{"id":"F2006B10171","name":"AD/GAF-N22/24 - Audio System Modification","slug":"ad-gaf-n22-24-audio-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55809,"registerId":"commonwealth-F2006B10171-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/24 - Audio System Modification","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 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  GAF N22 and N24 Series Aeroplanes\n\n \n\nAD/GAF-N22/24 Audio System Modification 11/78\n\nApplicability: All N22 and N22B aircraft fitted with Customer option G50 and not modified to Nomad Mod. N97 standard.\n\n \n\nDocument: GAF SB NMD-23-1 or an alternative modification which has been approved by the Secretary.\n\n \n\nCompliance: Within 100 hours time in service after 30 November 1978.\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\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive from 1978 with a narrow, specific scope (audio system modification for specific aircraft models). It has not expanded beyond its original purpose."},"complexity_factors":["Very short document (under 150 words)","Only 2 defined/applicable terms (Customer option G50, Nomad Mod. N97)","Single compliance requirement with clear deadline","No cross-references to other legislation or regulations","No conditional logic or nested exceptions","Straightforward applicability test (model + configuration + exclusion)"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) requiring specific repairs or modifications to aircraft.\n\n**What it does:** This AD applies to certain GAF Nomad aircraft (models N22 and N22B) that were built with a specific audio system option (\"Customer option G50\") and have not yet been upgraded to a newer standard (\"Nomad Mod. N97\"). It requires owners/operators to modify the aircraft's audio system by following the manufacturer's Service Bulletin NMD-23-1, or by using an alternative modification that has been approved by the Secretary (the government official responsible for aviation safety at the time).\n\n**Who it affects:** Owners and operators of GAF N22 and N22B Nomad aircraft with the specified audio system configuration.\n\n**Why it matters:** The modification addresses a safety issue with the audio system. The directive is mandatory — failure to comply makes the aircraft unairworthy (illegal to fly). Operators had a deadline: complete the work within 100 hours of flight time after 30 November 1978."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument sets a targeted, time-limited requirement for an audio-system modification for a specific set of aircraft models and configurations. The text supplied does not indicate any expansion or narrowing of that scope beyond the stated applicability (N22 and N22B with Customer option G50 and not modified to Nomad Mod. N97), the referenced document, and the compliance deadline; therefore there is no evidence in the supplied text that the scope has changed from the original requirement."},"complexity_factors":["Narrow, well-defined applicability (only N22 and N22B aircraft with Customer option G50 not modified to Nomad Mod. N97) (Applicability)","Single referenced technical document governs the modification (GAF SB NMD-23-1) with an explicit alternative pathway that requires Secretary approval (Document)","Short, fixed compliance window creates scheduling pressure but is straightforward to verify (100 hours after 30 Nov 1978) (Compliance)","Limited textual detail about technical steps, enforcement, or allowed maintenance providers increases reliance on the referenced document and external approvals (Document)","Secretary’s approval power for alternatives introduces a discrete administrative discretion point (Document)"],"plain_english_summary":"What this instrument does\n\n- Requires a particular audio-system modification for a narrow set of aircraft. The modification to be carried out is identified by the document GAF SB NMD-23-1, or an alternative modification if that alternative has first been approved by the Secretary. (Document)\n\nWho is affected\n\n- Owners/operators of GAF N22 and N22B aeroplanes that have Customer option G50 and that have not already been modified to Nomad Mod. N97. (Applicability)\n\nWhat actions are required and when\n\n- The affected aircraft must be modified to the standard specified in the referenced document within 100 hours time in service after 30 November 1978. That is the compliance deadline set by the instrument. (Compliance)\n\nWhy it matters (official claim and how that translates mechanically)\n\n- The instrument is an airworthiness directive that imposes a mandatory change to the aircraft audio system for the listed models. The document itself does not state a detailed technical rationale in the text provided, but by its form as an airworthiness directive it imposes a safety-related modification requirement. That requirement creates a short-window operational constraint, a technical-work obligation to be performed to the standard in GAF SB NMD-23-1 (or an approved alternative), and a decision point for the Secretary about whether any alternative modification will be permitted. (Applicability; Document; Compliance)\n\nWho pays, who decides, and how behaviour changes\n\n- Who pays: owners/operators of the affected aircraft pay for carrying out the modification and any associated downtime and parts. (Applicability; Compliance)\n- Who decides: the Secretary has the authority to approve an alternative modification to the one specified. The instrument therefore gives the Secretary discrete approval discretion. (Document)\n- Behaviour change: operators must schedule and perform the specified modification within the stated 100-hour window or comply with an approved alternative.\n\nPractical trade-offs, costs and implementation risks\n\n- Direct costs: the owner/operator bears the monetary cost of the modification and associated labour and parts; the instrument does not specify funding or compensation. (Applicability; Compliance)\n- Opportunity cost: aircraft will be temporarily unavailable while the modification is carried out; the compliance window (100 hours after 30 November 1978) concentrates that downtime into a short period. (Compliance)\n- Compliance burden: the technical work must follow the specification in GAF SB NMD-23-1 unless an alternative is approved by the Secretary; operators must obtain and apply the referenced document and ensure the modification meets its requirements. (Document)\n- Bureaucratic discretion and timing risk: the Secretary’s approval is required for any alternative modification, creating a single-point approval process; delays or conditions attached to approval can change operators’ options. (Document)\n- Effects on maintenance market: the directive creates demand for the specific modification work and any approved alternatives. The text does not prescribe who may perform the work but requires adherence to the cited technical document, which may practically concentrate business with technicians or organisations able to meet those technical specifications. (Document)\n\nConstraints and omissions in the instrument text\n\n- The instrument prescribes what to do, to which aircraft, and by when, but it does not set out the technical steps, cost estimates, enforcement mechanism or penalties in the text provided. The only technical guidance referenced is the external document GAF SB NMD-23-1 or a Secretary-approved alternative. (Document; Compliance)\n\nSource citations: Applicability; Document; Compliance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gaf-n22-24-audio-system-modification","history":"/api/acts/ad-gaf-n22-24-audio-system-modification/history","analysis":"/api/acts/ad-gaf-n22-24-audio-system-modification/analysis","conflicts":"/api/acts/ad-gaf-n22-24-audio-system-modification/conflicts","importantCases":"/api/acts/ad-gaf-n22-24-audio-system-modification/important-cases","documents":"/api/acts/ad-gaf-n22-24-audio-system-modification/documents"}}