{"id":"F2006B08648","name":"AD/CON/72 - Engine Mount Bracket","slug":"ad-con-72-engine-mount-bracket","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51706,"registerId":"commonwealth-F2006B08648-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CON/72 - Engine Mount Bracket","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/72 Engine Mount Bracket 1/95\n\nApplicability: Engine Series IO-346A, IO-346B, IO-520C, IO-520CB.\n\nRebuilt models IO-520C with serial numbers 287051-R and lower. Rebuilt models IO-520CB with serial numbers 282226-R and lower. Rebuilt models IO-550C with serial numbers 271742-R and lower.\n\nAll factory overhauled IO-520C, IO-520CB and IO-550C engines with a build date prior to 6 August 1992.\n\nNote: These engines are installed in but not limited to Beech models A23, A23A, 95- C55, 95-C55A, D55, D55A, E55, E55A, 58 and 58A.\n\nRequirement: 1. Inspect the lower left engine mount bracket, P/N 630695 for cracks using a dye penetrant technique in accordance with CAO 108.10, Appendix 2.\n\n2. Remove lower left engine mount bracket P/N 630695 and lower right engine mount bracket P/N 630694 and install improved design brackets P/N 653306 and 653305 respectively. This action constitutes terminating action for the inspection requirements of this AD.\n\nNote: FAA AD 94-09-07 Amdt 39-8896 and TCM Service Bulletin No. M92-13 refer.\n\nCompliance: 1. For engines with engine mount brackets which have completed one or more engine overhaul cycles, or have accumulated 2,500 or more hours time in service on 5 January 1995, inspect within 50 hours time in service. Repeat the inspection at intervals not exceeding 500 hours time in service since the last inspection. If cracking is detected, carry out Requirement Para.2 before further flight.\n\n2. For all engines, install new brackets at the next engine removal after 5 January 1995.\n\nBackground: TCM have advised that cracking has been reported in the lower left engine mount bracket. In order to prevent engine separation from the aircraft, this AD requires the lower left bracket to be inspected at 500 hour intervals using an approved dye penetrant procedure until replacement of both engine mount brackets with improved brackets at next engine removal.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD's scope aligns with its stated aim in the Background: address reported cracking of the lower left engine mount bracket on the listed engines and prevent engine separation. It limits action to specified engine models, serial/build‑date ranges and factory/overhauled engines, imposes interim inspection requirements and makes replacement at next engine removal the terminating action (see Applicability; Requirement; Compliance). No expansion beyond addressing the reported defect is introduced in the text."},"complexity_factors":["Multiple engine models and specific serial number/build‑date thresholds in the Applicability section","Two‑stage compliance: recurring dye‑penetrant inspections (terminating only after replacement) and mandatory replacement at next engine removal","Technical inspection procedure specified (dye penetrant per CAO 108.10, Appendix 2)","Part‑number specificity for affected and replacement brackets (P/N 630695, 630694 → P/Ns 653306, 653305)","Different triggers for inspection timing (overhaul history or ≥2,500 hours as of 5 Jan 1995) and fixed inspection interval (every 500 hours)","Immediate operational consequence if cracking is found (Requirement Para.2: replace before further flight)","Cross‑references to FAA AD 94‑09‑07 and TCM Service Bulletin No. M92‑13 that may require checking external documents"],"plain_english_summary":"This airworthiness directive requires owners/operators of specified Teledyne Continental piston engines (models IO‑346A/B, IO‑520C/CB, IO‑550C and listed serial/build‑date ranges) to inspect the lower left engine‑mount bracket P/N 630695 for cracks using dye‑penetrant and to replace both lower brackets with improved parts P/Ns 653306 and 653305 to reduce the risk of engine separation.\n\nEngines with an overhaul history or ≥2,500 hours on 5 Jan 1995 must be inspected within 50 hours and every 500 hours thereafter; all engines must fit the new brackets at the next engine removal after 5 Jan 1995. Owners/operators pay inspection and replacement costs; detected cracks must be fixed before further flight (Requirement; Compliance)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific engine models. The scope remains tightly focused on engine mount bracket integrity and has not expanded beyond this original safety purpose."},"complexity_factors":["Multiple applicability criteria requiring cross-referencing (engine series, serial numbers, rebuild status, factory overhaul dates, and aircraft models)","Two-tier compliance structure with different deadlines based on engine history (overhaul cycles vs. flight hours)","Conditional logic: 'if cracking is detected, carry out Requirement Para.2 before further flight'","Reference to external technical documents (CAO 108.10 Appendix 2, FAA AD 94-09-07, TCM Service Bulletin M92-13) without reproducing their content","Terminating action concept requires understanding that compliance with Para.2 ends the inspection obligation in Para.1"],"plain_english_summary":"This CASA Airworthiness Directive mandates dye‑penetrant inspection of the lower left engine‑mount bracket on certain Teledyne Continental piston engines used in specific Beech Bonanza and Baron models, and ultimately requires replacement of both left and right brackets with improved designs when the engine is next removed. \n\nCracks have been found that could allow in‑flight engine separation; the AD catches cracks early with periodic inspections and eliminates the risk by requiring bracket replacement at next engine removal."}},"importantCases":[],"_links":{"self":"/api/acts/ad-con-72-engine-mount-bracket","history":"/api/acts/ad-con-72-engine-mount-bracket/history","analysis":"/api/acts/ad-con-72-engine-mount-bracket/analysis","conflicts":"/api/acts/ad-con-72-engine-mount-bracket/conflicts","importantCases":"/api/acts/ad-con-72-engine-mount-bracket/important-cases","documents":"/api/acts/ad-con-72-engine-mount-bracket/documents"}}