{"id":"F2006B02681","name":"AD/B727/159 - Main Cargo Deck Floor Beams","slug":"ad-b727-159-main-cargo-deck-floor-beams","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41997,"registerId":"commonwealth-F2006B02681-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/159 - 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/B727/159 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) SA1767SO, SA1768SO, or SA7447SW.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 98-26-18 Amdt 39-10961.\n\nRevise the Limitations Sections of the Aircraft Flight Manual (AFM) and AFM Supplements to include the Flight Manual information specified in FAA AD 98-26-18 Amdt 39-10961. 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\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 standard, narrow airworthiness directive addressing a specific structural safety issue in a limited fleet of converted cargo aircraft. It has not expanded beyond its original purpose of adopting the FAA safety requirement for Australian-registered aircraft."},"complexity_factors":["Very short document (under 300 words)","Only 3 defined applicability criteria (the three STC numbers)","Single, straightforward compliance action (manual revision)","No nested conditions or exceptions","No cross-references to other Australian legislation beyond the enabling regulations (CAR 1998 Part 39)","Adopts external technical standard by reference (FAA AD 98-26-18) rather than reproducing complex technical requirements"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of Boeing 727s converted to freighters under FAA STCs SA1767SO, SA1768SO or SA7447SW to amend their Aircraft Flight Manuals with new main-deck cargo weight limits. It adopts the FAA safety action because unreinforced floors in these conversions can fail under existing loads, risking loss of the aircraft and crew. Compliance can be met by inserting the FAA directive into the manual by 25 March 1999."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"No. The Directive adopts the FAA AD's technical requirements for the specific subset of Boeing 727 freighters converted under STCs SA1767SO, SA1768SO or SA7447SW (Applicability; Requirement). It confines action to AFM revisions and follows the FAA-prescribed technical content, without expanding applicability to other models or conversion approvals; the primary change is mandatory incorporation of the FAA AD material into the AFM by the stated date (Requirement; Compliance)."},"complexity_factors":["Narrow applicability — only B727s converted under STCs SA1767SO, SA1768SO, SA7447SW (Applicability).","Dependence on an external instrument — requires implementation “in accordance with the technical requirements of FAA AD 98-26-18” (Requirement).","Administrative compliance — revising AFM and AFM supplements or inserting FAA AD text (Requirement).","Safety-critical technical implication — concerns structural strength of main cargo-deck floor beams and payload limits (Background).","Fixed compliance timing — effective/revised date imposed (Compliance).","Operator responsibility to identify affected fleet and maintain records; potential follow-up operational limits or inspections per FAA AD (Requirement/Background)."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 727 aircraft converted to freighters under STC SA1767SO, SA1768SO or SA7447SW to revise their Aircraft Flight Manual (AFM) and AFM supplements to include the Flight Manual information from FAA AD 98-26-18 (inserting a copy of that FAA AD is permitted). It addresses a finding that unreinforced main cargo-deck floor beams may not safely carry currently allowed payloads; operators must identify affected aircraft and make the AFM change by the stated compliance date."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-159-main-cargo-deck-floor-beams","history":"/api/acts/ad-b727-159-main-cargo-deck-floor-beams/history","analysis":"/api/acts/ad-b727-159-main-cargo-deck-floor-beams/analysis","conflicts":"/api/acts/ad-b727-159-main-cargo-deck-floor-beams/conflicts","importantCases":"/api/acts/ad-b727-159-main-cargo-deck-floor-beams/important-cases","documents":"/api/acts/ad-b727-159-main-cargo-deck-floor-beams/documents"}}