{"id":"F2006B02968","name":"AD/B737/68 - Sperry SP300 Autopilot Mode Control Panel","slug":"ad-b737-68-sperry-sp300-autopilot-mode-control-panel","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42310,"registerId":"commonwealth-F2006B02968-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/68 - Sperry SP300 Autopilot Mode Control Panel","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 737 Series Aeroplanes\n\n \n\nAD/B737/68 Sperry SP300 Autopilot Mode Control Panel 7/92\n\nApplicability: Model 737-300, -400 and -500 series aeroplanes equipped with Sperry SP300 Autopilot Flight Control Computers and Mode Control Panels (MCP).\n\n \n\nRequirement: Action in accordance with Boeing Alert Service Bulletin 22A1098.\n\n \n\nNote: FAA AD 92-07-09 Amendment 39-8205 refers.\n\n \n\nCompliance: Prior to 4 December 1993.\n\n \n\nBackground:  The FAA received reports of uncommanded changes in the MCP altitude window which resulted in changes in the aircraft altitude. This Directive requires that the MCP be modified to prevent uncommanded altitude changes.\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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive’s scope remains the same as its stated purpose: it mandates modification of the Sperry SP300 Mode Control Panel on the specified Boeing 737 models to prevent uncommanded altitude changes, to be done in accordance with Boeing Alert Service Bulletin 22A1098 by the compliance date. The instrument does not expand its applicability beyond the listed aircraft/equipment or add additional actions beyond the single modification requirement (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Narrow technical scope: applies only to Boeing 737‑300/‑400/‑500 series equipped with Sperry SP300 MCP (Applicability).","Single required action: a mandated modification following a specific Boeing Alert Service Bulletin (Requirement).","Fixed compliance deadline that creates scheduling pressure for operators (Compliance).","Dependence on manufacturer service instructions for the technical fix, which can affect parts/procedure choice (Requirement).","Safety-critical context increases operational and implementation risks despite simple regulatory text (Background)."],"plain_english_summary":"What this directive does mechanically\n\n- Requires operators of certain Boeing 737 variants (‑300, ‑400 and ‑500) that are fitted with a Sperry SP300 Autopilot Flight Control Computer and Mode Control Panel (MCP) to modify the MCP in accordance with Boeing Alert Service Bulletin 22A1098. (Applicability; Requirement)\n- Sets a firm compliance deadline: the modification had to be completed prior to 4 December 1993. (Compliance)\n\nWhy the change was made (the stated purpose)\n\n- The Directive states the FAA received reports of uncommanded changes in the MCP altitude window that resulted in changes in aircraft altitude. The required modification is intended to prevent those uncommanded altitude changes. (Background)\n\nWho pays, who decides, and what changes in behaviour\n\n- Who pays: Aircraft operators or owners are responsible for arranging and paying for the modification required by the Directive, because the action is cast as a mandatory modification that each applicable aeroplane must have performed. (Requirement; Compliance)\n- Who decides: The Civil Aviation Safety Authority (by issuing the AD) requires compliance; the actual work is to be done in accordance with the manufacturer’s Boeing Alert Service Bulletin, so the technical procedure and parts are determined by the Boeing service instructions. (Requirement)\n- Behaviour change: Operators must arrange maintenance to modify the Sperry SP300 MCP on affected aeroplanes by the stated date and follow Boeing’s service instructions when doing so. This may require scheduling downtime, ordering parts, and using appropriately certificated maintenance staff or organisations. (Requirement; Compliance)\n\nCosts, incentives and trade-offs (mechanical and operational effects)\n\n- Direct costs: The operator bears the monetary cost of the modification and associated downtime. The Directive’s reference to the Boeing Alert Service Bulletin implies the modification will be performed to the manufacturer’s specified method, which can affect parts sourcing and labour requirements. (Requirement)\n- Opportunity cost: Time in maintenance and allocation of engineering/maintenance resources to complete the modification rather than other tasks. (Requirement; Compliance)\n- Implementation