PHAK 7: Aircraft Systems

Question 1

Reciprocating Engines

What are reciprocating engines?

Answer 1

Engines where pistons move back-and-forth (reciprocate) to produce mechanical energy for work.

Question 2

Reciprocating Engines

What advancements have improved reciprocating engines recently?

Answer 2

Computerized engine management systems improving fuel efficiency, emissions, and reducing pilot workload.

Question 3

Reciprocating Engines

How do reciprocating engines convert energy?

Answer 3

They convert chemical energy (fuel) into mechanical energy through combustion in the cylinders.

Question 4

Reciprocating Engines

What are the two primary types of reciprocating engines?

Answer 4

Spark ignition and compression ignition engines.

Question 5

Reciprocating Engines

How does a spark ignition engine work?

Answer 5

It uses a spark plug to ignite a pre-mixed fuel-air mixture.

Question 6

Reciprocating Engines

How does a compression ignition engine work?

Answer 6

It compresses air in the cylinder, raising its temperature for automatic ignition when fuel is injected.

Question 7

Reciprocating Engines

What are the classifications of reciprocating engines?

Answer 7

• Cylinder arrangement: radial, in-line, V-type, or opposed.
• Operating cycle: two-stroke or four-stroke.
• Cooling method: liquid or air.

Question 8

Reciprocating Engines

What is a radial engine?

Answer 8

An engine with cylinders arranged in a circular pattern, offering a favorable power-to-weight ratio.

Question 9

Reciprocating Engines

What is the most popular reciprocating engine for small aircraft?

Answer 9

The horizontally-opposed engine, known for high power-to-weight ratios and reduced aerodynamic drag.

Question 10

Reciprocating Engines

What is the main advantage of a two-stroke engine?

Answer 10

Higher power-to-weight ratio due to a power stroke on each crankshaft revolution.

Question 11

Reciprocating Engines

What are the four strokes in a four-stroke engine cycle?

Answer 11

1. Intake: Draws fuel-air mixture into the cylinder.
2. Compression: Compresses the mixture for greater power.
3. Power: Ignites the mixture, pushing the piston down.
4. Exhaust: Removes burned gases from the cylinder.

Question 12

Reciprocating Engines

What innovation did Frank Thielert pioneer for aircraft engines?

Answer 12

Diesel-fueled piston engines capable of running on Jet-A fuel, offering reliability, cost savings, and operational independence.

Question 13

Reciprocating Engines

Which aircraft commonly use diesel cycle engines?

Answer 13

• Diamond DA40 and DA42 Twin Star.
• Retrofitted Cessna 172 and Piper PA-28 models.

Question 14

Reciprocating Engines

What is FADEC?

Answer 14

Full Authority Digital Engine Control, simplifying engine control in modern reciprocating engines.

Question 15

Propeller

What is a propeller?

Answer 15

A rotating airfoil that generates thrust to pull or push an aircraft through the air.

Question 16

Propeller

How does a propeller generate thrust?

Answer 16

By rotating and creating aerodynamic lift similar to how a wing produces lift.

Question 17

Propeller

What factors affect the thrust produced by a propeller?

Answer 17

• Shape of the airfoil.
• Angle of attack (AOA) of the blade.
• Engine revolutions per minute (RPM).

Question 18

Propeller

Why is a propeller blade twisted?

Answer 18

To produce uniform lift from the hub to the tip, compensating for the difference in speed along the blade.

Question 19

Propeller

What is the angle of incidence on a propeller?

Answer 19

The angle of the blade relative to its rotation, which changes from the hub (highest pitch) to the tip (lowest pitch).

Question 20

Propeller

What happens if the propeller blade has the same angle of incidence throughout?

Answer 20

• The portion near the hub would have a negative AOA.
• The tip would be stalled, making it inefficient.

Question 21

Propeller

What are the two main types of propellers on small aircraft?

Answer 21

1. Fixed-pitch propellers.
2. Adjustable-pitch propellers.

Question 22

Fixed-Pitch Propeller

What is a fixed-pitch propeller?

Answer 22

A propeller with fixed blade angles set by the manufacturer, which cannot be adjusted.

Question 23

Fixed-Pitch Propeller

What is the main drawback of a fixed-pitch propeller?

Answer 23

It is only efficient at a specific combination of airspeed and RPM, leading to compromises in cruise and climb performance.

Question 24

Fixed-Pitch Propeller

What are the two types of fixed-pitch propellers?

Answer 24

• Climb Propeller: Lower pitch, less drag, better takeoff and climb performance, less efficient during cruising.
• Cruise Propeller: Higher pitch, more drag, better cruising efficiency, less effective for takeoff and climb.

Question 25

# Fixed-Pitch Propeller How is a fixed-pitch propeller mounted?

Answer 25

It may be mounted directly on the engine crankshaft or on a shaft geared to the crankshaft, affecting the RPM relationship.

Question 26

# Fixed-Pitch Propeller What instrument indicates engine power in a fixed-pitch propeller aircraft?

Answer 26

The tachometer, which measures engine and propeller RPM, calibrated in hundreds of RPM.

Question 27

# Fixed-Pitch Propeller What controls RPM in a fixed-pitch propeller system?

Answer 27

The throttle, which regulates the fuel-air flow to the engine.

Question 28

# Fixed-Pitch Propeller How does altitude affect engine power and RPM in a fixed-pitch propeller?

Answer 28

* Higher altitude = lower air density = reduced engine power output. * The throttle must be opened more at higher altitudes to maintain the same RPM.

Question 29

# Fixed-Pitch Propeller Why does the same RPM produce different power at different altitudes?

Answer 29

Power output depends on air density, which decreases as altitude increases.

Question 30

# Adjustable-Pitch Propeller What is an adjustable-pitch propeller?

Answer 30

A propeller with blades that can be adjusted on the ground but not in flight; also called a ground adjustable propeller.

Question 31

# Adjustable-Pitch Propeller What is a constant-speed propeller?

Answer 31

A type of adjustable-pitch propeller that automatically varies blade pitch in flight to maintain a constant RPM.

Question 32

# Adjustable-Pitch Propeller Main advantage of a constant-speed propeller?

Answer 32

It efficiently converts engine brake horsepower (BHP) into thrust horsepower (THP) across a range of RPMs and airspeeds.

Question 33

# Adjustable-Pitch Propeller How is power controlled in a constant-speed propeller system?

Answer 33

* Throttle: Controls power output (manifold pressure). * Propeller control: Regulates engine and propeller RPM.

Question 34

# Adjustable-Pitch Propeller What happens when airspeed changes in a constant-speed propeller?

Answer 34

The governor adjusts blade angle to maintain selected RPM, increasing pitch at higher airspeeds and decreasing pitch at lower airspeeds.

Question 35

# Adjustable-Pitch Propeller What is the constant-speed range?

Answer 35

The range of blade angles between the high and low pitch stops, where constant RPM is maintained.

Question 36

# Adjustable-Pitch Propeller What happens when a pitch stop is reached?

Answer 36

The propeller behaves like a fixed-pitch propeller, and RPM changes with airspeed.

Question 37

# Adjustable-Pitch Propeller What instrument measures power output in constant-speed systems?

Answer 37

The manifold pressure gauge, which indicates the absolute pressure of the fuel-air mixture in the intake manifold.

Question 38

# Adjustable-Pitch Propeller Proper order for power adjustments to avoid engine overstress:

Answer 38

* Decreasing power: Reduce manifold pressure first, then RPM. * Increasing power: Increase RPM first, then manifold pressure.

Question 39

# Adjustable-Pitch Propeller Why should RPM and manifold pressure combinations follow manufacturer recommendations?

Answer 39

To avoid overstressing engine cylinders, which can weaken components and lead to engine failure.

Question 40

# Adjustable-Pitch Propeller Why should RPM and manifold pressure combinations follow manufacturer recommendations?

Answer 40

To avoid overstressing engine cylinders, which can weaken components and lead to engine failure.

Question 41

# FAA SAIB CE-10-21 Why was "best glide" speed insufficient in the incident that prompted FAA SAIB CE-10-21?

Answer 41

For some aircraft, the published best glide speed may not generate enough thrust when the propeller is at the low pitch stop position.

Question 42

# FAA SAIB CE-10-21 What does the SAIB recommend regarding airspeed in propeller overspeed scenarios?

Answer 42

Pilots should be aware that maintaining a lower airspeed than the published best glide speed might generate adequate thrust for level flight.

Question 43

# FAA SAIB CE-10-21 When should a pilot determine a more suitable airspeed during a propeller overspeed?

Answer 43

Only at a safe altitude and when there is enough time to evaluate alternatives beyond landing immediately.

Question 44

# FAA SAIB CE-10-21 Key takeaway for operators and pilots with variable pitch propellers:

Answer 44

Recognize that the necessary airspeed to maintain level flight during propeller overspeed may differ from engine-out best glide speed. Follow emergency procedures and adjust airspeed as needed.

Question 45

# Induction Systems What is the purpose of an induction system?

Answer 45

It brings in outside air, mixes it with fuel, and delivers the fuel-air mixture to the engine's cylinders for combustion.

Question 46

# Induction Systems Where does outside air enter the induction system?

Answer 46

Through an intake port on the front of the engine cowling, which usually contains an air filter.

Question 47

# Induction Systems What is the role of the air filter in the induction system?

Answer 47

It prevents dust and foreign objects from entering the engine.

Question 48

# Induction Systems What happens if the air filter becomes clogged?

Answer 48

An alternate air source provides air to the engine, bypassing the clogged filter.

Question 49

# Induction Systems How is alternate air sourced?

Answer 49

It typically comes from inside the engine cowling and may operate automatically or manually.

Question 50

# Induction Systems What are the two types of induction systems used in small aircraft?

Answer 50

* Carburetor system: Mixes fuel and air in the carburetor before entering the intake manifold. * Fuel injection system: Mixes fuel and air immediately before entry into each cylinder or injects fuel directly into the cylinders.

Question 51

# Carburetor Systems What are the two categories of aircraft carburetors?

Answer 51

* Float-type carburetors: Most common, with idling, accelerating, mixture control, and power enrichment systems. * Pressure-type carburetors: Deliver fuel under pressure by a fuel pump, usually not found on small aircraft.

