{"id":"F2006B09177","name":"AD/DHC-8/22 Amdt 1 - Bulkhead Smoke Seal","slug":"ad-dhc-8-22-amdt-1-bulkhead-smoke-seal","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52936,"registerId":"commonwealth-F2006B09177-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/22 Amdt 1 - Bulkhead Smoke Seal","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)  \nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAD/DHC-8/22\n\nAmdt 1\n\n  \nBulkhead Smoke Seal 12/93\n\nApplicability: Model DHC-8 series 100A aircraft with serial numbers 191 and 225 through 307\\. Requirement: Install close out block seals in accordance with de Havilland SB 8-25-80 Rev A.\n\nNote: Transport Canada AD CF-92-16 refers.\n\nCompliance: Unless already accomplished in accordance with the previous issue of the Requirement Document; prior to 11 March 1994.\n\nBackground: During the introduction of furnishing improvements by the manufacturer, close out block seals on the cabin/baggage compartment bulkhead were omitted on some aircraft. With no block seals installed, a direct smoke path exists between the baggage compartment and the cabin.\n\nAmendment 1 is issued in response to a revision of the Requirement Document which expands applicability and adds an inspection requirement.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the AD's applicability (includes additional serial-numbered aircraft) and adds an inspection requirement. This change is stated explicitly in the AD text. (Amendment 1)"},"complexity_factors":["Narrow, serial-number-limited applicability (specific aircraft only)","Dependence on an external manufacturer service bulletin (de Havilland SB 8-25-80 Rev A)","Retrofit installation requirement (parts, labour, aircraft downtime)","Added inspection requirement in the amendment","Fixed compliance deadline (prior to 11 March 1994) and limited grandfathering clause (if already done)","Regulatory enforcement under Civil Aviation Regulations Part 39 (CA S A authority)"],"plain_english_summary":"### What this directive does\n\n- This Airworthiness Directive (AD) comes from the Civil Aviation Safety Authority under the Civil Aviation Regulations (Part 39). (Header: \"COMMONWEALTH OF AUSTRALIA ... PART 39 - CIVIL AVIATION SAFETY AUTHORITY\")\n\n- Mechanically, it requires certain Bombardier (de Havilland) DHC-8 Series 100A aeroplanes to have \"close out block seals\" installed on the cabin/baggage compartment bulkhead. Operators must install those seals following the manufacturer's service bulletin: de Havilland SB 8-25-80 Rev A. (Requirement)\n\n- The AD also adds an inspection requirement as part of Amendment 1. (Amendment 1)\n\n- The aircraft affected are DHC-8 Series 100A with serial numbers 191 and 225 through 307. (Applicability)\n\n- The compliance timeline given is: unless already done in accordance with the previous Requirement Document, the work must be accomplished prior to 11 March 1994. (Compliance)\n\n- The AD notes that Transport Canada issued a related directive (Transport Canada AD CF-92-16). (Note)\n\n\n### Why the change was made (stated purpose)\n\n- The Background section states that when furnishing improvements were introduced, some aircraft were delivered without the close out block seals on the cabin/baggage bulkhead. Without those seals, a direct smoke path exists between the baggage compartment and the cabin. The AD therefore requires installation of the seals to close that smoke path. (Background)\n\n\n### Who pays and who decides\n\n- The aircraft operator or owner is the party responsible for complying with the AD: installing the required seals and performing the inspection as specified. The Requirement and Compliance entries create that obligation. (Requirement; Compliance)\n\n- The Civil Aviation Safety Authority issued the AD under Part 39 of the Civil Aviation Regulations. That is the deciding and enforcing authority named in the instrument. (Header)\n\n\n### Practical effects and compliance mechanics\n\n- Operators of affected serial-numbered aircraft must source the close out block seals and follow the detailed steps in de Havilland SB 8-25-80 Rev A. The AD points to that service bulletin as the prescriptive method. (Requirement)\n\n- If an operator has already installed the seals in line with the earlier Requirement Document, they do not need to repeat the work. Otherwise the installation (and the added inspection in Amendment 1) must be completed by the specified date. (Compliance; Amendment 1)\n\n- The AD references a related foreign regulator