{"id":"F2006B10711","name":"AD/HU 369/49 Amdt 2 - Main Rotor Retention Straps - Inspection","slug":"ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116685,"registerId":"commonwealth-F2006B10711-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HU 369/49 Amdt 2 - Main Rotor Retention Straps - 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)  \nMcDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters\n\nAD/HU 369/49\n\nAmdt 2\n\n  \nMain Rotor Retention Straps \\- Inspection 7/82\n\nApplicability: All 500D model 369D helicopters fitted with main rotor retention straps P/N 369D21210-501 with S/Nos. 7000 thru 9136 and subsequent.\n\nRequirement: Visually inspect each of the five main rotor strap pack assemblies, in the area of and within the pitch housing where the straps are accessible to view, for corrosion, cracks or breaks in any of the laminates. Refer to Figure 1 of either Hughes SIN DN-2.3 or SIN DN-77.1 for maximum permissible crack limits.\n\nCompliance: 1. Within 10 hours time in service after 16 June 1982, unless already accomplished, and thereafter at intervals not exceeding 100 hours time in service for model helicopters fitted with strap S/Nos. 7000 thru 8530 and 9136 and subsequent.\n\n2. Prior to further flight after 7 July 1981, unless already accomplished within the last 25 hours time in service, and thereafter at intervals not exceeding 25 hours time in service or 30 days whichever occurs sooner, for model helicopters fitted with strap S/Nos. 8531 thru 9135.\n\nBackground: The inspection requirement is based on FAA AD 81-10-08 amendment 39-4144.\n\nThis amendment has increased the S/No. applicability of the inspections as a result of the manufacturers recommendation. These inspections are similar and additional to those of AD/HU 369/28D.","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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The amendment broadens applicability by increasing the serial-number range of straps covered (per the manufacturer’s recommendation). It therefore expands the set of helicopters subject to the inspection regime and adds inspections that are described as similar and additional to those in AD/HU 369/28D."},"complexity_factors":["Different compliance intervals tied to strap serial-number groups (S/Ns 7000–8530 & 9136+ vs S/Ns 8531–9135) create scheduling complexity.","Two timing regimes: short-term mandatory inspection windows (10 hours TIS or prior-to-flight) then recurring intervals (100 hours TIS vs 25 hours TIS or 30 days).","Inspection limited to accessible area within the pitch housing — accessibility may vary by airframe configuration and affect labour/time.","Visual inspection criteria reference manufacturer figures (Hughes SIN DN-2.3 or DN-77.1) for maximum permissible crack limits, requiring cross-reference to external documents.","Amendment increases serial-number applicability per manufacturer recommendation, expanding the population of affected parts (requires operators to review records).","Cross-references to FAA AD 81-10-08 and previous AD/HU 369/28D increase regulatory context operators must reconcile."],"plain_english_summary":"This Airworthiness Directive requires operators of McDonnell Douglas (Hughes) / Kawasaki 500D model 369D helicopters fitted with specified main rotor retention strap part and serial numbers to carry out repeated visual inspections of each of the five strap pack assemblies for corrosion, cracks or laminate breaks, using the manufacturer’s figures for permissible crack limits. CASA issued the requirement, operators must schedule and fund the inspections at the stated intervals (which vary by strap serial-number group), and act on any defects found."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"This is Amendment 2 to the original directive. The scope has expanded from earlier versions — the serial number applicability has been increased ('increased the S/No. applicability') to cover more helicopters based on manufacturer recommendations. The original directive likely covered a narrower range of serial numbers, and this amendment brings additional aircraft into the mandatory inspection regime without removing existing requirements."},"complexity_factors":["Multiple compliance schedules based on serial number ranges (two distinct tracks: 7000-8530/9136+ vs 8531-9135)","Cross-references to external documents (Hughes SIN DN-2.3 and SIN DN-77.1 for crack limit diagrams)","Conditional timing language ('unless already accomplished', 'whichever occurs sooner')","Reference to prior directive (AD/HU 369/28D) indicating overlapping regulatory requirements","Specific part and serial number applicability requiring careful record-checking by operators"],"plain_english_summary":"This AD from CASA mandates visual inspections of the layered main-rotor retention straps on Hughes 500D (369D) helicopters for corrosion, cracks or breaks. It applies to straps P/N 369D21210-501 within specific serial ranges and expands the affected range per the amendment.\n\nThese flight‑critical straps must be inspected on the prescribed schedules; failure could lead to main‑rotor separation. The AD mirrors earlier FAA action and tightens inspection coverage."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection","history":"/api/acts/ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection/history","analysis":"/api/acts/ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection/analysis","conflicts":"/api/acts/ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection/conflicts","importantCases":"/api/acts/ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection/important-cases","documents":"/api/acts/ad-hu-369-49-amdt-2-main-rotor-retention-straps-inspection/documents"}}