MODULE 15. GAS TURBINE ENGINE

15.1 Fundamentals

Potential energy, kinetic energy, Newton’s laws of motion, Brayton cycle;
The relationship between force, work, power, energy, velocity, acceleration;
Constructional arrangement and operation of turbojet, turbofan, turboshaft, turboprop.

15.2 Engine Performance

Gross thrust, net thrust, choked nozzle thrust, thrust distribution, resultant thrust, thrust horsepower, equivalent shaft horsepower, specific fuel consumption;
Engine efficiencies;
By-pass ratio and engine pressure ratio;
Pressure, temperature and velocity of the gas flow;
Engine ratings, static thrust, influence of speed, altitude and hot climate, flat rating, limitations.

15.3 Inlet

Compressor inlet ducts
Effects of various inlet configurations;
Ice protection.

15.4 Compressors

Axial and centrifugal types;
Constructional features and operating principles and applications;
Fan balancing;
Operation:
Causes and effects of compressor stall and surge;
Methods of air flow control: bleed valves, variable inlet guide vanes, variable stator vanes, rotating stator blades;
Compressor ratio.

15.5 Combustion Section

Constructional features and principles of operation.

15.6 Turbine Section

Operation and characteristics of different turbine blade types;
Blade to disk attachment;
Nozzle guide vanes;
Causes and effects of turbine blade stress and creep.

15.7 Exhaust

Constructional features and principles of operation;
Convergent, divergent and variable area nozzles;
Engine noise reduction;
Thrust reversers.

15.8 Bearings and Seals

Constructional features and principles of operation.

15.9 Lubricants and Fuels
Properties and specifications;
Fuel additives;
Safety precautions.

15.10 Lubrication Systems

System operation/lay-out and components.

15.11 Fuel Systems

Operation of engine control and fuel metering systems including electronic engine control (FADEC);
Systems lay-out and components.

15.12 Air Systems

Operation of engine air distribution and anti-ice control systems, including internal cooling, sealing and external air services.

15.13 Starting and Ignition Systems

Operation of engine start systems and components;
Ignition systems and components;
Maintenance safety requirements.

15.14 Engine Indication Systems

Exhaust Gas Temperature/Interstage Turbine Temperature;
Engine Thrust Indication: Engine Pressure Ratio, engine turbine discharge pressure or jet pipe pressure systems;
Oil pressure and temperature;
Fuel pressure and flow;
Engine speed;
Vibration measurement and indication;
Torque;
Power.

15.15 Power Augmentation Systems

Operation and applications;
Water injection, water methanol;
Afterburner systems.

15.16 Turbo-prop Engines

Gas coupled/free turbine and gear coupled turbines;
Reduction gears;
Integrated engine and propeller controls;
Overspeed safety devices.

15.17 Turbo-shaft Engines

Arrangements, drive systems, reduction gearing, couplings, control systems.

15.18 Auxiliary Power Units (APUs)

Purpose, operation, protective systems.

15.19 Powerplant Installation

Configuration of firewalls, cowlings, acoustic panels, engine mounts, anti-vibration mounts, hoses, pipes, feeders, connectors, wiring looms, control cables and rods, lifting points and drains.

15.20 Fire Protection Systems

Operation of detection and extinguishing systems.

15.21 Engine Monitoring and Ground Operation

Procedures for starting and ground run-up;
Interpretation of engine power output and parameters;
Trend (including oil analysis, vibration and boroscope) monitoring;
Inspection of engine and components to criteria, tolerances and data specified by engine manufacturer;
Compressor washing/cleaning;
Foreign Object Damage.

15.22 Engine Storage and Preservation

Preservation and depreservation for the engine and accessories/systems.