Private Pilot-Oral Exam-Airplane Systems

Front 1

A. Aircraft and Engine Operations
1. What are the four main control surfaces and what are their functions?

Back 1

Elevators - Pitch: movement about the lateral axis.

Ailerons - Roll: movement about the longitudinal axis.

Rudder - Yaw: movement about the vertical axis.

Trim tabs - small, adjustable hinged-surfaces on the aileron, rudder, or elevator. Labor saving devices that enable the pilot to release manual pressure on the primary control.

Hint 1

FAA-H-8083-25

Front 2

A. Aircraft and Engine Operations
2. How are the various flight controls operated?

Back 2

Manually actuated through the use of either rod or cable system. A control wheel actuates the ailerons and elevator, and rudder/brake pedals actuate the rudder.

Hint 2

AFM

Front 3

A. Aircraft and Engine Operations
3. What are flaps and what is their function?

Back 3

Movable panels on the inboard trailing edges of the wings. The are hinged so that they may be extended downward into the flow of air beneath the wings to increase both lift and drag. Their purpose is to permit a slower airspeed and a steeper angle of descent during landing approach. In some cases, they may also be used to shorten the takeoff distance.

Hint 3

FAA-H-8083-25

Front 4

A. Aircraft and Engine Operations
4. Describe the landing gear system on this airplane.

Back 4

A tricycle-type system utilizing two main wheels and a steerable nose-wheel. Tubular spring steel main gear struts provide main gear shock absorption, while nose gear shock absorption is provided by a combination air/oil shock strut.

Hint 4

AFM

Front 5

A. Aircraft and Engine Operations
5. Describe the braking system on this aircraft.

Back 5

Hydraulically actuated disc-type brakes are utilized on each main gear wheel. A hydraulic line connects each brake to a master cylinder located on each pilot's rudder pedals. The brakes may be applied by applying pressure to the top of either the pilot's or co-pilot's set of rudder pedals.

Hint 5

AFM

Front 6

A. Aircraft and Engine Operations
6. How is steering accomplished on the ground?

Back 6

Light airplanes are generally provided with nose-wheel steering capabilities through a simple system of mechanical linkage connected to the rudder pedals. When a rudder pedal is depressed, a spring-loaded bungee (push-pull rod) connected to the pivotal portion of a nose-wheel strut will tun the nose-wheel.

Hint 6

AFM

Front 7

A. Aircraft and Engine Operations
7. What type of engine does your aircraft have?

Back 7

Textron Lycoming IO-360-L2A, normally aspirated, direct drive, air cooled, horizontally opposed, fuel injected, four cylinder engine with 360 cu. in. displacement and 180 BHP at 2700 RPM.

Hint 7

POH

Front 8

A. Aircraft and Engine Operations
8. What four strokes must occur in each cylinder of a typical four stoke engine in order for it to produce full power?

Back 8

The four strokes are:
Intake - fuel mixture is drawn into cylinder by downward stroke

Compression - mixture is compressed by upward stroke

Power - spark ignites mixture forcing piston downward and producing power

Exhaust - burned gases pushed out of cylinder by upward stroke

Hint 8

FAA-H-8083-25

Front 9

A. Aircraft and Engine Operations
9. What does the carburetor do?

Back 9

Carburetion may be defined as the process of mixing fuel and air in the correct proportions so as to form a combustible mixture. The carburetor vaporizes liquid fuel into small particles and then mixes it with air. It measures the airflow and meters fuel accordingly.

Hint 9

FAA-H-8083-25

Front 10

A. Aircraft and Engine Operations
10. How does the carburetor heat system work?

Back 10

A carburetor heat valve, controlled by the pilot, allows unfiltered, heated air from a shroud located around an exhaust riser or muffler to be directed to the induction air manifold prior to the carburetor. Carburetor heat should be used anytime suspected or known carburetor icing conditions exist.

