Chapter 3 Engines

Question 1

Most general aviation airplane engines are of the ___ opposed variety.

Answer 1

Horizontally

Question 2

Horizontally opposed cylinder arrangements pack a lot of engine into a ___ amount of space. Less space used by the engine means less overall ___.

Answer 2

Small, Drag

Question 3

Name the four cycles of an airplane engine:

Answer 3

Intake, compression, power, exhaust

Question 4

While the piston is in its downward journey, the ___ valve opens, and a mixture of fuel and air rushes in.

Answer 4

Intake

Question 5

The ___ cycle occurs when the intake valve closes and the piston rises.

Answer 5

Compression

Question 6

Just before the cylinder hits the top of its return journey, the ___ ___ fire.

Answer 6

Spark Plugs

Question 7

The burning mixture pushes the piston downward. This is the ___ stroke.

Answer 7

Power

Question 8

One purpose of the dual ignition system on an aircraft engine is to provide for …

Answer 8

improved engine performance

Question 9

Magnetos contain spinnable magnets, housed in metal cases. When the internal magnets are spun, they generate electricity for the ___ ___.

Answer 9

Spark Plugs

Question 10

What’s particularly interesting about magnetos is that they are self-contained spark generators and require no outside source of electrical energy to work other than the ___ motion of the airplane engine.

Answer 10

Turning

Question 11

What is the purpose of the magneto’s impulse coupling?

Answer 11

To provide extra spin energy for the magneto’s internal magnets

Question 12

Normally, airplanes are operated with the magneto switch in the ___ position.

Answer 12

Both

Question 13

Is it permissible to operate the engine on one magneto?

Answer 13

yes. If one magneto goes bad, it’s permissible to switch to a single magneto

Question 14

In many cases we’re concerned not only with the RPM drop on each magneto, but with the ___ in RPM between each mag drop.

Answer 14

Difference

Question 15

Selecting the right or left magneto ___ the other mag by grounding it to the air frame.

Answer 15

Deactivates

Question 16

The mag is grounded to the air frame via a wire called the …

Answer 16

P-lead

Question 17

Mechanics (and flight instructors) sometimes recommend doing a P-lead security check just before shutting down. With the engine idling, quickly turn the mag switch from ___ to off, then immediately back to ___ again.

Answer 17

both, both

Question 18

Exhaust gases sometimes have an afterlife. They can be put to use spinning a ___ or indirectly heating the ___ or cabin.

Answer 18

Turbocharger, carburetor

Question 19

The ___, ___ and ___ manifold (pipes connected to each cylinder) make up the induction system on carburetor equipped airplanes.

Answer 19

air filter, carburetor, intake

Question 20

Airplane carburetors located underneath the engine are called ___ type carburetors because air and fuel must be drawn upward toward each cylinder.

Answer 20

Updraft

Question 21

The operating principle of float-type carburetors is based on the…

Answer 21

difference in air pressure at the venturi throat and the air inlet

Question 22

The ___ jet is that portion of the carburetor that allows the engine to run when the throttle is pulled full aft.

Answer 22

Idling

Question 23

Why doesn’t the engine quit or falter when the throttle is opened abruptly?

Answer 23

The accelerator pump supplies a shot of fuel into the throat of the carburetor along with the inrushing air.

Question 24

Assuming the airplane has an updraft carburetor with an accelerator pump, what happens when the engine isn’t running and the throttle is pumped?

Answer 24

Fuel may fall to the bottom of the carburetor and soak the air filter, creating an opportunity for an engine fire.

Question 25

Fuel-air ratios of approximately ___ part(s) fuel to ___ parts of air are the most efficient for combustion

Answer 25

one, 13

Question 26

Temperature drops of as much as ___ within the carburetor’s throat are not uncommon.

Answer 26

70 degrees

Question 27

your carburetor is a fine ice maker. because of the considerable drop in temp caused by the atomization and evaporation of fuel, any ___ present can and will freeze

Answer 27

moisture

Question 28

be prepared for carburetor ice to form at almost any outside air temp, though it’s most likely to occur between outside temps of ___

Answer 28

20 degree F to 70 degrees F

Question 29

Impact ice occurs when ___ ___ is present and the outside air temp (OAT) is at or below freezing

Answer 29

visible moisture

Question 30

When is it possible to have an air filter freeze over while nowhere near a cloud?

