{"id":"F2006B02678","name":"AD/B727/156 - Main Cargo Deck Floor Beams","slug":"ad-b727-156-main-cargo-deck-floor-beams","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41994,"registerId":"commonwealth-F2006B02678-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/156 - Main Cargo Deck Floor Beams","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 727 Series Aeroplanes\n\nAD/B727/156 Main Cargo Deck Floor Beams 3/99\n\nApplicability: Model 727 series aircraft that have been converted from a passenger to a cargo- carrying (“freighter”) configuration in accordance with Supplemental Type Certificate (STC) SA1444SO, SA1509SO, SA1543SO, SA1896SO, SA1740SO, or SA1667SO.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 98-26-21 Amdt 39- 10964.\n\nRevise the Limitations Sections of the Aircraft Flight Manual (AFM) and AFM Supplements to include the Flight Manual information specified in FAA AD 98-26-21 Amdt 39-10964. This task may be accomplished by inserting a copy of the FAA AD in the AFM and AFM Supplements.\n\nCompliance: As specified in the Requirement Document with a revised effective date of 25 March 1999.\n\nThis Airworthiness Directive becomes effective on 25 March 1999.\n\nBackground: The FAA has determined that under certain conditions unreinforced floor structure of the main cargo deck is not strong enough to enable the aircraft to safely carry the maximum payload that is currently allowed in this area. The actions specified by this Directive are intended to prevent failure of the floor structure, which could lead to loss of the aircraft.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted airworthiness directive addressing a specific structural safety issue in converted Boeing 727 freighters. The scope remains precisely limited to the identified safety risk and affected aircraft configurations."},"complexity_factors":["Very short document (under 200 words)","Only 6 defined STC numbers in the applicability section","Single compliance pathway (revise flight manuals)","No nested conditions or exceptions","References only one external document (FAA AD 98-26-21)","No interpretation section or defined terms"],"plain_english_summary":"This FAA safety order requires operators of certain Boeing 727 passenger-to-freighter conversions (those modified under STCs SA1444SO, SA1509SO, SA1543SO, SA1896SO, SA1740SO, or SA1667SO) to insert the FAA directive into their flight manuals to impose new operating limits. \n\nIt addresses an unreinforced cargo floor that can fail under heavy loads, reducing the risk of structural loss until proper reinforcements are made. Effective 25 March 1999."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains focused on converted Boeing 727 freighters specified by the listed STCs and requires AFM revisions to incorporate FAA AD 98‑26‑21. The Directive does not broaden applicability beyond those aircraft or add new structural mandates beyond adopting the FAA AD material."},"complexity_factors":["Cross‑reference to an external technical document (FAA AD 98‑26‑21) — requires operators to follow another regulator’s detailed requirements rather than containing full technical steps.","Narrow applicability: only affects Boeing 727 aircraft converted to freighters under specific STCs (SA1444SO, SA1509SO, SA1543SO, SA1896SO, SA1740SO, SA1667SO).","Action required is administrative (revise/insert AFM material) rather than immediate structural modification, which reduces hands‑on complexity but creates operational constraints.","Fixed compliance deadline (effective 25 March 1999) imposes a concrete timetable for operators to act.","Safety‑critical consequence if not complied with (risk of floor failure and potential loss of aircraft) increases regulatory and enforcement significance.","Operational impact: enforcing revised payload limits may change loading practices and commercial capacity for affected aircraft.","Administrative burden on operators to update AFMs and ensure crew and ground staff follow the new limitations."],"plain_english_summary":"Mandates Boeing 727s converted to freighters under the listed Supplemental Type Certificates to update their Aircraft Flight Manual (AFM) limitations with the FAA’s cargo‑deck strength guidance (Applicability; Requirement). Operators must insert or otherwise adopt FAA AD 98‑26‑21 into AFMs by 25 March 1999; operators pay for the manual change and must apply any revised payload limits to prevent main cargo deck floor failure (Compliance; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-156-main-cargo-deck-floor-beams","history":"/api/acts/ad-b727-156-main-cargo-deck-floor-beams/history","analysis":"/api/acts/ad-b727-156-main-cargo-deck-floor-beams/analysis","conflicts":"/api/acts/ad-b727-156-main-cargo-deck-floor-beams/conflicts","importantCases":"/api/acts/ad-b727-156-main-cargo-deck-floor-beams/important-cases","documents":"/api/acts/ad-b727-156-main-cargo-deck-floor-beams/documents"}}