Aircraft Systems Pt. 4

Question 1

What are aircraft turbine engine consists of?

Answer 1

• Air inlet
• Compressor
• Combustion chambers
• Turbine Section
• Exhaust

Question 2

What fuel do gas turbine engines use?

Answer 2

Kerosene-based (JP-8 and Jet A-1)

Question 3

What are the four types of aircraft turbine engines?

Answer 3

• Turbojet
• Turboprop
• Turbofan
• Turboshaft

Question 4

What are the four sections of a turbojet engine?

Answer 4

• Compressor
• Combustion Chamber
• Turbine Section
• Exhaust

Question 5

This passes inlet air at a high rate of speed to the combustion

Answer 5

Compressor section

Question 6

This contains the fuel inlet and igniter for combustion

Answer 6

Combustion chamber

Question 7

State the pros of a turbojet

Answer 7

• Relatively simple design
• Capable of very high speeds
• Takes up little space

Question 8

State the cons of a turbojet

Answer 8

• High fuel consumption
• Loud
• Poor performance at slow speeds

Question 9

This is a turbine engine that drives a propeller through a reduction gear.

Answer 9

Turboprop

Question 10

Why is reduction gearing necessary in turboprop engines?

Answer 10

Because optimum propeller performance is achieved at much slower speeds than the engine’s operating rpm.

Question 11

In which speeds are turboprops most efficient?

Answer 11

Between 250 and 400 mph and altitudes between 18,000 and 30,000 feet

Question 12

The minimum specific fuel consumption of the turboprop engine is normally available in the altitude range of?

Answer 12

25,000 feet to the tropopause

Question 13

State the pros of turboprop

Answer 13

• Very fuel efficient
• Most efficient at mid-range speed between 250-400 knots
• Most efficient at mid-range altitudes of 18,000-30,000 feet

Question 14

State the cons of turboprop

Answer 14

• Limited forward airspeed
• Gearing systems are heavy and can break down

Question 15

These are designed to create additional thrust by diverting a secondary airflow around the combustion chamber

Answer 15

Turbofan

Question 16

This generates increased thrust, cools the engine, and aids in exhaust noise suppression.

Answer 16

Turbofan bypass air

Question 17

The inlet air that passes through a turbofan engine is usually divided into two separate streams of air. Explain these two streams.

Answer 17

One stream passes through the engine core, second stream bypasses the engine core. This bypass stream of air that is responsible for the term “bypass engine”

Question 18

State the Pros of a Turbofan

Answer 18

• Fuel efficient
• Quieter than turbojets
• They look awesome

Question 19

State the cons of turbofan

Answer 19

• Heavier than turbojets
• Larger frontal area than turbojets
• Inefficient at very high altitudes

Question 20

This delivers power to a shaft that drives something other than a propeller.

Answer 20

Turboshaft

Question 21

What is the biggest difference between a turbojet and a turboshaft engine?

Answer 21

On a turboshaft engine, most of the energy produced by the expanding gases is used to drive a turbine rather than produce thrust.

Question 22

These are essentially a turbojet engine with a large shaft connected to the back of it.

Answer 22

Turboshaft

Question 23

State the pros of a turboshaft

Answer 23

• Much higher power-to-weight ratio than piston engines
• Typically smaller than piston engines

Question 24

State the cons of a turboshaft

Answer 24

• Loud
• Gear Systems connected to the shaft can be complex and break down