Answer 30

If the air is moist and temps are low, water can accumulate and the air filter’s membrane can freeze.

Question 31

Another occasion where impact ice is likely is during ___

Answer 31

freezing rain

Question 32

if your air filter ever becomes clogged by impact ice, you have a remedy at hand. It’s called the ___ control

Answer 32

Carb Heat

Question 33

Fuel ice forms ___ of the main discharge nozzle.

Answer 33

Downstream

Question 34

Which condition is most favorable for the development of carb icing?

Answer 34

Temps between 20 degrees F and 70 degrees F and High humidity

Question 35

Fuel ice can occur at outside air temps as high as ___ and at humidities as low as ___

Answer 35

85°F and 50% Humidity

Question 36

Throttle ice forms on the ___ side of the throttle valve.It is more likely to occur when the throttle is in a ___ position.

Answer 36

rear, partially closed

Question 37

Pulling the carb heat lever allows heated air to enter the carburetor, raising the air temp within its throat as much as ___

Answer 37

90°F

Question 38

If an aircraft is equipped with a fixed pitch propeller and a float-type carburetor, the first indication of carb ice would most likely be ___

Answer 38

Loss of RPM

Question 39

The presence of carb ice in an aircraft equipped with a fixed pitch propeller can be verified by applying car heat and noting…

Answer 39

a further decrease in RPM and then a gradual increase in RPM

Question 40

Generally speaking, the use of carb heat tends to

Answer 40

decrease engine performance

Question 41

Applying carb heat will

Answer 41

enrich the fuel/air mixture

Question 42

What change occurs in the fuel/air mixture when carb heat is applied?

Answer 42

The fuel/air mixture becomes richer

Question 43

A carburetor air temp gauge allows you to identify the ___ temp range where carburetor ice is most likely to occur.

Answer 43

Critical

Question 44

All engines ___ have the same carb icing potential

Answer 44

DO NOT

Question 45

Pulling out (toward you) on the mixture control ___ the amount of fuel for a given amount of air entering the engine

Answer 45

decreases

Question 46

with an increase in altitude the air becomes thinner and doesn’t ___ as much for a given volume

Answer 46

Weigh

Question 47

The basic purpose of adjusting the fuel/air mixture at altitude is to…

Answer 47

decrease the fuel flow in order to compensate for decreased air density.

Question 48

Most engine manufacturers recommend leaning the mixture whenever you’re operating at or below ___ of the engine’s maximum power output.

Answer 48

75%

Question 49

How might you estimate that you’re operating at power levels greater than 75% in a non-turbocharged engine?

Answer 49

If the airplane is operating with full throttle at less than 5,000 feet MSL

Question 50

Remember, failure to lean appropriately means you’ll use up ___ portion of fuel unnecessarily

Answer 50

an extra

Question 51

Airplanes with fixed pitch propellers (propellers having one pitch that can’t be changed in flight) and float-type carburetors can be leaned by reference to the ___

Answer 51

Tachometer

Question 52

While leaning with reference to the tachometer, the RPM peaks. this means that you are at the fuel-air ratio that produces maximum ___ for a given air density and throttle setting.

Answer 52

power

Question 53

A mixture that is too rich causes engine ___

Answer 53

roughness

Question 54

A fouled spark plus in flight can sometimes be detected by ___

Answer 54

an increase in EGT

Question 55

An excessively rich mixture contributes to ___,___,___, and ___.

Answer 55

A rough running engine, high fuel consumption, less range, smaller fuel reserves

Question 56

During the run-up at a high elevation airport, a pilot notes a slight engine roughness that is not affected by the magneto check but grows worse during the carburetor heat check. Under these circumstances, what would be the most logical initial action?

Answer 56

Check the results obtained with a leaner setting of the mixture

Question 57

The biggest danger with an excessively lean mixture is that it ___

Answer 57

burns hot

Question 58

What is one procedure to aid in cooling an engine that is overheating?