Question 52

# Carburetor Systems What is the main difference between float-type and pressure-type carburetors?

Answer 52

The delivery of fuel: * Float-type uses gravity and atmospheric pressure. * Pressure-type uses a fuel pump to deliver fuel under pressure

Question 53

# Carburetor Systems How does a float-type carburetor operate?

Answer 53

* Air passes through a filter and venturi, creating low pressure. * Fuel is drawn through the main jet into the airstream. * A float in the float chamber regulates fuel flow via a needle valve. * The throttle valve controls the flow of the fuel-air mixture to the engine.

Question 54

# Carburetor Systems What are the disadvantages of a float-type carburetor?

Answer 54

* Poor performance during abrupt maneuvers. * Incomplete fuel vaporization at low pressure. * High tendency for icing due to temperature drops in the venturi and throttle valve.

Question 55

# Carburetor Systems How does a pressure-type carburetor address the issues of a float-type carburetor?

Answer 55

* Discharges fuel above atmospheric pressure, improving vaporization. * Positions the discharge nozzle on the engine side of the throttle valve, reducing icing risks. * Maintains fuel flow during rapid maneuvers and rough air conditions.

Question 56

# Mixture Control What happens to the fuel-air mixture as altitude increases?

Answer 56

Air density decreases while fuel density remains constant, creating a richer mixture.

Question 57

# Mixture Control What problems can a rich fuel-air mixture cause?

Answer 57

* Engine roughness: Due to spark plug fouling from excessive carbon buildup. * Power loss: Resulting from incomplete combustion.

Question 58

# Mixture Control Why does carbon buildup occur in a rich mixture?

Answer 58

Lower cylinder temperatures inhibit complete fuel combustion, leading to carbon deposits.

Question 59

# Mixture Control How is the mixture adjusted at higher altitudes?

Answer 59

Leaning the mixture: Reduces fuel flow to compensate for decreased air density.

Question 60

# Mixture Control What happens if the mixture becomes too lean?

Answer 60

May cause detonation, leading to rough engine operation, overheating, or power loss.

Question 61

# Mixture Control What should be monitored to maintain proper fuel-air mixture?

Answer 61

Engine temperature and adjustments using an Exhaust Gas Temperature (EGT) gauge.

Question 62

# Mixture Control Why is the mixture enriched during descent from high altitude?

Answer 62

To prevent the mixture from becoming too lean as air density increases.

Question 63

# Mixture Control Where should you refer for specific mixture adjustment procedures?

Answer 63

The Airplane Flight Manual (AFM) or Pilot’s Operating Handbook (POH).

Question 64

# Carburetor Icing What causes carburetor icing?

Answer 64

Fuel vaporization and air pressure drop in the venturi reduce temperature, potentially freezing water vapor inside the carburetor.

Question 65

# Carburetor Icing Where does carburetor ice typically form?

Answer 65

Around the throttle valve and in the venturi throat.

Question 66

# Carburetor Icing What are the ideal conditions for carburetor icing?

Answer 66

Temperatures below 70°F (21°C) and relative humidity above 80%, but it can occur at temperatures as high as 100°F (38°C) with humidity as low as 50%.

Question 67

# Carburetor Icing How much can the temperature drop in a carburetor?

Answer 67

As much as 60 to 70°F (33 to 39°C) due to pressure and vaporization effects.

Question 68

# Carburetor Icing What is the first sign of carburetor icing in an aircraft with a fixed-pitch propeller?

Answer 68

A decrease in engine RPM, possibly followed by engine roughness.

Question 69

# Carburetor Icing What indicates carburetor icing in a constant-speed propeller aircraft?

Answer 69

A decrease in manifold pressure with no change in RPM.

Question 70

# Carburetor Icing When is carburetor icing most dangerous?

Answer 70

During reduced power operations, such as a descent, when ice may build unnoticed until power is added.

Question 71

# Carburetor Icing How is carburetor icing mitigated?

Answer 71

Using a carburetor heat system to prevent or melt ice formation.

Question 72

# Carburetor Heat What is the purpose of carburetor heat?

Answer 72

It preheats air entering the carburetor to prevent or melt carburetor ice.

Question 73

# Carburetor Heat When should carburetor heat be used?

Answer 73

In conditions conducive to carburetor icing or as an alternate air source if the intake filter clogs.

Question 74

# Carburetor Heat What happens to engine power when carburetor heat is applied?

Answer 74

Engine power decreases (up to 15%) because heated air is less dense, enriching the mixture.

Question 75

# Carburetor Heat What is the correct response if carburetor ice is detected?

Answer 75

Apply full carburetor heat immediately and keep it on until all ice is removed.

Question 76

# Carburetor Heat How can you check for carburetor ice in a fixed-pitch propeller aircraft?

Answer 76

Look for an initial decrease in RPM followed by a gradual increase as the ice melts.

Question 77

# Carburetor Heat How does carburetor ice affect constant-speed propeller aircraft?

Answer 77

Ice causes a decrease in manifold pressure, followed by a gradual increase as ice melts.

Question 78

# Carburetor Heat Why should carburetor heat not be used during takeoff or normal operations?

Answer 78

It reduces engine power and increases operating temperature, which is not ideal for full-power scenarios.

Question 79

# Carburetor Heat What should a pilot do if power loss and engine roughness occur due to carburetor icing?

Answer 79

Apply full carburetor heat and wait for normal power to return, even if roughness occurs temporarily.

Question 80

# Carburetor Heat Why is periodic throttle opening recommended during closed-throttle operations?

Answer 80

To keep the engine warm and ensure the carburetor heater provides enough heat to prevent icing.

Question 81

# Carburetor Heat What should a pilot monitor during carburetor heat application in icing conditions?

Answer 81

Watch for RPM or manifold pressure changes, smoother engine operation, and recovery of power.

Question 82

# Carburetor Air Temperature Gauge What is the purpose of a carburetor air temperature gauge?

Answer 82

To detect potential icing conditions in the carburetor.

Question 83

# Carburetor Air Temperature Gauge How is the gauge calibrated?

Answer 83

In degrees Celsius, with a yellow arc indicating temperatures where icing may occur.

Question 84

# Carburetor Air Temperature Gauge What is the typical range of the yellow arc?

Answer 84

Between –15 °C and +5 °C (5 °F to 41 °F).

Question 85

# Carburetor Air Temperature Gauge What should a pilot do if the gauge indicates a yellow arc and icing conditions are possible?

Answer 85

Use carburetor heat to keep the indicator outside the yellow arc.

Question 86

# Carburetor Air Temperature Gauge What does a red radial on some gauges indicate?

Answer 86

The maximum permissible carburetor inlet air temperature recommended by the engine manufacturer.

Question 87

# Carburetor Air Temperature Gauge What does a green arc on the gauge signify?

Answer 87

The normal operating range for the carburetor inlet air temperature.

Question 88

# Outside Air Temperature Gauge What is the purpose of the Outside Air Temperature (OAT) gauge?

Answer 88

To measure the outside or ambient air temperature.

Question 89

# Outside Air Temperature Gauge How is the OAT gauge calibrated?

Answer 89

In both degrees Celsius and Fahrenheit.

Question 90

# Outside Air Temperature Gauge What are two primary uses of the OAT gauge?

Answer 90

Calculating true airspeed and detecting potential icing conditions.

Question 91

# Fuel Injection Systems What does a fuel injection system do?

Answer 91

Injects fuel directly into the cylinders or just ahead of the intake valve.

Question 92

# Fuel Injection Systems What is the purpose of the alternate air source in a fuel injection system?

Answer 92

To provide air if the external air source is obstructed.

Question 93

# Fuel Injection Systems What are the six basic components of a fuel injection system?

Answer 93

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

Question 94

# Fuel Injection Systems How does the fuel injection system work?

Answer 94

The engine-driven fuel pump supplies fuel to the fuel-air control unit, which meters and sends it to the fuel manifold valve. The valve distributes the fuel to discharge nozzles in each cylinder.

Question 95

# Fuel Injection Systems What type of icing can affect fuel injection systems?

Answer 95

Impact icing, caused by ice forming on the aircraft's exterior and blocking openings like the air intake.

Question 96

# Fuel Injection Systems What are six advantages of fuel injection systems?

Answer 96

1. Reduction in evaporative icing 2. Better fuel flow 3. Faster throttle response 4. Precise mixture control 5. Better fuel distribution 6. Easier cold weather starts

Question 97

# Fuel Injection Systems What are three disadvantages of fuel injection systems?

Answer 97

1. Difficulty starting a hot engine 2. Vapor lock during ground operations on hot days 3. Problems restarting after fuel starvation

Question 98

# Superchargers and Turbosuperchargers What is the purpose of supercharger and turbosupercharger systems?

Answer 98

To compress intake air, increasing its density and engine horsepower.

Question 99

# Superchargers and Turbosuperchargers What is the key difference between a supercharger and a turbosupercharger?

Answer 99

* Supercharger: Powered by an engine-driven air pump or compressor. * Turbosupercharger: Powered by the exhaust stream driving a turbine that spins the compressor.

Question 100

# Superchargers and Turbosuperchargers What instrument is used to monitor manifold pressure in these systems?

Answer 100

A manifold pressure gauge (MAP).

Question 101

# Superchargers and Turbosuperchargers What does the manifold pressure gauge indicate on a standard day at sea level with the engine off?

Answer 101

29.92 "Hg, the ambient absolute air pressure.

Question 102

# Superchargers and Turbosuperchargers How does atmospheric pressure change with altitude?

Answer 102

Atmospheric pressure decreases approximately 1 "Hg per 1,000 feet of altitude.

Question 103

# Superchargers and Turbosuperchargers What is the service ceiling of an aircraft?

Answer 103

The altitude where manifold pressure becomes insufficient for normal climb.

Question 104

# Superchargers and Turbosuperchargers How do superchargers and turbosuperchargers affect service ceiling?

Answer 104

They increase induction air pressure, allowing the aircraft to reach higher altitudes and benefit from higher true airspeeds and weather circumnavigation.

Question 105

# Superchargers What is a supercharger?

Answer 105

An engine-driven air pump or compressor that increases the pressure of the induction air to boost engine power.