Hint 10

FAA-H-8083-25

Front 11

A. Aircraft and Engine Operations
11. What change occurs to the fuel-air mixture when applying carburetor heat?

Back 11

Normally, the introduction of heated air into the carburetor will result in a richer mixture. Warm air is less dense, resulting in less air for the same amount of fuel.

Hint 11

FAA-H-8083-25

Front 12

A. Aircraft and Engine Operations
12. What does the throttle do?

Back 12

The throttle allows the pilot to manually control the amount of fuel/air charge entering the cylinders. This in turn regulates the engine speed and power.

Hint 12

FAA-H-8083-25

Front 13

A. Aircraft and Engine Operations
13. What does the mixture control do?

Back 13

It regulates the fuel-to-air ratio. All airplane engines incorporate a device called a mixture control, by which the fuel/air ratio can be controlled by the pilot during flight. The purpose of the mixture control is to prevent the mixture from becoming too rich at high altitudes, due to decreasing air density. It is also used to lean the mixture during cross-country flights to conserve fuel and provide optimum power.

Hint 13

FAA-H-8083-25

Front 14

A. Aircraft and Engine Operations
14. What type of ignition system does your airplane have?

Back 14

Engine ignition is provided by two engine-driven magnetos, and two spark plugs per cylinder. The ignition system is completely independent of the aircraft electrical system. The magnetos are engine-driven self-contained units supplying electrical current without using an external source of current. However, before they can produce current, the magnetos must be actuated, as the engine crankshaft is rotated by some other means. To accomplish this, the aircraft battery furnishes electrical power to operate a starter which, through a series of gears, rotates the engine crankshaft. This in turn actuates the armature of the magnetos to produces the sparks for ignition of the fuel in each cylinder. After the engine starts, the starter system is disengaged, and the battery no longer contributes to the actual operation of the engine.

Hint 14

AFM

Front 15

A. Aircraft and Engine Operations
15. What are the two main advantages of a dual ignition system?

Back 15

a. Increased safety: in case one system fails the engine may be operated on the other until a landing is safely made.

b. More complete and even combustion of the mixture, and consequently, improved engine performance; i.e., the fuel/air mixture will be ignited on each side of the combustion chamber and burn toward the center.

Hint 15

FAA-H-8083-25

Front 16

A. Aircraft and Engine Operations
16. What type of fuel system does your aircraft have?

Back 16

The system consists of two vented integral fuel tanks, a three-position selector valve, fuel reservoir tank, auxiliary fuel pump, fuel shutoff valve, fuel strainer, engine driven fuel pump, fuel-air control unit, fuel distribution valve and fuel injection nozzles.

Fuel flows by gravity from the two wing tanks to a three-position selector valve and on to the reservoir tank. From the reservoir tank fuel flows through the auxiliary fuel pump, past the fuel pump shutoff valve, through the fuel strainer to an engine driven fuel pump.

From the engine-driven fuel pump, fuel is deliverd to the fuel-air control unit, where it is metered and directed to a fuel distribution valve (manifold) which distributes it to each cylinder. Fuel flow into each cylinder is continuous, and flow rate is determined by the amount of air passing through the fuel/air control unit.

Hint 16

POH

Front 17

A. Aircraft and Engine Operations
17. What purpose do the fuel vents have?

Back 17

As the fuel level in an aircraft fuel tank decreases, a vacuum would be created within the tank which would eventually result in a decreasing fuel flow and finally engine stoppage. Fuel system venting provides a way of replacing fuel with outside air, preventing formation of a vacuum.

Hint 17

AFM

Front 18

A. Aircraft and Engine Operations
18. Does your aircraft use a fuel pump?

Back 18

Yes

Hint 18

POH

Front 19

A. Aircraft and Engine Operations
19. What type fuel does your aircraft require (minimum octane rating and color)?

Back 19

100LL - Blue

Hint 19

POH

Front 20

A. Aircraft and Engine Operations
20. Can other types of fuel be used if the specified grade is not available?

Back 20

Airplane engines are designed to operate using a specific grade of fuel as recommended by the manufacturer. If the proper grade of fuel is not available, it is possible, but not desirable, to use the next higher grade as a substitute. Always reference the aircraft's AFM or POH.

