{"id":"F2006B10167","name":"AD/GAF-N22/20 Amdt 1 - Hot Air Check Valve - Inspection and Modification","slug":"ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55801,"registerId":"commonwealth-F2006B10167-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/20 Amdt 1 - Hot Air Check Valve - Inspection and 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-N22/20\n\nAmdt 1\n\n\nHot Air Check Valve - Inspection and Modification\n\n\n8/78\n\n \n\nApplicability: As detailed in GAF Alert SB AN22.74.1 Revision 1. Document:  GAF Alert SB AN22-74-1 Revision 1.\n\nCompliance: In accordance with the requirement document.\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\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"This instrument is labelled as Amendment 1 to AD/GAF-N22/20 and therefore modifies the earlier AD. The amended text makes compliance contingent on the actions in GAF Alert SB AN22-74-1 Revision 1 (see \"Applicability\" and \"Compliance\"). The AD text does not list the precise technical changes; those are contained in the referenced service bulletin and in the amendment history."},"complexity_factors":["The AD does not reproduce technical steps; it delegates all action detail to an external service bulletin (GAF Alert SB AN22-74-1 Revision 1), so understanding obligations requires consulting that document (see \"Applicability\" and \"Compliance\").","Technical nature of the required work (inspection and modification of a hot air check valve) typically requires qualified maintenance personnel and specialised parts/tools.","Potential operational impacts (aircraft downtime and scheduling) depend on the unspecified timing and scope in the referenced service bulletin.","Record-keeping and proof of compliance are implicit obligations under an AD but are not detailed in the AD text itself, adding administrative uncertainty.","The instrument is an amendment (Amdt 1), meaning changes were made relative to an original AD; compliance requires checking the amendment history and the specific revision cited."],"plain_english_summary":"This airworthiness directive mandates inspection and modification of the hot air check valve on GAF N22 and N24 series aeroplanes by requiring compliance with GAF Alert SB AN22-74-1 Revision 1. It applies to aircraft owners/operators and the maintenance organisations that must carry out the work.\n\nOperators pay for and schedule the work to remain airworthy and avoid enforcement; maintenance providers must follow the referenced service bulletin’s procedures to demonstrate compliance, creating workload and potential aircraft downtime."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive that has remained focused on its original purpose since 1978. The amendment (Amdt 1) appears to be a routine update rather than a scope expansion. The directive continues to address only the specific hot air check valve issue in GAF N22/N24 aircraft without creeping into broader operational or design requirements."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section — relies entirely on external referenced document (GAF Alert SB AN22-74-1)","No conditional logic or exceptions within the text itself","Single compliance pathway: 'In accordance with the requirement document'","Cross-reference to only one external technical document","No nested provisions or subsections"],"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 owners and operators of specific aircraft to take action to fix a safety problem.\n\n**What it does:**\n- **Targets:** GAF N22 and N24 series aeroplanes (small Australian-made aircraft, often used for agricultural work and training)\n- **The problem:** Issues with the **hot air check valve** — a component that controls heated air flow in the aircraft's systems (likely related to cabin heating or carburettor anti-icing)\n- **Required action:** Owners must **inspect and modify** this valve following the exact instructions in **GAF Alert Service Bulletin AN22-74-1 Revision 1**\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains a GAF N22 or N24 aircraft\n- Licensed aircraft maintenance engineers working on these planes\n\n**Why it matters:**\n- **Safety-critical:** Faulty hot air valves can lead to overheating, fire risk, or loss of engine performance\n- **Legally binding:** Non-compliance grounds the aircraft — it cannot legally fly until the work is done\n- **Traceable:** The \"8/78\" indicates this requirement originated in August 1978; \"Amdt 1\" means this is an updated version of the original directive\n\n**Key point:** This isn't optional maintenance advice — it's a **compulsory safety fix** backed by federal aviation law."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification","history":"/api/acts/ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification/history","analysis":"/api/acts/ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification/analysis","conflicts":"/api/acts/ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification/important-cases","documents":"/api/acts/ad-gaf-n22-20-amdt-1-hot-air-check-valve-inspection-and-modification/documents"}}