Question 106

# Superchargers How does a supercharger increase engine power?

Answer 106

It compresses the air to a higher density, allowing the engine to produce more power by increasing manifold pressure.

Question 107

# Superchargers What is the advantage of a supercharger at high altitudes?

Answer 107

It maintains manifold pressure similar to sea level, enabling the engine to produce the same power at higher altitudes.

Question 108

# Superchargers What is a single-stage, single-speed supercharger?

Answer 108

A supercharger with a single gear-driven impeller that boosts engine power but decreases effectiveness with altitude.

Question 109

# Superchargers What are two-speed superchargers?

Answer 109

Superchargers with an impeller that operates at low and high speeds, adjusted using an oil-operated clutch controlled from the flight deck.

Question 110

# Superchargers What are the terms for the two speeds of a two-speed supercharger?

Answer 110

Low blower (low speed) and high blower (high speed).

Question 111

# Superchargers When is a supercharger's high blower setting typically used?

Answer 111

After reaching a specified altitude, where power is reduced, and the setting is switched to high blower to maintain desired performance.

Question 112

# Superchargers What is an altitude engine?

Answer 112

An engine equipped with a supercharger designed to maintain performance at higher altitudes.

Question 113

# Superchargers What process does the supercharger use to compress the fuel-air mixture?

Answer 113

It accelerates the mixture through an impeller and diffuser, trading velocity for pressure energy before directing it to the cylinders.

Question 114

# Turbosuperchargers What is a turbosupercharger?

Answer 114

A system that uses exhaust gases to drive a turbine, compressing intake air to boost engine power, especially at higher altitudes.

Question 115

# Turbosuperchargers How does a turbosupercharger differ from a supercharger?

Answer 115

A supercharger is engine-driven, while a turbosupercharger is powered by exhaust gases.

Question 116

# Turbosuperchargers What are the two main components of a turbosupercharger?

Answer 116

The compressor (increases air pressure) and the turbine (driven by exhaust gases).

Question 117

# Turbosuperchargers What is the critical altitude of a turbosupercharged engine?

Answer 117

The maximum altitude where the engine can produce rated horsepower before power begins to decrease.

Question 118

# Turbosuperchargers What is the role of the waste gate in a turbocharger system?

Answer 118

It controls the amount of exhaust gas flowing into the turbine, regulating the level of boost.

Question 119

# Turbosuperchargers What happens when the waste gate is fully closed?

Answer 119

Most exhaust gases are directed through the turbine to maximize boost pressure.

Question 120

# Turbosuperchargers Why is an intercooler used in some turbocharged engines?

Answer 120

To cool the compressed induction air and reduce the risk of detonation.

Question 121

# Turbosuperchargers What is overboosting?

Answer 121

A condition where manifold pressure exceeds engine limits, potentially causing detonation or damage.

Question 122

# Turbosuperchargers How can overboosting occur in a turbocharged engine?

Answer 122

By leaving the waste gate closed during descent or applying takeoff power with cold engine oil.

Question 123

# Turbosuperchargers Why should a turbocharger be allowed to cool down before engine shutdown?

Answer 123

To prevent oil from boiling and forming carbon deposits on the bearings and shaft.

Question 124

# Turbosuperchargers What is the function of the automatic waste gate?

Answer 124

It adjusts waste gate position automatically to maintain the desired manifold pressure.

Question 125

# Turbosuperchargers What should a pilot do if manifold pressure decreases before reaching critical altitude?

Answer 125

Have the turbocharging system inspected by a qualified AMT.

Question 126

# Turbosuperchargers What are the benefits of a turbocharger?

Answer 126

It recovers lost exhaust energy, provides higher true airspeeds, and enables flight at higher altitudes.

Question 127

# Turbosuperchargers What precautions should be taken with turbochargers during high-power operations?

Answer 127

Ensure the oil temperature is in the normal operating range before applying high throttle settings.

Question 128

# Ignition System What is the purpose of the ignition system in a spark ignition engine?

Answer 128

To provide a spark that ignites the fuel-air mixture in the cylinders.

Question 129

# Ignition System What are the main components of an ignition system?

Answer 129

1. Magnetos 2. Spark plugs 3. High-tension leads 4. Ignition switch

Question 130

# Ignition System How does a magneto work?

Answer 130

It uses a permanent magnet to generate an electrical current independent of the aircraft's electrical system.

Question 131

# Ignition System What is the advantage of a dual ignition system?

Answer 131

It improves reliability and ensures continued engine operation if one magneto or spark plug fails.

Question 132

# Ignition System How does the dual ignition system improve engine performance?

Answer 132

By firing two spark plugs per cylinder, it ensures better combustion and slightly higher power output.

Question 133

# Ignition System What are the five positions of the ignition switch?

Answer 133

1. OFF 2. R (Right) 3. L (Left) 4. BOTH 5. START

Question 134

# Ignition System What happens during a pretakeoff ignition system check?

Answer 134

A small decrease in rpm is observed when switching from BOTH to RIGHT or LEFT.

Question 135

# Ignition System What indicates a malfunction during the ignition system check?

Answer 135

An rpm drop exceeding limits, engine stopping on one magneto, or no rpm drop.

Question 136

# Ignition System Why is the ignition switch turned OFF after engine shutdown?

Answer 136

To prevent accidental engine start since the magneto requires no external power and can fire if the propeller is moved.

Question 137

# Ignition System What can happen if the ground wire to the magneto is disconnected or broken?

Answer 137

The engine could accidentally start if the propeller is moved due to residual fuel in the cylinders.

Question 138

# Ignition System What should you do if the engine starts unexpectedly due to a broken ground wire?

Answer 138

Move the mixture lever to the idle cutoff position to stop the engine and have the system checked by a qualified AMT.

Question 139

# Oil Systems What are five primary functions of the engine oil system?

Answer 139

1. Lubricates moving parts 2. Cools the engine 3. Removes heat from cylinders 4. Provides a seal between cylinder walls and pistons 5. Carries away contaminants

Question 140

# Oil Systems What are the two types of oil systems used in reciprocating engines?

Answer 140

Wet-sump and dry-sump systems.

Question 141

# Oil Systems Where is oil stored in a wet-sump system?

Answer 141

In a sump that is an integral part of the engine.

Question 142

# Oil Systems Where is oil stored in a dry-sump system?

Answer 142

In a separate oil tank external to the engine.

Question 143

# Oil Systems How is oil circulated in a wet-sump system?

Answer 143

The oil pump draws oil from the sump, routes it through the engine, and returns it to the sump.

Question 144

# Oil Systems What additional feature does a dry-sump system have for oil circulation?

Answer 144

Scavenge pumps return oil from the engine to the external oil tank.

Question 145

# Oil Systems What are the advantages of a dry-sump system?

Answer 145

Allows for a greater oil volume and is suitable for large reciprocating engines.

Question 146

# Oil Systems What does the oil pressure gauge indicate?

Answer 146

The pressure (in psi) of oil supplied to the engine. The green area indicates normal pressure; the red line shows minimum and maximum limits.

Question 147

# Oil Systems What does the oil temperature gauge indicate?

Answer 147

The temperature of the oil. The green area indicates the normal range, and the red line shows the maximum allowable temperature.

Question 148

# Oil Systems What might high oil temperature indicate?

Answer 148

A plugged oil line, low oil quantity, blocked oil cooler, or a defective temperature gauge.

Question 149

# Oil Systems What might low oil temperature indicate?

Answer 149

Improper oil viscosity during cold weather operations.

Question 150

# Oil Systems Where can the oil filler cap and dipstick usually be accessed?

Answer 150

Through a panel in the engine cowling.

Question 151

# Oil Systems What should you consult to determine the correct oil type, weight, and quantity?

Answer 151

The AFM/POH or placards near the access panel.

Question 152

# Engine Cooling Systems Why is engine cooling necessary?

Answer 152

To prevent overheating, which can cause loss of power, excessive oil consumption, detonation, and engine damage.

Question 153

# Engine Cooling Systems How is most engine heat expelled?

Answer 153

Through the exhaust system.

Question 154

# Engine Cooling Systems What are the two types of engine cooling systems?

Answer 154

Air cooling and liquid cooling.

Question 155

# Engine Cooling Systems How does air cooling work?

Answer 155

Air flows into the engine compartment, over baffles and fins on the engine cylinders, absorbing heat, and exits through openings in the engine cowling.

Question 156

# Engine Cooling Systems When is air cooling less effective?

Answer 156

During ground operations, takeoffs, go-arounds, and other high-power, low-airspeed situations.

Question 157

# Engine Cooling Systems What is shock cooling, and when can it occur?

Answer 157

Shock cooling happens during high-speed descents, where abrupt temperature drops subject the engine to thermal stress.

Question 158

# Engine Cooling Systems What damage can high engine temperatures cause? (4)

Answer 158

* Cylinder scoring * Piston and ring damage * Valve warping * Excessive oil consumption.

Question 159

# Engine Cooling Systems What instruments help monitor engine temperature?

Answer 159

Oil temperature gauge and cylinder-head temperature (CHT) gauge.

Question 160

# Engine Cooling Systems How does the oil temperature gauge indicate engine temperature?

Answer 160

Indirectly and with delay, showing overall engine temperature trends.

Question 161

# Engine Cooling Systems What is a cylinder-head temperature (CHT) gauge, and how is it calibrated?

Answer 161

A CHT gauge shows direct and immediate cylinder temperature changes; calibrated in degrees Celsius or Fahrenheit with a green arc (normal range) and red line (maximum allowable).

Question 162

# Engine Cooling Systems How can high engine temperatures be reduced? (3)

Answer 162

* Increasing airspeed * Enriching the fuel-air mixture * Reducing power

Question 163

# Engine Cooling Systems What are cowl flaps, and how do they help control temperature?

Answer 163

Cowl flaps are hinged covers that control airflow. Open to decrease temperature by increasing airflow; close to increase temperature by restricting airflow.

Question 164

# Exhaust Systems What are the primary functions of the exhaust system?

Answer 164

Vents burned gases, provides cabin heat, and defrosts the windscreen.

