{"id":"F2006B01942","name":"AD/A320/52 - Rear Fuselage Skin Lap Joints","slug":"ad-a320-52-rear-fuselage-skin-lap-joints","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41164,"registerId":"commonwealth-F2006B01942-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A320/52 - Rear Fuselage Skin Lap Joints","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/A320/52 Rear Fuselage Skin Lap Joints 5/95\n\nApplicability: A320 series aircraft, serial numbers in Airbus Industrie Service Bulletin (SB) A320- 53-1057, without Modification 21905K2008 incorporated.\n\nRequirement: Inspect, using detailed visual or eddy current method, the upper rivet row of the longitudinal lap joints between:-\n\nFrame 48 and Frame 64 next to stringer 6 LH and RH Frame 60 and Frame 64 next to stringer 32 LH\n\nFrame 59 and Frame 64 next to stringer 32 RH Frame 58 and Frame 64 next to stringer 41 RH\n\nInspect in accordance with Airbus Industrie SB A320-53-1057.\n\nNote: The inspection of stringer 32 RH lap joint is only applicable to aircraft SN 003, 004, 045 to 051, 056 and 057 which do not have the additional rear cargo door installed (modification number 20029).\n\nCompliance: Initially inspect before 20 000 flights.\n\nRe-inspect at intervals not to exceed:\n\n    4 000 flights, if last inspected visually; or,\n\n    ii. 12 000 flights, if last inspected by eddy current.\n\nNote: Modification in accordance with Airbus Industrie SB A320-53-1056, after the inspection area has been shown to be crack free, cancels the inspection requirements of this AD.\n\nBackground: Cracks have been found in the longitudinal lap joints of the fatigue test specimen at 76000 flights. Inspections around NAS1097-5 rivets installed in upper skins which are less than 1.8 mm thick are required to prevent multi-site damage causing loss of pressurisation.","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 a discrete, targeted airworthiness directive focused on a specific structural integrity issue identified during fatigue testing. The scope remains tightly confined to the original safety concern: preventing multi-site damage in rear fuselage lap joints. The various conditions and exceptions are technical precision tools to target only affected aircraft, not scope creep."},"complexity_factors":["Multiple conditional applicability criteria (serial number ranges, modification status, cargo door configuration)","Technical aviation terminology requiring specialized knowledge (stringers, frames, lap joints, eddy current testing)","Cross-references to external Airbus documents (Service Bulletins A320-53-1057 and A320-53-1056)","Nested exception for stringer 32 RH inspection (limited to specific serial numbers AND specific modification status)","Dual compliance pathways with different intervals (4,000 vs 12,000 flights depending on inspection method)","Termination condition requiring both modification installation AND crack-free verification"],"plain_english_summary":"This Airworthiness Directive requires operators of certain Airbus A319/A320/A321 aircraft (specified serials without factory Mod 21905K2008) to inspect riveted joints in the upper rear fuselage for cracks, using visual or eddy‑current methods. The first check is before 20,000 flights, with repeat inspections every 4,000 flights (visual) or 12,000 flights (eddy current); one joint inspection is limited to ten listed aircraft. Installing the specified modification and proving no cracks ends the inspections. It responds to fatigue‑test cracks that could cause loss of cabin pressure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope is focused and unchanged from its stated purpose: inspect specified rear fuselage lap joints on listed A320‑series airframes to detect fatigue cracks. It does not broaden to other structures or the wider fleet beyond the serial numbers and modification exceptions set out in the directive."},"complexity_factors":["Applicability tied to aircraft serial numbers as listed in an external Airbus Service Bulletin (SB A320‑53‑1057), requiring cross‑referencing","Conditional applicability for one lap joint (stringer 32 RH) depending on presence of additional rear cargo door (Mod 20029)","Two inspection methods with different re‑inspection intervals (detailed visual: 4,000 flights; eddy current: 12,000 flights)","Initial compliance deadline (before 20,000 flights) plus recurring inspection regime","Provision allowing modification (SB A320‑53‑1056) to cancel recurring inspections, creating an alternate compliance pathway"],"plain_english_summary":"Requires certain Airbus A319/A320/A321 aeroplanes (those listed in Airbus SB A320‑53‑1057 that do not have Mod 21905K2008) to undergo detailed visual or eddy‑current inspection of the upper rivet row at specified rear fuselage lap joints. Operators must inspect initially before 20,000 flights and re‑inspect every 4,000 flights if visual or every 12,000 flights if eddy‑current; completing Airbus SB A320‑53‑1056 after a crack‑free inspection cancels the recurring inspections. The directive aims to detect fatigue cracks that could cause loss of pressurisation; inspection and modification costs fall to aircraft operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-52-rear-fuselage-skin-lap-joints","history":"/api/acts/ad-a320-52-rear-fuselage-skin-lap-joints/history","analysis":"/api/acts/ad-a320-52-rear-fuselage-skin-lap-joints/analysis","conflicts":"/api/acts/ad-a320-52-rear-fuselage-skin-lap-joints/conflicts","importantCases":"/api/acts/ad-a320-52-rear-fuselage-skin-lap-joints/important-cases","documents":"/api/acts/ad-a320-52-rear-fuselage-skin-lap-joints/documents"}}