{"id":"F2006B05091","name":"AD/CESSNA 180/78 Amdt 2 - Exhaust System - Inspection","slug":"ad-cessna-180-78-amdt-2-exhaust-system-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45070,"registerId":"commonwealth-F2006B05091-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 180/78 Amdt 2 - Exhaust System - 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)  \n![](image.002.png)  \nCessna 180, 182 and Wren 460 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/CESSNA 180/78 Amdt 1 under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nAD/CESSNA 180/78\n\nAmdt 2\n\n  \nExhaust System \\- Inspection 7/2000\n\nApplicability: Model 182S aeroplanes serial numbers 18280001 through 18280286 not incorporating improved design engine exhaust mufflers P/N 1254017-19 or P/N 9954200-9.\n\nRequirement: 1. Carry out an inspection of exhaust system for cracking of the muffler end plates in accordance with procedures in Cessna Single Engine Service Bulletin SB98- 78-02 Revision 1.\n\n    2. Replace engine exhaust mufflers with one of improved design, P/N 1254017-19 or P/N 9954200-9, in accordance with Cessna SB 98-78-03 dated December 14, 1998.\n\nNote 1: Replacement with improved design muffler P/N 1254017-19 or P/N 9954200- 9 provides terminating action for the requirements of this Directive.\n\n    3. Fabricate and install on the instrument panel in the cockpit, in clear view of the pilot in command, a placard that specifies inspection, before further flight, of all exhaust system muffler end plates following the occasion of an engine backfire upon start up. The placard should utilise letters of at least 3 millimetres in height and contain the following words: “If the engine backfires upon start-up, prior to further flight, inspect and replace (as necessary) all engine exhaust muffler end plates in accordance with AD/CESSNA 180/78 Amdt 2”.\n\nNote 2: FAA AD 2000-02-14 Amdt 39-11532 refers and supersedes FAA AD 98-13-\n\n10 Amdt 39-10598.\n\nCompliance: 1. Unless previously accomplished; within 25 hours time-in-service (TIS) of the effective date of this Directive and thereafter at intervals not to exceed 25 hours TIS and, prior to flight following a reported engine backfire on engine start up.\n\n    2. Unless previously accomplished, prior to further flight if replacement is due to end plate cracking or within 12 calendar months time in service after the effective date of this directive. Remove placard from the instrument panel upon fitment of improved design muffler.\n\n    3. Within 5 days time in service after 13 July 2000.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThis Amendment becomes effective on 13 July 2000.\n\nBackground: This directive was originally issued to address reports of cracks found in the engine exhaust muffler end plates of several Cessna Model 182S aircraft. The FAA determined that immediate AD action should be taken to detect and correct damage to the engine exhaust mufflers which could result in exhaust gases entering the aircraft with consequent crew and passenger injury.\n\nAmendment 2 issued to provide terminating action for the muffler inspection and to remove the placard from the instrument panel on fitment of the improved muffler design.\n\nAmendment 1 was issued to limit applicability to certain aeroplanes by serial number which have not yet been fitted with improved mufflers and to reflect the manufacturer’s revision of the requirement document.\n\nAmendment 1 of this Airworthiness Directive became effective on 22 April 1999.\n\nThe original issue of this Airworthiness Directive became effective on 10 September 1998.\n\n![](image.003.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 30 May 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 14 June 2000.","sortOrder":0}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amendment 2 refines and finalises remedial measures rather than expanding the AD’s original purpose. Compared with the original issue, the AD was narrowed (Amendment 1 limited applicability to a serial-number subset) and Amendment 2 added a terminating action (fit improved mufflers) and removed the placard requirement once the improved muffler is fitted. These are refinements and operational clarifications that keep the directive focused on correcting the same unsafe condition rather than growing its regulatory reach."},"complexity_factors":["Single-aircraft type and narrow serial-number applicability (single serial-number range)","Three discrete requirements with different compliance timings (inspection, replacement, placard)","Recurring inspection interval (every 25 hours TIS) plus an immediate-before-flight condition after engine backfire","Terminating action provision (replacement removes recurring requirements)","Cross-references to two Cessna Service Bulletins and to FAA ADs (external documents required for procedural detail)","Specific part numbers required for replacement (P/N 1254017-19 and P/N 9954200-9)","Prescriptive placard wording and minimum letter size (3 mm)"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- Applies to Cessna Model 182S aeroplanes, serial numbers 18280001 through 18280286, that do NOT already have the improved exhaust mufflers P/N 1254017-19 or P/N 9954200-9 (Applicability).\n\n- Requires three actions (Requirement):\n  - **Inspection:** Inspect the exhaust system for cracks in the muffler end plates following the procedures in Cessna Single Engine Service Bulletin SB98-78-02 Rev 1 (Requirement 1).\n  - **Replacement:** Replace the engine exhaust mufflers with an improved-design muffler (either P/N 1254017-19 or P/N 9954200-9) following Cessna SB 98-78-03 (Requirement 2). Replacing with an improved muffler ends (terminates) the need for the inspection and placard requirement (Note 1).\n  - **Placard:** Fabricate and install a cockpit placard (visible to the pilot) instructing that, if the engine backfires on start-up, the muffler end plates must be inspected before further flight. The placard must use letters at least 3 mm high and contain specified wording (Requirement 3).