risk and compliance burden: The modification requires competent maintenance actions; delays in parts supply, availability of approved maintenance facilities or scheduling constraints could delay compliance and extend aircraft downtime. The AD sets a specific compliance date, creating a hard scheduling constraint for operators. (Requirement; Compliance)\n- Incentives: Operators have an incentive to complete the modification promptly to meet the compliance deadline and to eliminate the operational risk of uncommanded altitude changes. There is also an implicit incentive to follow Boeing’s procedure to satisfy the AD’s technical requirement. (Requirement)\n\nEffects on private markets and competition\n\n- The AD directs operators to use a manufacturer-issued service bulletin for the fix, which means the technical solution is set by Boeing. That can shape the demand for specific parts, tools, or authorised maintenance capability; operators may choose manufacturer-authorised providers or independent maintenance organisations that can meet the service instructions. The Directive does not itself prescribe which maintenance provider must be used. (Requirement)\n\nWho benefits and who bears costs\n\n- The stated safety benefit (reduced risk of uncommanded altitude changes) accrues to operators, crew and passengers of affected aircraft. The costs of achieving that safety improvement are borne by the operators through the required modification and associated downtime. (Background; Requirement)\n\nNotes on legal/administrative context\n\n- The AD cites a related FAA airworthiness directive (FAA AD 92-07-09). The practical requirement in this instrument is to follow Boeing Alert Service Bulletin 22A1098 within the compliance timeframe set by the AD. (Requirement; Note)\n\nPlain summary in one line\n\n- This airworthiness directive requires owners/operators of Boeing 737‑300/‑400/‑500 aeroplanes with the Sperry SP300 autopilot MCP to modify that MCP per Boeing Alert Service Bulletin 22A1098 by the stated compliance date to prevent uncommanded altitude changes. (Applicability; Requirement; Compliance; Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific technical defect in specific aircraft. It has not expanded beyond its original purpose of mandating a single hardware modification to prevent uncommanded altitude changes."},"complexity_factors":["Single, discrete technical requirement (one specific modification)","No defined terms section — uses plain technical language","No conditional logic or nested exceptions","Minimal cross-referencing (only one Boeing service bulletin and one FAA AD reference)","Extremely short document (approximately 150 words of substantive content)","Clear applicability criteria (specific aircraft models and equipment)","Single compliance deadline with no alternative methods or phased implementation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Boeing 737 aircraft.\n\n**What it does:**\n- Requires owners/operators of certain Boeing 737 models (-300, -400, and -500 series) to fix a dangerous glitch in the autopilot control panel\n- The problem: The Sperry SP300 autopilot's Mode Control Panel (MCP) could spontaneously change the target altitude without the pilots touching it — causing the plane to climb or descend unexpectedly\n- The fix: Modify the control panel following Boeing's official repair instructions (Alert Service Bulletin 22A1098)\n\n**Who it affects:**\n- Airlines and operators flying Boeing 737-300/400/500 series planes with this specific Sperry autopilot system installed\n\n**Why it matters:**\n- Uncommanded altitude changes pose serious collision risks (with other aircraft or terrain) and could lead to loss of control\n- This was a mandatory fix — operators had to comply by December 4, 1993, or ground their aircraft\n\n**Key point:** This document references an American FAA safety order (AD 92-07-09), showing how Australia often adopts or mirrors US aviation safety standards."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-68-sperry-sp300-autopilot-mode-control-panel","history":"/api/acts/ad-b737-68-sperry-sp300-autopilot-mode-control-panel/history","analysis":"/api/acts/ad-b737-68-sperry-sp300-autopilot-mode-control-panel/analysis","conflicts":"/api/acts/ad-b737-68-sperry-sp300-autopilot-mode-control-panel/conflicts","importantCases":"/api/acts/ad-b737-68-sperry-sp300-autopilot-mode-control-panel/important-cases","documents":"/api/acts/ad-b737-68-sperry-sp300-autopilot-mode-control-panel/documents"}}