) — administrative burden on operators and record-keeping.","Mandatory physical retrofit per manufacturer Service Bulletin AR4201-01/03 dated 22 July 2003 (Requirement 3) — cost and maintenance resources fall to aircraft owners/operators.","Prohibition on installing unmodified units as replacement or new installs effective immediately (Requirement 5) — affects maintenance and parts procurement.","Cross-reference to foreign AD (LBA AD 2003-234) and reliance on manufacturer service instructions — introduces dependence on external documents for technical compliance."],"plain_english_summary":"This Airworthiness Directive covers Becker AR4201 VHF transceivers with serial numbers 150–9499. It requires operators to inspect serial numbers, insert a temporary Aircraft Flight Manual (AFM) limitation restricting the unit to VFR, have the unit modified per Becker Service Bulletin AR4201-01/03, then remove the AFM restriction once modified; unmodified units may not be installed after the directive takes effect. The rule addresses an identified unsafe condition by forcing inspection and retrofit, with short-term operational limits and a retrofit requirement."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-rad-78-becker-ar4201-vhf-transceiver","history":"/api/acts/ad-rad-78-becker-ar4201-vhf-transceiver/history","analysis":"/api/acts/ad-rad-78-becker-ar4201-vhf-transceiver/analysis","conflicts":"/api/acts/ad-rad-78-becker-ar4201-vhf-transceiver/conflicts","importantCases":"/api/acts/ad-rad-78-becker-ar4201-vhf-transceiver/important-cases","documents":"/api/acts/ad-rad-78-becker-ar4201-vhf-transceiver/documents"}}