Hint 20

FAA-H-8083-25

Front 21

A. Aircraft and Engine Operations
21. What color of dye is added to the following fuel grades: 80, 100, 100LL, Turbine?

Back 21

80 = Red
100 = Green
100LL = Blue
Turbine = Colorless

Hint 21

FAA-H-8083-25

Front 22

A. Aircraft and Engine Operations
22. What is the function of the manual primer, and how does it operate?

Back 22

The manual primer's main function is to provide assistance in starting the engine. The primer draws fuel from the fuel strainer and injects it directly into the cylinder intake ports. This usually results in a quicker, more efficient engine start.

Hint 22

AFM

Front 23

A. Aircraft and Engine Operations
23. Describe the electrical system on your aircraft?

Back 23

The airplane is equipped with a 28-volt, direct current electrical system, powered by a belt-driven, 60-amp alternator and a 24-volt battery, located on the left forward side of the firewall. Power is supplied to most general electrical circuits through a split primary bus bar, with an essential bus wired between the two primaries to provide power for the master switch, annunciator circuits and interior lighting.

Each primary bus bar is also connected to an avionics bus bar via a single avionics master switch. The primary buses are on anytime the master switch is turned on, and are not affected by the starter or external power usage. The avionics buses are on when the master switch and avionics master switch are in the ON position.

Hint 23

AFM

Front 24

A. Aircraft and Engine Operations
24. How are the circuits for the various electrical accessories within the aircraft protected?

Back 24

Most of the electrical circuits in an airplane are protected from an overload condition by either circuit breakers or fuses or both. Circuit breakers perform the same function as fuses except when an overload occurs, a circuit breaker can be reset.

Hint 24

AFM

Front 25

A. Aircraft and Engine Operations
25. The electrical system provides power for what equipment in an airplane?

Back 25

Normally, the following:
a. Radio equipment
b. Turn coordinator
c. Fuel gauges
d. Pitot heat
e. Landing lights
f. Taxi light
g. Strobe lights
h. Interior lights
i. Instrument lights
j. Position lights
k. Flaps
l. Oil temperature gauge
m. Electric fuel pump

Hint 25

AFM

Front 26

A. Aircraft and Engine Operations
26. What does the ammeter indicate?

Back 26

The ammeter indicates the flow of current, in amperes, from the alternator to the battery or from the battery to the electrical system. With the engine running and master switch on, the ammeter will indicate the charging rate of the battery. If the alternator has gone off-line and is no longer functioning, or the electrical load exceeds the output of the alternator, the ammeter indicates the discharge rate of the battery.

Hint 26

AFM

Front 27

A. Aircraft and Engine Operations
27. What function does the voltage regulator have?

Back 27

The voltage regulator is a device which monitors system voltage, detects changes, and makes the required adjustments in the output of the alternator to maintain a constant regulated system voltage. It must do this at low RPM, such as during taxi, as well as at high RPM in flight. In a 28-volt system, it will maintain 28 volts +/-0.5 volts.

Hint 27

AFM

Front 28

A. Aircraft and Engine Operations
28. Why is the generator/alternator voltage output slightly higher that the battery voltage?

Back 28

The difference in voltage keeps the battery charged. For example, a 12-volt battery would be supplied with 14 volts.

Hint 28

FAA-H-8083-25

Front 29

A. Aircraft and Engine Operations
29. How does the aircraft cabin heat work?

Back 29

Fresh air, heated by an exhaust shroud, is directed to the cabin through a series of ducts.

