{"id":"F2006B06830","name":"AD/SD3-30/29 - Main Landing Gear - Beam Sub Assembly","slug":"ad-sd3-30-29-main-landing-gear-beam-sub-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114694,"registerId":"commonwealth-F2006B06830-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SD3-30/29 - Main Landing Gear - Beam Sub Assembly","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)  \nShort SD3-30 Series Aeroplanes\n\nAD/SD3-30/29 Main Landing Gear \\- Beam Sub Assembly 5/95\n\nApplicability: All Model SD3-30 series aeroplanes equipped with Menasco MLG beam assembly P/N 17501 serial numbers MMC-005 to MMC-068 and MMC-071 to MMC-188 inclusive.\n\nRequirement: 1. Rework the MLG beam sub-assembly P/N 17604-9, \\-13, \\-13A/14A, \\-15/16 or\n\n\\-17/18 in accordance with Shorts Service Bulletin SD3-32-90, Revision 2.\n\n2. Remove from service MLG beam sub-assembly P/N 17604-9, \\-13 or \\-13A/14A.\n\nNote: FAA AD 93-14-03 refers.\n\nCompliance: 1. Rework in accordance with Requirement 1 before 13 500 total component landings or before 2 300 component landings from 27 April 1995, whichever occurs later.\n\n2. Action in accordance with Requirement 2 before 20 000 total component landings.\n\nBackground: Fatigue testing has revealed that there is a stress raiser at the lower edge of the bore where the beam ID intersects with the axle hole. The rework increases the radius of the intersection. Other locations of high stress are also radiused.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific safety-critical component failure mode. It has not expanded beyond its original purpose of mandating repairs to prevent landing gear fatigue failures in the specified aircraft fleet."},"complexity_factors":["Single, specific technical subject matter (one aircraft type, one component)","Limited applicability criteria clearly specified by part numbers and serial numbers","Two distinct requirements with clear compliance deadlines","Minimal cross-referencing (only one FAA AD reference and one Service Bulletin)","No nested conditional logic or exceptions","Short document (approximately 200 words)","Technical aviation terminology requires domain knowledge but is precisely defined"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of Short SD3-30 aircraft fitted with certain Menasco main landing‑gear beam assemblies to either rework specific beam sub‑assemblies to remove a fatigue‑inducing sharp corner or permanently remove the oldest-design beams from service. \n\nIt matters because testing found a stress raiser that can lead to landing‑gear failure; compliance is mandatory and subject to landing‑count deadlines for repair or removal to maintain airworthiness."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The AD targets specific Menasco main landing‑gear beam sub‑assembly part numbers and serial ranges on SD3‑30 aeroplanes; it does not expand to other models or components beyond those listed. It imposes component‑level obligations (rework/removal) and deadlines but does not otherwise change the fleet or airworthiness scope described."},"complexity_factors":["Technical engineering rework specified by a service bulletin (SD3‑32‑90 Rev 2) requiring shop capability and inspection","Multiple affected part numbers and discrete serial‑number ranges increase identification and logistics burden","Two different compliance actions (rework and removal) with separate landing‑count deadlines","Compliance metric is 'total component landings', requiring precise recordkeeping and life‑tracking of parts","Reference to an FAA AD introduces cross‑jurisdictional regulatory alignment and potential coordination issues","Safety basis is fatigue testing of a stress‑raiser geometry, so verifiable inspection and measurement are necessary","Operational impacts: aircraft downtime, parts replacement lead times, and scheduling to avoid exceeding landing thresholds"],"plain_english_summary":"This Airworthiness Directive requires operators of *Short SD3‑30* aeroplanes fitted with specified Menasco main‑landing‑gear beam assemblies to rework certain beam sub‑assemblies (per *Shorts Service Bulletin SD3‑32‑90 Rev 2*) and to remove particular older beam part numbers from service. Compliance is measured by component landing counts and includes staged deadlines.\n\nFatigue testing identified a stress raiser at the bore–axle intersection; the rework increases the radius. Operators pay for rework or replacement, face downtime and scheduling costs, and must track landing counts to comply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-30-29-main-landing-gear-beam-sub-assembly","history":"/api/acts/ad-sd3-30-29-main-landing-gear-beam-sub-assembly/history","analysis":"/api/acts/ad-sd3-30-29-main-landing-gear-beam-sub-assembly/analysis","conflicts":"/api/acts/ad-sd3-30-29-main-landing-gear-beam-sub-assembly/conflicts","importantCases":"/api/acts/ad-sd3-30-29-main-landing-gear-beam-sub-assembly/important-cases","documents":"/api/acts/ad-sd3-30-29-main-landing-gear-beam-sub-assembly/documents"}}