{"id":"F2006B03218","name":"AD/B747/38 Amdt 4 - Body Station 1241 Bulkhead Splice","slug":"ad-b747-38-amdt-4-body-station-1241-bulkhead-splice","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42590,"registerId":"commonwealth-F2006B03218-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/38 Amdt 4 - Body Station 1241 Bulkhead Splice","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/B747/38\n\nAmdt 4\n\n  \nBody Station 1241 Bulkhead Splice 6/95\n\nApplicability: Boeing B747 aircraft Serial Number 1-675, 677- 678, 680-684, 686-689 in 18 groups as listed in Boeing Service Bulletin (SB) 747-53-2283, Revision 4.\n\nRequirement: Inspect, visually, by eddy current and ultrasonically, the body station (BS) 1241 splice strap and forging in accordance with Boeing SB 747-53-2283, Revision 4.\n\nNote: FAA AD 92-08-02 refers.\n\nCompliance: Inspect at the thresholds & intervals specified in Boeing SB 747-53-2283, Rev 4. The effective date of changes introduced by this Amendment is 25 May 1995.\n\nBackground: Cracks have been found in the BS 1241 splice strap and forging, even on aircraft which have been modified to SB 747-53-2219 or the production equivalent.\n\nUndetected cracking could lead to loss of cabin pressure and structural failure.\n\nThis Amendment references the latest FAA AD and Revision 4 of the actioning document, SB 747-53-2283, which requires additional inspections in response to the recommendations of the Ageing Fleet B747 Structures Working Group.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 4 to an existing Airworthiness Directive. It remains tightly focused on its original purpose: inspecting the BS 1241 bulkhead splice for cracks. The amendment simply updates the technical reference to the latest Boeing Service Bulletin revision and incorporates new FAA requirements, without expanding the scope beyond this specific structural inspection."},"complexity_factors":["Short, single-purpose directive (approximately 250 words)","Only 1 defined term implicitly referenced (Body Station 1241)","Single cross-reference to FAA AD 92-08-02 and Boeing Service Bulletin 747-53-2283 Rev 4","Clear applicability list (specific serial numbers)","Straightforward compliance requirement with no nested exceptions or conditional logic","Technical aviation terminology requires domain knowledge but the legal structure is simple"],"plain_english_summary":"This safety order requires operators of early Boeing 747s (roughly the first 689 airframes, excluding a few) to inspect the Body Station 1241 bulkhead splice—a critical fuselage joint—using visual, eddy-current, and ultrasonic methods. It responds to discovered cracks (including recurring defects) and updates prior directives to prevent loss of cabin pressure or structural failure by imposing the inspection regime in Boeing SB 747-53-2283 (Rev. 4)."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This Amendment expands the inspection programme: it references FAA AD 92-08-02 and Boeing SB 747-53-2283 Revision 4 and requires additional inspections in response to the Ageing Fleet B747 Structures Working Group recommendations, beyond prior modifications (Background; Requirement)."},"complexity_factors":["Narrow, aircraft-specific applicability referencing serial-number groups in Boeing SB 747-53-2283 (Applicability)","Technical inspection methods required: visual, eddy-current and ultrasonic (Requirement)","Mandatory reliance on an external normative document (Boeing SB 747-53-2283 Rev 4) for procedures, thresholds and intervals (Requirement; Compliance)","Cross-reference to an FAA airworthiness directive and Ageing Fleet working group recommendations (Background)","Safety-critical consequences driving inspection urgency (undetected cracking → cabin pressure loss/structural failure) (Background)","Effective date and amendment history that change compliance timing (Compliance; AD header)"],"plain_english_summary":"Issued by the Civil Aviation Safety Authority, this AD requires operators of specified Boeing 747s (serial numbers listed in Boeing SB 747-53-2283 Rev 4) to inspect the body station 1241 splice strap and forging by visual, eddy‑current and ultrasonic methods, following the procedures and intervals in that Service Bulletin; operators must arrange the inspections. The Amendment adds inspections after cracks were found because undetected cracking could lead to loss of cabin pressure and structural failure. (Applicability; Requirement; Compliance; Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-38-amdt-4-body-station-1241-bulkhead-splice","history":"/api/acts/ad-b747-38-amdt-4-body-station-1241-bulkhead-splice/history","analysis":"/api/acts/ad-b747-38-amdt-4-body-station-1241-bulkhead-splice/analysis","conflicts":"/api/acts/ad-b747-38-amdt-4-body-station-1241-bulkhead-splice/conflicts","importantCases":"/api/acts/ad-b747-38-amdt-4-body-station-1241-bulkhead-splice/important-cases","documents":"/api/acts/ad-b747-38-amdt-4-body-station-1241-bulkhead-splice/documents"}}