{"id":"F2006B10159","name":"AD/GAF-N22/13 Amdt 1 - Fuel Crossfeed Selector Knob - Inspection and Replacement","slug":"ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55759,"registerId":"commonwealth-F2006B10159-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GAF-N22/13 Amdt 1 - Fuel Crossfeed Selector Knob - Inspection and Replacement","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-N22/13\n\nAmdt 1\n\n\nFuel Crossfeed Selector Knob - Inspection and Replacement\n\n\n8/77\n\n \n\nApplicability: All models N22 and N22B. Document:  1. GAF Alert SB No. N22.28.4’ and\n\n2. GAF SB No. N22.28.5.\n\n \n\nCompliance: For GAF Alert SB No. N22.28.4: Before further flight after 7 February 1977 and thereafter at intervals not exceeding 100 hours time in service until GAF SB No. N22.28.5 is incorporated.\n\n \n\nFor GAF SB No. N22.28.5: Before 1 November 1977.\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 narrow, targeted safety directive addressing a specific mechanical defect in specific aircraft models. It has not expanded beyond its original purpose of ensuring fuel selector knob integrity."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined compliance deadlines","No nested exceptions or conditional logic","Simple binary applicability (all N22 and N22B models)","References only 2 external technical documents (Service Bulletins)","Single mechanical issue addressed with straightforward inspection/replacement requirements"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of **GAF N22 and N22B aircraft** (small Australian-made planes, often used for agricultural work or training) to inspect and replace a specific part — the **fuel crossfeed selector knob**.\n\n**Why it matters:**\nThe fuel crossfeed system allows fuel to flow between tanks. If the selector knob fails, it could cause fuel starvation or incorrect fuel management, potentially leading to engine failure or loss of control.\n\n**Who must comply:**\nAnyone operating these specific GAF aircraft models.\n\n**What must be done:**\n- **Immediate inspection** (Alert SB N22.28.4): Check the knob before flying again after 7 February 1977, then re-check every 100 flight hours until the permanent fix is installed.\n- **Permanent replacement** (SB N22.28.5): Install the improved knob before 1 November 1977.\n\n**In short:** If you fly one of these planes, you had to keep checking that fuel knob regularly until you replaced it with a better version by November 1977."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This instrument is labelled an amendment (Amdt 1) and, within the text provided, imposes a two‑stage compliance approach: immediate and recurrent inspections under GAF Alert SB No. N22.28.4 until the incorporation of GAF SB No. N22.28.5, and a firm incorporation deadline of 1 November 1977 (Applicability; Compliance). Concretely, the amendment changes operational requirements for all N22 and N22B operators by adding a recurring 100‑hour inspection obligation until the replacement SB is incorporated and by setting a final date for that incorporation (Compliance)."},"complexity_factors":["Technical specificity: the requirement references two separate GAF service bulletins (N22.28.4 and N22.28.5) that contain the detailed inspection/replacement procedures (Applicability).","Dual compliance regime: an immediate and recurring inspection schedule applies until a separate bulletin is incorporated, plus a hard deadline for incorporation (Compliance).","Temporal constraints: multiple dated requirements (inspect before next flight after 7 Feb 1977; repeat every 100 hours; incorporate by 1 Nov 1977) create scheduling and record‑keeping demands (Compliance).","Scope limited to particular airframe models (N22 and N22B), so applicability is narrow but absolute for affected operators (Applicability).","Operational impact factors: parts availability, maintenance capacity and aircraft downtime affect ability to comply, although those operational details are outside the AD text (Compliance)."],"plain_english_summary":"What this instrument does (mechanics)\n\n- This is an airworthiness directive that requires inspections and replacement actions for the fuel crossfeed selector knob on certain aircraft. (Title)\n- It applies to all GAF N22 and N22B aeroplanes. (Applicability)\n- It requires operators to follow two GAF service bulletins: GAF Alert SB No. N22.28.4 and GAF SB No. N22.28.5. (Applicability)\n- Under GAF Alert SB No. N22.28.4, operators must inspect the selector knob before the next flight after 7 February 1977 and then repeat that inspection at intervals not exceeding 100 hours time in service, until GAF SB No. N22.28.5 has been incorporated into the aircraft. (Compliance)\n- Under GAF SB No. N22.28.5, operators must incorporate that bulletin (which provides the replacement action) before 1 November 1977. (Compliance)\n\nWho this affects and who pays\n\n- Aircraft owners and operators of GAF N22 and N22B models must ensure the inspections and the eventual incorporation of the replacement SB are carried out. (Applicability; Compliance)\n- The direct costs — labour for inspections, any parts and labour for replacement, and aircraft downtime for maintenance — will be borne by those owners/operators. (Compliance)\n\nWhy it matters (stated purpose and trade-offs)\n\n- The directive’s stated mechanical purpose is to inspect and, where required by the later service bulletin, replace the fuel crossfeed selector knob (see title and referenced SBs). That is the action the regulator requires. (Title; Applicability)\n- The regulator enforces an immediate inspection regime (first inspection before next flight after 7 Feb 1977) and an interim recurrent inspection frequency (every 100 hours) until the later bulletin is incorporated, and an absolute deadline (incorporation by 1 Nov 1977). Those are the concrete compliance levers used. (Compliance)\n\nCosts, incentives and implementation considerations\n\n- Who decides and performs the work: maintenance organisations or certificated engineers must perform the inspections and the replacement actions according to the referenced service bulletins; operators decide how to schedule the work to meet the mandated dates. (Applicability; Compliance)\n- Who pays: owners/operators pay for parts, labour and downtime. (Compliance)\n- Incentives: the rule creates an incentive to either perform the interim inspections repeatedly (every 100 hours) or to incorporate the permanent modification before repeated inspections accumulate; operators will weigh the cost of repeated inspections versus the cost and availability of parts and the downtime to incorporate the SB. (Compliance)\n- Compliance burden and opportunity cost: repeated 100‑hour inspections impose ongoing labour and scheduling costs until the SB N22.28.5 is incorporated; incorporation by the set date eliminates the need for further 100‑hour inspections under this AD but requires a one‑off investment of parts and labour. (Compliance)\n- Implementation risks: availability of replacement parts, access to appropriately rated maintenance personnel, and scheduling aircraft out of service could affect the ability to meet the prescribed dates. The AD does not specify alternative compliance methods or exemptions in the text provided. (Compliance)\n\nConcrete behaviour changes mandated\n\n- Immediate behaviour: inspect the fuel crossfeed selector knob before the next flight after 7 Feb 1977. (Compliance)\n- Short-term recurring behaviour: repeat inspections at intervals not exceeding 100 hours TIS until the replacement SB is incorporated. (Compliance)\n- Final behaviour change: incorporate GAF SB No. N22.28.5 by 1 Nov 1977, after which the interim inspection schedule ceases to apply. (Compliance)\n\nNotes on documentation and authority\n\n- The directive references two specific service bulletins as the technical means to carry out the inspection and replacement. Operators must follow those SBs to comply. (Applicability)\n- This instrument is issued as an amendment (Amdt 1) to AD/GAF-N22/13; the text sets the required dates and intervals as the compliance standard. (Title; Compliance)\n\nCitations: Applicability and Compliance paragraphs in the AD text."}},"importantCases":[],"_links":{"self":"/api/acts/ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement","history":"/api/acts/ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement/history","analysis":"/api/acts/ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement/important-cases","documents":"/api/acts/ad-gaf-n22-13-amdt-1-fuel-crossfeed-selector-knob-inspection-and-replacement/documents"}}