Question 165

# Exhaust Systems What components are included in an exhaust system? (3)

Answer 165

* Exhaust piping * Muffler * Muffler shroud

Question 166

# Exhaust Systems How is cabin heat generated?

Answer 166

Outside air is ducted through a shroud around the muffler, where it is heated by exhaust gases and then sent to the cabin.

Question 167

# Exhaust Systems What is a key safety concern with exhaust systems?

Answer 167

Exhaust gases contain carbon monoxide (odorless, colorless, deadly). The system must be free of cracks to prevent leaks.

Question 168

# Exhaust Systems What does an Exhaust Gas Temperature (EGT) gauge measure?

Answer 168

The temperature of gases at the exhaust manifold.

Question 169

# Exhaust Systems How is EGT used in flight?

Answer 169

To adjust the fuel-air mixture for optimal performance and reduced fuel consumption.

Question 170

# Exhaust Systems What should be referenced for proper leaning procedures?

Answer 170

The manufacturer’s recommendations in the aircraft manual.

Question 171

# Starting System What type of starter system is commonly used in small aircraft?

Answer 171

A direct-cranking electric starter system.

Question 172

# Starting System What are the components of the starter system? (5)

Answer 172

* Source of electricity * Wiring * Switches * Solenoids * Starter motor

Question 173

# Starting System How does the starter engage the engine?

Answer 173

The starter engages the flywheel, rotating the engine to start and maintain operation.

Question 174

# Starting System What powers the starter system?

Answer 174

Typically powered by an onboard battery or external power through a receptacle.

Question 175

# Starting System What prevents the starter motor from being driven by the engine?

Answer 175

A clutch in the starter drive allows the engine to run faster than the starter motor.

Question 176

# Starting System What safety measures should be taken before starting an engine? (3)

Answer 176

* Ensure no one is near the propeller * Chock the wheels * Set the brakes.

Question 177

# Starting System Where should the aircraft be positioned when starting?

Answer 177

In an area where the propeller will not stir up gravel or dust to prevent damage.

Question 178

# Combustion What occurs during normal combustion?

Answer 178

The fuel-air mixture burns in a controlled and predictable manner, ensuring maximum force to the piston at the right time in the power stroke.

Question 179

# Combustion What is detonation?

Answer 179

An uncontrolled, explosive ignition of the fuel-air mixture, causing excessive temperatures and pressures that can damage engine components.

Question 180

# Combustion What are four common causes of detonation?

Answer 180

* Using a lower fuel grade * High manifold pressure with low rpm * High power settings with an excessively lean mixture * Reduced cooling during extended ground operations or steep climbs

Question 181

# Combustion How can detonation be avoided? (5)

Answer 181

* Use the proper fuel grade * Keep cowl flaps open during ground operations * Use an enriched fuel mixture * Avoid extended high-power steep climbs * Monitor engine instruments

Question 182

# Combustion What is preignition?

Answer 182

Premature ignition of the fuel-air mixture, usually caused by a hot spot in the combustion chamber, such as a carbon deposit or damaged spark plug.

Question 183

# Combustion What are the effects of preignition? (3)

Answer 183

* Loss of power * High operating temperature * Excessive pressure on the piston during the compression stroke, potentially causing severe damage.

Question 184

# Combustion How can detonation and preignition be reduced? (2)

Answer 184

* Use the recommended fuel grade * Operate the engine within its proper temperature, pressure, and rpm ranges

Question 185

# Combustion What is the relationship between detonation and preignition?

Answer 185

They can occur simultaneously, with one potentially causing the other, and both result in high temperatures and reduced engine performance.

Question 186

# FADEC What does FADEC stand for?

Answer 186

Full Authority Digital Engine Control

Question 187

# FADEC What is FADEC?

Answer 187

A system consisting of a digital computer and ancillary components that control an aircraft’s engine and propeller, initially used in turbine-powered aircraft and now in piston-powered aircraft.

Question 188

# FADEC How does FADEC work in spark-ignition engines?

Answer 188

It uses speed, temperature, and pressure sensors to monitor each cylinder, calculates ideal injector pulses, and adjusts ignition timing for optimal performance.

Question 189

# FADEC How does FADEC differ in compression-ignition engines as opposed to spark-ignition engines?

Answer 189

It performs similar functions but excludes processes specific to spark ignition.

Question 190

# FADEC What systems does FADEC eliminate?

Answer 190

Magnetos, carburetor heat, mixture controls, and engine priming.

Question 191

# FADEC What is a key characteristic of a FADEC-equipped aircraft?

Answer 191

A single throttle lever that the pilot uses to select detents like start, idle, cruise power, or max power, with the FADEC adjusting engine and propeller settings automatically.

Question 192

# FADEC What does FADEC control during aircraft starting?

Answer 192

It primes cylinders, adjusts the mixture, and positions the throttle based on engine temperature and ambient pressure.

Question 193

# FADEC What are FADEC’s benefits during cruise flight?

Answer 193

FADEC monitors and adjusts fuel flow and ignition timing for each cylinder, leading to decreased fuel consumption and increased horsepower.

Question 194

# FADEC What powers the FADEC system?

Answer 194

It can be powered by the aircraft's main electrical system or a separate generator connected to the engine, with a backup electrical source for redundancy.

Question 195

# FADEC What redundancy is built into FADEC systems?

Answer 195

Two separate and identical digital channels, each capable of performing all engine and propeller functions independently.

Question 196

# Turbine Engines What are the five main components of an aircraft turbine engine?

Answer 196

* Air inlet * Compressor * Combustion chambers * Turbine section * Exhaust

Question 197

# Turbine Engines How is thrust produced in a turbine engine?

Answer 197

By increasing the velocity of air flowing through the engine.

Question 198

# Turbine Engines What are the key advantages of turbine engines?

Answer 198

Smooth operation, high power-to-weight ratio, and use of readily available jet fuel.

Question 199

# Turbine Engines Why were turbine engines previously less common in small aircraft?

Answer 199

High costs due to material limitations, engine design, and manufacturing processes.

Question 200

# Turbine Engines What has made turbine engines more accessible for small/light aircraft?

Answer 200

Advances in materials, engine design, and manufacturing have reduced costs.

Question 201

# Turbine Engines What are very light jets (VLJs) or microjets?

Answer 201

Smaller turbine-powered aircraft that seat between three and seven passengers.

Question 202

# Types of Turbine Engines How are turbine engines classified?

Answer 202

By the type of compressor they use: * Centrifugal flow * Axial flow * Centrifugal-axial flow

Question 203

# Types of Turbine Engines How does a centrifugal flow compressor work?

Answer 203

It accelerates air outward perpendicular to the engine's longitudinal axis.

Question 204

# Types of Turbine Engines How does an axial flow compressor work?

Answer 204

It compresses air using rotating and stationary airfoils to move air parallel to the longitudinal axis.

Question 205

# Types of Turbine Engines What is a centrifugal-axial flow compressor?

Answer 205

A compressor design combining centrifugal and axial flow for desired compression.

Question 206

# Types of Turbine Engines What determines the type of turbine engine?

Answer 206

The airflow path through the engine and how power is produced.

Question 207

# Types of Turbine Engines What are the four types of aircraft turbine engines?

Answer 207

* Turbojet * Turboprop * Turbofan * Turboshaft

Question 208

# Types of Turbine Engines: Turbojet What are the four main sections of a turbojet engine?

Answer 208

1. Compressor 2. Combustion chamber 3. Turbine section 4. Exhaust

Question 209

# Types of Turbine Engines: Turbojet What is the function of the compressor in a turbojet engine?

Answer 209

It passes inlet air at a high rate of speed to the combustion chamber.

Question 210

# Types of Turbine Engines: Turbojet What happens in the combustion chamber of a turbojet engine?

Answer 210

It contains the fuel inlet and igniter, where the fuel-air mixture is burned.

Question 211

# Types of Turbine Engines: Turbojet How does the turbine section contribute to engine operation?

Answer 211

The expanding air drives a turbine, which is connected by a shaft to the compressor to sustain engine operation.

Question 212

# Types of Turbine Engines: Turbojet How is thrust produced in a turbojet engine?

Answer 212

By the accelerated exhaust gases exiting the engine.

Question 213

# Types of Turbine Engines: Turbojet What are the limitations of turbojet engines?

Answer 213

Limited range and endurance; slow response to throttle applications at low compressor speeds.

Question 214

# Types of Turbine Engines: Turboprop What is a turboprop engine?

Answer 214

A turbine engine that drives a propeller through a reduction gear.

Question 215

# Types of Turbine Engines: Turboprop Why is reduction gearing necessary in turboprop engines?

Answer 215

Because optimum propeller performance occurs at slower speeds than the engine’s operating rpm.

Question 216

# Types of Turbine Engines: Turboprop How does a turboprop engine operate?

Answer 216

Exhaust gases drive a power turbine, which is connected by a shaft to the reduction gear assembly.

Question 217

# Types of Turbine Engines: Turboprop What is the efficiency range for turboprop engines?

Answer 217

Most efficient at speeds of 250–400 mph and altitudes between 18,000 and 30,000 feet.

Question 218

# Types of Turbine Engines: Turboprop What altitude range offers minimum specific fuel consumption for turboprop engines?

Answer 218

Normally between 25,000 feet and the tropopause.

Question 219

# Types of Turbine Engines: Turboprop How do turboprop engines compare to turbojet engines?

Answer 219

They are a compromise between turbojets and reciprocating powerplants, offering fuel efficiency and good performance at slow airspeeds for takeoff and landing.

Question 220

# Types of Turbine Engines: Turbofan What is a turbofan engine?

Answer 220

A turbine engine that creates additional thrust by diverting a secondary airflow around the combustion chamber.

Question 221

# Types of Turbine Engines: Turbofan What are the benefits of the bypass airflow in a turbofan engine?

Answer 221

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

Question 222

# Types of Turbine Engines: Turbofan What type of performance do turbofan engines offer?

Answer 222

Turbojet-type cruise speed with lower fuel consumption.

Question 223

# Types of Turbine Engines: Turbofan How is inlet air divided in a turbofan engine?

Answer 223

One stream passes through the engine core, while a second stream bypasses the core.

Question 224

# Types of Turbine Engines: Turbofan What does the bypass ratio of a turbofan engine indicate?

Answer 224

The ratio of mass airflow bypassing the core to the mass airflow passing through the core.

