Aircraft Systems Part 1/2

Question 1

Name 10 aircraft systems

Answer 1

Engine
Propeller
Induction
Ignition
Fuel
Lubrication
Cooling
Electrical
Landing Gear
Environmental Control

Question 2

Most small aircraft are designed with what kind of engine?

Answer 2

Reciprocating engine (pistons move back and forth)

Question 3

Name the two primary reciprocating engine designs (not types)

Answer 3

• Spark ignition

- Compression ignition

Question 4

Name the most popular reciprocating engine used on smaller aircraft

Answer 4

Opposed-Type engine (can be spark or compression ignition)

Question 5

Most common engine type used in general aviation

Answer 5

Spark 4 stroke engine

Question 6

Continuous operation of the engine depends on what auxiliary systems

Answer 6

• Induction
• Ignition
• Fuel
• Oil
• Cooling
• Exhaust

Question 7

A propeller is a:

Answer 7

Rotating Airfoil

Question 8

The amount of thrust a propeller produces depends on:

Answer 8

• Shape of the airfoil
• Angle of attack of the propeller blade
• Revolutions per minute

Question 9

Why is a propeller twisted?

Answer 9

To produce uniform lift. There is a difference in speed through out the blade.

Question 10

Name two types of propellers

Answer 10

Fixed pitch vs adjustable pitch propellers

Question 11

Name two types of fixed pitch propellers & describe them

Answer 11

Climb (less drag, higher rpm, more horsepower, decreased performance for cruising flight)

cruise propellers (more drag, less rpm, less horsepower, increased efficiency in cruising flight)

Question 12

Name the indicator of engine power & how is it calibrated?

Answer 12

Tachometer - calibrated in hundreds of rpm

Question 13

What does a tachometer indicate

Answer 13

engine power via engine and propeller rpm

Question 14

What is the green arch on a tachometer?

Answer 14

maximum continuous operating rpm

Question 15

How is rpm regulated?

Answer 15

Throttle - controls the fuel/airflow through the engine

Question 16

What does engine power output depend on?

Answer 16

Air density (decreases as altitude increases)

Question 17

What does a decrease in air density result in? When?

Answer 17

Decreased power output of the engine. As you increase in altitude

Question 18

How to you maintain the same rpm as you gain altitude?

Answer 18

Position of throttle must be changed

Question 19

Describe a constant-speed propeller

Answer 19

• Pitch automatically varied during flight by a governor
• Constant rpm despite varying air loads
• Most common type of adjustable pitch propeller
• more efficient

Question 20

Two controls for adjustable propeller aircraft:

Answer 20

• Throttle (controls power output)

- Propeller control (regulates engine RPM)

Question 21

On an aircraft with a constant speed propeller, power output is controlled by:

Answer 21

The throttle and indicated by a manifold pressure gauge

Question 22

What does a manifold pressure gauge measure?

Answer 22

Measures absolute pressure of fuel-air inside intake manifold

Question 23

What does an induction system do?

Answer 23

Brings in air from the outside, mixes it with fuel and delivers the fuel-air mixture to the cylinder where the combustion occurs

Question 24

Name two types of induction systems

Answer 24

Carburetor system & fuel injection system

Question 25

What are two types of carburetor systems

Answer 25

Float type (most common)
Pressure type (uses fuel pump)

Question 26

Name disadvantages of float type carburetors

Answer 26

• Disrupted by abrupt maneuvers
• Low pressure fuel discharge causes incomplete vaporization & inhibits injection systems
• icing tendency

Question 27

When does carbon buildup occur?

Answer 27

As altitude increases, air density decreases. Since density of fuel remains the same, it creates a progressively richer mixture that can result in engine roughness & loss of power. Rich mixture lowers the temp inside the cylinder, inhibiting complete combustion of the fuel.

Question 28

During descent, mixture must be:

Answer 28

enriched to avoid an excessively lean mixture

Question 29

Overly lean mixture can cause:

Answer 29

Detonation & rough engine operation, overheating, loss of power, damage engine

Question 30

Best way to maintain proper mixture

Answer 30

Monitor engine temperature. An exhaust gas temperature gauge can aid proper mixture.

Question 31

What is carb ice caused by?

Answer 31

A sharp decrease in temp in the carb, due to vaporization of the fuel and the low pressure at the Venturi

Question 32

Ice is most likely to occur when temperature & humidity is:

Answer 32

Below 70degF or 21degC & relative humidity is above 80%

Question 33

First indication of icing in an aircraft with a fixed pitch propeller

Answer 33

Decrease in engine RPM

Question 34

First indication of icing in an aircraft with a constant speed propeller

Answer 34

Drop in manifold pressure but no reduction in rpm

Question 35

Ice is particularly dangerous during:

Answer 35

low power descents where engine temp is low & ice may build unnoticed until power is increased

Question 36

Carb heat causes a decrease in engine power, why?

Answer 36

Heated air is less dense than outside air that had been entering the engine, thus the mixture is enriched

Question 37

Name 6 basic components of a fuel injection system

Answer 37

1. Engine driven fuel pump
2. Fuel/air control unit
3. Fuel manifold valve
4. Fuel distributor
5. Discharge nozzles
6. Auxiliary fuel pump
7. Fuel pressure/flow indicators

Question 38

What is impact icing?

Answer 38

Ice forms on exterior of the aircraft & blocks openings such as air intake

Question 39

Name advantages of fuel injection

Answer 39

• Reduction in evaporative icing
• Better fuel flow
• Faster throttle response
• Precise control of mixture
• Better fuel distribution
• Easier cold weather starts

Question 40

Disadvantages of fuel injection

Answer 40

• Difficulty in starting hot engines
• Vapor lock during ground ops on hot days
• Problems restarting of fuel-starved engine