CAA NZ AME Licence Exam - Turbine Engines (Subject 6) study guide
CAA NZ AME Licence Exam - Turbine Engines (Subject 6) · Work through your exam, one topic at a time.
Subject 6: Turbine Engines is one of the knowledge-examination subjects that CAA New Zealand administers for people seeking an Aircraft Maintenance Engineer licence with a turbine engine rating. It is aimed at trainee and practising AMEs, and at engineers converting from piston engines, who need to show they understand how gas turbine engines work and how they are maintained to an airworthiness standard. The CAA NZ AME Licence Exam - Turbine Engines (Subject 6) study guide has 11 sections and about 3,574 words.
01Fundamentals of Gas Turbine Theory
The exam tests the Brayton (constant-pressure) cycle, how pressure ratio and turbine entry temperature set efficiency and specific work, the thrust equation, and the station numbering used in later domains. Ideal thermal efficiency is η = 1 − 1/PR^((γ−1)/γ).
337 words, about 2 min02Engine Construction and Materials
The exam tests material selection by temperature zone, blade manufacturing methods, coatings, and structural and containment design. Aluminium and composites: fan case and cowls.
327 words, about 2 min03Compressors and Airflow
The exam tests axial and centrifugal compressor operation, stage matching, surge and stall, and the variable geometry used to protect surge margin. Axial stage pressure ratio is typically 1.1–1.4.
334 words, about 2 min04Combustion Section and Fuels
The exam tests combustor types, fuel scheduling, fuel properties and contamination effects. Can, can-annular and annular combustors are used; annular is standard on modern turbofans because it is shorter, lighter and gives a more uniform outlet temperature.
334 words, about 2 min05Turbines and Exhaust
The exam tests turbine stage design, cooling, clearance control and exhaust hardware. Impulse stages take the whole pressure drop across the nozzle guide vanes; reaction stages split it between NGV and rotor.
332 words, about 2 min06Lubrication and Cooling Systems
The exam tests oil system layout, oil condition monitoring and engine heat management. A dry-sump system has a tank, pressure pump, filter, oil/air or fuel/oil cooler, main bearing jets, scavenge pumps, chip detector and breather.
327 words, about 2 min07Ignition, Starting and Engine Control
The exam tests ignition systems, start sequences, start faults and FADEC or hydro-mechanical control. Ignition consists of an exciter and high-energy igniter plugs, usually two with one selectable as backup.
362 words, about 2 min08Indicating and Monitoring Systems
The exam tests sensor types, the indication chain, exceedance recording and trend monitoring. Primary indications are N1 (fan or LP spool), N2 (HP spool), EGT or ITT, fuel flow, oil pressure and temperature, vibration, EPR or thrust, and torque on turboprop and turboshaft engines.
307 words, about 2 min09Auxiliary Systems and Power Off-takes
The exam tests accessory gearbox drives, bleed air systems and the performance cost of off-takes. The accessory gearbox is driven from the HP spool and drives the fuel pump, oil pumps, hydraulic pumps, IDG or CSD, starter/generator and sometimes the APU.
301 words, about 2 min10Maintenance Practices
The exam tests approved data, torque and safetying, FOD control and configuration control. Approved data includes the AMM, IPC, SRM, TSM, airworthiness directives and service bulletins.
284 words, about 1 min11Inspection and Troubleshooting
The exam tests fault isolation logic, borescope interpretation, vibration and oil analysis, and trend-based diagnosis. Troubleshoot from indication to system: confirm the indication by cross-check or gauge swap, then check sensor, harness, control unit and finally the component.
329 words, about 2 min