{"id":"F2006B09050","name":"AD/DHC-2/31 - Fuselage Station 228 Bulkhead","slug":"ad-dhc-2-31-fuselage-station-228-bulkhead","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52773,"registerId":"commonwealth-F2006B09050-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-2/31 - Fuselage Station 228 Bulkhead","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)  \nDHC-2 (Beaver) Series Aeroplanes\n\nAD/DHC-2/31 Fuselage Station 228 Bulkhead 1/99\n\nApplicability: All model DHC-2 Mk. I and Mk. II “Beaver” aircraft and Mk. III “Turbo Beaver” aircraft.\n\nRequirement: Inspect the rear fuselage bulkhead at station 228 in accordance with Bombardier Inc. de Havilland Service Bulletin 2/52 or TB/60, as applicable.\n\nIf cracks are found, before further flight, replace the bulkhead, or repair the bulkhead in accordance with repair instructions from the manufacturer.\n\nNote: Transport Canada AD CF-98-38 refers.\n\nCompliance: Unless the initial inspection is already accomplished, before 1 December 1999; thereafter at intervals not to exceed 5 years.\n\nThis Airworthiness Directive becomes effective on 28 January 1999.\n\nBackground: Transport Canada received reports of cracks in the bulkhead at fuselage station 228 of three DHC-2 aircraft which had accumulated between 10,000 and 12,000 flight hours.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, targeted Airworthiness Directive addressing a specific safety-of-flight issue (fatigue cracking in a known vulnerable location). The scope remains precisely limited to the identified safety risk on the specified aircraft type, with no evidence of scope creep or expansion beyond the original safety purpose."},"complexity_factors":["Single, clearly defined applicability (three specific aircraft models)","One primary requirement with a straightforward conditional (inspect → if cracks found, repair/replace)","Only 2 cross-references (to manufacturer service bulletins and a Canadian AD)","Simple compliance timeline (initial deadline + recurring 5-year interval)","No defined terms section, no nested exceptions, no delegated legislation references","Total length: approximately 150 words of substantive content"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding. If you own or operate the affected planes, you MUST follow these instructions.\n\n**Who it affects:** Owners and operators of **DHC-2 \"Beaver\" aircraft** — specifically the Mk. I, Mk. II, and Mk. III \"Turbo Beaver\" models. These are Canadian-built bush planes popular in Australia for remote area operations.\n\n**What it requires:**\n- **Inspect** a specific structural part called the \"fuselage station 228 bulkhead\" (a metal wall/frame in the rear of the plane's body) using manufacturer instructions from Bombardier/de Havilland.\n- **If cracks are found:** You cannot fly the aircraft again until you either replace the bulkhead entirely or repair it using official manufacturer repair procedures.\n- **When:** First inspection due before 1 December 1999 (unless already done), then repeat every 5 years.\n\n**Why it matters:** Transport Canada (the Canadian aviation regulator) found cracks in this bulkhead on three aircraft after 10,000–12,000 flight hours. Cracks in a fuselage bulkhead can compromise the plane's structural integrity — potentially catastrophic in flight. This AD prevents accidents by forcing inspection and repair before failure occurs.\n\n**Key point:** This is **not optional**. Non-compliance means the aircraft is not legally airworthy."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive's scope aligns with the stated purpose in the Background: it targets the rear fuselage bulkhead at station 228 on the listed DHC-2 models in response to reported cracking. It requires inspections, and where cracks are found, repair or replacement before further flight (Background; Requirement). The applicability, required action and inspection interval are all specified within the directive and do not broaden or narrow the stated technical target beyond addressing that bulkhead on the named models (Applicability; Requirement; Compliance)."},"complexity_factors":["Technical inspection and repair procedures are defined outside the text and must be followed via Bombardier de Havilland Service Bulletin 2/52 or TB/60 (Requirement).","Mandatory immediate action if cracks are found: replacement or manufacturer-authorised repair before further flight (Requirement).","Recurring compliance interval (every 5 years) creates ongoing obligation and cost (Compliance).","Applicability covers multiple DHC-2 model variants, so operators must check fleet applicability (Applicability).","Reference to a foreign airworthiness directive (Transport Canada AD CF-98-38) as related material, requiring cross-reference by operators (Note).","Directive is issued and effective as of a stated date, establishing enforceable timing (Effective date, Compliance)."],"plain_english_summary":"This directive requires owners/operators of specified DHC‑2 “Beaver” models to inspect the rear fuselage bulkhead at station 228 per Bombardier service bulletin/technical bulletin, initially by 1 Dec 1999 and every five years thereafter. If cracks are found the aircraft must not fly until the bulkhead is repaired or replaced per manufacturer instructions. Costs and downtime fall to operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-2-31-fuselage-station-228-bulkhead","history":"/api/acts/ad-dhc-2-31-fuselage-station-228-bulkhead/history","analysis":"/api/acts/ad-dhc-2-31-fuselage-station-228-bulkhead/analysis","conflicts":"/api/acts/ad-dhc-2-31-fuselage-station-228-bulkhead/conflicts","importantCases":"/api/acts/ad-dhc-2-31-fuselage-station-228-bulkhead/important-cases","documents":"/api/acts/ad-dhc-2-31-fuselage-station-228-bulkhead/documents"}}