{"id":"F2006B03203","name":"AD/B747/31 - Aileron Control System - Modification","slug":"ad-b747-31-aileron-control-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42575,"registerId":"commonwealth-F2006B03203-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/31 - Aileron Control System - 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 747 Series Aeroplanes\n\n \n\nAD/B747/31 Aileron Control System - Modification 6/83\n\nApplicability: All model 747 with S/Nos. referenced in Boeing SB. 27-2065, SB 27-2095, SB 27- 2161 and SB 51-2032 as applicable.\n\n \n\nDocument: Boeing SBs 747-27-2065, 747-27-2095, 747-27-2161, 747-51-2032.\n\n \n\nNote: FAA AD 82-02-10 refers.\n\n \n\nCompliance: Unless previously accomplished, within 3000 hours time in service after 30 June 1983.\n\n \n\nBackground: Numerous occurrences of binding in the aileron control system are attributed to the accumulation of ice on the aileron control system in the wing gear wheel well area.\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","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive issued in 1983. It has not grown beyond its original purpose of addressing a specific icing-related defect in Boeing 747 aileron control systems. The scope remains precisely limited to the aircraft serial numbers and modification requirements originally identified."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 defined applicability criteria (the four Boeing Service Bulletins)","Single compliance requirement with clear deadline","No nested exceptions or conditional logic","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Straightforward cause-and-effect: ice buildup → binding → mandatory modification"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or modifications to aircraft.\n\n**What it does:** It orders owners and operators of certain **Boeing 747 aircraft** to modify the **aileron control system** (the mechanism that controls the small hinged surfaces on the wings that help the plane bank and turn).\n\n**Why it's needed:** Ice was building up in the wing gear wheel well area (where the landing gear retracts into the wing), causing the aileron controls to **bind** — meaning they could stick or jam. This is obviously dangerous during flight.\n\n**Who must comply:** All Boeing 747 models with specific serial numbers listed in four Boeing Service Bulletins (SB 27-2065, SB 27-2095, SB 27-2161, and SB 51-2032).\n\n**What must be done:** The modifications described in those four Boeing Service Bulletins must be completed **within 3,000 flight hours after 30 June 1983** — unless the work was already done earlier.\n\n**Why it matters:** This directive prevents potentially catastrophic loss of roll control due to ice accumulation. It reflects a known safety issue that Boeing identified and CASA mandated be fixed across the affected fleet."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The directive imposes a new mandatory modification obligation on the affected aircraft defined by the listed service bulletins and serial numbers, to be completed within a defined hours-in-service compliance window unless already done. The AD changes operators' obligations from voluntary or maintenance-as-usual to a time-bound regulatory requirement; the AD text itself does not change which aircraft are covered beyond those referenced in the Boeing SBs. (Applicability; Document; Compliance)"},"complexity_factors":["Narrow applicability limited to specific Boeing 747 serial numbers (Applicability)","Single, well-defined required action (modify aileron control system) referenced to manufacturer Service Bulletins (Document)","Compliance deadline specified as an hours-in-service window, requiring operational scheduling (Compliance)","Technical detail is externalized to Boeing Service Bulletins, requiring implementers to consult and follow separate technical documents (Document)","Regulatory enforcement by CASA with no procedural exemptions stated in the AD text (Header; Compliance)","Cross-reference to an FAA AD increases the regulatory context but does not add procedural steps in this text (Note)"],"plain_english_summary":"The Civil Aviation Safety Authority requires owners/operators of the Boeing 747 airframes listed in the cited Boeing Service Bulletins to modify the aileron control system as described in those SBs to address aileron binding from ice accumulation.  \n\nCompliance is mandatory under the AD; if not already done, the retrofit must be completed within 3,000 flight hours after 30 June 1983, at the owner/operator’s expense, following Boeing’s SB procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-31-aileron-control-system-modification","history":"/api/acts/ad-b747-31-aileron-control-system-modification/history","analysis":"/api/acts/ad-b747-31-aileron-control-system-modification/analysis","conflicts":"/api/acts/ad-b747-31-aileron-control-system-modification/conflicts","importantCases":"/api/acts/ad-b747-31-aileron-control-system-modification/important-cases","documents":"/api/acts/ad-b747-31-aileron-control-system-modification/documents"}}