{"id":"F2006B06542","name":"AD/RB211/11 - Fuel Metering Valve Torque Motor Test","slug":"ad-rb211-11-fuel-metering-valve-torque-motor-test","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48235,"registerId":"commonwealth-F2006B06542-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/RB211/11 - Fuel Metering Valve Torque Motor Test","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nRolls Royce Turbine Engines \\- RB211 Series\n\nAD/RB211/11 Fuel Metering Valve Torque Motor Test 9/90\n\nApplicability: All Rolls Royce RB 211-524G2-19/11, RB 211-524G2-19/15, RB 211-524G3-19/15, RB 211-524H2-19/15 AND RB 211-524H2-19/15 engines with fuel metering units (FMU) at pre S.B. 73-9282 (increased rating inlet filter mesh) status.\n\nNote: Lucas SB 600-73-6726 also refers.\n\nRequirement: Perform an on wing test to determine the serviceability of the fuel metering unit metering torque valve motor in accordance with Rolls Royce Service Bulletin RB.211-71-9270.\n\nNote: Compliance with this SB has been made mandatory by the UK CAA.\n\nCompliance: Initially, prior to 6 October 1990, and thereafter at intervals not exceeding 350 hours time in service.\n\nBackground: There have been three recent reports of uncommanded engine run down to a sub-idle condition, one during cruise, one during descent, and one during taxi. All three failures have been attributed to a virtual blockage of the fuel metering valve torque motor inlet filter. To reduce the possibility of uncommanded engine run down, a fuel metering unit metering valve torque motor test is required to be carried out in accordance with this AD.","sortOrder":0}],"analysis":{"summary":{"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This is an original airworthiness directive, not an amendment to an existing directive."},"complexity_factors":["Narrow applicability to a small sub-set of engines with a specific pre-modification configuration","Single, straightforward repetitive test requirement","Simple compliance interval with a clear initial deadline"],"plain_english_summary":"This AD applies to Rolls‑Royce RB211‑524G/H engines with pre‑Service Bulletin 73‑9282 fuel metering unit inlet filters and requires periodic on‑wing testing of the fuel‑metering valve torque motor to confirm serviceability. It was issued after incidents of uncommanded engine run‑down caused by virtual blockage of the torque‑motor inlet filter; the tests aim to detect filter deterioration and prevent unexpected power loss. Engines already modified to the post‑SB filter standard are excluded."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"No. The directive stays focused on the specified RB211‑524 variants with FMUs at pre‑S.B. 73‑9282 status and requires the single Rolls‑Royce SB test at defined intervals. It does not broaden applicability or add actions beyond the referenced Service Bulletins; it formalises mandatory testing to address reported inlet‑filter blockages."},"complexity_factors":["Narrow applicability: specific RB211‑524 submodels listed","Conditioned on FMU status (pre S.B. 73‑9282) which requires fleet records check","Mandates a specific Rolls‑Royce Service Bulletin procedure (RB.211‑71‑9270)","Fixed compliance timing: initial date (before 6 Oct 1990) and recurring 350‑hour interval","Cross‑reference to another SB (Lucas SB 600‑73‑6726) for related information","Operational impact: on‑wing test causes maintenance time and direct costs to operators","Regulatory linkage: made mandatory by UK CAA and enforced by CASA (reciprocal enforcement consideration)"],"plain_english_summary":"This airworthiness directive requires operators of specified Rolls‑Royce RB211‑524 engine variants with fuel metering units at pre‑Service Bulletin 73‑9282 status to carry out an on‑wing test of the fuel metering valve torque motor using Rolls‑Royce Service Bulletin RB.211‑71‑9270. The Civil Aviation Safety Authority mandates initial compliance before 6 October 1990 and repeat tests at intervals not exceeding 350 hours. Aircraft operators bear the testing cost and operational downtime; the test targets inlet‑filter virtual blockages that caused uncommanded engine rundown."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical failure mode. It has not expanded beyond its original purpose of preventing fuel system blockages in specific RB211 engines."},"complexity_factors":["Single, specific technical requirement (one test procedure)","Limited applicability (5 specific engine models, pre-modification status only)","No defined terms section — uses standard aviation terminology","Simple compliance structure: initial deadline + recurring interval","No cross-references to other legislation or complex conditional logic","Background provided in plain narrative form explaining the safety rationale"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft engines.\n\n**What it does:**\nIt requires airlines and aircraft operators to perform a specific test on certain Rolls Royce RB211 jet engines. The test checks whether a component called the **fuel metering unit torque motor** is working properly. This motor controls fuel flow to the engine.\n\n**Who it affects:**\nOperators of aircraft using specific Rolls Royce RB211 engine models (the -524G2 and -524H2 series) that haven't had a particular filter upgrade (Service Bulletin 73-9282).\n\n**Why it matters:**\nThree engines had suddenly lost power — one mid-flight during cruise, one during descent, and one while taxiing. Investigators found the cause was a blocked filter in the fuel metering system. This directive forces operators to test for this problem before October 1990, then repeat the test every 350 flight hours, to prevent engines from unexpectedly shutting down.\n\n**The bottom line:** If you don't do this test, your plane could lose engine power without warning."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-11-fuel-metering-valve-torque-motor-test","history":"/api/acts/ad-rb211-11-fuel-metering-valve-torque-motor-test/history","analysis":"/api/acts/ad-rb211-11-fuel-metering-valve-torque-motor-test/analysis","conflicts":"/api/acts/ad-rb211-11-fuel-metering-valve-torque-motor-test/conflicts","importantCases":"/api/acts/ad-rb211-11-fuel-metering-valve-torque-motor-test/important-cases","documents":"/api/acts/ad-rb211-11-fuel-metering-valve-torque-motor-test/documents"}}