Question 225

# Types of Turbine Engines: Turboshaft What is a turboshaft engine?

Answer 225

A jet engine that delivers power to a shaft to drive something other than a propeller.

Question 226

# Types of Turbine Engines: Turboshaft How does a turboshaft engine differ from a turbojet engine?

Answer 226

A turboshaft engine uses most of its energy to drive a turbine, whereas a turbojet engine uses it to produce thrust.

Question 227

# Types of Turbine Engines: Turboshaft What are common uses of turboshaft engines?

Answer 227

Powering helicopters and serving as auxiliary power units (APUs) on large aircraft.

Question 228

# Types of Turbine Engines: Turboshaft What is the primary function of the turbine in a turboshaft engine?

Answer 228

To convert expanding gases into mechanical energy to drive a shaft.

Question 229

# Turbine Engine Instruments What five engine instruments are common to both turbine and reciprocating engines?

Answer 229

1. Oil pressure 2. Oil temperature 3. Engine speed 4. Exhaust gas temperature (EGT) 5. Fuel flow

Question 230

# Turbine Engine Instruments What three instruments are unique to turbine engines?

Answer 230

1. Engine pressure ratio (EPR) 2. Turbine discharge pressure 3. Torque indicators

Question 231

# Turbine Engine Instruments What do thermocouples in turbine engines measure?

Answer 231

They provide temperature readings in and around the turbine section.

Question 232

# Turbine Engine Instruments Why are turbine engine instruments important?

Answer 232

They monitor critical parameters to ensure safe and efficient engine operation.

Question 233

# Turbine Engine Instruments: EPR What does EPR stand for?

Answer 233

Engine Pressure Ratio

Question 234

# Turbine Engine Instruments: EPR What does an EPR gauge measure?

Answer 234

The power output of a turbojet/turbofan engine.

Question 235

# Turbine Engine Instruments: EPR How is EPR calculated?

Answer 235

As the ratio of turbine discharge pressure to compressor inlet pressure.

Question 236

# Turbine Engine Instruments: EPR Where are pressure measurements taken for EPR?

Answer 236

By probes in the engine inlet and at the exhaust.

Question 237

# Turbine Engine Instruments: EPR How is EPR data displayed?

Answer 237

Through a differential pressure transducer indicated on a flight deck EPR gauge.

Question 238

# Turbine Engine Instruments: EPR Does EPR compensate for airspeed and altitude?

Answer 238

Yes, the system automatically compensates for airspeed and altitude.

Question 239

# Turbine Engine Instruments: EPR What must be adjusted for ambient temperature changes in EPR?

Answer 239

Corrections must be applied to ensure accurate power settings.

Question 240

# Turbine Engine Instruments: EGT What does EGT stand for?

Answer 240

Exhaust Gas Temperature

Question 241

# Turbine Engine Instruments: EGT What does an EGT gauge monitor?

Answer 241

The temperature of the turbine section to prevent overheating.

Question 242

# Turbine Engine Instruments: EGT Why is monitoring turbine temperature important?

Answer 242

To protect turbine blades and exhaust section components from damage.

Question 243

# Turbine Engine Instruments: EGT What does EGT indicate?

Answer 243

Overall engine operating conditions and limits.

Question 244

# Turbine Engine Instruments: EGT What are four common variations of EGT systems?

Answer 244

* Turbine Inlet Temperature (TIT) * Turbine Outlet Temperature (TOT) * Interstage Turbine Temperature (ITT) * Turbine Gas Temperature (TGT)

Question 245

# Turbine Engine Instruments: EGT What determines the name of the EGT system?

Answer 245

The location of the temperature sensors within the turbine section.

Question 246

# Turbine Engine Instruments: Torquemeter What does a torquemeter measure?

Answer 246

The torque (twisting force) applied to a shaft.

Question 247

# Turbine Engine Instruments: Torquemeter What types of engines use a torquemeter?

Answer 247

Turboprop and turboshaft engines.

Question 248

# Turbine Engine Instruments: Torquemeter Why is torque measurement important in turboprop/turboshaft engines?

Answer 248

These engines are designed to produce torque for driving a propeller.

Question 249

# Turbine Engine Instruments: Torquemeter How is torque displayed on a torquemeter?

Answer 249

It is calibrated in percentage units, foot-pounds, or psi.

Question 250

# Turbine Engine Instruments: N1 Indicator What does N1 represent?

Answer 250

The rotational speed of the low-pressure compressor.

Question 251

# Turbine Engine Instruments: N1 Indicator How is N1 displayed on the indicator?

Answer 251

As a percentage of design rpm.

Question 252

# Turbine Engine Instruments: N1 Indicator What governs the speed of the low-pressure compressor after start?

Answer 252

The N1 turbine wheel

Question 253

# Turbine Engine Instruments: N1 Indicator How is the N1 turbine wheel connected to the low-pressure compressor?

Answer 253

Through a concentric shaft.

Question 254

# Turbine Engine Instruments: N2 Indicator What does N2 represent?

Answer 254

The rotational speed of the high-pressure compressor.

Question 255

# Turbine Engine Instruments: N2 Indicator How is N2 displayed on the indicator?

Answer 255

As a percentage of design rpm.

Question 256

# Turbine Engine Instruments: N2 Indicator What governs the speed of the high-pressure compressor?

Answer 256

The N2 turbine wheel.

Question 257

# Turbine Engine Instruments: N2 Indicator How is the N2 turbine wheel connected to the high-pressure compressor?

Answer 257

Through a concentric shaft.

Question 258

# Turbine Engine Operational Considerations What are five common turbine engine operational considerations?

Answer 258

1. Engine temperature limits 2. Foreign object damage (FOD) 3. Hot starts 4. Compressor stalls 5. Flameouts.

Question 259

# Turbine Engine Operational Considerations What is the highest temperature in a turbine engine?

Answer 259

The turbine inlet temperature (TIT).

Question 260

# Turbine Engine Operational Considerations Why does turbine engine thrust decrease with altitude?

Answer 260

Due to decreased air density.

Question 261

# Turbine Engine Operational Considerations What does FOD stand for?

Answer 261

Foreign Object Damage

Question 262

# Turbine Engine Operational Considerations What causes FOD?

Answer 262

Ingestion of debris (e.g., small objects, bird strikes, or ice).

Question 263

# Turbine Engine Operational Considerations How can FOD be prevented?

Answer 263

Using vortex dissipaters, screens, deflectors, and preflight inspections.

Question 264

# Turbine Engine Operational Considerations What causes a hot start in a turbine engine?

Answer 264

Excessive fuel entering the combustion chamber or insufficient turbine RPM.

Question 265

# Turbine Engine Operational Considerations What is a hung start?

Answer 265

Failure of the engine to reach proper idle RPM after ignition.

Question 266

# Turbine Engine Operational Considerations What causes a compressor stall?

Answer 266

Compressor blade's angle of attack (AOA) exceeding the critical AOA.

Question 267

# Turbine Engine Operational Considerations What are the symptoms of a compressor stall?

Answer 267

* Transient stalls: Intermittent "bang" sound. * Steady stalls: Strong vibrations, loud roar, fluctuating RPM, and increased EGT.

Question 268

# Turbine Engine Operational Considerations How can a compressor stall be recovered?

Answer 268

Reduce power, decrease aircraft AOA, and increase airspeed.

Question 269

# Turbine Engine Operational Considerations What is a flameout?

Answer 269

Unintentional extinguishing of the engine flame.

Question 270

# Turbine Engine Operational Considerations What are common causes of flameouts?

Answer 270

* Rich flameout: Excessive fuel during rapid acceleration. * Lean flameout: Insufficient airflow or fuel pressure, often at high altitudes

Question 271

# Turbine Engine Operational Considerations How can a flameout be addressed?

Answer 271

Attempt an airstart following procedures in the AFM/POH.

Question 272

# Performance Comparison What is BHP?

Answer 272

Horsepower delivered to the output shaft; actual usable horsepower.

Question 273

# Performance Comparison What does BHP stand for?

Answer 273

Brake Horsepower

Question 274

# Performance Comparison What is Net Thrust?

Answer 274

Thrust produced by a turbojet or turbofan engine.

Question 275

# Performance Comparison What does THP stand for?

Answer 275

Thrust Horsepower

Question 276

# Performance Comparison What is THP?

Answer 276

Horsepower equivalent of the thrust produced by a turbojet or turbofan engine.

Question 277

# Performance Comparison What does ESHP stand for?

Answer 277

Equivalent Shaft Horsepower

Question 278

# Performance Comparison What is ESHP?

Answer 278

For turboprop engines, the sum of Shaft Horsepower (SHP) delivered to the propeller and THP produced by exhaust gases.

Question 279

# Performance Comparison What does SHP stand for?

Answer 279

Shaft Horsepower

Question 280

# Performance Comparison Which engine type allows the highest maximum aircraft speed?

Answer 280

Turbojet

Question 281

# Performance Comparison Which engine type has a higher maximum speed than a turboprop or reciprocating powerplant?

Answer 281

Turbofan

Question 282

# Fuel Systems What is the purpose of the fuel system?

Answer 282

To provide an uninterrupted flow of clean fuel from the fuel tanks to the engine under all operating conditions.

Question 283

# Fuel Systems What conditions must the fuel system operate under?

Answer 283

All engine power levels, altitudes, attitudes, and approved flight maneuvers.

Question 284

# Fuel Systems What are the two common classifications of fuel systems in small aircraft?

Answer 284

Gravity-feed systems and fuel-pump systems.

Question 285

# Fuel Systems: Gravity-Feed System What is a gravity-feed fuel system?

Answer 285

A system that uses gravity to transfer fuel from the tanks to the engine.

Question 286

# Fuel Systems: Gravity-Feed System Where are fuel tanks typically located in gravity-feed systems?

Answer 286

In the wings, above the carburetor, such as in high-wing airplanes.

Question 287

# Fuel Systems: Gravity-Feed System What happens if gravity cannot transfer fuel effectively?

Answer 287

Fuel pumps are installed, as in low-wing airplanes where the fuel tanks are below the carburetor.

Question 288

# Fuel Systems: Fuel-Pump System What is a fuel-pump system?

Answer 288

A fuel system that uses pumps to transfer fuel from the tanks to the engine.