Answer 58

Enrichen the fuel mixture

Question 59

High cylinder head temps also lead to something known as ___

Answer 59

detonation

Question 60

While cruising at 9,500 feet MSL, the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?

Answer 60

The fuel/air mixture may become excessively lean.

Question 61

For best power (most usable power per unit of air), enrich the mixture until the temperature ___. (check your POH to ensure the proper procedure for your aircraft.)

Answer 61

Decreases 125°F from peak EGT

Question 62

Water is the most frequent contaminant found in fuel. Water, weighing approximately ___ pounds per gallon, ___ ___ than fuel, which weighs approximately ___ pounds per gallon

Answer 62

8, is heavier, 6

Question 63

If it’s present, water rests on the ___ of the fuel tanks, where it’s often the first thing to go to the engine.

Answer 63

Bottom

Question 64

Filling the fuel tanks after the last flight of the day is considered a good operating procedure because this will…

Answer 64

prevent moisture condensation by eliminating airspace in the tanks

Question 65

Fuel tanks have sump drains found at the ___ part of the tank. The sumps should be drained after every ___

Answer 65

lowest, refueling

Question 66

Different grades of aviation fuel (called AVGAS) are dyed for easy identification. Red colored fuel is of the ___ octane variety (very hard to find nowadays). ___ Fuel is of the 100LL or low lead variety and is one of the most common aviation fuels in use today. ___ fuel is 100 octane and is also very hard to find.

Answer 66

80, blue, green

Question 67

What type fuel can be substituted for an aircraft if the recommended octane is not available?

Answer 67

The next higher octane aviation gas

Question 68

As the fuel pump sucks from the tank, air must replace the departing fuel or a ___ forms

Answer 68

Vacuum

Question 69

Boost pumps are often used during ___ to pressurized the fuel system. This helps purge air trapped within the fuel lines. After the engine starts, the electric boost pump is ___ to see if the ___ pump is operational and is pressurizing the system.

Answer 69

Engine start, turned off, mechanical

Question 70

On aircraft equipped with fuel pumps, the practice of running a fuel tank dry before switching tanks is considered unwise because…

Answer 70

the engine-driven fuel pump or electric fuel boost pump may draw air into the fuel system and cause vapor lock.

Question 71

The primer usually squirts fuel in the ___ portions of the induction system, ___ the carburetor completely.

Answer 71

Upper, bypassing

Question 72

The regulations require fuel gauges to be accurate in only two conditions: when the tank is ___ and then it’s ___

Answer 72

Full, empty (no usable fuel on board)

Question 73

Remember Rod Machado’s fuel axiom No. 13: If you smell fuel on take off, go back and land. You probably left the cap off your ___

Answer 73

Tank

Question 74

If an airplane’s oil cap is left off or comes loose during flight, oil may be ___ ___ the engine

Answer 74

expelled from

Question 75

For internal cooling, reciprocating aircraft engines are especially dependent on …

Answer 75

the circulation of lubricating oil

Question 76

What should be the first action after starting an aircraft engine?

Answer 76

Adjust for proper RPM and check for desired indications on the engine gauges

Question 77

Engines are generally preheated in extreme cold. Lycoming, for example, recommends the engine be preheated at temps below ___ to prevent engine damage during startup. Continental says ___.

Answer 77

10°F, 20°F

Question 78

An abnormally high engine oil temp indication may be caused by…

Answer 78

the oil level being too low

Question 79

Excessively high engine temps will…

Answer 79

cause loss of power, excessive oil consumption, and possible permanent internal engine damage

Question 80

If the engine oil temp and cylinder head temp gauges have exceeded their normal operating range, the pilot may have been operating with…

Answer 80

too much power and the with the mixture set too lean

Question 81

What action can a pilot take to aid in cooling an engine that is overheating during a climb?

Answer 81

Reduce rate of clime and increase airspeed

Question 82

Inside most airplane engines is something known as an ___. This valve provides an alternate path for the flow of oil if the pressure within the system becomes dangerously ___

Answer 82

Oil pressure relief valve, high

Question 83

Most modern airplane engines are ___ cooled. Water cooling may be more efficient, but it would mean carrying considerably more ___

Answer 83

Air, weight

Question 84

In order to avoid shock-cooling a high performance engine during a cruise descent, make small power changes. A good rule of thumb is to make no more than a ___ RPM per minute reduction in engine speed on small engines and no more than ___ of manifold pressure per minute on high performance airplanes. Always leave enough power on so as not to cool the cylinder head temps below allowable limits.

