{"id":"F2006B03043","name":"AD/B747/142 - Fuselage Skin Lap Joints","slug":"ad-b747-142-fuselage-skin-lap-joints","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42402,"registerId":"commonwealth-F2006B03043-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/142 - Fuselage Skin Lap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)  \nBoeing 747 Series Aeroplanes\n\nAD/B747/142 Fuselage Skin Lap Joints 5/95\n\nApplicability: All B747 aircraft listed in Boeing Service Bulletin 747-53-2367 revision 1 dated 27 January 1994.\n\nRequirement: 1. Inspect, using the specified surface high frequency eddy current method, the upper fastener row of the lap joints nominated in Boeing Service Bulletin 747-53-2367 revision 1 dated 27 January 1994.\n\n2. If cracks are found, remove the upper row fasteners for one frame bay either side of the crack, and inspect the open holes using the high frequency eddy current inspection method specified in Boeing Service Bulletin 747-53-2367 revision 1, dated 27 January 1994.\n\nNote: FAA AD 94-12-04 refers.\n\nCompliance: 1. Initial inspection, before 22000 full pressure cycles or within 1000 full pressure cycles after 27 April 1995, whichever occurs last.\n\nRe-inspect at intervals not exceeding 3000 full pressure cycles.\n\n2. Before further flight.\n\nNote: A full pressure cycle shall be that where the cabin differential pressure equals or exceeds 2.0 psi.\n\nBackground: Boeing has completed extended pressure tests on two B747 fuselage test articles.\n\nThese tests have identified areas of the fuselage lap joints where fatigue cracking is likely to occur. The inspection and repair of these areas is necessary to ensure continued safe operation of the B747.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1412},"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope as a targeted structural inspection requirement. It addresses the specific safety risk of fatigue cracking in B747 fuselage lap joints identified during Boeing's extended pressure testing, without expanding into broader operational or maintenance areas."},"complexity_factors":["Technical aviation terminology requiring specialized knowledge (eddy current inspection, lap joints, frame bays, pressure cycles)","Cross-reference to external Boeing Service Bulletin documentation for specific applicability and methods","Conditional compliance pathways (immediate action required if cracks detected vs. routine monitoring)","Precise numerical thresholds for compliance timing (22000 cycles, 1000 cycles, 3000 cycles, 2.0 psi differential)"],"plain_english_summary":"This rule requires operators of Boeing 747s identified in Boeing Service Bulletin 747‑53‑2367 to perform regular, specialized high‑frequency eddy‑current inspections of lap‑joint fasteners (top row) to detect metal‑fatigue cracks. It mandates initial and recurring checks and removal/inspection of affected fasteners when cracking is found. The inspections target a known fatigue risk to prevent fuselage structural failure and rapid decompression."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-142-fuselage-skin-lap-joints","history":"/api/acts/ad-b747-142-fuselage-skin-lap-joints/history","analysis":"/api/acts/ad-b747-142-fuselage-skin-lap-joints/analysis","conflicts":"/api/acts/ad-b747-142-fuselage-skin-lap-joints/conflicts","importantCases":"/api/acts/ad-b747-142-fuselage-skin-lap-joints/important-cases","documents":"/api/acts/ad-b747-142-fuselage-skin-lap-joints/documents"}}