action (Transport Canada AD CF-92-16), which may affect how operators locate technical guidance or prioritise the work. (Note)\n\n\n### Costs, incentives, and trade-offs (mechanical assessment)\n\n- Direct costs: operators pay for parts, labour, and aircraft downtime to perform the retrofit and inspection. (Requirement; Compliance)\n\n- Incentives: the AD creates a compliance incentive (a regulatory obligation with a deadline) to install the seals rather than leave the aircraft as-is. The only explicit flexibility is that work already done under the previous Requirement Document need not be repeated. (Compliance)\n\n- Opportunity costs: time spent on the retrofit and inspection may displace other maintenance or operations during the compliance window. (Compliance)\n\n- Implementation risk and compliance burden: operators must obtain and follow the manufacturer's service bulletin (de Havilland SB 8-25-80 Rev A) and carry out the installation/inspection to the AD standard. The AD does not include alternative methods of compliance or explicit waivers in the text provided. (Requirement)\n\n\n### Distribution of benefits and costs\n\n- The AD targets a narrow set of aircraft by serial number, concentrating the compliance cost on owners/operators of those specific aeroplanes. (Applicability)\n\n- The stated safety benefit — removing a direct smoke path between baggage compartment and cabin — is the operative justification given in the Background. That safety effect is the stated benefit that the required work is intended to produce. (Background)\n\n\n### What changed with Amendment 1\n\n- The AD text states that Amendment 1 was issued because the Requirement Document was revised to expand applicability and to add an inspection requirement. That is the explicit scope change described by the instrument. (Amendment 1)\n\n\nSources cited from the instrument: Applicability; Requirement; Compliance; Background; Note; Amendment 1; Header."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"Amendment 1 explicitly expands the scope beyond the original 1993 directive. The amendment was issued specifically because the 'Requirement Document' (the manufacturer's service bulletin) was revised to cover more aircraft and add inspection requirements. This represents a deliberate expansion of regulatory coverage rather than mere clarification."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability criteria (model series and specific serial numbers)","Single primary requirement with one referenced technical standard (Service Bulletin)","Simple compliance deadline structure (single date with exception for prior compliance)","No nested exceptions or conditional logic — straightforward 'unless already done' carve-out","Minimal cross-referencing (one Canadian AD mentioned in a note, not incorporated by complex reference)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:**\nOrders owners and operators of certain Bombardier DHC-8 Series 100A aircraft to install \"close out block seals\" — basically rubber or foam seals that block gaps — on the bulkhead (wall) between the passenger cabin and the baggage compartment.\n\n**Why it matters:**\nSome aircraft were built without these seals during a manufacturing upgrade. Without them, smoke from a fire in the baggage area could flow directly into the cabin, endangering passengers and crew. This directive closes that safety gap.\n\n**Who it affects:**\n- **Specific aircraft:** DHC-8-100A planes with serial numbers 191 and 225 through 307\n- **What they must do:** Install the seals following the manufacturer's Service Bulletin (SB 8-25-80 Rev A)\n- **Deadline:** Before 11 March 1994 (unless already done under the original 1993 directive)\n\n**What's new in this version (Amendment 1):**\nThe manufacturer revised their instructions, so this update:\n- Expands which aircraft are covered (broader applicability)\n- Adds an inspection requirement to check the work\n\n**Cross-reference:** This aligns with a Canadian safety order (Transport Canada AD CF-92-16) since the aircraft are Canadian-made."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-22-amdt-1-bulkhead-smoke-seal","history":"/api/acts/ad-dhc-8-22-amdt-1-bulkhead-smoke-seal/history","analysis":"/api/acts/ad-dhc-8-22-amdt-1-bulkhead-smoke-seal/analysis","conflicts":"/api/acts/ad-dhc-8-22-amdt-1-bulkhead-smoke-seal/conflicts","importantCases":"/api/acts/ad-dhc-8-22-amdt-1-bulkhead-smoke-seal/important-cases","documents":"/api/acts/ad-dhc-8-22-amdt-1-bulkhead-smoke-seal/documents"}}