Answer 84

100, 1 inch

Question 85

Keep in mind that engine cooling is least effective at ___ power settings and ___ airspeeds, where a limited amount of air enters the engine cowling.

Answer 85

high, low

Question 86

Keeping the ___ flaps closed helps maintain engine temps during the descent.

Answer 86

Cowl

Question 87

During a descent, your job is to maintain stable cylinder head temps (CHT) and oil tmeps. On some airplanes, ___ entensoin or even ___ extension at high speeds can be used in lieu of large power reductions to start a descent (check your POH)

Answer 87

gear, partial flap

Question 88

In an airplane with a fixed pitch prop, one lever, the ___ controls both power and propeller blade RPM.

Answer 88

Throttle

Question 89

As you move up into higher performance airplanes you encounter constant speed (controllable pitch) propellers. Airplanes with these propellers usually have both a ___ and a/an ___ control, so you manage engine power and propeller RPM separately.

Answer 89

throttle, propeller

Question 90

What is an advantage of a constant speed propeller?

Answer 90

It permits the pilot to select the blade angle for the most efficient performance

Question 91

On airplanes with constant speed propellers, movement of the ___ determines the amount of fuel and air reaching the cylinders.

Answer 91

throttle

Question 92

Simply stated, the ___ determines how much power the engine can develop.

Answer 92

throttle

Question 93

Movement of the propeller control changes the propeller’s…

Answer 93

pitch

Question 94

On an airplane with a constant speed propeller, the ___ determines engine power while the ___ determines how efficiently that power is used

Answer 94

throttle, propeller’s pitch

Question 95

Forward movement of the propeller control causes both havlves of the propeller to rotate about their axes and attack the wind at a ___ angle

Answer 95

smaller

Question 96

Pulling the propeller control rearward causes the propeller to attack the wind at a ___ angle of attack

Answer 96

larger

Question 97

On an airplane with a constant speed propeller, the ___ tells you how fast the propeller spins (its RPM), and the manifold pressure gauge gives you an approximate measure of engine ___

Answer 97

tachometer, power

Question 98

Opening the throttle slightly causes an increase in ___ pressure. More air and fuel are drawn inside the engine, and power ___. Eventually, as the throttle is fully opened, the pressure downstream of the throttle valve approaches that of the ___

Answer 98

Manifold, increases, atmostphere

Question 99

Under normal conditions ( assuming a non-turbocharged engine), the engine’s manifold pressure can’t rise above ___ pressure

Answer 99

atmospheric

Question 100

As a non-turbocharged airplane climbs, you’ll notice the manifold pressure gauge shows ___ even though the throttle is fulled opened

Answer 100

a decrease

Question 101

Why have a propeller that can change its pitch in flight in the first place?

Answer 101

Airplanes with controllable pitch propellers can select the optimum angle of attack for climb and cruise.

Question 102

Engine power is dependent on RPM. For an engine to develop its maximum power, it must be operated at its ___ allowable RPM. At any lower RPM the engine develops only a fraction of its total horsepower. That’s why on takeoff we want the propeller set to its ___ pitch (highest RPM) position.

Answer 102

Highest, Lowest

Question 103

During cruise flight, is it necessary to always fly with maximum power and maximum RPM?

Answer 103

NO!!

Question 104

Controllable pitch propellers on GA airplanes are of the constant speed variety. Once the RPM is established, changes in manifold pressure (by moving the throttle) ___ affect engine speed.

Answer 104

won’t

Question 105

When you want to increase both the manifold pressure and RPM, change the ___ first, then increase the ___.

Answer 105

RPM, manifold pressure

Question 106

A precaution for the operation of an engine equipped with a constant speed propeller is to…

Answer 106

avoid high manifold pressure setting with low RPM

Question 107

Follow the same philosophy when decreasing manifold pressure and RPM. Pull the ___ back first, followed by the ___.

