{"id":"F2006B08635","name":"AD/CON/53 Amdt 1 - Starter Adaptor Shafts","slug":"ad-con-53-amdt-1-starter-adaptor-shafts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51643,"registerId":"commonwealth-F2006B08635-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CON/53 Amdt 1 - Starter Adaptor Shafts","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nTeledyne Continental Motors Piston Engines\n\nAD/CON/53\n\nAmdt 1\n\n  \nStarter Adaptor Shafts 12/88\n\nApplicability: IO-520BA, IO-520BB, IO-550B, TSIO-520BE, TSIO-520LB, TSIO-520UB, TSIO-\n\n520WB engines fitted with a starter adaptor shaft driving a freon compressor.\n\nRequirement: Part 1 Action in accordance with TCM SB M87-24.\n\nNote: FAA AD 88-17-03 Amdt 39-5943 Para (a) refers.\n\nPart 2 Replace starter drive assy in accordance with (IAW) TCM SB M88-5 and drive belt IAW TCM SB M88-6.\n\nNote: FAA AD 88-17-03 Amdt 39-5943 Para (b) refers.\n\nCompliance: For Part 1 Before further flight after 1 February 1988.\n\nFor Part 2 Prior to refitment of compressor drive belt and reactivation of airconditioning system.\n\nNote: Compliance with CAO 106 AD/CON/50 does not constitute compliance with this Directive.\n\nBackground: This Directive is amended to reflect and reference FAA AD 88-17-03 Amdt 39-5943 which supersedes FAA AD 87-26-01 Amdt 39-5882.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment simply updates the directive to reference a newer FAA Airworthiness Directive (88-17-03) that supersedes the previous one (87-26-01). The scope remains unchanged — it still addresses the same safety issue with starter adaptor shafts on the same engine models. This is a technical housekeeping amendment to maintain alignment with US safety standards."},"complexity_factors":["Very short document (under 300 words)","Only 7 specific engine models listed in applicability","Two distinct compliance actions with clear deadlines","Simple conditional logic: applies only if engine has starter adaptor shaft driving freon compressor","Cross-references to 3 manufacturer service bulletins and 1 FAA Airworthiness Directive, but these are external technical documents rather than legislative cross-references","No defined terms section","Single amendment updating reference to superseded FAA directive"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance actions on certain aircraft engines.\n\n**What it does:**\nThis directive orders owners and operators of specific Teledyne Continental Motors piston engines to inspect and replace faulty starter adaptor shafts. These shafts connect the engine's starter motor to a freon compressor (used for air conditioning). The concern is that these shafts can fail, potentially causing engine damage or in-flight emergencies.\n\n**Who it affects:**\n- Owners and operators of aircraft with these specific engine models: **IO-520BA, IO-520BB, IO-550B, TSIO-520BE, TSIO-520LB, TSIO-520UB, and TSIO-520WB**\n- Only applies if the engine has a starter adaptor shaft driving a freon compressor (air conditioning unit)\n\n**What must be done:**\n- **Part 1:** Inspect the starter adaptor shaft following manufacturer's Service Bulletin M87-24 — must be done before flying again after 1 February 1988\n- **Part 2:** Replace the starter drive assembly and drive belt following Service Bulletins M88-5 and M88-6 — must be done before reconnecting the air conditioning system\n\n**Why it matters:**\nThis directive prevents mechanical failures that could lead to loss of engine power or damage during flight. It aligns Australian requirements with a US Federal Aviation Administration (FAA) safety order (AD 88-17-03), ensuring Australian-registered aircraft meet the same safety standards as American ones. The note clarifies that complying with a similar earlier directive (AD/CON/50) does not satisfy this new requirement — operators must follow this updated directive specifically."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment updates the Directive to reflect and reference the later FAA AD (FAA AD 88-17-03 Amdt 39-5943) that supersedes an earlier FAA AD, but the core mandatory actions, the listed engine applicability, and the compliance requirements are stated in this instrument and remain the operative requirements (Requirement; Applicability; Compliance; Background). The Background language indicates an update of references rather than a change to the types of actions required in this Directive."},"complexity_factors":["Cross-references to multiple external documents (TCM service bulletins M87-24, M88-5, M88-6 and FAA AD 88-17-03), creating dependency on those external technical documents for detailed work instructions (Requirement; Note; Background).","Two-part requirement structure with different timing triggers (immediate 'before further flight' for Part 1; conditional 'prior to refitment/reactivation' for Part 2) requiring different operational scheduling (Requirement; Compliance).","Narrow technical applicability limited to specific engine models and to installations with a starter adaptor shaft driving a freon compressor, requiring accurate configuration checks by operators (Applicability).","Explicit exclusion of an alternative compliance path (compliance with CAO 106 AD/CON/50 does not satisfy this AD), reducing flexibility for operators (Note).","Potential logistical complexity from obtaining specific replacement parts and scheduling maintenance windows (implied by Requirement and Compliance)."],"plain_english_summary":"This AD mandates specific maintenance on certain Teledyne Continental piston engines with a starter‑adaptor‑shaft driving a freon compressor: perform TCM SB M87‑24 immediately (before next flight after the AD date) and replace the starter drive assembly and belt per TCM SB M88‑5 and M88‑6 before refitting the belt/reactivating air‑conditioning.  \n\nIt affects owners/operators and their maintenance organisations, who bear parts, labour and downtime; the AD follows an FAA AD and disallows reliance on CAO 106 AD/CON/50."}},"importantCases":[],"_links":{"self":"/api/acts/ad-con-53-amdt-1-starter-adaptor-shafts","history":"/api/acts/ad-con-53-amdt-1-starter-adaptor-shafts/history","analysis":"/api/acts/ad-con-53-amdt-1-starter-adaptor-shafts/analysis","conflicts":"/api/acts/ad-con-53-amdt-1-starter-adaptor-shafts/conflicts","importantCases":"/api/acts/ad-con-53-amdt-1-starter-adaptor-shafts/important-cases","documents":"/api/acts/ad-con-53-amdt-1-starter-adaptor-shafts/documents"}}