{"id":"F2006B01964","name":"AD/A320/75 - Longitudinal Floor Beams at Frame 43","slug":"ad-a320-75-longitudinal-floor-beams-at-frame-43","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41186,"registerId":"commonwealth-F2006B01964-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A320/75 - Longitudinal Floor Beams at Frame 43","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)  \nAirbus Industrie A319, A320 and A321 Series Aeroplanes\n\nAD/A320/75 Longitudinal Floor Beams at Frame 43 2/97\n\nApplicability: Airbus A320, all models, all serial numbers, without Airbus Industrie Modification 20904 or Airbus Industrie Service Bulletin (SB) A320-53-1008 incorporated.\n\nRequirement: Inspect the bottom flanges of the longitudinal floor beams at frame 43 in accordance with Airbus Industrie SB A320-53-1085.\n\nNote: French DGAC AD 96-236-089(B) refers.\n\nCompliance: Inspect before exceeding 20 000 flights. Re-inspect at intervals not exceeding 6000 flights or, if cracks are detected, re-inspect at the intervals defined in Airbus Industrie SB A320-53-1085.\n\nNote: Modification of the aircraft in accordance with Airbus Industrie SB A320-53-1008 is terminating action for this Directive.\n\nThis Airworthiness Directive becomes effective on 30 January 1997.\n\nBackground: During the full-scale fatigue test of the airframe, cracks were detected in the bottom flange of the longitudinal floor beams, which attach the pressure diaphragm at frame\n\n43. This directive is issued to detect cracks in this area before the structural integrity of the airframe is affected.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original, narrow scope. It addresses a specific structural issue discovered during fatigue testing — cracks in floor beams at frame 43 of A320 aircraft. The directive has not expanded beyond this original safety purpose."},"complexity_factors":["Single, specific mechanical component addressed (longitudinal floor beams at frame 43)","Clear applicability criteria (specific aircraft models, serial numbers, and modification status)","Straightforward compliance timeline (initial inspection at 20,000 flights, recurring every 6,000 flights)","Single terminating action clearly identified (Service Bulletin A320-53-1008)","No nested exceptions or conditional logic beyond the standard 'if cracks detected' scenario","Minimal cross-referencing (only references to specific Airbus Service Bulletins and French DGAC AD)","Short document length (approximately 200 words)"],"plain_english_summary":"This safety order requires operators of Airbus A319/A320/A321 airplanes that have not received Modification 20904 or SB A320‑53‑1008 to inspect the bottom flanges of the longitudinal floor beams at frame 43 for cracks. A first check is required before 20,000 flights and then every 6,000 flights; discovered cracks must follow Airbus SB A320‑53‑1085 re‑inspection intervals. Installing the SB/modification is a terminating action. The measure addresses fatigue cracks found during testing to prevent structural failure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope aligns with the directive's stated purpose in the Background: detect cracks in the frame‑43 floor beam bottom flanges before airframe integrity is affected. It applies only to aircraft without Mod 20904 or SB A320‑53‑1008 and provides a terminating modification; there is no indication in the text that the applicable population or inspection objectives were expanded beyond that intent."},"complexity_factors":["Targeted applicability: affects only A319/A320/A321 without Mod 20904 or SB A320‑53‑1008 (Applicability) — requires checking operator records to determine status.","Technical inspection delegated to Airbus SB A320‑53‑1085 (Requirement) — operators must follow an external service bulletin for inspection method and criteria.","Flight-count compliance metric: deadlines set in flights (before 20,000 flights; re‑inspect ≤6,000‑flight intervals) (Compliance) — requires accurate flight logging and cumulative tracking.","Terminating action: incorporation of SB A320‑53‑1008 or Mod 20904 ends recurring inspections (Compliance/Note) — creates a one-time upgrade trade‑off versus recurring inspection costs.","Contingent escalation: if cracks are found, re‑inspection intervals follow the Airbus SB (Compliance) — inspection burden may increase unpredictably based on findings.","Regulatory dependency: references French DGAC AD and Airbus documentation (Note/Requirement) — implementation depends on external technical guidance rather than self-contained rule text."],"plain_english_summary":"Requires operators of Airbus A319/A320/A321 aeroplanes (unless Mod 20904 or SB A320‑53‑1008 is already embodied) to inspect the bottom flanges of the longitudinal floor beams at frame 43 in line with Airbus SB A320‑53‑1085. Inspections must occur before 20,000 flights and then at intervals no greater than 6,000 flights; incorporating SB A320‑53‑1008 or Mod 20904 stops the inspection requirement. The action responds to fatigue cracks found in testing; operators pay inspection and modification costs and must track flight counts to comply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-75-longitudinal-floor-beams-at-frame-43","history":"/api/acts/ad-a320-75-longitudinal-floor-beams-at-frame-43/history","analysis":"/api/acts/ad-a320-75-longitudinal-floor-beams-at-frame-43/analysis","conflicts":"/api/acts/ad-a320-75-longitudinal-floor-beams-at-frame-43/conflicts","importantCases":"/api/acts/ad-a320-75-longitudinal-floor-beams-at-frame-43/important-cases","documents":"/api/acts/ad-a320-75-longitudinal-floor-beams-at-frame-43/documents"}}