Reciprocating Engine Induction and Cooling Systems

Question 1

The basic induction system of an aircraft reciprocating engine consists of what components?

Answer 1

Air scoop and ducting

Question 2

What are the three major parts of a reciprocating induction system?

Answer 2

Air scoop, fuel delivery system, and intake manifold

Question 3

What effect does induction system icing have on engine performance?

Answer 3

Can cause an engine to act erratically and lose power and may possibly quit

Question 4

What method is used to prevent or remove induction system ice in a reciprocating engine?

Answer 4

Heated air

Question 5

How is ice cleared in some aircraft induction systems if the carburetor heat is too low to clear the ice?

Answer 5

Anti-icing fluids such as alcohol are sprayed into the induction system

Question 6

What engine indication can be the result of a dirty air filter?

Answer 6

Low power

Question 7

What is the danger of using carburetor heat when operating at high power settings?

Answer 7

Detonation and possible engine failure

Question 8

Carburetor throttle ice is most likely to form when the throttle is in which position?

Answer 8

Partially closed position

Question 9

What are two general classifications of supercharges used in reciprocating engine induction systems?

Answer 9

Internally or externally driven supercharger systems

Question 10

What is the purpose of a distribution impeller in a radial engine?

Answer 10

Break up the fuel globules and better distribution to the cylinders

Question 11

How does an internally driven supercharger get its power?

Answer 11

They are mechanically engine driven. A high-speed impeller is driven through a gear train from the crankshaft

Question 12

Where does an externally driven supercharger get its power?

Answer 12

By the exhaust gases that are directed against a turbine.

Question 13

What unit regulates the amount of exhaust gases to the turbine of a turbocharger?

Answer 13

Waste gate

Question 14

What type of power is used to control the position of the turbocharger waste gate on some engines?

Answer 14

Oil pressure to an actuating piston

Question 15

What can cause the waste gate to stick?

Answer 15

A buildup of carbon

Question 16

What are the most common ways to control a waste gate?

Answer 16

Mechanically or by an actuator driven by oil pressure

Question 17

What causes fuel evaporation ice?

Answer 17

Because of the decrease in air temperature resulting from evaporation of fuel after it is introduced into the airstream

Question 18

What is the function of the turbocharger waste gate?

Answer 18

Controls the volume of exhaust gas that is directed onto the turbine

Question 19

What may be the indication of leaking intake pipes?

Answer 19

Engine runs rough

Question 20

What may be the indication if a turbocharger waste gate will not close fully?

Answer 20

Aircraft may not be able to reach critical altitude

Question 21

What could be the probable cause of a turbocharger engine that surges?

Answer 21

Waste gate or controller malfunction

Question 22

What is used on many turbocharged engines for the waste gate actuator power?

Answer 22

Oil Pressure

Question 23

How does a divergent shaped jet engine inlet affect the air flowing to the engine when an airplane is in subsonic flight?

Answer 23

Causes the air velocity to decrease and the air pressure to increase

Question 24

Bellmouth inlet ducts are used typically on what type of aircraft?

Answer 24

Helicopters

Question 25

The Venturi type particle separator, found on many turbine powered helicopters, utilizes what characteristic of matter to help remove debris from induction air?

Answer 25

Inertia

Question 26

What is the most common means of regulating the cooling air flow through a reciprocating engine?

Answer 26

Cowl flaps

Question 27

What is the purpose of the fins on engine cylinders?

Answer 27

Increase the surface area of the cylinder for cooling

Question 28

What other engine characteristics are designed to aid in engine cooling besides cooling fins?

Answer 28

Engine cowlings and baffles

Question 29

How is an engine designed to provide more cooling area?

Answer 29

The outer surface of the cylinder is increased by use of cooling fins

Question 30

Why is the “open and close” adjustment during installation of cowl flaps important?

Answer 30

The cowl flaps are set for a tolerance that will permit them to open and close the correct amount to keep the cylinder head temperature within allowable limits

Question 31

What should be done to cylinders when too much of the cooling fin area is broken off?

Answer 31

Cylinder should be replaced

Question 32

When should cowl flaps be kept in the fully open position?

Answer 32

During all ground operations

Question 33

What publication should be referred to before re-profiling cylinder cooling fins?

Answer 33

Manufacturer’s service or overhaul manual

Question 34

What power sources are used to operate cowl flaps?

Answer 34

Electrical and hydraulic power or manually

Question 35

What is the purpose of blast tubes?

Answer 35

Direct jets of cooling air to accessories of the engine that have high heat concentrations

Question 36

What are the main reasons that excessive heat in a reciprocating engine is undesirable?

Answer 36

Shortens the life of the engine parts, impairs lubrication, and affects combustion

Question 37

Describe the augmenter system.

Answer 37

Helps to keep the temperature of air-cooled engines down by using exhaust gas energy to draw cool air over the engine.

Question 38

What is the source of air directed to engine bearings for cooling?

Answer 38

Bleed air from the compressor section

Question 39

What is the purpose of insulation on the exhaust duct of a turbine engine?

Answer 39

Reduce the temperature of the structures in the vicinity of the exhaust duct or afterburner and to eliminate the possibility of fuel or oil coming into contact with the hot parts of the engine

Question 40

What types of materials are used to make insulation blankets for turbine engines?

Answer 40

Stainless steel, fiberglass, silver foil and layers of aluminum foil

Question 41

What areas of a turbine engine are cooled by the secondary air passing through the engine?

Answer 41

Combustion chamber and the turbines

Question 42

What is the purpose of an engine cowling?

Answer 42

Streamlines the engine to reduce drag and forms an envelope around the engine which forces the airstream between the cylinders to cool them

Question 43

What is the purpose of an oil cooler bypass valve?

Answer 43

Allows thick oil to bypass the cooler when the oil is cold

Question 44

Where should cowl flaps be positioned during ground operations?

Answer 44

Fully open

Question 45

What is the purpose of cowl air seals?

Answer 45

Force air to circulate around and through the baffle system

Question 46

Where must most cooling air flow to cool a turbine engine?

Answer 46

Inside of the engine

Question 47

What areas of a turbine engine are cooled by air passing through the engine?

Answer 47

Combustion chamber and turbine

Question 48

What is the relationship between turbine engine upper temperature limits and power produced?

Answer 48

The higher the combustion temperatures that an engine can withstand without damage, the more power it is capable of producing

Question 49

What is the approximate percentage of air passing through a turbine engine that is used for cooling rather than combustion?

Answer 49

75 percent