Answer 107

Throttle, propeller contorl

Question 108

Be aware that the propeller governor starts working only when the engine is operating above a specific ___ and not below

Answer 108

RPM

Question 109

Detonation occurs in a reciprocating aircraft engine when…

Answer 109

the unburned charge in the cylinders explodes instead of burning normally

Question 110

Which would most likely cause the cylinder head temp and engine oil temp gauges to exceed their normal operating ranges?

Answer 110

Using fuel that has a lower-than-specified fuel rating

Question 111

If a pilot suspects that an airplane engine with a fixed-pitch propeller is detonating during climbout after takeoff, the initial corrective action to take would be to …

Answer 111

lower the nose slightly to increase airspeed

Question 112

If the grade of fuel used ina n aircraft engine is lower than specified for the engine, it will most likely cause…

Answer 112

detonation

Question 113

The uncontrolled firing of the fuel/air charge in advance of normal spark ignition is known as …

Answer 113

preignition

Question 114

Preignition causes peak pressures within the cylinder to occur before the beginning of the ___ cycle.

Answer 114

power

Question 115

Fuel injection is a process in which fuel is directly ___ and ___ to each cylinder without the use of a carburetor.

Answer 115

metered, distributed

Question 116

The FCU (fuel control unit) regulates botht he volume of the ___ entering the engine and the quantity of ___ delivered to the FMU (fuel manifold unit).

Answer 116

air, fuel

Question 117

You can’t get carb ice in a fuel injection system for one very important reason: there is ___

Answer 117

no carburetor associated with this system

Question 118

With regard to carb ice, float-type caruretor systems in comparison to fuel injection systems are generally considered to be …

Answer 118

more susceptible to icing

Question 119

A major advantage of fuel injection is…

Answer 119

improved control of fuel-air ratio

Question 120

A major disadvantage of Fuel Injection is

Answer 120

contamination of dirt and water can more easily affect fuel injected engines due to the small orifices of injector nozzles.

Question 121

Airplanes with turbochargers are able to produce___ power at high altitudes

Answer 121

sea level

Question 122

Turbocharging compresses air into the intake manifold by utilizing the normally unused ___ exiting the engine.

Answer 122

exhaust gases

Question 123

The ___ valve closes (either automatically or manually, depending on your airplane) allowing more ___ to flow over the turbine. This spins the ___, allowing compressed air to be pumped into the induction system.

Answer 123

Wastegate, exhaust, compressor

Question 124

Pressurizing an airplane allows you to fly at very high altitudes while remaining in a cabin environment with near ___ pressures. This is accomplished by directing ___ air from the ___ (or from an auxiliary compressor) into the cabin.

Answer 124

Sea-level, compressed, turbocharger

Question 125

Temps drop as much as ___ within the carburetor’s throat are not uncommon.

Answer 125

70 degrees

Question 126

Your carburetor is a fine ice maker. Because of the considerable drop in temp caused by the atomization and evaporation of fuel, any ___ present can and will freeze.

Answer 126

Moisture

Question 127

Be prepared for carburetor ice to form at almost any outside air temp, though it’s most likely to occur between outside temps of ___.

Answer 127

20 degrees to 70 degrees.

Question 128

Impact ice occurs when ___ ___ is present and. The tide air temp (OAT) is at or below freezing

Answer 128

Visible moisture

Question 129

When is it possible to have an air filter freeze o

Ver while nowhere near a cloud?

Answer 129

If the air is moist and temps are low, water can accumulate on the air filter’s membrane and freeze.

Question 130

Another occasion where impact ice is likely is during ___.

Answer 130

Freezing rain

Question 131

If your air filter ever becomes clogged by impact ice, you have a remedy at hand. It’s called the ___ control.

Answer 131

Carb heat

Question 132

Fuel ice forms ___ of the main discharge nozzle.

Answer 132

Downstream

Question 133

Which condition is post favorable for the development of carb icing?

Answer 133

Temps between 29 degrees and 70 degrees and high humidity

Question 134

Fuel ice can occur at outside air temps as high as ___ and at humidities as low as ___.

