{"id":"F2006B02625","name":"AD/B727/102 Amdt 1 - Bolt Attaching Slat to Slat Track","slug":"ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41941,"registerId":"commonwealth-F2006B02625-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/102 Amdt 1 - Bolt Attaching Slat to Slat Track","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 727 Series Aeroplanes\n\n \n\n# AD/B727/102\n\nAmdt 1\n\nApplicability: All Models.\n\n\n# Bolt Attaching Slat to Slat Track  4/87 DM\n\n \n\nRequirement: Retire from service all NAS 1305-43W bolts which attach the wing leading edge slats to the slat tracks. All slats (ie. Nos. 1 to 8) are affected.\n\n \n\nNote: Larger (3 inch) diameter bolts installed in accordance 8 with Boeing SB No. 727-57-134 are not affected.\n\n \n\nCompliance: Before exceeding 20,000 landings component time in service, or:\n\n \n\nfor bolts fitted to slats 2, 7, 4 and 5 - within the next 1,000 landings after 20 February\n\n1987; or\n\n \n\nfor bolts fitted to slats 1, 8, 3 and 6 - at the next “C” check after 20 February 1987; whichever is the later.\n\nBackground: Numerous fatigue failures have occurred in the NAS 1305-43W bolt which attach the wing leading edge slats to the slat tracks. All slats are at risk. This amendment increases the retirement life to 20,000 landings for all bolts, based on a more rigorous analysis of the reported defect experience and failure effects. The initial compliance period for high time bolts has been extended where that experience shows this to be permissible.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive (AD/B727/102), but it remains tightly scoped to its original purpose: addressing fatigue failures in specific slat attachment bolts on Boeing 727 aircraft. The amendment slightly extends compliance timeframes based on improved failure analysis, which is a standard refinement within the original safety intent rather than scope creep."},"complexity_factors":["Single technical requirement with clear applicability","Only 4 defined elements (bolt type, slat positions, compliance deadlines, exception)","Simple conditional logic: two-tier compliance schedule based on slat position numbers","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Straightforward exception for modified aircraft (one service bulletin reference)","Document is essentially a one-page maintenance instruction"],"plain_english_summary":"This directive requires Australian operators of Boeing 727s to remove and replace NAS 1305-43W bolts that attach all eight slats per wing because of metal-fatigue failures. It sets landing- and maintenance-based compliance deadlines for different slat positions, with an exception for larger 3‑inch bolts installed per Boeing SB 727-57-134. The change prevents slat failures that could impair control during takeoff/landing."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment increases the retirement life for the specified NAS 1305-43W bolts to 20,000 landings and modifies initial compliance timing for higher-time bolts (Background). It also clarifies that larger 3-inch bolts fitted per Boeing Service Bulletin 727-57-134 are excluded from the retirement requirement (Note). The change adjusts previous retirement and scheduling requirements by lengthening component life and extending initial compliance where experience permits (Background)."},"complexity_factors":["Applicability is broad: affects all Boeing 727 models (Applicability: All Models).","Specific part targeted: NAS 1305-43W bolts that attach slats to slat tracks (Requirement).","Different compliance windows by slat position: slats 2,7,4,5 have a 1,000-landing window after 20 Feb 1987; slats 1,8,3,6 must comply at next “C” check after that date (Compliance).","Universal retirement life set at 20,000 landings for all affected bolts (Compliance; Background).","Exception for larger 3-inch bolts installed per Boeing SB 727-57-134 — those are not affected (Note).","Timing rule uses a mixed trigger: 'before exceeding 20,000 landings component time in service, or [earlier specified windows], whichever is the later' — creates scheduling complexity (Compliance).","Operational compliance burden on aircraft operators: tracking component landing counts, planning replacements during maintenance checks, procuring replacement fasteners (Requirement; Compliance).","No enforcement mechanism or penalties stated in the text — compliance relies on regulatory oversight and operator maintenance practices (text silent on penalties).","Amendment rationale and change in life limit are data-driven per the Background, which alters prior maintenance planning (Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 727 aircraft to remove from service all NAS 1305-43W bolts that attach the wing leading edge slats to slat tracks and replace them before they reach a specified life limit. It affects every model of the 727 and matters because the bolts have suffered fatigue failures; operators must schedule replacements and track landing counts to meet the retirement and timing rules (Requirement; Compliance; Note; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track","history":"/api/acts/ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track/history","analysis":"/api/acts/ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track/analysis","conflicts":"/api/acts/ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track/conflicts","importantCases":"/api/acts/ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track/important-cases","documents":"/api/acts/ad-b727-102-amdt-1-bolt-attaching-slat-to-slat-track/documents"}}