{"id":"F2006B10176","name":"AD/GAF-N22/29 - Horizontal Stabiliser - Weather Proofing","slug":"ad-gaf-n22-29-horizontal-stabiliser-weather-proofing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55820,"registerId":"commonwealth-F2006B10176-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/29 - Horizontal Stabiliser - Weather Proofing","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-N22/29 Horizontal Stabiliser - Weather Proofing 11/79\n\nApplicability: All models N22, N22B and N24 referenced in SB No. NMD 55-7. Document:  Nomad SB No. NMD-55-7.\n\nCompliance: As detailed in the requirement document.\n\n \n\nBackground: It has been found that water can be ingested and stored in the horizontal stabiliser.\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":3,"scope_assessment":{"changed":false,"description":"The AD text provides applicability (all models N22, N22B and N24 referenced in SB No. NMD 55-7) and makes the service bulletin the requirement document (Applicability; Document; Compliance). The AD does not indicate any change to that applicability or scope from an earlier intent within the text provided."},"complexity_factors":["Reference to an external technical document (Nomad SB NMD-55-7) for all technical and compliance detail (Document; Compliance) increases implementation complexity because the AD itself contains no step‑by‑step instructions.","Broad applicability across multiple models (N22, N22B, N24) requires operators to check model‑specific applicability in the service bulletin (Applicability).","Absence in the AD of explicit timeframes, cost estimates or alternative compliance routes means additional procedural steps are required to determine obligations (Compliance).","Regulatory formality: the AD is issued under Civil Aviation Safety Authority procedures, so there is a formal legal obligation to comply once the AD is in force (header: COMMONWEALTH OF AUSTRALIA ... CIVIL AVIATION SAFETY AUTHORITY)."],"plain_english_summary":"This AD, issued by the Civil Aviation Safety Authority, makes compliance with Nomad Service Bulletin NMD‑55‑7 mandatory: owners/operators and maintenance organisations of GAF Nomad N22, N22B and N24 aircraft must carry out weather‑proofing work on the horizontal stabiliser to address water ingress. The directive shifts the SB’s previously voluntary tasks into compulsory action, with affected operators bearing the cost and relying on the service bulletin for technical detail and deadlines."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive from 1979 (indicated by '11/79' in the title) addressing a specific maintenance defect. It has not expanded beyond its original purpose of mandating weatherproofing repairs for the horizontal stabiliser of GAF Nomad aircraft."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section — uses only common aviation terminology","No conditional logic or nested exceptions","Single, straightforward compliance requirement (follow the referenced service bulletin)","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Clear, unambiguous applicability statement (specific aircraft models only)"],"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) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific GAF aircraft (the N22, N22B, and N24 \"Nomad\" models) to fix a weatherproofing problem with the horizontal stabiliser (the small wing at the tail of the plane that keeps the aircraft level).\n\n**The safety issue:** Water was getting into and collecting inside the horizontal stabiliser. This is dangerous because trapped water can cause corrosion (rust), add unexpected weight, or freeze at altitude — all of which could compromise the aircraft's structural integrity and control.\n\n**Who must comply:** Anyone operating the affected GAF Nomad aircraft models listed in Service Bulletin NMD-55-7.\n\n**What they must do:** Follow the specific repair instructions detailed in the manufacturer's Service Bulletin No. NMD-55-7.\n\n**Why it matters:** This is a **mandatory** safety fix. Non-compliance means the aircraft cannot legally fly in Australian airspace. Airworthiness Directives exist to prevent accidents by forcing prompt correction of known design or maintenance defects."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gaf-n22-29-horizontal-stabiliser-weather-proofing","history":"/api/acts/ad-gaf-n22-29-horizontal-stabiliser-weather-proofing/history","analysis":"/api/acts/ad-gaf-n22-29-horizontal-stabiliser-weather-proofing/analysis","conflicts":"/api/acts/ad-gaf-n22-29-horizontal-stabiliser-weather-proofing/conflicts","importantCases":"/api/acts/ad-gaf-n22-29-horizontal-stabiliser-weather-proofing/important-cases","documents":"/api/acts/ad-gaf-n22-29-horizontal-stabiliser-weather-proofing/documents"}}