{"id":"F2006B11139","name":"AD/LEARJET/22 - Aft Engine Beam Pylon Bolts - Inspection","slug":"ad-learjet-22-aft-engine-beam-pylon-bolts-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56823,"registerId":"commonwealth-F2006B11139-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LEARJET/22 - Aft Engine Beam Pylon Bolts - Inspection","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)  Gates Learjet 24 & 25 Series Aeroplanes\n\n \n\nAD/LEARJET/22 Aft Engine Beam Pylon Bolts - Inspection 5/80\n\nApplicability: All model 23 S/Nos. 23-003 to 23-099;\n\n \n\nAll model 24 S/Nos. 24-100 to 24-357;\n\n \n\nAll model 25 S/Nos. 25-003 to 25-286 and 25-288.\n\n \n\nDocument: Gates Learjet SB 23/24/25-299. Compliance: As per requirement document.\n\nBackground: To ensure that the aft engine beam pylon bolts are secure and properly torqued.\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, targeted airworthiness directive focused on a specific mechanical inspection. It has not expanded beyond its original purpose of ensuring engine pylon bolt integrity on specified Learjet models."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 defined applicability criteria (specific aircraft models and serial numbers)","Single technical requirement referencing an external service bulletin","No nested exceptions or conditional logic","No cross-references to other legislation or regulations beyond the enabling Civil Aviation Regulations 1998","Straightforward imperative language ('Compliance: As per requirement document')"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Gates Learjet aircraft (models 23, 24, and 25 series) to inspect the **aft engine beam pylon bolts**.\n\n**What it does:**\n- Mandates an inspection of bolts that attach the engine pylon (the structure holding the engine to the wing) to the aft engine beam\n- Requires checking that these bolts are secure and tightened to the correct torque specification (tightness)\n\n**Who it affects:**\n- Owners and operators of specific Learjet aircraft with serial numbers listed in the applicability section (covering most Model 23, 24, and 25 aircraft)\n\n**Why it matters:**\n- Engine pylon bolts are critical structural components. If they fail or loosen, the engine could separate from the wing — a catastrophic failure\n- This directive ensures ongoing airworthiness and prevents potential accidents due to hardware failure\n\n**Compliance:**\n- Operators must follow the procedures in Gates Learjet Service Bulletin 23/24/25-299 to complete the inspection"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The provided AD text defines a limited, targeted requirement: inspect aft engine beam pylon bolts on the listed Learjet serial numbers and comply with Gates Learjet SB 23/24/25-299. The document does not indicate any change in scope from an earlier version or intent; the AD as provided is self-contained in its applicability and referrals."},"complexity_factors":["Narrow, specific applicability by model and serial number (Applicability) reduces breadth of affected parties.","Procedural detail is delegated to an external service bulletin (Gates Learjet SB 23/24/25-299), so the AD text is short but requires consulting another document (Document; Compliance).","The AD does not include operational intervals, acceptance criteria, or cost details in the text, creating a dependency on the service bulletin for implementation specifics (Compliance).","Issued under Civil Aviation Regulations Part 39, so legal enforceability is clear though enforcement/remedy details are not set out in the AD text (header; Compliance)."],"plain_english_summary":"This Airworthiness Directive mandates inspection and torque verification of aft engine beam pylon bolts on specified Gates Learjet 23/24/25 serial numbers by requiring compliance with Gates Learjet Service Bulletin 23/24/25-299. It affects owners, operators and their maintenance providers for those aircraft and matters because it enforces a manufacturer’s inspection to ensure bolts are secure and properly torqued, while delegating procedural detail and cost implications to the service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-learjet-22-aft-engine-beam-pylon-bolts-inspection","history":"/api/acts/ad-learjet-22-aft-engine-beam-pylon-bolts-inspection/history","analysis":"/api/acts/ad-learjet-22-aft-engine-beam-pylon-bolts-inspection/analysis","conflicts":"/api/acts/ad-learjet-22-aft-engine-beam-pylon-bolts-inspection/conflicts","importantCases":"/api/acts/ad-learjet-22-aft-engine-beam-pylon-bolts-inspection/important-cases","documents":"/api/acts/ad-learjet-22-aft-engine-beam-pylon-bolts-inspection/documents"}}