Question 289

# Fuel Systems: Fuel-Pump System How many fuel pumps are typically in a fuel-pump system?

Answer 289

Two: an engine-driven main pump and an electrically-driven auxiliary (boost) pump.

Question 290

# Fuel Systems: Fuel-Pump System What is the purpose of the auxiliary pump?

Answer 290

To assist in engine starting and provide reliability if the engine pump fails.

Question 291

# Fuel Systems: Fuel-Pump System How is the auxiliary pump operated?

Answer 291

It is controlled by a switch in the flight deck.

Question 292

# Fuel Systems: Fuel Primer What is the purpose of a fuel primer?

Answer 292

To draw fuel from the tanks and vaporize it directly into the cylinders to aid in starting the engine.

Question 293

# Fuel Systems: Fuel Primer When is a fuel primer especially useful?

Answer 293

During cold weather when insufficient heat is available to vaporize fuel in the carburetor

Question 294

# Fuel Systems: Fuel Primer What should be done with the primer knob after use?

Answer 294

Lock it in place to prevent it from vibrating out of position during flight.

Question 295

# Fuel Systems: Fuel Primer What issue can occur if the primer knob is not locked?

Answer 295

It may cause an excessively rich fuel-air mixture.

Question 296

# Fuel Systems: Fuel Primer How can overpriming be avoided?

Answer 296

Follow the aircraft's specific priming instructions.

Question 297

# Fuel Systems: Fuel Tanks Where are the fuel tanks typically located in an airplane?

Answer 297

Inside the wings.

Question 298

# Fuel Systems: Fuel Tanks How are the fuel tanks filled?

Answer 298

Through a filler opening on top of the wing, covered by a filler cap.

Question 299

# Fuel Systems: Fuel Tanks Why are fuel tanks vented?

Answer 299

To maintain atmospheric pressure inside the tank.

Question 300

# Fuel Systems: Fuel Tanks How can fuel tanks be vented?

Answer 300

Through the filler cap or a tube extending through the surface of the wing.

Question 301

# Fuel Systems: Fuel Tanks What is the purpose of the overflow drain?

Answer 301

To allow fuel to expand with temperature increases without damaging the tank.

Question 302

# Fuel Systems: Fuel Tanks What might happen if fuel tanks are filled on a hot day?

Answer 302

Fuel may come out of the overflow drain due to expansion

Question 303

# Fuel Systems: Fuel Gauges What do fuel quantity gauges measure?

Answer 303

The amount of fuel in each tank, displayed in gallons or pounds.

Question 304

# Fuel Systems: Fuel Gauges When are fuel gauges required to be accurate?

Answer 304

Only when they read “empty.”

Question 305

# Fuel Systems: Fuel Gauges What should you do to verify fuel quantity?

Answer 305

Visually check the fuel level during the preflight inspection and compare it to the gauge reading.

Question 306

# Fuel Systems: Fuel Gauges What does a fuel pressure gauge indicate if installed?

Answer 306

The pressure in the fuel lines.

Question 307

# Fuel Systems: Fuel Gauges Where can normal operating pressure be found?

Answer 307

In the AFM/POH or on the gauge via color coding.

Question 308

# Fuel Systems: Fuel Selectors What is the purpose of the fuel selector valve?

Answer 308

It allows selection of fuel from various tanks.

Question 309

# Fuel Systems: Fuel Selectors What are the common positions of a fuel selector valve?

Answer 309

* LEFT * RIGHT * BOTH * OFF

Question 310

# Fuel Systems: Fuel Selectors Why would you select LEFT or RIGHT on the fuel selector?

Answer 310

To feed fuel from a specific tank or balance fuel remaining in the tanks.

Question 311

# Fuel Systems: Fuel Selectors What does the BOTH position do?

Answer 311

It feeds fuel from both tanks simultaneously.

Question 312

# Fuel Systems: Fuel Selectors What should you avoid doing with fuel tanks?

Answer 312

Running a tank completely dry, as it can introduce air into the fuel system and cause vapor lock.

Question 313

# Fuel Systems: Fuel Selectors What are fuel placards used for?

Answer 313

To indicate limitations such as "level flight only" or "both" for specific phases of flight, like landings and takeoffs.

Question 314

# Fuel Systems: Fuel Strainers, Sumps, and Drains What is the purpose of a fuel strainer?

Answer 314

It removes moisture and sediments from the fuel system.

Question 315

# Fuel Systems: Fuel Strainers, Sumps, and Drains What is a sump in the fuel system?

Answer 315

A low point where contaminants and water settle.

Question 316

# Fuel Systems: Fuel Strainers, Sumps, and Drains What three components may be collocated in the fuel system?

Answer 316

* Sump * Fuel strainer * Fuel tank drains

Question 317

# Fuel Systems: Fuel Strainers, Sumps, and Drains When should the fuel strainer be drained?

Answer 317

Before each flight.

Question 318

# Fuel Systems: Fuel Strainers, Sumps, and Drains What should you check for when draining fuel samples?

Answer 318

Water and other contaminants.

Question 319

# Fuel Systems: Fuel Strainers, Sumps, and Drains Why is water in the sump hazardous?

Answer 319

It can freeze in cold weather and block fuel lines or flow into the carburetor and stop the engine.

Question 320

# Fuel Systems: Fuel Strainers, Sumps, and Drains What should be done if water is found in the sump?

Answer 320

Drain the fuel tanks until no evidence of water remains.

Question 321

# Fuel Systems: Fuel Strainers, Sumps, and Drains What resource should you consult for specific fuel system procedures?

Answer 321

The Aircraft Flight Manual (AFM) or Pilot’s Operating Handbook (POH).

Question 322

# Fuel Systems: Fuel Grades What does the grade of AVGAS indicate?

Answer 322

The octane or performance number representing the antiknock value or resistance to detonation.

Question 323

# Fuel Systems: Fuel Grades How do higher and lower grades of AVGAS differ?

Answer 323

Higher grades withstand more pressure without detonating and are used in higher-compression engines; lower grades ignite at lower temperatures and are used in lower-compression engines.

Question 324

# Fuel Systems: Fuel Grades What should you do if the proper fuel grade is unavailable?

Answer 324

Use the next higher grade, never a lower grade.

Question 325

# Fuel Systems: Fuel Grades What are the common grades of AVGAS?

Answer 325

AVGAS 80, 100, and 100LL.

Question 326

# Fuel Systems: Fuel Grades What does "LL" in AVGAS 100LL stand for?

Answer 326

Low lead content.

Question 327

# Fuel Systems: Fuel Grades What is 100VLL, and how does it compare to 100LL?

Answer 327

100VLL is a reduced-lead AVGAS (19% less lead) that meets the same performance requirements as 100LL.

Question 328

# Fuel Systems: Fuel Grades What are the classifications of turbine engine fuel?

Answer 328

* JET A * JET A-1 * JET B

Question 329

# Fuel Systems: Fuel Grades What is the main component of jet fuel?

Answer 329

Kerosene

Question 330

# Fuel Systems: Fuel Grades What is the color of AVGAS 80, 100, and 100LL?

Answer 330

* AVGAS 80: Red * AVGAS 100: Green * AVGAS 100LL: Blue

Question 331

# Fuel Systems: Fuel Grades How are AVGAS and jet fuel visually identified?

Answer 331

* AVGAS: White letters on a red background. * Jet fuel: White letters on a black background.

Question 332

# Fuel Systems: Fuel Grades Can automobile gas be used in aircraft engines?

Answer 332

Only if the aircraft has been modified with an FAA-issued Supplemental Type Certificate (STC).

Question 333

# Fuel Systems: Fuel Contamination What are four common causes of fuel contamination?

Answer 333

* Inadequate preflight inspection. * Using improperly filtered fuel. * Storing aircraft with partially filled tanks. * Lack of proper maintenance.

Question 334

# Fuel Systems: Fuel Contamination Why should fuel be drained from the fuel strainer and tank sumps?

Answer 334

To check for dirt and water contaminants.

Question 335

# Fuel Systems: Fuel Contamination How do you identify water in the fuel?

Answer 335

By its cloudy appearance or clear separation from colored fuel after settling.

Question 336

# Fuel Systems: Fuel Contamination What should you do if contaminants are found in the first fuel sample?

Answer 336

Continue draining and sampling until no trace of contaminants remains.

Question 337

# Fuel Systems: Fuel Contamination Where does water in fuel tanks typically settle?

Answer 337

At the bottom of the tank

Question 338

# Fuel Systems: Fuel Contamination What is the best way to prevent moisture condensation in fuel tanks?

Answer 338

Fill the tanks after each flight or at the end of the day.

Question 339

# Fuel Systems: Fuel Contamination Why is refueling from cans and drums discouraged?

Answer 339

It increases the risk of fuel contamination.

Question 340

# Fuel Systems: Fuel Contamination Can a chamois filter ensure decontaminated fuel?

Answer 340

No, especially if the chamois is worn, wet, or imitation.

Question 341

# Fuel Systems: Fuel Contamination When should fuel sumps be drained?

Answer 341

Before every flight during the preflight inspection.

Question 342

# Fuel Systems: Fuel Contamination What should you do in remote areas if using unfiltered fuel sources?

Answer 342

Use a chamois and funnel cautiously but note they may not guarantee water-free fuel.

Question 343

# Fuel Systems: Fuel System Icing What causes ice formation in the aircraft fuel system?

Answer 343

The presence of water in the fuel system, either undissolved or dissolved.

Question 344

# Fuel Systems: Fuel System Icing What is entrained water?

Answer 344

Minute water particles suspended in the fuel due to mechanical agitation or temperature reduction.

Question 345

# Fuel Systems: Fuel System Icing What is free water?

Answer 345

Water that collects at the bottom of fuel tanks, often introduced through refueling or settling of entrained water.

Question 346

# Fuel Systems: Fuel System Icing What happens when free water freezes in fuel tanks or reservoirs?

Answer 346

It can render water drains useless and may later melt, causing engine malfunctions or stoppage.

Question 347

# Fuel Systems: Fuel System Icing How does entrained water behave when frozen?

Answer 347

It forms ice crystals that may block fuel screens, strainers, and filters.

