{"id":"F2006B06998","name":"AD/SF340/69 Amdt 1 - MLG Support Assembly Bearing Housings","slug":"ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48617,"registerId":"commonwealth-F2006B06998-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/69 Amdt 1 - MLG Support Assembly Bearing Housings","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)  \nSAAB SF340 Series Aeroplanes\n\nAD/SF340/69\n\nAmdt 1\n\n  \nMLG Support Assembly Bearing Housings 1/2000\n\nApplicability: Model SF 340A, serial numbers 340A-004 though \\-159.\n\nModel 340B, serial numbers 34B-160 through \\-444.\n\nRequirement: Action in accordance with SAAB Aircraft Mandatory Service Bulletin SAAB 340-57- 036.\n\nNote: LFV AD 1-146 refers.\n\nCompliance: For aircraft with 32,000 total flight cycles or more; within 4,000 flight cycles after 31 December 1999.\n\nFor aircraft with 24,000 to 32,000 total flight cycles; within 6,000 flight cycles after 31 December 1999.\n\nFor aircraft with less than 24,000 total flight cycles; perform at scheduled overhauls (at 12,000 or 24,000 total flight cycles) of the landing gears, or within 6,000 flights after 31 December 1999, whichever occurs later.\n\nThis Amendment becomes effective on 31 December 1999.\n\nBackground: Corrosion has been found in the inboard and outboard bearing housings of the main landing gear support assembly. The cause is considered to be ingress of moisture between the bearing and bearing housing surface. These fittings are currently classified as Safe Life item and not normally considered as Fatigue Critical. Pitting corrosion may initiate fatigue cracks and lead to a reduction of the fatigue life of the support assembly.\n\nAmendment 1 is issued in response to a new LBA AD which introduces an improved NDT method of inspection and a new Requirement document.\n\nThe original issue of this Airworthiness Directive became effective on 25 March 1999.","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":3,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive. The original AD was issued in March 1999; this Amendment 1 updates the inspection method in response to new technical guidance from the German aviation authority (LBA). The scope remains tightly focused on the specific landing gear component and does not expand beyond the original safety purpose."},"complexity_factors":["Short, single-purpose document (1 page)","Only 4 defined applicability categories (two aircraft models with serial number ranges)","Three-tier compliance schedule based on flight cycle thresholds","Single cross-reference to SAAB Aircraft Mandatory Service Bulletin 340-57-036","One external reference to Swedish aviation authority directive (LFV AD 1-146)","Technical aviation terminology requires domain knowledge but is clearly explained in context"],"plain_english_summary":"This AD mandates inspections of the main landing gear support assembly bearing housings on Saab SF340A/B aircraft in Australia after corrosion was found that can lead to crack growth and possible landing gear failure. Compliance timeframes vary by usage (high/medium/low flight counts) and hinge on scheduled overhauls or flight thresholds.\n\nIt matters because these parts were treated as “safe life” but require ongoing NDT monitoring; the amendment updates inspection methods to improved non‑destructive testing to close the safety gap."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Amendment 1 updates the required inspection document and mandates an improved nondestructive inspection method (see 'Amendment 1 is issued...' and 'Requirement: Action in accordance with SAAB...'). Applicability by model and serial number remains the same, but the procedural requirement and inspection technique were changed from the original AD (original effective 25 March 1999; this amendment effective 31 December 1999)."},"complexity_factors":["External normative reference: mandatory reliance on SAAB Mandatory Service Bulletin 340‑57‑036 (Requirement).","Multiple applicability limits by model and serial-number ranges (Applicability).","Tiered compliance windows tied to total flight cycles with different thresholds (<24,000; 24,000–32,000; ≥32,000) and linkage to scheduled overhauls at 12,000/24,000 cycles (Compliance).","Effective-date and retroactive timing (deadlines specified relative to 31 December 1999) creating scheduling pressure (Compliance/Effective date).","Technical inspection change: Amendment introduces an improved NDT method, requiring different procedures and training/equipment (Amendment 1/Background).","Operational burden lies with aircraft operators who must plan, pay for and record inspections and any corrective work (Requirement/Compliance).","Interplay with foreign authority AD (LFV AD 1‑146 and LBA AD referenced), creating cross-jurisdictional compliance considerations (Note/Background).","Safety classification nuance: parts were Safe Life but corrosion may make them fatigue critical, affecting maintenance philosophy and lifecycle planning (Background)."],"plain_english_summary":"Requires operators of Saab SF340A and SF340B aeroplanes (listed serial numbers) to carry out the inspections and corrective actions set out in SAAB Mandatory Service Bulletin 340‑57‑036 for main landing‑gear support assembly bearing housings. Compliance deadlines are tied to total flight‑cycle thresholds or scheduled landing‑gear overhauls; operators must schedule and fund inspections and any repairs. Amendment 1 mandates an improved nondestructive inspection method and updates the required document (effective 31 December 1999) after corrosion was found that can reduce fatigue life."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings","history":"/api/acts/ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings/history","analysis":"/api/acts/ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings/analysis","conflicts":"/api/acts/ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings/conflicts","importantCases":"/api/acts/ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings/important-cases","documents":"/api/acts/ad-sf340-69-amdt-1-mlg-support-assembly-bearing-housings/documents"}}