Turbine Engine Accessories Test 2

The afterburner increases thrust for a turbine engine by increasing the ___________________ of the air passing out of the engine.

acceleration

Which thrust augmentation system increases the thrust of a gas turbine engine by increasing the mass airflow through the engine?

Water injection

Water injection systems on turbine aircraft use only demineralized or distilled water because:

It prevents deposit build up on engine parts`

Why is water injection used on some turbine engines?

to restore or boost take off thrust lost due to high temp and/or high altitude conditions

Alcohol is used in some water injection systems of turbine engines:

lowers the freezing point of water

Afterburners can increase thrust up to ______%, with an increase in fuel consumption of ______%.

100, 300

Electric starters are limited to _______________ ______________.

smaller engines

Air turbine(pneumatic) starters are used most often on ______________ ______________ _____________.

large turbine engines

The electric starter-generator:

has the advantage of being lighter than a separate electric starter and separate generator

How many igniter plugs are normally used in a turbine engine?

2

When a reduction in thrust or shaft horsepower occurs due to a reduction in atmospheric pressure, power can be restored or even boosted as much as(%):

10-15

Electric starter motors require a ____ power source for starting a turbine engine.

DC

How does the ignition system of a gas turbine engine differ from that of a recip engine?

a high energy, high heat intensity spark is required for ignition for a turbine engine

Why are turbine engine igniter plugs less susceptible to fouling than recip engine spark plugs?

the high heat intensity spark cleans the igniter

Why does the constrained gap igniter plug used in some gas turbine engines operate at a cooler temp?

the tip of the igniter plug does not extend into the combustion chamber

When removing a turbine engine igniter plug, in order to eliminate the possibility of the technician receiving lethal shock, the ignition switch is turned off and:

the high tension lead is removed from the plug and the center electrode is grounded to the engine case to ensure discharge of the capacitor, after the system has been shut down for a specified time.

Extreme caution should be exercised in handling and disposing of damaged turbine engine igniter exciter/transformer units because:

some contain radioactive material

Igniter plugs used in turbine engines are subjected to high electrode erosion due to the high heat energy spark discharges, yet they have a long service life because:

they do not require continuous operation

Which statement is correct regarding the ignition system of a turbine engine?

the system is normally de-energized shortly after then engine reaches self-accelerating speeds.

Why are turbine engine ignition systems required to supply a high energy, high heat spark?

to ignite fuel under conditions of high alt, low temp, and high air velocities.

Which of the following are included in a typical turbine engine ignition system?

1. One transformer.

2. Two transformer(exciter) units.

3. Two igniter plugs.

4. Two low-tension leads.

5. One exciter unit.

6 Two high tension leads.

2,3,6

Turbine engine ignition systems are rated in:

joules

Which choice is the most important characteristic of any turbine engine ignition system?

the temp of the spark

What designations are given to the two types of igniter plug gaps?

annular and constrained

The intense spark released across the gap of an igniter plug is obtained by:

expending a small amount of electric energy in a very small amount of time

The __________ __________ located downstream of the fuel spray bars in an afterburner provide a region in which turbulent eddies are formed and where the local gas velocity is reduced.

flame holder

The normal spark rate of a typical ignition system is between:

60-100 sparks a minute

What are the basic parts of an igniter plug?

outer shell, ceramic insulator, electrode, and ceramic seals

Which type of starter does not require a mechanism to disengage it from the engine once the engine is started?

starter generator

When operationally testing igniter plugs(besides glow plugs) a satisfactorily operating igniter will have a _____________ pulse firing sound.

steady

On a high voltage capacitor ignition system, when the first spark bridges the gap of the igniter, the gap is said to be:

ionized

Bleed air is used for aircraft de-icing, pressurization, heating, and cooling systems is known as:

customer bleed air

At ____________ power settings, the IGV's will be closed then opened as power is ____________________________________.

lower, increased to takeoff power

Which turbine engine anti-stall system helps prevent compressor stalls by dumping excessive compressor air overboard at lower power settings?

variable bleed valves (VBV) system

The _________________________________________ helps prevent compressor stall by limiting the amount of air allowed to pass through the compressor and engine.

Veritable inlet guide vanes (VIGV)

Power in a turbine engine can be restored or boosted up to 35% with the use of water injection. T or F?

False

1 multiple choice option

Low tension ignition systems typically operate on AC power input. T or F?

False

1 multiple choice option

The starter and ignition system on a gas turbine engine cut off just after the engine attains self-accelerating speed. T or F?

True

1 multiple choice option

Before you inspect any low voltage igniter plug, be sure to remove the deposits and residue from the firing end of the igniter. T or F?

False

1 multiple choice option

The turbine engine ignition system is used primarily during engine operation. T or F?

False

1 multiple choice option