CAA NZ AME Licence Exam - Turbine Engines (Subject 6) study plan

Explain the Brayton cycle and, for a simple single-spool turbojet, calculate how pressure ratio and turbine entry temperature each change specific thrust and thermal efficiency

Derive the relationship between compressor work, turbine work and net thrust, and state why a gas turbine needs a pressure ratio above roughly 4:1 to produce positive net work

Sketch a two-spool turbofan and label station numbers (intake, LP compressor, HP compressor, combustor, HP turbine, LP turbine, exhaust), stating pressure and temperature trend across each

Describe creep, fatigue, thermal fatigue and oxidation as the four principal damage mechanisms in hot-section components, and match each to a component where it dominates

List the material families used for compressor blades, turbine blades, discs and casings, and state one property driving each choice

Describe axial compressor stage construction: rotor blades, stator vanes, discs, drums, shrouds and tip clearance, and explain the function of inlet guide vanes and variable stators

Explain the mechanism of compressor surge and rotating stall, list the symptoms a flight crew or engineer would observe, and describe how bleed valves and variable geometry are scheduled to prevent them

Distinguish centrifugal from axial compressors by pressure ratio per stage, mass flow capability, surge tolerance and typical application

Calculate stage temperature rise and pressure ratio from inlet and outlet temperatures using the isentropic relation, and compute compressor efficiency from actual versus ideal temperature rise

Explain the causes and consequences of compressor blade fouling, erosion and tip-clearance growth, and describe water wash and clearance-check practices

Describe combustor types (can, can-annular, annular) and label the diffuser, swirler, primary, intermediate and dilution zones with the function of each

Explain fuel staging, fuel-air ratio limits, lean blowout and rich blowout, and how combustor exit temperature profile (pattern factor) affects turbine life

Compare the properties and handling requirements of Jet A-1 and alternative fuels relevant to the exam: flash point, freezing point, thermal stability, water content and microbial growth

Describe turbine blade and nozzle guide vane cooling: convection, film, impingement and transpiration, and explain why cooling air is taken from the HP compressor

Explain turbine blade attachment (fir-tree), tip clearance control, blade tip shrouds and the function of active clearance control on modern engines

Describe exhaust types (convergent, convergent-divergent), thrust reverser types (cascade, target, bucket) and the sequence and interlocks of reverser operation

Trace the full oil system: tank, pump, filter, pressure regulating valve, bearings and seals, scavenge, cooler and chip detector, and state the purpose of each component

Distinguish dry-sump from wet-sump lubrication and explain the consequences of low oil pressure, high oil temperature and oil consumption trends on engine serviceability

Describe the ignition system: exciter, igniter plugs, high-energy versus low-energy ignition, and the difference between starting ignition and relight/continuous ignition use

Explain the start sequence and the parameters that must be monitored (N2, EGT, fuel flow, oil pressure, start time), and describe a hot start, hung start and wet start with the correct crew/engineer response to each

Explain the function of the fuel control unit or FADEC, including N1/N2 governing, acceleration scheduling, EGT limiting and overspeed protection

Describe the construction and inspection points of turbine discs, blades, vanes and casings, including creep life limits, blade tip shroud wear and cooling hole blockage

Interpret engine indication parameters: N1, N2, EGT, fuel flow, oil pressure, oil temperature, vibration and thrust, stating what each indicates and its typical trend significance

Explain EGT margin, how it is established and how it degrades, and describe how trend monitoring is used to predict on-wing life and plan removal

Describe vibration monitoring: sources (fan imbalance, bearing damage, blade rub), units, and how a rising vibration trend changes maintenance action

Explain borescope inspection of the combustion chamber, turbine blades and vanes, and list the findings that require engine removal versus continued service

Describe accessory gearbox drives and power off-takes: starter/generator, hydraulic pumps, fuel pump, oil pump and their drive arrangements and shear-section protection

Explain bleed air extraction for cabin pressurisation, anti-ice and engine starting, and state the effect of bleed extraction on thrust and EGT

Describe thrust reverser, variable stator vane and bleed valve actuation systems (hydraulic, pneumatic, electric) and their failure modes

Apply a systematic troubleshooting method: gather symptoms, form hypotheses, isolate by component or system, confirm by test, and record findings

Describe scheduled maintenance tasks for a turbine engine: borescope intervals, oil sampling, filter and chip detector checks, compressor washes, and the documentation required for each

Identify the common human-factor traps in engine maintenance (wrong part, omitted O-ring, incorrect torque, unrecorded defect) and describe the dual-inspection and documentation controls that mitigate them

Re-derive the key cycle and compressor calculations from memory without notes, and check answers against week 1-3 worked sets

Produce a one-page summary of every hot-section material and damage mechanism, and self-test by covering the table and reciting each entry

Explain, without notes, the cause and prevention of surge, the combustor zones and their airflow split, and the four turbine cooling methods

Answer 40 mixed practice questions across the five technical domains under timed conditions and review every wrong answer to root cause

Recite the oil system component chain, the ignition system components and the start-sequence abort criteria from memory

Explain trend monitoring, EGT margin and vibration interpretation, and apply them to two unseen scenarios

Walk through a full fault-isolation case for an unseen defect using the systematic method, stating the tests and the acceptance criteria

Complete a full-length timed mock examination covering all ten domains and review every error

Consolidate a final one-page personal weak-point sheet and schedule revision of only those items before the exam