{"id":"F2006B03447","name":"AD/B767/94 - Thrust Management Computer Replacement","slug":"ad-b767-94-thrust-management-computer-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43001,"registerId":"commonwealth-F2006B03447-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B767/94 - Thrust Management Computer Replacement","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 767 Series Aeroplanes\n\nAD/B767/94 Thrust Management Computer Replacement 4/97\n\nApplicability: All 767 aircraft line positions 001 to 556, 558 to 587 and 589 to 615 inclusive. Requirement: Replace the thrust management computer in accordance with Boeing Alert Service\n\nBulletin 767-22A0097 dated 30 May 1996.\n\nNote: FAA AD 97-02-19 Amdt 39-9904 refers.\n\nCompliance: Unless previously carried out, replace the thrust management computer before 26 October 1998.\n\nThis Airworthiness Directive becomes effective on 27 March 1997.\n\nBackground: Boeing has had reported instances of uncommanded throttle advancement apparently due to a high impedance connection to the excitation phase of the servo motor. The actions mandated by this Airworthiness Directive are intended to prevent uncommanded runaway of the autothrottle during flight or ground operations as a result of the problems associated with the thrust management computer.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive applies to the expressly listed Boeing 767 line positions and mandates replacement of the thrust management computer per Boeing Alert Service Bulletin 767-22A0097, to be completed by 26 October 1998. The text contains no provision that expands or narrows that applicability or the required action beyond those elements (Applicability; Requirement; Compliance)."},"complexity_factors":["Single mandatory hardware replacement specified (Requirement)","Clear list of affected aircraft line positions (Applicability)","Single external technical reference: Boeing Alert Service Bulletin 767-22A0097 (Requirement)","One firm compliance deadline (Compliance)","Technical cause and safety purpose explicitly stated (Background)","Cross-reference to FAA AD noted but not elaborated (Note)"],"plain_english_summary":"What this rule does\n\n- The Civil Aviation Safety Authority (CASA) requires specified Boeing 767 aeroplanes to have their thrust management computer (TMC) replaced. (Applicability; Requirement)\n- The replacement must be done following Boeing Alert Service Bulletin 767-22A0097 dated 30 May 1996. (Requirement)\n- Aircraft that have not already had the work done must complete the replacement before 26 October 1998. The directive became effective on 27 March 1997. (Compliance)\n\nWho is affected\n\n- Operators or owners of Boeing 767 aircraft at the listed line positions (001–556, 558–587 and 589–615) are directly affected because the directive applies to those specific aircraft. (Applicability)\n- Maintenance organisations and technicians who perform the work will be involved because the AD mandates a technical replacement carried out in accordance with Boeing’s service bulletin. (Requirement)\n\nWhy it matters (stated purpose and the safety mechanism)\n\n- Boeing reported incidents of uncommanded throttle advancement which were traced to a high-impedance connection to the excitation phase of the servo motor in the thrust management computer. (Background)\n- The AD explicitly states the mandated replacement is intended to prevent uncommanded autothrottle runaway during flight or ground operations caused by the identified TMC problem. (Background)\n\nPractical mechanics, who pays, who decides, and what changes in behaviour\n\n- The AD is mandatory: affected operators must carry out the replacement by the compliance date; CASA is the regulator issuing the directive. (Compliance; Applicability)\n- The AD directs compliance by following Boeing’s Alert Service Bulletin; Boeing provides the technical procedure for replacement. (Requirement)\n- The text does not state a source of funding. Because the AD imposes a mandatory modification on named aircraft, the immediate financial and operational consequences fall on the parties required to comply (operators/owners and their chosen maintenance providers) in order to return aircraft to service. (Requirement; Compliance)\n- Behavioural change required: operators must schedule and perform a hardware replacement on each affected aeroplane by the deadline and apply the Boeing procedure when doing so. (Requirement; Compliance)\n\nTrade-offs, compliance burden, and implementation