{"id":"F2006B02730","name":"AD/B727/3 - Inboard Flap Asymmetry Shut-Off Wiring - Modification","slug":"ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42046,"registerId":"commonwealth-F2006B02730-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/3 - Inboard Flap Asymmetry Shut-Off Wiring - Modification","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\nAD/B727/3 Inboard Flap Asymmetry Shut-Off Wiring - Modification\n\nApplicability: All models specified in Boeing SB 27-44. Document:  Boeing SB 27-44.\n\nCompliance: Forthwith.\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\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\n3/65\n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on flap wiring modifications for one aircraft type. It has not expanded beyond its original narrow safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section","No cross-references to other legislation beyond a single Boeing Service Bulletin","Simple conditional structure: single applicability criterion and single compliance requirement","No exceptions, exemptions, or nested logic","Straightforward command structure: applies to X, do Y, by Z"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nRequires owners and operators of **Boeing 727 series aircraft** to modify the wiring for the \"inboard flap asymmetry shut-off\" system. This system is a safety mechanism that stops the flaps (the movable surfaces on the wings that help with takeoff and landing) from moving if they become uneven or \"asymmetrical\" — a dangerous condition that could cause the plane to roll unexpectedly.\n\n**Who it affects:**\nAnyone who owns or operates Boeing 727 aircraft in Australia. The directive applies to all models covered by Boeing Service Bulletin 27-44.\n\n**Why it matters:**\nFlap asymmetry can lead to loss of control during critical flight phases like takeoff and landing. This directive mandates a specific wiring modification to ensure the shut-off system works properly, preventing potential accidents.\n\n**Compliance:**\nAircraft operators must complete this modification **\"forthwith\"** — meaning immediately, without delay."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument, as presented, applies to all Boeing 727 models listed in Boeing SB 27-44 and requires the wiring modification forthwith. The AD text does not indicate any change from a prior scope or any amendment to earlier applicability; it sets a clear, limited scope tied to the referenced Service Bulletin."},"complexity_factors":["Very short instrument text with minimal procedural detail (only title, applicability, document reference, and compliance timing).","Technical specifics are delegated to an external service bulletin (Boeing SB 27-44), requiring consultation of another document for implementation details.","Immediate (forthwith) compliance increases operational complexity for scheduling and resourcing maintenance work.","Narrow scope of applicability (limited to models listed in SB 27-44) reduces regulatory breadth but concentrates burden on a defined set of operators.","No alternative compliance paths or exemptions stated in the AD itself, limiting discretionary options for operators."],"plain_english_summary":"What this directive does, in plain terms:\n\n- This Airworthiness Directive (AD/B727/3) requires a modification to the inboard flap asymmetry shut-off wiring on certain Boeing 727 aeroplanes. The modification to be carried out is the one described in Boeing Service Bulletin (SB) 27-44. (Title: AD/B727/3; Document: Boeing SB 27-44.)\n\nWho it affects:\n\n- The requirement applies to every Boeing 727 model that is listed in Boeing SB 27-44. Operators of those aeroplanes are legally required to comply. (Applicability: All models specified in Boeing SB 27-44.)\n\nWhen it must be done:\n\n- The directive must be complied with immediately. It is not deferred or phased; it is mandatory forthwith. (Compliance: Forthwith.)\n\nHow it works mechanically:\n\n- The AD directs maintenance personnel to implement the wiring modification detailed in Boeing SB 27-44. The directive does not, in this text, reproduce technical steps; it points operators to the Service Bulletin as the controlling document. (Document: Boeing SB 27-44.)\n\nStated purpose and how that translates into concrete effects:\n\n- The directive’s stated procedural effect is to change aircraft wiring per Boeing SB 27-44. The text of the AD itself does not set out an explicit safety rationale here, but by ordering the wiring modification it creates an obligation on operators to alter aircraft systems as described in the referenced SB. (AD/B727/3; Document: Boeing SB 27-44.)\n\nCosts, incentives and trade-offs (source-grounded):\n\n- Who pays: operators of the applicable Boeing 727 models will bear the direct costs of the modification (parts, labour, and any associated maintenance overhead), because the AD makes the modification mandatory for those aircraft. (Applicability; Compliance.)\n\n- Incentives: operators have a legal obligation to comply forthwith; that creates an incentive to schedule the modification promptly to remain airworthy and legal to operate. (Compliance: Forthwith.)\n\n- Trade-offs and opportunity cost: carrying out the modification requires diverting maintenance capacity, workshop time and possibly aircraft downtime that could otherwise be used for commercial flying or other maintenance tasks. The AD text itself does not quantify these costs. (Applicability; Compliance.)\n\nImplementation risk and compliance burden:\n\n- Implementation requires access to the Boeing SB 27-44 instructions and appropriate maintenance resources. The AD does not provide alternate compliance methods or deferrals; the operator must follow the SB or otherwise satisfy the authority. That creates an operational burden concentrated on affected operators and their maintenance providers. (Document: Boeing SB 27-44; Compliance: Forthwith.)\n\nBureaucratic discretion and private choice:\n\n- The AD prescribes a mandatory action with immediate effect; the text contains no discretionary carve-outs or staged timetable. The primary decision left to operators is how and when, within the requirement to comply forthwith, to schedule and resource the modification and which maintenance provider to use. (Compliance: Forthwith; Applicability.)\n\nMarket effects (source-grounded observations):\n\n- The directive transfers direct compliance costs to affected operators and creates demand for maintenance work tied to the SB. The AD does not state any compensatory measures or funding. (Applicability; Document; Compliance.)\n\nImplementation detail note:\n\n- The AD references Boeing SB 27-44 as the technical instruction set. To execute the modification, operators and maintenance organisations must consult that Service Bulletin for the precise wiring changes, parts lists and work instructions. (Document: Boeing SB 27-44.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification","history":"/api/acts/ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification/history","analysis":"/api/acts/ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification/analysis","conflicts":"/api/acts/ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification/conflicts","importantCases":"/api/acts/ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification/important-cases","documents":"/api/acts/ad-b727-3-inboard-flap-asymmetry-shut-off-wiring-modification/documents"}}