Hint 29

AFM

Front 30

A. Aircraft and Engine Operations
30. How does the pilot control temperature in the cabin?

Back 30

Temperature is controlled by mixing outside air (cabin air control) with heated air (cabin heat control) in a manifold near the cabin firewall. This air is then ducted to vents located on the cabin floor.

Hint 30

AFM

Front 31

A. Aircraft and Engine Operations
31. What are the two types of oil available for use in your airplane?

Back 31

Mineral Oil - Also known as non-detergent oil. It contains no additives. This type of oil is normally used after an engine overhaul or when an aircraft engine is new, for engine break-in purposes.

Ashless Dispersant - Mineral oil with additives. It has high anti-wear properties along with multi-viscosity (ability to perform in a wide range of temperatures). It also picks up contamination and carbon particles and keeps them suspended so that buildups and sludge do not form in the engine.

Hint 31

AFM

Front 32

B. System and Equipment Malfunctions
1. What causes "carburetor icing", and what are the indications of its presence?

Back 32

The vaporization of fuel, combined with the expansion of air as it passes through the carburetor, causes a sudden cooling of the mixture. The temperature of the air passing through the carburetor may drop as much as 60*F within a fraction of a second. Water vapor is squeezed out by this cooling, and if the temperature in the carburetor reaches 32*F or below, the moisture will be deposited as frost or ice inside the carburetor. For airplanes with a fixed-pitch propeller, the first indication of carburetor icing is loss of RPM. For airplanes with controllable-pitch (constant-speed) propellers, the first indication is usually a drop in manifold pressure.

Hint 32

FAA-H-8083-25

Front 33

B. System and Equipment Malfunctions
2. What method is used to determine that carburetor ice has been eliminated?

Back 33

When heat is first applied, there will be a drop in RPM in airplane equipped with a fixed-pitch propeller; there will be a drop in manifold pressure in airplanes equipped with a controllable-pitch propeller. If ice is present there will be a rise in RPM or manifold pressure after the initial drop (often accompanied by intermittent engine roughness); and then, when the carburetor heat is turned "off", the RPM or manifold pressure will rise to a setting greater than that before application of heat. The engine should run more smoothly after the ice has been removed.

Hint 33

FAA-H-8083-25

Front 34

B. System and Equipment Malfunctions
3. What conditions are favorable for carburetor icing?

Back 34

Carburetor ice is most likely to occur when temperature are below 70*F (21*C) and the relative humidity is above 80 percent. However, due to the sudden cooling that takes place in the carburetor, icing can occur even with temperatures as high as 100*F (38*C) and humidity as low as 50 percent. This temperature drop can be as much as 60* to 70*F.

Hint 34

FAA-H-8083-25

Front 35

B. System and Equipment Malfunctions
4. What is "detonation"?

Back 35

Detonation is an uncontrolled, explosive ignition of the fuel/air mixture withing the cylinder's combustion chamber. It causes excessive temperature and pressure which, if not corrected, can quickly lead to failure of the piston, cylinder, or valves. In less severe cases, detonation causes engine overheating, roughness, or loss of power. Detonation is characterized by high cylinder head temperatures, and is most likely to occur when operating at high power settings.

Hint 35

FAA-H-8083-25

Front 36

B. System and Equipment Malfunctions
5. What action should be taken if detonation is suspected?

Back 36

Corrective action for detonation may be accomplished by adjusting any of the engine controls which will reduce both temperature and pressure of the fuel air charge.

a. Reduce power
b. Reduce the climb rate for better cooling
c. Enrich the fuel/air mixture
d. Open cowl flaps if available

Also, ensure that the airplane has been serviced with the proper grade of fuel.

Hint 36

FAA-H-8083-25

Front 37

B. System and Equipment Malfunctions
6. What is "pre-ignition"?

Back 37

Pre-ignition occurs when the fuel/air mixture ignites prior to the engine's normal ignition event resulting in reduced engine power and high operating temperatures. Premature burning is usually caused by a residual hot spot in the combustion chamber, often created by a small carbon deposit on a spark plug, a cracked spark plug insulator, or other damage in the cylinder that causes a part to heat sufficiently to ignite the fuel/air charge. As with detonation, pre-ignition may also cause severe engine damage, because the expanding gases exert excessive pressure on the piston while still on its compression stroke.