Question 348

# Fuel Systems: Fuel System Icing What additional problems can frozen entrained water cause in carbureted engines?

Answer 348

It can lead to carburetor metering component icing, even under conditions not otherwise conducive to icing.

Question 349

# Fuel Systems: Fuel System Icing How can free water be removed from fuel tanks?

Answer 349

Through sump drains specifically designed for that purpose.

Question 350

# Fuel Systems: Fuel System Icing What is a sign of entrained water in the fuel?

Answer 350

Slight haziness in the fuel under extreme conditions.

Question 351

# Fuel Systems: Fuel System Icing Why is it difficult to remove entrained water under field conditions?

Answer 351

Settling depends on temperature, quiescence, droplet size, and other factors.

Question 352

# Fuel Systems: Fuel System Icing How can frozen free water in reservoirs be addressed?

Answer 352

By placing the aircraft in a warm hangar to thaw the water and draining all sumps and reservoirs before flight.

Question 353

# Fuel Systems: Fuel System Icing What are three approved anti-icing additives for preventing fuel system icing?

Answer 353

* Hexylene glycol * Certain methanol derivatives * Ethylene glycol monomethyl ether (EGME)

Question 354

# Fuel Systems: Fuel System Icing What is the maximum concentration of EGME for effective icing prevention?

Answer 354

0.15 percent by volume.

Question 355

# Fuel Systems: Fuel System Icing What happens if the concentration of anti-icing additives is incorrect?

Answer 355

Too little or too much additive can result in marked deterioration of its effectiveness.

Question 356

# Fuel Systems: Fuel System Icing Can anti-icing additives replace carburetor heat?

Answer 356

No, anti-icing additives are not a substitute for carburetor heat.

Question 357

# Fuel Systems: Fuel System Icing What should pilots do when operating under atmospheric conditions conducive to icing?

Answer 357

Adhere to aircraft operating instructions involving the use of carburetor heat.

Question 358

# Refueling Procedures What generates static electricity during refueling?

Answer 358

Friction from air passing over the aircraft and fuel flowing through the hose and nozzle.

Question 359

# Refueling Procedures Why is grounding critical before refueling?

Answer 359

To prevent static electricity from igniting fuel fumes.

Question 360

# Refueling Procedures What must be attached to the aircraft before removing the fuel cap?

Answer 360

A ground wire.

Question 361

# Refueling Procedures What does bonding achieve during refueling?

Answer 361

Equalizes the static differential charge between the aircraft and refueling equipment.

Question 362

# Refueling Procedures What is the sequence for grounding and bonding when using fuel drums?

Answer 362

1. Drum to ground 2. Ground to aircraft 3. Drum to aircraft or nozzle to aircraft before removing the fuel cap

Question 363

# Refueling Procedures What is the sequence for disonnecting grounding and bonding when using fuel drums?

Answer 363

Disconnect in reverse order. 1. Drum to aircraft or nozzle to aircraft before removing the fuel cap 2. Ground to aircraft 3. Drum to ground

Question 364

# Refueling Procedures Why should plastic or nonconductive containers not be used during refueling?

Answer 364

They cannot bond or ground, increasing the risk of static discharge.

Question 365

# Refueling Procedures What increases the static electricity charge during fuel transfer?

Answer 365

Fuel passing through a chamois filter.

Question 366

# Refueling Procedures What components must be bonded during refueling?

Answer 366

* The nozzle * Chamois filter * Funnel * Aircraft

Question 367

# Heating System Why is it important to understand the heating system in an aircraft?

Answer 367

Different systems have unique repair, inspection, and operational criteria.

Question 368

# Heating System What should always be referenced for specific heating system operations?

Answer 368

The aircraft operator's manual.

Question 369

# Heating System: Fuel-Fired Heaters What powers a fuel-fired heater?

Answer 369

The aircraft's fuel system or a separate fuel tank.

Question 370

# Heating System: Fuel-Fired Heaters What prevents fuel from flowing unless the fan is operational?

Answer 370

A built-in safety switch.

Question 371

# Heating System: Fuel-Fired Heaters What is a potential risk of improperly maintained fuel-fired heaters?

Answer 371

Exposure to carbon monoxide and other combustion byproducts.

Question 372

# Heating System: Exhaust Heating Systems How does an exhaust heating system provide cabin heat?

Answer 372

By routing air over exhaust pipes to transfer heat into the cabin.

Question 373

# Heating System: Exhaust Heating Systems What are risks associated with defective exhaust heating systems?

Answer 373

Carbon monoxide poisoning, reduced engine performance, and fire hazards.

Question 374

# Heating System: Combustion Heater Systems How does a combustion heater work?

Answer 374

Fuel burns in a sealed chamber, and air passing over the chamber is heated and ducted to the cabin.

Question 375

# Heating System: Combustion Heater Systems What ensures safety in combustion heaters?

Answer 375

Overheat switches shut off fuel if a malfunction occurs.

Question 376

# Heating System: Combustion Heater Systems Why is carbon monoxide poisoning less likely with combustion heaters?

Answer 376

Higher external air pressure prevents leaks into the cabin, venting carbon monoxide outside the aircraft.

Question 377

# Heating System: Bleed Air Heating Systems Which aircraft use bleed air heating systems?

Answer 377

Turbine-engine aircraft.

Question 378

# Heating System: Bleed Air Heating Systems How is air temperature controlled in bleed air systems?

Answer 378

Hot compressor bleed air is mixed with cooler ambient or re-circulated air.

Question 379

# Heating System: Bleed Air Heating Systems What safety features are included in bleed air systems?

Answer 379

Temperature sensors, check valves, and engine sensors to prevent excessive heat or loss of compressor bleed air.

Question 380

# Aircraft Electrical System What voltage do most small aircraft electrical systems use?

Answer 380

Either 14 volts or 28 volts DC.

Question 381

# Aircraft Electrical System What are the eight primary components of an aircraft electrical system?

Answer 381

* Alternator/generator * Battery * Master/battery switch * Alternator/generator switch * Bus bar, fuses, and circuit breakers * Voltage regulator * Ammeter/loadmeter * Associated wiring

Question 382

# Aircraft Electrical System What does the alternator/generator do?

Answer 382

Supplies current to the electrical system and charges the battery.

Question 383

# Aircraft Electrical System What is the role of the aircraft battery?

Answer 383

Provides power for engine starting and acts as a backup if the alternator/generator fails.

Question 384

# Aircraft Electrical System Why are alternators preferred over generators?

Answer 384

They produce sufficient current at lower engine speeds and provide a more constant output.

Question 385

# Aircraft Electrical System What is a GPU, and when is it used?

Answer 385

A ground power unit provides external electrical energy for starting, especially useful in cold weather.

Question 386

# Aircraft Electrical System What does the master switch control?

Answer 386

It turns on/off the electrical system except for the ignition.

Question 387

# Aircraft Electrical System What does the alternator switch do?

Answer 387

Excludes the alternator from the electrical system in case of alternator failure.

Question 388

# Aircraft Electrical System What is a bus bar?

Answer 388

A terminal that connects the electrical system to various components, simplifying wiring.

Question 389

# Aircraft Electrical System What is the purpose of fuses and circuit breakers?

Answer 389

To protect the electrical system from overload. Circuit breakers can be reset, while fuses must be replaced.

Question 390

# Aircraft Electrical System What does an ammeter indicate?

Answer 390

The performance of the electrical system, showing battery charging/discharging and alternator/generator output.

Question 391

# Aircraft Electrical System What does a loadmeter measure?

Answer 391

The load placed on the alternator/generator, showing the percentage of generating capacity in use.

Question 392

# Aircraft Electrical System What is the role of a voltage regulator?

Answer 392

Stabilizes generator/alternator output and controls the rate of battery charging.

Question 393

# Aircraft Electrical System What should the generator/alternator voltage be compared to the battery voltage?

Answer 393

Slightly higher to keep the battery charged (e.g., 14 volts for a 12-volt battery system)

Question 394

# Aircraft Electrical System What are thirteen peices of equipment that commonly uses the electrical system for their source of energy includes?

Answer 394

* Position lights * Anticollision lights * Landing lights * Taxi lights * Interior cabin lights * Instrument lights * Radio equipment * Turn indicator * Fuel gauges * Electric fuel pump * Stall warning system * Pitot heat * Starting motor

Question 395

# Hydraulic Systems What are three common applications of hydraulic systems in small aircraft?

Answer 395

* Wheel brakes * Retractable landing gear * Constant-speed propellers

Question 396

# Hydraulic Systems What are three common applications of hydraulic systems in large aircraft?

Answer 396

* Flight control surfaces * Wing flaps * Spoilers

Question 397

# Hydraulic Systems What are the six basic components of a hydraulic system?

Answer 397

* Reservoir * Pump (hand, electric, or engine-driven) * Filter * Selector valve * Relief valve * Actuator or servo

Question 398

# Hydraulic Systems What does a servo do in a hydraulic system?

Answer 398

Converts fluid power into mechanical work to move an aircraft system or control surface.

Question 399

# Hydraulic Systems What type of hydraulic fluid is commonly used in small aircraft?

Answer 399

Mineral-based hydraulic fluid, a kerosene-like petroleum product with additives to inhibit foaming and corrosion.

Question 400

# Hydraulic Systems: Landing Gear What are the primary types of landing gear configurations?

Answer 400

Conventional landing gear (tailwheel) and tricycle landing gear (nosewheel).

Question 401

# Hydraulic Systems: Landing Gear What are three advantages of tricycle landing gear?

Answer 401

* Allows more forceful braking * Better forward visibility * Greater directional stability, preventing ground looping

Question 402

# Hydraulic Systems: Landing Gear How is a steerable nosewheel controlled?

Answer 402

Linked to the rudder pedals via cables or rods.

Question 403

# Hydraulic Systems: Landing Gear What is the main disadvantage of tailwheel landing gear?

Answer 403

More difficult directional control due to the center of gravity (CG) being behind the main wheels, making it prone to ground looping.

Question 404

# Hydraulic Systems: Landing Gear What are the two main types of landing gear based on retraction?

Answer 404

* Fixed landing gear: Always extended; simple and low maintenance. * Retractable landing gear: Stows inside the structure for improved aerodynamics.

