Turbine Engines - Oral & Practical Study Guide

Vocabulary flashcards covering key turbine engine concepts from the notes.

Two basic sections of a turbine engine

Hot section and cold section.

Types of compressors in aircraft turbine engines

Axial-flow and centrifugal.

Stators in an axial-flow compressor

Convert velocity energy into pressure energy and direct air for the next rotor stage.

Types of combustors used on aircraft turbine engines

Can-type, annular-type, and can-annular-type.

Igniters in aircraft turbine engines

Normally two.

Turbine nozzle function

Directs hot gases leaving the combustors to turn the turbine wheel with maximum efficiency.

Free-turbine turboshaft engine

A turbine wheel not used to drive the gas generator compressor; drives the propeller or helicopter rotor.

Two-spool turbine engine

Has separate low-pressure and high-pressure compressor/turbine assemblies, each driven by its own turbine.

Bearings in turbine engines

Anti-friction bearings such as ball or roller bearings.

Turbofan engine

An axial-flow engine with a bypass air around the gas generator produced by a longer first-stage compressor.

Limits of repair for compressor blades

Found in the FAA-approved service manual issued by the engine manufacturer.

Cooling a turbojet before shutdown

Cool before shutdown to prevent shroud contraction around the turbine wheel and rotor seizure.

Hung start

Ignition occurs, but the engine does not accelerate to a self-sustaining speed.

Hot start

Ignition occurs, but temperatures become high enough to risk engine damage.

Creep of turbine blades

Permanent elongation of blades caused by high temperature and centrifugal loading.

Compressor cleaning methods

Emulsion cleaner sprayed through the engine with a water rinse; aggressive cleaning uses abrasive material (e.g., apricot pits or walnut shells) at low speed.

Water injection locations for cooling

Into the compressor inlet and into the engine diffuser case.

Location of highest temperature in a turbine engine

At the inlet to the high-pressure turbine.

Interconnect tubes in can-type combustors

Connect cans to allow flame to travel between cans during starting.

Types of thrust reversers on turbojet engines

Mechanical blockage-type and aerodynamic blockage-type.

Trimming a turbojet engine

Adjusting the fuel control for correct idle and maximum-thrust RPM.

Location of most APUs in modern jet transports

In the tail cone of the fuselage.

Function of an APU

Provides electric power and compressed air when the main engines are not operating.

APU compressed air sources

Bleed air from the APU turbine compressor or from a load compressor driven by a free turbine in the engine.

ATA-100 maintenance location for airborne APU engine servicing

Section 49-20.

APU troubleshooting method

Fault codes generated by the FADEC.