{"id":"F2006B11060","name":"AD/LA-4/1 - Nose Landing Gear Drag Strut - Inspection","slug":"ad-la-4-1-nose-landing-gear-drag-strut-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56688,"registerId":"commonwealth-F2006B11060-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LA-4/1 - Nose Landing Gear Drag Strut - Inspection","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nConsolidated Aeronautics, Colonial and LA-4 Series Aeroplanes\n\nAD/LA-4/1 Nose Landing Gear Drag Strut \\- Inspection 8/65\n\nApplicability: All Lake LA-4 Series.\n\nRequirement: Inspect the bolt at the top of the nose landing gear drag strut at fuselage Station 12 5/8 to ensure that AN 5-16A bolt or an approved equivalent is installed and that the bolt head is on the right hand side of the aircraft. If an AN5-15A bolt is found installed it will be necessary to inspect the bolt holes in the drag strut and the supporting assembly for elongation and if worn rework in accordance with Lake Aircraft Division SL No. 11B dated February 22, 1965. All replacement bolts must be AN 5- 16A or AN 5-17A with the head on the right side of the aircraft.\n\nAN 5-17A is used when bushings are installed.\n\nCompliance: Before 30 September 1965.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to \"All Lake LA-4 Series\" and sets a focused inspection and corrective-action requirement for a particular bolt and assembly at fuselage Station 12 5/8. The text does not indicate any expansion or narrowing of applicability beyond that group or the stated mechanical elements; it prescribes specific replacement parts and references a service letter for rework, with a single compliance deadline (Applicability; Requirement; Compliance)."},"complexity_factors":["Technical specificity of required parts and fitment (AN 5-16A, AN 5-15A, AN 5-17A; bolt head orientation) increases technical precision but not procedural complexity (Requirement).","Single, spatially specific inspection location (fuselage Station 12 5/8) reduces breadth but requires physical access and knowledge of station numbering (Requirement).","Reference to an external rework document (Lake Aircraft Division SL No. 11B) requires obtaining and following a separate technical instruction, adding dependency on external material (Requirement).","The term \"approved equivalent\" introduces regulatory/maintenance discretion about acceptable substitutions, requiring a decision by an approving authority or maintenance certifier (Requirement).","A firm, time-limited compliance date creates scheduling pressure but makes the obligation one-off rather than ongoing (Compliance)."],"plain_english_summary":"This directive mandates a one‑time inspection of the nose‑gear drag‑strut bolt on Lake LA‑4 series aeroplanes to confirm the correct bolt type and head orientation, with required rework or replacement where wear or incorrect hardware is found. Compliance is mandatory by the specified deadline.\n\nIt affects aircraft owners/operators (who pay for inspections/repairs), maintenance organisations and mechanics (who perform the work), and parts suppliers (who may provide specified bolts and bushings)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific safety-of-flight issue with a particular aircraft type. It has not expanded beyond its original purpose of ensuring correct bolt installation in the nose landing gear drag strut."},"complexity_factors":["Single, specific mechanical component addressed (one bolt location)","Clear binary compliance test (correct bolt type yes/no)","Simple conditional branch (if wrong bolt found → additional inspection required)","Only 2 defined bolt specifications referenced (AN 5-16A, AN 5-17A)","Single cross-reference to manufacturer service letter (SL No. 11B)","No nested exceptions or complex definitional sections","Length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's aviation safety regulator (CASA) requiring owners and operators of specific aircraft to perform a critical inspection.\n\n**What it does:**\n- Requires inspection of a specific bolt on the nose landing gear (front wheel assembly) of Lake LA-4 series aircraft\n- Checks that the correct bolt type (AN 5-16A or approved equivalent) is installed with the bolt head positioned on the right side of the aircraft\n- If the wrong bolt (AN5-15A) is found, requires additional inspection for wear/damage to the bolt holes, with repairs following specific manufacturer instructions\n- Mandates that any replacement bolts must be the correct type (AN 5-16A or AN 5-17A if bushings are used), always with the head on the right side\n\n**Who it affects:**\n- Owners and operators of all Lake LA-4 series aircraft (a type of small amphibious plane originally built by Lake Aircraft)\n- Maintenance engineers responsible for these aircraft\n\n**Why it matters:**\nLanding gear failures can be catastrophic. This directive addresses a specific safety concern about bolt specification and placement that could affect the structural integrity of the nose landing gear drag strut — a component that helps stabilize the front wheel during takeoff, landing, and ground operations. The deadline (30 September 1965) indicates this was an urgent safety fix required to prevent potential accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-la-4-1-nose-landing-gear-drag-strut-inspection","history":"/api/acts/ad-la-4-1-nose-landing-gear-drag-strut-inspection/history","analysis":"/api/acts/ad-la-4-1-nose-landing-gear-drag-strut-inspection/analysis","conflicts":"/api/acts/ad-la-4-1-nose-landing-gear-drag-strut-inspection/conflicts","importantCases":"/api/acts/ad-la-4-1-nose-landing-gear-drag-strut-inspection/important-cases","documents":"/api/acts/ad-la-4-1-nose-landing-gear-drag-strut-inspection/documents"}}