considerations (mechanical, not evaluative)\n\n- Compliance requires a physical hardware replacement on each listed airframe; that implies aircraft will be taken out of service for the work for at least the duration of the maintenance task. (Requirement; Compliance)\n- The AD references a single Boeing Alert Service Bulletin as the required method; operators must obtain and follow that bulletin to meet the AD. (Requirement)\n- The directive creates demand for the specific replacement parts and qualified maintenance labour for the affected fleet. The AD text does not allocate costs or state subsidies or reimbursements. (Requirement; Compliance)\n- The AD cross-references an FAA airworthiness directive (FAA AD 97-02-19 Amdt 39-9904), indicating alignment with at least one other regulator’s action; the text does not elaborate on coordination mechanisms. (Note)\n\nConcrete incentives and risks implied by the text\n\n- Incentives: Operators have a mandatory compliance deadline to avoid regulatory non‑compliance; maintenance providers have demand for the required replacement work. (Compliance; Requirement)\n- Risks noted in the source: the background identifies a specific failure mode (high-impedance connection to the servo motor excitation phase) that the replacement is intended to eliminate. The AD frames the replacement as preventive to avoid uncommanded throttle advance or autothrottle runaway. (Background)\n\nNet effect on private choices and markets (mechanism-focused)\n\n- The AD changes the options available to operators of the affected 767s: they must either perform the mandated replacement or, if non-compliant, face regulatory consequences. (Applicability; Requirement; Compliance)\n- The replacement requirement channels technical work through Boeing’s Alert Service Bulletin as the prescribed method, which makes that bulletin the operative technical standard for compliance. (Requirement)\n\nSource citations\n\n- Applicability, Requirement, Compliance, Background and Note are the source sections used to describe what the AD mandates and why it was issued."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a specific, targeted airworthiness directive addressing a known hardware defect in a particular aircraft model. The scope remains precisely limited to thrust management computer replacement on affected Boeing 767 aircraft, exactly as intended when issued."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly used ('line positions' referring to aircraft serial numbers)","No cross-references to other legislation sections","Single, unconditional requirement with clear deadline","No exceptions or conditional logic","Straightforward applicability criteria using simple number ranges"],"plain_english_summary":"This is a **safety order for Boeing 767 aircraft**.\n\n**What it does:**\nIt requires airlines and aircraft operators to replace a faulty computer called the **thrust management computer** on specific Boeing 767 planes. This computer controls the auto-throttle system (the automatic system that adjusts engine power).\n\n**Why it matters:**\nBoeing discovered that some of these computers had a wiring problem that could cause the **throttle to suddenly increase on its own** — what the directive calls \"uncommanded throttle advancement.\" This could happen during flight or while the plane is on the ground, creating a serious safety risk. The replacement prevents dangerous engine runaway situations.\n\n**Who it affects:**\n- **Aircraft covered:** Boeing 767 planes with serial numbers (\"line positions\") from 001 to 556, 558 to 587, and 589 to 615\n- **Operators:** Airlines and companies flying these specific aircraft in Australia\n- **Deadline:** The replacement must be done before 26 October 1998\n\n**Key details:**\n- The directive became effective on 27 March 1997\n- Operators must follow Boeing's specific repair instructions (Alert Service Bulletin 767-22A0097 from May 1996)\n- This aligns with a similar US safety order (FAA AD 97-02-19)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-94-thrust-management-computer-replacement","history":"/api/acts/ad-b767-94-thrust-management-computer-replacement/history","analysis":"/api/acts/ad-b767-94-thrust-management-computer-replacement/analysis","conflicts":"/api/acts/ad-b767-94-thrust-management-computer-replacement/conflicts","importantCases":"/api/acts/ad-b767-94-thrust-management-computer-replacement/important-cases","documents":"/api/acts/ad-b767-94-thrust-management-computer-replacement/documents"}}