Hint 37

FAA-H-8083-25

Front 38

B. System and Equipment Malfunctions
7. What action should be taken if pre-ignition is suspected?

Back 38

Corrective actions for pre-ignition include any type of engine operation which would promote cooling such as:

a. Reduce power
b. Reduce the climb rate for better cooling
c. Enrich the fuel/air mixture
d. Open cowl flaps if available

Hint 38

FAA-H-8083-25

Front 39

B. System and Equipment Malfunctions
8. During the before-takeoff run-up, you switch the magnetos from the "BOTH" position to the "RIGHT" position and notice there is no RPM drop. What condition does this indicate?

Back 39

The left P-lead is not grounding, or the engine has been running only on the right magneto because the left magneto has totally failed.

Front 40

B. System and Equipment Malfunctions
9. Interpret the following ammeter indications:
a. Ammeter indicates a right deflection (positive).
- After starting
- During flight

b. Ammeter indicates a left deflection (negative).
- After starting
- During flight

Back 40

a. Right (positive) deflection
- After starting: Power from the battery used for starting is being replenished by the alternator; or, if a full-scale charge is indicated for more than 1 minute, the starter is still engaged and a shutdown is indicated.
- During flight: A faulty voltage regulator is causing the alternator to overcharge the battery. Reset the system and if the condition continues, terminate the flight as soon as possible.

b. Left (negative) deflection:
- After starting: It is normal during start. At other times this indicates the alternator is not functioning or an overload condition exists in the system. The battery is not receiving a charge.
- During flight: The alternator is not functioning or an overload exists in the system. The battery is not receiving a charge. Possible causes: the master switch was accidentally shut off, or the alternator circuit breaker tripped.

Front 41

B. System and Equipment Malfunctions
10. What action should be taken if the ammeter indicates a continuous discharge while in flight?

Back 41

The alternator has quit producing a charge, so the alternator circuit breaker should be checked and reset if necessary. If this does not correct the problem, the following should be accomplished:
a. The alternator should be turned off; pull the circuit breaker (the field circuit will continue to draw power from the battery).
b. All electrical equipment not essential to flight should be turned off (the battery is now the only source of electrical power).
c. The flight should be terminated and a landing made as soon as possible.

Front 42

B. System and Equipment Malfunctions
11. What action should be taken if the ammeter indicates a continuous charge while in flight (more than two needle widths)?

Back 42

If a continuous excessive rate of charge were allowed for any extended period of time, the battery would overheat and evaporate the electrolyte at an excessive rate. A possible explosion of the battery could result. Also, electronic components in the electrical system would be adversely affected by higher than normal voltage. Protection is provided by an over-voltage sensor which will shut the alternator down if an excessive voltage is detected. If this should occur the following should be done:
a. The alternator should be turned off; pull the circuit breaker (the field circuit will continue to draw power from the battery).
b. All electrical equipment not essential to flight should be turned off (the battery is now the only source of electrical power).
c. The flight should be terminated and a landing made as soon as possible.

Front 43

B. System and Equipment Malfunctions
12. During a cross-country flight you notice that the oil pressure is low, but the oil temperature is normal. What is the problem and what action should be taken?

Back 43

A low oil pressure in flight could be the result of any one of several problems, the most common being that of insufficient oil. If the oil temperature continues to remain normal, a clogged oil pressure relief valve or an oil pressure gauge malfunction could be the culprit. In any case, a landing at the nearest airport is advisable to check for the cause of trouble.

