CAA NZ Basic Turbine Knowledge (Helicopter) Exam study plan

Define the Brayton (constant-pressure) cycle stage by stage and sketch pressure–volume and temperature–entropy diagrams from memory

Calculate ideal thermal efficiency from pressure ratio and explain why real efficiency falls short (compressor and turbine isentropic efficiency, pressure losses)

Distinguish static from stagnation (total) temperature and pressure and state where each is used in engine ratings

Explain how altitude, ambient temperature and humidity change mass flow, turbine entry temperature and available shaft power

Describe how a turboshaft converts gas energy into shaft power via a free power turbine rather than jet thrust

Label the modules of a turboshaft engine (inlet, compressor, combustor, compressor turbine, free power turbine, exhaust) and state the function and typical materials of each

Compare axial and centrifugal compressors and explain surge, rotating stall and the purpose of bleed valves and variable inlet guide vanes

Trace airflow and fuel flow through a can-annular or annular combustor and explain primary, secondary and dilution zones

Describe turbine blade cooling, tip clearance and why turbine entry temperature limits engine life

Calculate compressor pressure ratio and temperature rise across a stage using the isentropic relation with a given efficiency

Explain the dry-sump oil system: tank, pressure pump, filter, cooler, jets, scavenge pumps, chip detectors and breather

State the purpose, grades and limitations of turbine oils and interpret pressure, temperature and consumption limits

Describe the fuel system from tank to combustor: boost pumps, low-pressure filter, high-pressure pump, fuel control unit, flow divider and nozzles

Explain fuel scheduling during start, acceleration and deceleration and the role of the fuel shut-off valve

Interpret oil pressure and temperature indications and identify the likely cause of abnormal readings

Identify the parameters displayed on a typical helicopter turbine instrument panel and state the normal range and redline for each

Explain how torque, N1 (gas producer), N2 (power turbine) and turbine outlet temperature are sensed and transmitted

Describe the ignition system: exciter, igniter plugs, dual-ignition redundancy and when continuous ignition is used

Sequence a normal start: cranking, ignition, fuel-on, light-off, acceleration to idle, and the parameters to monitor at each step

Diagnose a hot start, hung start and false start and state the corrective action for each

Explain the function of the engine control unit or hydro-mechanical fuel control, including governing, acceleration scheduling and overspeed protection

Describe the freewheeling unit (sprag or overrunning clutch) and how it allows autorotation with the engine stopped

Trace the drive path from engine output shaft through main gearbox, tail rotor drive shaft and gearboxes to the rotors

Explain the main gearbox lubrication system and the consequence of loss of oil pressure in the gearbox

Describe how torque is measured and transmitted and why torque, not just N2, limits power in a helicopter

Interpret limits on torque, N1, N2, turbine outlet temperature and oil pressure and explain the difference between transient and continuous limits

Explain exceedance reporting: what must be recorded, who is notified and why exceedances affect airworthiness

Describe the indications and handling of compressor surge, flame-out, engine fire and loss of oil pressure in flight

Explain how power available changes with density altitude, temperature and aircraft mass and how to plan for margin

Describe vibration monitoring and chip detection as early warning of transmission or engine degradation

Describe scheduled maintenance inspections for the engine and transmission and the role of the maintenance control manual

Explain the purpose of borescope inspection, chip detector checks, oil sampling and filter inspection

State the safety precautions for working around turbine engines: intake suction, exhaust heat, fuel and ignition isolation, and lockout

Explain how maintenance actions are recorded and released to service and what constitutes an airworthiness directive or service bulletin

Describe the maintenance implications of an exceedance or defect report and the correct escalation path

Re-derive the Brayton cycle efficiency formula and the compressor temperature-rise relation without notes

Recite the module functions, oil and fuel system components and drive-train layout from blank diagrams

Answer timed practice questions across all seven domains and review every wrong answer to its source

Re-test the weakest two domains identified by practice scores and close remaining gaps

Confirm familiarity with limits, abnormal procedures and maintenance release requirements before sitting the exam