Answer 134

85 degrees F, 50%

Question 135

Throttle ice forms on the ___ side if

The throttle valve. It is more likely to occur when the throttle is in a ___ position.

Answer 135

Rear, partially open

Question 136

Pulling the carburetor heat lever allows heated air to enter the carburetor, raising the air temperature within it’s throat as much as ___

Answer 136

90 degrees

Question 137

If an aircraft is equipped with a fixed pitch propeller and a float-type carburetor, the first indication of carburetor ice wo uld most likely be ___

Answer 137

Loss of RPM

Question 138

THe presence of carb ice in an aircraft equipped with a fixed pitch propeller can be verified by applying carb heat and noting ___

Answer 138

A further decrease in RPM and then a gradual increase in RPM

Question 139

Generally speaking, the use of carb heat tends to …

Answer 139

Decrease engine performance

Question 140

Applying carb heat will …

Answer 140

Enrich the fuel/air mixture

Question 141

What change occurs in the fuel/air mixture when carb heat is applied?

Answer 141

The fuel/air mixture becomes richer

Question 142

A carburetor air temperature gauge allows you to identify the ___ temperature range where carb ice is most likely to occur.

Answer 142

Critical

Question 143

All engines ___ have the same carb icing potential.

Answer 143

Do not

Question 144

Pulling out (toward you) on the mixture control ___ the amount of fuel given amount of air entering the engine.

Answer 144

Decreases

Question 145

With an increase in altitude the air becomes t hinder and doesn’t ___ as much for a given volume.

Answer 145

Weigh

Question 146

The basic purpose of adjusting the fuel/air moisture at altitude is to …

Answer 146

Decrease the fuel flow in order to compensate for decreased air density

Question 147

Most engine manufacturers recommend leaning the mixture whenever you’re operating at or below ___ of the engine’s maximum power output (check your POH to be sure)

Answer 147

75%

Question 148

How might you estimate that you’re operating at power levels greater than 75% in a non-turbocharged engine?

Answer 148

If the airplane is operating with full throttle at less than 5000 feet MSL.

Question 149

Remember, failure to lean appropriately means you’ll use up ___ portion of fuel unnecessarily.

Answer 149

An extra

Question 150

Airplanes with fixed pitch propellers (propellers having one pitch that can’t be changed in flight) and float-type carburetor a can be leaned by reference to the …

Answer 150

Tachometer

Question 151

While leaning with reference to the tachometer, the RPM peaks. This means that you are at the fuel-air ratio that produces maximum ___ for a given air density and throttle setting.

Answer 151

Power

Question 152

A mixture that is too rich causes engine …

Answer 152

Roughness

Question 153

A fouled spark plug in flight can sometimes be detected by …

Answer 153

An increase in Exhaust Gas Temp (EGT)

Question 154

An excessively rich mixture contributes to ___,___,___and ___.

Answer 154

A rough running engine, high fuel consumption, less range, smaller fuel reserves

Question 155

During the run-up at a high elevation airport, a pilot notes a slight engine roughness that is not affected by the magneto check but grows worse during the carburetor heat check. Under these circumstances, what would be the most logical initial action?

Answer 155

Check the results obtained with a leaner setting of the mixture.

Question 156

The biggest danger with an excessively lean mixture is that it …

Answer 156

Burns hot

Question 157

Want is one procedure to aid in cooling an engine that is overheating?

Answer 157

Enriched the fuel mixture

Question 158

High cylinder head temperatures also lead to something known as …

Answer 158

Detonation

Question 159

Wile cruising at 9,500 feet MSL the fuel/air mixture is properly adjusted. What will occur if a descent to 4,500 feet MSL is made without readjusting the mixture?

Answer 159

The fuel/air intrude may become excessively lean.

Question 160

For best power (most useable power per unit of air), enrich the mixture until the temp ___. (Check your POH to ensure the proper procedure for your aircraft.)

Answer 160

Decreases 125 degrees F from peak EGT

Question 161

Water is the most frequent contaminant found in fuel. Water, weighing approximately ___ pounds per gallon, ___ than fuel which weighs approximately ___ pounds per gallon.

Answer 161

8, is heavier, 6