{"id":"F2006B08241","name":"AD/CESSNA 337/21 Amdt 1 - Pre-Certification Requirements - Modification","slug":"ad-cessna-337-21-amdt-1-pre-certification-requirements-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115506,"registerId":"commonwealth-F2006B08241-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 337/21 Amdt 1 - Pre-Certification Requirements - Modification","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)  \nCessna 337 Series Aeroplanes\n\nAD/CESSNA 337/21\n\nAmdt 1\n\n  \nPre-Certification Requirements \\- Modification 8/75\n\nApplicability: All model 337G.\n\nRequirement: Modify the aircraft in accordance with the requirements of ANO 101.22 in respect of the following:\n\n    a. Install placards clearly visible to the occupants of seat rows 1 and 2 specifying the periods during which smoking is prohibited.\n\nInstall a “NO SMOKING” placard clearly visible to the occupant/s of seat row 3.\n\n    2. Install and identify:\n\nfuelling equipment bonding points at each fuel filling point.\n\nexternal earthing points for the attachment of ground connections on each main undercarriage assembly or on the nose gear.\n\n    3. a. Modify the second row seat backrest locking pin P/No. 1514201-18 to permit the backrest to be pushed forward by the occupant/s of the third row seats when applying a forward force of 18 lb. to 22 lb. at the top of the backrest, to a scheme approved by the Secretary.\n\nNote: Modification to ARCAV ALBURY drawing No. 20 issue 2 or Rex Aviation Ltd. Drawing No. RA-A-1390-1 is an acceptable means of compliance.\n\nInstall a placard on the rear of each second row seat backrest, clearly visible to the occupant/s of the third row seats, as follows:\n\nIN EMERGENCY\n\nPUSH CENTRE SEAT BACKREST FORWARD\n\nNote: All lettering shall be in white on a black back- ground. Underlined lettering shall be a minimum of 6 mm (1/4\") high and other lettering shall be a minimum of 3 mm (1/8\") high.\n\n    4. Install an easily readable placard in a prominent position on the pilot”s instrument panel as follows:\n\n“ENSURE CENTRE SEATS LATCHED DOWN BEFORE FLIGHT”.\n\n    5. a. The third row seat/s shall be positively attached to the cabin floor structure, with the seat/s firmly positioned against the cabin rear bulkhead lining, in accordance with a scheme approved by the Secretary.\n\nNote: Modification to Rex Aviation Ltd., Drawing No. RA-C-1341 or Arcav Albury Drawing No. 20 Issue 2 is an acceptable means of compliance.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThe third row seat backrest/s shall be positively attached to the seat base by modifying the assembly in accordance with a scheme approved by the Secretary.\n\nNote: Modification to Arcav Albury Drawing No. 20 Issue 2 or Aerospace Industries (Aust.) Drawing No. AC 313 is an acceptable means of compliance.\n\n    6. Replace all flexible hose assemblies carrying flammable fluids in engine compartments which do not meet the fire resistance standards of FAA TSO C35B Type C or D, or render such hoses fire resistant to that standard by fitting an approved fire sleeve.\n\nNote: This requirement need not apply to breather, vent and drain lines the failure of which will not result in, or add to, a fire hazard.\n\nCompliance: Before issue of a Certificate of Airworthiness.","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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original scope as a pre-certification safety mandate for Cessna 337G aircraft. The amendment (Amdt 1) appears to be a routine update to the original AD/CESSNA 337/21, continuing the established purpose of ensuring specific safety modifications are completed before airworthiness certification. There is no evidence of scope creep into operational requirements or other aircraft types."},"complexity_factors":["Multiple distinct modification requirements (6 separate items) with sub-clauses","Specific technical references to external standards (FAA TSO C35B Type C or D) and engineering drawings from multiple suppliers (Rex Aviation, Arcav Albury, Aerospace Industries)","Precise mechanical specifications (18–22 lb. force, 6mm/3mm lettering heights, specific colour schemes)","Conditional exemption for breather/vent/drain lines in item 6","Requirement for Secretary approval for certain modifications without mandating specific technical solutions","Mix of prescriptive requirements (placard wording) and performance-based requirements (\"scheme approved by the Secretary\")"],"plain_english_summary":"This CASA Airworthiness Directive requires specified safety modifications to Cessna 337G aircraft before they can be certified as airworthy. It mandates changes addressing smoking signage, fuel static/earthing, emergency seat release and third‑row seat security, a pilot reminder placard, and replacement/protection of engine hoses with fire‑resistant materials.\n\nIt affects Cessna 337G owners, operators and maintenance organisations in Australia and matters because it mitigates fire and evacuation risks; compliance is required for Certificate of Airworthiness."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"This instrument is labelled Amendment 1 to AD/CESSNA 337/21 and prescribes specific pre‑certification modifications for all model 337G aircraft (Amdt 1; Applicability). It therefore alters the regulatory obligations by making these listed modifications mandatory before the issue of a Certificate of Airworthiness (Compliance). Several requirements refer to Secretary‑approved schemes and specified drawings as acceptable means of compliance, changing how compliance is demonstrated (Requirement 3a, 5a; notes)."},"complexity_factors":["Multiple discrete technical requirements across airframe, seating, electrical bonding/earthing and hose fire resistance (Requirement paras 1–6).","Several modifications must follow schemes approved by the Secretary, creating administrative discretion and approval lead time (Requirement 3a, 5a).","Acceptable means of compliance are referenced to specific third‑party drawings and standards, requiring parts/engineering conforming to those drawings or equivalent approvals (notes to Requirement 3a and 5a).","A prescriptive technical standard is mandated for hoses (FAA TSO C35B Type C or D), which may force part replacement or certified sleeves and supply‑chain constraints (Requirement 6).","Timing constraint: all work must be completed before issue of a Certificate of Airworthiness, concentrating cost and downtime at certification (Compliance).","Detailed placard legibility and location specifications create small but enforceable workmanship standards (Requirement 1a; Requirement 3a placard note; Requirement 4).","Who pays and bears operational impact: aircraft owners/operators and their maintenance organisations carry retrofit, parts and labour costs and scheduling impacts (Compliance; Requirements 1–6).","Potential for substitution effects: materially equivalent drawings or schemes are allowed only if approved, which may require engineering submissions and follow‑up inspections (notes to Requirement 3a and 5a)."],"plain_english_summary":"This airworthiness directive requires specific pre‑certification modifications to all Cessna 337G aeroplanes before a Certificate of Airworthiness is issued: add no‑smoking and safety placards, fit fuel bonding and external earthing points, modify and placard second‑row seatbacks to allow third‑row egress and secure third‑row seats to floor/bulkhead, and replace or sleeve flammable engine‑compartment hoses to meet FAA TSO C35B Type C/D. It affects owners/operators and maintenance organisations by imposing retrofit work, parts meeting technical standards, and Secretary‑approved modification schemes."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-337-21-amdt-1-pre-certification-requirements-modification","history":"/api/acts/ad-cessna-337-21-amdt-1-pre-certification-requirements-modification/history","analysis":"/api/acts/ad-cessna-337-21-amdt-1-pre-certification-requirements-modification/analysis","conflicts":"/api/acts/ad-cessna-337-21-amdt-1-pre-certification-requirements-modification/conflicts","importantCases":"/api/acts/ad-cessna-337-21-amdt-1-pre-certification-requirements-modification/important-cases","documents":"/api/acts/ad-cessna-337-21-amdt-1-pre-certification-requirements-modification/documents"}}