Turbine Engines
Turbine Engines is a core knowledge area on the AMT — Powerplant FAA written exam. This hub collects our 16 in-depth, ACS-aligned turbine engines articles — each written in plain English and grounded in the official FAA handbooks. Work through them below, then drill the topic with practice questions.
Turbine Engine Station Numbering and Gas Path Stations
Turbine engine station numbering is a standardized system that identifies discrete locations along the engine gas path, enabling precise performance monitoring, troubleshooting, and certification of turbine powerplants.
Axial-Flow Compressor Design and Stage Pressure Ratio
Axial-flow compressors build pressure incrementally through multiple rotor-stator stages, with each stage contributing a small pressure ratio that multiplies into the high overall ratios modern turbine engines demand.
Centrifugal-Flow Compressor Operating Principles
Centrifugal-flow compressors use rotating impellers to accelerate air outward and convert velocity to pressure, forming the heart of many small turbine engines and APUs.
Compressor Stall and Surge Causes and Remedies
Compressor stall and surge are dangerous disruptions to airflow in turbine engines that can cause power loss, structural damage, or flameout if not recognized and corrected quickly.
Annular Combustion Chamber Construction and Operation
The annular combustion chamber is the most common design in modern turbine engines, wrapping a single continuous combustion ring around the engine core to deliver efficient, even combustion with minimal length and weight.
Turbine Nozzle Guide Vane Function and Cooling Methods
Turbine nozzle guide vanes direct hot combustion gases onto turbine rotor blades at the correct angle and velocity while surviving extreme temperatures through sophisticated internal and external cooling techniques.
Turbofan Bypass Ratio and Thrust Contribution
Bypass ratio defines how much air a turbofan moves around its core versus through it, directly controlling fuel efficiency and thrust; higher bypass ratios dominate modern airliners while lower ratios suit high-speed military jets.
Turbine Blade Creep, Fatigue, and Hot-Section Inspection
Turbine blade creep, fatigue, and hot-section inspection are critical concepts for AMT powerplant exams, covering how extreme heat and stress degrade turbine components and how technicians detect and manage that damage.
Turboprop Reduction Gearbox and Propeller Coupling
Turboprop reduction gearboxes and propeller coupling systems slow turbine RPM to efficient propeller speeds while transmitting enormous torque — a critical system for any powerplant technician.
Turboshaft Engine Power Turbine and Output Shaft Design
Turboshaft engines use a free-spinning power turbine to extract shaft horsepower from hot gases, delivering mechanical power through an output shaft to helicopters, turboprops, and industrial drives rather than producing jet thrust.
Fuel Control Unit and Hydromechanical Metering Principles
The fuel control unit (FCU) precisely meters fuel flow to a turbine engine by translating pilot thrust demands and sensed engine parameters into exactly the right fuel quantity — preventing rich blowout, lean blowout, surge, and flameout across all flight conditions.
Engine Pressure Ratio (EPR) as a Thrust Indicator
Engine Pressure Ratio (EPR) measures turbine engine thrust by comparing turbine exhaust pressure to engine inlet pressure, giving pilots and mechanics a reliable, direct indication of actual thrust output.
Turbine Engine Oil System: Pressure, Scavenge, and Breather Subsystems
Turbine engine oil systems use three interconnected subsystems—pressure, scavenge, and breather—to lubricate, cool, and clean bearings and gears while continuously recirculating oil throughout the engine.
Foreign Object Damage (FOD) Recognition and Prevention in Turbine Engines
Foreign Object Damage (FOD) is a leading cause of turbine engine failures; understanding how debris enters engines, what damage it causes, and how to prevent it is critical knowledge for every AMT and pilot.
Full Authority Digital Engine Control (FADEC) System Operation
FADEC systems replace manual engine controls with a digital computer that automatically optimizes fuel delivery, turbine temperatures, and engine parameters throughout every phase of flight—maximizing efficiency and safety.
Turbine Engine Starts: Normal, Hot, Hung, and Wet Start Identification
Learn to identify and respond to normal, hot, hung, and wet turbine engine starts — covering EGT limits, RPM behavior, fuel flow, and what to do when a start goes wrong.
More AMT — Powerplant subjects
Articles are original summaries grounded in the public-domain FAA handbooks and cite their source. ACS-aligned study aids — not a substitute for the official handbooks or regulations.