Question 405

# Hydraulic Systems: Brakes Where are airplane brakes located, and how are they operated?

Answer 405

Located on the main wheels; operated by hand controls or foot pedals.

Question 406

# Hydraulic Systems: Brakes What is differential braking, and why is it used?

Answer 406

Independent operation of left and right brakes, used for tight turns and supplementing nosewheel or tailwheel steering during ground operations

Question 407

# Pressurized Aircraft Why are aircraft flown at high altitudes?

Answer 407

To improve fuel efficiency and avoid bad weather and turbulence.

Question 408

# Pressurized Aircraft How is pressurization achieved in turbine- and piston-powered aircraft?

Answer 408

* Turbine-powered: Bleed air from the engine compressor section. * Piston-powered: Air from the engine turbocharger via a sonic venturi (flow limiter).

Question 409

# Pressurized Aircraft What is the typical cabin pressure altitude maintained in pressurized aircraft?

Answer 409

Approximately 8,000 feet at maximum cruising altitude.

Question 410

# Pressurized Aircraft What is differential pressure?

Answer 410

The difference between cabin pressure and ambient atmospheric pressure.

Question 411

# Pressurized Aircraft What are the primary functions of the pressurization control system?

Answer 411

Cabin pressure regulation, pressure relief, vacuum relief, and cabin pressure dumping.

Question 412

# Pressurized Aircraft What does the cabin pressure regulator do?

Answer 412

Controls cabin pressure and prevents it from exceeding maximum differential pressure.

Question 413

# Pressurized Aircraft What is the purpose of the outflow valve?

Answer 413

Regulates air exit to maintain consistent cabin pressure.

Question 414

# Pressurized Aircraft What are the functions of the safety valve?

Answer 414

Acts as a pressure relief, vacuum relief, and dump valve.

Question 415

# Pressurized Aircraft What instruments monitor pressurization?

Answer 415

Cabin differential pressure gauge, cabin altimeter, and cabin rate-of-climb gauge.

Question 416

# Pressurized Aircraft What is explosive decompression?

Answer 416

A rapid pressure change faster than the lungs can decompress, occurring in less than 0.5 seconds.

Question 417

# Pressurized Aircraft What is rapid decompression?

Answer 417

A pressure change where the lungs decompress faster than the cabin.

Question 418

# Pressurized Aircraft What happens during decompression?

Answer 418

Noise, fog, and potential lung damage; reduction in useful consciousness due to rapid oxygen loss.

Question 419

# Pressurized Aircraft What is hypoxia?

Answer 419

A state of oxygen deficiency in the body, posing a primary danger during decompression.

Question 420

# Pressurized Aircraft What precautions should be taken at high altitudes?

Answer 420

Use oxygen masks and ensure proper oxygen regulator settings (e.g., 100% oxygen for demand systems).

Question 421

# Pressurized Aircraft What is decompression sickness?

Answer 421

Formation of nitrogen bubbles in the body due to pressure drops, causing adverse effects.

Question 422

# Pressurized Aircraft What structural risks are associated with decompression?

Answer 422

Individuals may be blown out of the aircraft near openings; seatbelts and harnesses are crucial.

Question 423

# Pressurized Aircraft What should pilots do after decompression?

Answer 423

Initiate a rapid descent to lower altitudes to minimize hypoxia and decompression sickness risks.

Question 424

# Pressurized Aircraft What safety features are included in pressurized aircraft?

Answer 424

Automatic visual and aural warning systems for decompression alerts.

Question 425

# Aircraft Oxygen Systems When is supplemental oxygen required for flight crews?

Answer 425

* After 30 minutes at cabin altitudes between 12,500 and 14,000 feet. * Immediately above 14,000 feet.

Question 426

# Aircraft Oxygen Systems When must all passengers have access to supplemental oxygen?

Answer 426

Above 15,000 feet cabin pressure altitude.

Question 427

# Aircraft Oxygen Systems At what altitudes is oxygen recommended for enhanced safety?

Answer 427

Above 10,000 feet during the day and above 5,000 feet at night.

Question 428

# Aircraft Oxygen Systems What is the typical pressure range for stored aviation oxygen?

Answer 428

1,800 to 2,200 psi

Question 429

# Aircraft Oxygen Systems What type of oxygen should be used in aircraft systems?

Answer 429

Aviator’s Breathing Oxygen meeting SAE AS8010 standards.

Question 430

# Aircraft Oxygen Systems How does temperature affect oxygen cylinder pressure?

Answer 430

Pressure decreases with lower temperatures, which may mimic depletion.

Question 431

# Aircraft Oxygen Systems What is a cannula, and where is it suitable?

Answer 431

A plastic tubing system that fits under the nose; effective below 18,000 feet.

Question 432

# Aircraft Oxygen Systems What is a diluter-demand system, and its altitude limit?

Answer 432

Supplies oxygen when inhaled, mixing with cabin air or 100% oxygen; usable up to 40,000 feet.

Question 433

# Aircraft Oxygen Systems What is a pressure-demand system, and its altitude limit?

Answer 433

Supplies pressurized oxygen to the mask; safe above 40,000 feet.

Question 434

# Aircraft Oxygen Systems What is a continuous-flow system, and who typically uses it?

Answer 434

Provides constant oxygen flow, usually for passengers with reservoir bags.

Question 435

# Aircraft Oxygen Systems What is an electrical pulse-demand system?

Answer 435

Delivers oxygen only during inhalation, reducing oxygen waste by 50–85%.

Question 436

# Aircraft Oxygen Systems What precautions are necessary for oxygen masks?

Answer 436

Ensure compatibility with the oxygen system. Clean regularly with mild soap and disinfect.

Question 437

# Aircraft Oxygen Systems What risks are associated with oil and grease near oxygen systems?

Answer 437

These materials can ignite spontaneously under high oxygen pressure.

Question 438

# Aircraft Oxygen Systems What is a pulse oximeter, and how is it used?

Answer 438

A device measuring blood oxygen saturation and heart rate, useful for monitoring hypoxia risks.

Question 439

# Aircraft Oxygen Systems What are the risks of using oxygen improperly?

Answer 439

Increased fire risk; materials that are fireproof in air may ignite in oxygen.

Question 440

# Aircraft Oxygen Systems What preflight inspections should be conducted for oxygen systems?

Answer 440

Check oxygen supply, mask condition, tubing, regulator settings, and ensure all components are functioning.

Question 441

# Aircraft Oxygen Systems Why should oxygen servicing be performed outside the hangar?

Answer 441

To minimize fire risks from ignition sources.

Question 442

# Aircraft Oxygen Systems What is the procedure for cleaning hands and tools before working with oxygen systems?

Answer 442

Ensure all are free of oil, grease, and dirt to prevent ignition.

Question 443

# Aircraft Oxygen Systems What should pilots do during an oxygen emergency?

Answer 443

Don masks immediately, verify system functionality, and descend to a safer altitude if needed.

Question 444

# Aircraft Oxygen Systems What should not be done during oxygen system servicing?

Answer 444

Avoid servicing during fueling operations or while passengers are on board.

Question 445

# Aircraft Oxygen Systems What is hypoxia?

Answer 445

A state of oxygen deficiency in the body sufficient to impair functions of the brain and other organs.

Question 446

# Anti-Ice and Deice Systems What is the difference between anti-icing and deicing systems?

Answer 446

* Anti-icing prevents ice formation. * Deicing removes ice once it has formed.

Question 447

# Anti-Ice and Deice Systems What six parts of an aircraft are typically protected by anti-ice and deice systems?

Answer 447

Leading edges of wings and tail surfaces Pitot and static ports Fuel tank vents Stall warning devices Windshields Propeller blades

Question 448

# Anti-Ice and Deice Systems What should non-certified aircraft do if they encounter icing conditions?

Answer 448

Exit icing conditions immediately.

Question 449

# Anti-Ice and Deice Systems: Airfoil Systems How do inflatable deicing boots work?

Answer 449

Engine-driven pneumatic pumps inflate rubber boots on the leading edge to crack and remove ice.

Question 450

# Anti-Ice and Deice Systems: Airfoil Systems What is thermal anti-ice, and how does it work?

Answer 450

Heat (often from engine bleed air) is applied to leading edge surfaces to prevent ice formation.

Question 451

# Anti-Ice and Deice Systems: Airfoil Systems What is a "weeping wing"?

Answer 451

A system that pumps antifreeze solution through small holes in the leading edge to prevent or break ice.

Question 452

# Anti-Ice and Deice Systems: Windscreen Systems What are the two main types of windscreen anti-icing systems?

Answer 452

Alcohol spray systems and electrically heated windscreens.

Question 453

# Anti-Ice and Deice Systems: Windscreen Systems Why should heated windscreens not be used during ground operations?

Answer 453

They can overheat and damage the windscreen.

Question 454

# Anti-Ice and Deice Systems: Propeller Systems How is alcohol used for propeller anti-icing?

Answer 454

Discharged from nozzles at the blade root and spread by centrifugal force along the leading edge.

Question 455

# Anti-Ice and Deice Systems: Propeller Systems What are propeller boots, and how do they function?

Answer 455

Electrically heated elements embedded in the propeller to prevent ice formation.

Question 456

# Anti-Ice and Deice Systems: Propeller Systems How can the operation of the propeller anti-ice system be monitored?

Answer 456

By checking the prop anti-ice ammeter.

Question 457

# Anti-Ice and Deice Systems: Additional Systems What other three components are protected by electrical heating elements?

Answer 457

* Pitot and static ports * Fuel vents * Stall warning sensors

Question 458

# Anti-Ice and Deice Systems: Additional Systems Why are operational checks of anti-ice and deice systems important before flight?

Answer 458

To ensure proper functioning before encountering icing conditions.

Question 459

# Anti-Ice and Deice Systems: Best Practices Can anti-icing and deicing systems sustain prolonged flight in icing conditions?

Answer 459

No, they are designed for temporary protection, and immediate action should be taken to exit icing conditions.

Question 460

# Anti-Ice and Deice Systems: Best Practices What is the myth of ice "bridging" with deicing boots?

Answer 460

It was believed that early activation expanded rather than removed ice. Modern boots do not cause this issue, and activation should occur as soon as ice is detected.