{"id":"F2006B09178","name":"AD/DHC-8/23 Amdt 3 - NLG Upper Drag Strut Trunnion Fittings","slug":"ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52939,"registerId":"commonwealth-F2006B09178-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/23 Amdt 3 - NLG Upper Drag Strut Trunnion Fittings","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-8/23\n\nAmdt 3\n\n  \nNLG Upper Drag Strut Trunnion Fittings 11/95\n\nApplicability: Model DHC-8, Series 100 and 300, serial numbers 003 through 395, except 011, 362, and 391, and which have accumulated more than 500 flight cycles.\n\nRequirement: Action in accordance with the Accomplishment Instructions contained in de Havilland ASB A8-53-40 Revision A:\n\n    Visually inspect, in-situ, the drag strut trunnion fittings for cracks, and torque check all the fasteners securing the fittings.\n\nIf cracks are found on either fitting, replace both fittings with serviceable fittings prior to further flight.\n\n    2. (a) During the initial inspection, any fasteners found loose by the torque check must be replaced with new parts.\n\n(b) During subsequent inspections, any fastener found loose by the torque check must be tightened properly.\n\n    3. For aircraft already fitted with de Havilland Modification 8/1880, re-instate (or commence) the repetitive inspection required by parts 1 and 2 above in accordance with the schedule below:\n\n    (a) If the aircraft has 900 or more flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed within the subsequent 100 flight cycles.\n\n    (b) If the aircraft has less than 900 flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed at or before the due date of the actual 1000 flight cycle interval, determined from the last inspection (or incorporation of Modification 8/1880).\n\nIncorporation of de Havilland Modification 8/2139 (Introduction of New Trunnion Fittings and Fasteners for Drag Link of Nose Landing Gear) provides terminating action to the inspection requirements of this Directive. De Havilland Service Bulletin 8-53-49, dated 30 June 1995, provides approved instructions to incorporate Modification 8/2139 for aircraft not incorporating this modification during production.\n\nNote: Transport Canada AD CF-92-18R3 refers.\n\nCompliance: Initially, within 500 flight cycles after 12 November 1992, unless already accomplished during the last 500 flight cycles; and thereafter at intervals not to exceed 1000 flight cycles.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThe compliance of the initial issue of this Directive remains unchanged. This Amendment is effective from 12 October 1995.\n\nBackground: Cracks have been found in the two trunnion fittings that retain and support the nose landing gear upper drag strut. Investigations have indicated that this cracking problem is caused by ground handling loads that appear to be higher than originally predicted. This condition may be further aggravated by loose fasteners.\n\nAmendment 1 introduced optional terminating action. Amendment 2 rescinded the terminating action provided by an earlier issue of the AD. This action was prompted by reports that, due to bolt head gapping, installation difficulties have been encountered during incorporation of Modification 8/1880 on the aircraft, resulting in improper attachment of the fitting which, in turn, may cause the bolts to lose pre- tension.\n\nAmendment 3 is issued to introduce optional terminating action to the inspection requirements of this Directive.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Yes. The Directive's inspection requirements remain, but Amendment 3 re-introduces an optional terminating action—incorporation of Modification 8/2139—to end the repetitive inspections. Earlier amendments had introduced and then rescinded terminating action; Amendment 3 restores optional terminating relief and points operators to de Havilland Service Bulletin 8-53-49 for modification instructions."},"complexity_factors":["Technical specificity: precise aircraft models and limited serial-number range (003–395, except 011, 362, 391)","Multiple flight-cycle thresholds and timing rules (initial within 500 cycles, recurring ≤1000 cycles, special scheduling around 900/1000-cycle markers)","Conditional actions: different responses for cracks (replace both fittings) and loose fasteners (replace on initial inspection, tighten on subsequent inspections)","Terminating action via incorporation of Modification 8/2139 and cross-reference to a Service Bulletin for approved instructions","Interaction with previous amendments: Amendment 1, 2 and 3 changed availability/status of terminating action, requiring careful tracking of amendment history","References to related directives and foreign AD (Transport Canada AD CF-92-18R3), increasing cross-regulatory coordination","Operational impact on maintenance planning and part procurement (serviceable fittings, new fasteners where required)"],"plain_english_summary":"This airworthiness directive requires operators of Bombardier DHC-8 Series 100 and 300 aeroplanes (specific serial numbers) with more than 500 flight cycles to inspect the nose-landing-gear upper drag strut trunnion fittings for cracks, torque-check fasteners, and replace fittings if cracks are found. It sets initial and recurring inspection intervals and allows terminating the inspections if a specified modification (8/2139) is installed. It matters to aircraft owners, maintenance organisations and pilots because cracking was found that could affect landing-gear support."},"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":true,"description":"The original directive (1992) required repetitive inspections only. Amendment 1 added optional terminating action, which Amendment 2 then rescinded due to installation problems. Amendment 3 now reintroduces a different optional terminating action (Modification 8/2139 instead of the problematic 8/1880). The scope has evolved from pure inspection mandate to inspection-with-optional-termination, then back to pure inspection, and now back to inspection-with-optional-termination using different hardware."},"complexity_factors":["Multiple amendment history referenced (Amendments 1, 2, and 3) with cross-references to previous regulatory actions","Conditional logic for inspection intervals based on flight cycle counts (500, 900, 1000 cycles) and modification status","Different treatment of loose fasteners between initial vs. subsequent inspections (replacement vs. tightening)","Specific serial number applicability with three explicit exclusions (011, 362, 391)","Reference to external technical documents (de Havilland ASB A8-53-40, Service Bulletin 8-53-49, Transport Canada AD CF-92-18R3, Modifications 8/1880 and 8/2139)","Nested conditions for aircraft already modified vs. unmodified aircraft","Dual effective dates mentioned (12 November 1992 for original, 12 October 1995 for this amendment)"],"plain_english_summary":"This directive requires operators of Bombardier DHC‑8 Series 100/300 (S/N 003–395, excluding three) with more than 500 flights to inspect nose‑landing‑gear trunnion fittings for cracks and check bolt torque, repair or replace cracked fittings before further flight, and repeat inspections at intervals (or until the approved hardware upgrade is installed). It addresses cracking from heavy ground handling and loose bolts to prevent landing‑gear failure; installing Modification 8/2139 eliminates the inspection requirement."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings","history":"/api/acts/ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings/history","analysis":"/api/acts/ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings/analysis","conflicts":"/api/acts/ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings/conflicts","importantCases":"/api/acts/ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings/important-cases","documents":"/api/acts/ad-dhc-8-23-amdt-3-nlg-upper-drag-strut-trunnion-fittings/documents"}}