Front 44

B. System and Equipment Malfunctions
13. What procedures should be followed concerning partial loss of power in flight?

Back 44

If a partial loss of power occurs, the first priority is to establish and maintain a suitable airspeed (best glide airspeed if necessary). Then, select an emergency landing area and remain within gliding distance. As time allows, attempt to determine the cause and correct it.

Complete the following checklist:
a. Check the carburetor heat.
b. Check the amount of fuel in each tank and switch the fuel tanks if necessary.
c. Check the fuel selector valve's current position.
d. Check the mixture control.
e. Check that the primer control is all the way in and locked.
f. Check the operation of the magnetos in all three positions

Hint 44

AFM

Front 45

B. System and Equipment Malfunctions
14. What procedures should be followed if an engine fire develops in flight?

Back 45

In the event of an engine fire in flight, the following procedures should be used:
a. Set the mixture control to "Idle cut-off".
b. Set the fuel selector valve to "Off".
c. Turn the master switch to "Off".
d. Set the cabin heat and air vents to "Off"; leave the overhead vents on.
e. Establish an airspeed of 100 KIAS and increase the descent, if necessary, to find an airspeed that will provide for an incombustible mixture.
f. Execute a forced landing procedures checklist.

Hint 45

AFM

Front 46

B. System and Equipment Malfunctions
15. What procedures should be followed if an engine fire develops on the ground during starting?

Back 46

Continue to attempt an engine start as a start will cause flames and excess fuel to be sucked back through the carburetor.
a. If the engine starts:
- Increase the power to a higher RPM for a few moments; and
- Shut down the engine and inspect it.

b. If the engine does not start:
- Set the throttle to the "Full" position.
- Set the mixture control the "Idle cut-off".
- Continue to try an engine start in an attempt to put out the fire by vacuum.

c. If the fire continues:
- Turn the ignition switch to "Off".
- Turn the master switch to "Off".
- Set the fuel selector to "Off".

In all cases, evacuate the aircraft and obtain a fire extinguisher and/or assistance.

Hint 46

AFM

Front 47

C. Pitot/Static Flight Instruments
1. What instruments operate off of the pitot/static system?

Back 47

Altimeter, Vertical Speed Indicator, and Airspeed Indicator.

Hint 47

FAA-H-8083-15

Front 48

C. Pitot/Static Flight Instruments
2. How does an altimeter work?

Back 48

Aneroid wafers expand and contract as atmospheric pressure changes, and through a shaft and gear linkage, rotate pointers on the dial of the instrument.

Hint 48

FAA-H-8083-15

Front 49

C. Pitot/Static Flight Instruments
3. What are the limitations of a pressure altimeter?

Back 49

Nonstandard pressure and temperature; temperature variations expand or contract the atmosphere and raise or lower pressure levels that the altimeter senses.
1. On a warm day - pressure level is higher, so the altimeter indicates lower than actual altitude.
2. On a cold day - pressure level is lower, so the altimeter indicates higher than actual altitude.

Changes in surface pressure also affect pressure levels at altitude.
1. Higher than standard pressure - pressure level is higher, so altimeter indicates lower than actual altitude.
2. Lower than standard pressure - pressure level is lower, so altimeter indicates higher than actual altitude.

Hint 49

FAA-H-8083-15

Front 50

C. Pitot/Static Flight Instruments
4. Define and state how you would determine the following altitudes:
a. Indicated Altitude
b. Pressure Altitude
c. True Altitude
d. Density Altitude
e. Absolute Altitude

Back 50

a. Indicated Altitude - the altitude read directly from the altimeter (uncorrected) after it is set to the current altimeter setting.

b. Pressure Altitude - the altitude when the altimeter setting window is adjusted to 29.92. Pressure altitude is used for computer solutions to determine density altitude, true altitude, true airspeed, etc.

c. True Altitude - the true vertical distance of the aircraft above sea level. Airport, terrain, and obstacle elevations found on aeronautical charts are true altitude.

d. Density Altitude - pressure altitude corrected for non-standard temperature variations. Directly related to an aircraft's takeoff, climb, and landing performance.

e. Absolute Altitude - the vertical distance of an aircraft above the terrain.

