{"id":"F2006B11193","name":"AD/LYC/101 Amdt 1 - Superior Cylinders","slug":"ad-lyc-101-amdt-1-superior-cylinders","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56901,"registerId":"commonwealth-F2006B11193-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/LYC/101 Amdt 1 - Superior Cylinders","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)  \nLycoming Piston Engines\n\nAD/LYC/101\n\nAmdt 1\n\n  \nSuperior Cylinders 3/97\n\nApplicability: All Lycoming TIO/LTIO-540-A2C, \\-J2B, \\-F2BD, \\-J2BD, \\-N2BD, \\-R2AD, \\-S1AD\n\nand IO-540-M1B5D engines fitted with Superior Air Parts Inc. cylinders part number (P/N) SL54000-A1, SL54000-A2, SL54000-A2P, SL54000-A20P and SL54000-\n\nA21P with serials numbers 001 through 650.\n\nRequirement: 1. To prevent the possible loss of a cylinder head, the subsequent loss of engine power and a possible engine fire, carry out:\n\n    A visual inspection of applicable cylinder assemblies for evidence of combustion leaks and/or cracking in the area adjacent to the location of the inlet valve seat as detailed in Figure 1, and\n\n    b. An 80psi pressure “wet” leak check of the cylinder assemblies paying particular attention to the area detailed in Figure 1.\n\nRemove from service before further flight, any cylinder showing either combustion gas leakage or cracks.\n\n2. Remove applicable cylinders from service.\n\nNote 1: For the purpose of Requirement 1.(B), a wet leak check may be carried out by using soapy water or a commercial leak detector product such as “Sherlock Leak Detector”.\n\nNote 2: FAA Airworthiness Directive 97-01-04 refers.\n\n![](image.002.png)  \n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nCompliance: 1\\. Cylinders with a time in service greater than 250 hours; within 5 hours time in service from the effective date of this directive and thereafter at intervals not to exceed 25 hours time in service.\n\nCylinders with a time in service less than 250 hours; prior to exceeding 250 hours time in service and thereafter at intervals not to exceed 25 hours time in service.\n\n2. Prior to exceeding 300 hours cylinder time in service. This Amendment becomes effective on 27 February 1997.\n\nBackground: This directive was originally issued to require the inspection of certain cylinder assemblies. The requirement follows the CASA investigation of a PA31-350 cylinder head failure in service. This amendment reflects the issue of an FAA airworthiness directive based on the results on the CASA investigation and the subsequent revision to the cylinder manufacturer’s published requirements.\n\nFAA Airworthiness Directive 97-01-04 increases the engine models applicable, reduces the compliance threshold and adds a terminating action by replacement of affected cylinders.\n\nThe original issue of this Airworthiness Directive became effective on 27 November 1996.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment expanded the list of applicable engine models, reduced the compliance thresholds for inspection, and added a terminating action requiring replacement of affected cylinders compared with the original directive. (See Background: \"FAA Airworthiness Directive 97-01-04 increases the engine models applicable, reduces the compliance threshold and adds a terminating action by replacement of affected cylinders.\")"},"complexity_factors":["Narrow applicability defined by multiple engine models and specific part numbers and serial range, increasing the need for accurate parts tracking (Applicability).","Two-step inspection: visual inspection for cracks/leaks plus an 80 psi wet leak check — operators must have means and skills for both (Requirement 1.(A)-(B); Note 1).","Immediate removal mandate: any cylinder showing leakage or cracks must be removed before further flight, creating potential on‑the‑spot operational disruption and replacement cost (Requirement 1; \"Remove from service before further flight\").","Differential compliance timing based on existing cylinder hours: >250 hours require inspection within 5 hours then every 25 hours; <250 hours require inspection before exceeding 250 hours then every 25 hours — creates frequent recurrent checks and recordkeeping (Compliance 1).","Terminating action: mandatory removal/replacement prior to 300 hours cylinder time as an end‑state remedy, which imposes replacement cost and logistics (Requirement 2; Compliance 2).","Low administrative discretion: pass/fail tied to observable cracks or leakage (Figure 1 reference), but detection can involve inspector judgment and variable sensitivity of wet‑test methods (Requirement; Note 1).","Cross‑reference to FAA AD and manufacturer's revised requirements, which can create additional compliance interpretation issues where documents diverge (Background; Note 2).","Short effective dates (directive effective 27 Feb 1997) create implementation time pressure for affected operators (Compliance intro)."],"plain_english_summary":"Requires operators of certain Lycoming TIO/LTIO-540 and IO-540-M1B5D engines fitted with specified Superior Air Parts cylinders (P/N SL54000‑A1, ‑A2, ‑A2P, ‑A20P, ‑A21P; serials 001–650) to carry out a visual inspection and an 80 psi “wet” leak check for combustion leaks or cracking near the inlet valve seat, remove any defective cylinder before further flight, and replace affected cylinders before 300 hours. The directive is presented as a safety measure to prevent cylinder‑head loss, engine power loss and possible fire (Requirement; Compliance; Background)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"This Amendment 1 expanded the original directive's scope. The original AD (effective 27 November 1996) was revised to: (1) increase the number of engine models covered, (2) lower the compliance threshold (making inspections required sooner), and (3) add a terminating action (mandatory replacement of all affected cylinders at 300 hours). This reflects the FAA's adoption of CASA's investigation findings and represents a significant strengthening from the original inspection-only approach."},"complexity_factors":["Limited defined scope: only 8 specific engine models and 5 specific cylinder part numbers with serial number range 001–650","Two-tier compliance schedule based on hours-in-service thresholds (above/below 250 hours)","Two-part requirement structure: ongoing inspections (Requirement 1) versus terminating action (Requirement 2)","Cross-reference to FAA Airworthiness Directive 97-01-04 for additional context","Technical terminology requires aviation engineering knowledge (e.g., 'time in service', 'wet leak check', 'combustion leaks')","Simple conditional logic: 'if cracks or leaks found → remove from service'"],"plain_english_summary":"This CASA Airworthiness Directive mandates urgent inspections and pressure testing of certain Superior Air Parts cylinders installed on specified Lycoming piston engines, and immediate removal of any cylinder showing cracks or combustion leaks. It affects owners/operators of the listed Lycoming models fitted with those Superior cylinder part/serial numbers and requires replacement of all affected cylinders before they reach 300 hours.\n\nThe AD aims to prevent cylinder head failure that can cause sudden power loss or engine fire in flight, prompted by a recent in‑flight failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-lyc-101-amdt-1-superior-cylinders","history":"/api/acts/ad-lyc-101-amdt-1-superior-cylinders/history","analysis":"/api/acts/ad-lyc-101-amdt-1-superior-cylinders/analysis","conflicts":"/api/acts/ad-lyc-101-amdt-1-superior-cylinders/conflicts","importantCases":"/api/acts/ad-lyc-101-amdt-1-superior-cylinders/important-cases","documents":"/api/acts/ad-lyc-101-amdt-1-superior-cylinders/documents"}}