\n\n- Sets time limits for compliance (Compliance):\n  - Inspections: within 25 hours time-in-service (TIS) of the directive becoming effective, then every 25 hours TIS thereafter, and always before flight after any reported engine backfire on start-up (Compliance 1).\n  - Replacements: if replacement is needed because of cracking, do so before further flight; otherwise replacement must be done within 12 calendar months TIS after the directive’s effective date (Compliance 2). Remove the placard once an improved muffler is fitted.\n  - Placard installation: within 5 days TIS after 13 July 2000 (Compliance 3).\n\n**Who this affects**\n\n- Owners and operators of the specified Cessna 182S aircraft without the improved muffler parts.\n- Maintenance facilities and parts suppliers who carry out inspections, supply the improved mufflers, and install the placard.\n\n**Why the rule exists (as stated by the regulator)**\n\n- The CASA/FAA record states cracks were found in muffler end plates; damaged mufflers can allow exhaust gases into the cabin and injure occupants. The directive’s stated aim is to detect and correct muffler damage to prevent that hazard (Background).\n\n**Practical effects, costs and incentives**\n\n- Direct costs fall on aircraft owners/operators: labor for repetitive inspections (every 25 hours TIS until replacement), costs to buy and fit improved mufflers, and minor material/labour to make and install the placard (Requirement & Compliance sections).\n- Replacing with the improved muffler is a one-off cost that removes the recurring inspection and placard requirements (Note 1). That creates a clear economic incentive to upgrade to the improved part.\n- Maintenance downtime may increase if inspections detect cracking that requires immediate replacement (Compliance 1 and 2). Operators must ground the aircraft until defects are fixed when cracking is found or after a backfire event that triggers inspection.\n- Parts suppliers for the specified P/Ns may see concentrated demand from the affected serial-number cohort; operators of unaffected serial numbers or those already fitted with improved parts incur no new obligations.\n- The directive references Cessna service bulletins and FAA ADs (cross-references). Compliance requires following those manufacturer procedures exactly (Requirement notes and references), which directs how maintenance organisations perform the work.\n\n**Implementation and compliance risks**\n\n- Risk of non-compliance is operational (missed inspections or replacement) and can cause continued exposure to the described hazard; the AD’s compliance times and the ‘‘prior to further flight after backfire’’ rule are strict operational constraints (Compliance).\n- Administrative friction: small operators may bear higher relative costs for frequent inspections; installation lead times for the improved muffler could delay achieving the terminating action.\n- The regulator’s action leaves little discretion: this is a mandatory airworthiness directive requiring prescribed actions and timelines (Requirement & Compliance). The manufacturer SBs dictate technical procedures, constraining alternative repair choices.\n\n**Summary statement of responsibilities**\n\n- Owners/operators pay for inspections and replacements, decide whether to accept the one-off cost to stop recurring inspections, and must ensure placards are fitted until improved mufflers are installed. Maintenance organisations must perform the inspections and replacements to the referenced service bulletin procedures.\n\n(References: AD/CESSNA 180/78 Amdt 2 — Requirements 1–3, Notes, and Compliance 1–3.)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original directive (September 1998) applied broadly to address exhaust cracks. Amendment 1 (April 1999) narrowed scope to specific serial numbers not yet fitted with improved mufflers. Amendment 2 (this version) further refines the scope by adding 'terminating action' — allowing owners to permanently end the inspection burden by installing improved mufflers, and adding the placard requirement as an interim safety measure. The directive has evolved from a simple inspection mandate to a more sophisticated regulatory mechanism with multiple compliance pathways and exit conditions."},"complexity_factors":["Multiple compliance deadlines with conditional triggers (25 hours TIS, 12 calendar months, 5 days TIS, 'prior to further flight' conditions)","Cross-references to external manufacturer documents (Cessna Service Bulletins SB98-78-02 Rev 1 and SB98-78-03)","Specific part number identification required for terminating action (P/N 1254017-19 or P/N 9954200-9)","Nested applicability criteria (specific model, serial number range, AND exclusion of already-upgraded aircraft)","Reference to related FAA Airworthiness Directive for context (FAA AD 2000-02-14)"],"plain_english_summary":"This safety order targets Cessna 182S aeroplanes (S/N 18280001–18280286) that lack the improved muffler parts and addresses cracked exhaust muffler end plates that can leak deadly carbon monoxide into the cabin. It requires owners/operators to inspect the muffler every 25 flight hours and after any engine backfire, install a cockpit warning placard until the safer muffler is fitted, and replace the old muffler with the improved design within 12 months (replacement ends the inspection and placard requirements)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-180-78-amdt-2-exhaust-system-inspection","history":"/api/acts/ad-cessna-180-78-amdt-2-exhaust-system-inspection/history","analysis":"/api/acts/ad-cessna-180-78-amdt-2-exhaust-system-inspection/analysis","conflicts":"/api/acts/ad-cessna-180-78-amdt-2-exhaust-system-inspection/conflicts","importantCases":"/api/acts/ad-cessna-180-78-amdt-2-exhaust-system-inspection/important-cases","documents":"/api/acts/ad-cessna-180-78-amdt-2-exhaust-system-inspection/documents"}}