Hint 50

FAA-H-8083-25

Front 51

C. Pitot/Static Flight Instruments
5. How does the airspeed indicator work?

Back 51

The airspeed indicator is a sensitive pressure gauge which measures the difference between impact pressure from the pitot head and the undisturbed atmospheric pressure from the static source. The difference is registered by the airspeed pointer on the face of the instrument.

Hint 51

FAA-H-8083-25

Front 52

C. Pitot/Static Flight Instruments
6. What is the limitation of the airspeed indicator?

Back 52

The airspeed indicator is subject to proper flow of air in the pitot/static system.

Hint 52

FAA-H-8083-25

Front 53

C. Pitot/Static Flight Instruments
7. What are the errors of the airspeed indicator?

Back 53

Position error - caused by the static ports sensing erroneous static pressure; slipstream flow causes disturbances at the static port preventing actual atmospheric pressure measurement. It varies with airspeed, altitude and configuration, and may be a plus or minus value.

Density error - changes in altitude and temperature are not compensated for by the instrument.

Compressibility error - caused by the packing of air into the pitot tube at high airspeeds, resulting in higher than normal indications. It is usually not a factor at slower speeds.

Hint 53

FAA-H-8083-25

Front 54

C. Pitot/Static Flight Instruments
8. What are the different types of aircraft speeds?

Back 54

Indicated Airspeed (IAS) - read off the instrument.

Calibrated Airspeed (CAS) - IAS corrected for instrument and position errors; obtained from the POH or off the face of the instrument.

Equivalent Airspeed (EAS) - CAS corrected for adiabatic compressible airflow at altitude.

True Airspeed (TAS) - CAS corrected for nonstandard temperature and pressure; obtained from the flight computer, POH or A/S indicator slide computer.

Ground Speed (GS) - TAS corrected for wind; speed across the ground; use the flight computer.

Hint 54

FAA-H-8083-25

Front 55

C. Pitot/Static Flight Instruments
9. Name several important airspeed limitations not marked on the face of the airspeed indicator.

Back 55

Maneuvering speed (Va) - the "rough air" speed and the maximum speed for abrupt maneuvers. If rough air or severe turbulence is encountered during flight, the airspeed should be reduced to maneuvering speed or less to minimize the stress on the airplane structure.

Landing Gear Operating speed (Vlo) - the maximum speed for extending or retracting the landing gear if using aircraft equipped with retractable landing gear.

Best Angle-of-Climb speed (Vx) - important when a short-field takeoff to clear an obstacle is required.

Best Rate-of-Climb speed (Vy) - the airspeed that will give the pilot the most altitude in a given period of time.

Hint 55

FAA-H-8083-25

Front 56

C. Pitot/Static Flight Instruments
10. What airspeed limitations apply to the color-coded marking system of the airspeed indicator?

Back 56

White Arc.....flap operating range
- Lower limit.....Vso (stall speed landing config)
- Upper limit.....Vfe (maximum flap extension speed)

Green Arc.....normal operating range
- Lower limit.....Vs1 (stall speed clean or specific config)
- Upper limit.....Vno (normal operation or max structure cruise)

Yellow Arc.....Caution Range (operations in smooth air only)
- Red line....Vne (max speed for operations in smooth air only)

Hint 56

FAA-H-8083-25

Front 57

C. Pitot/Static Flight Instruments
11. How does the vertical speed indicator work?

Back 57

The vertical speed indicator is a pressure differential instrument. inside the instrument case is an aneroid very much like the one in the airspeed indicator. Both the inside of this aneroid and the inside of the instrument case are vented to the static system, but the case is vented through a calibrated orifice that causes the pressure inside the case to change more slowly than the pressure inside the aneroid. As the aircraft ascends, the static pressure becomes lower and the pressure inside the case compresses the aneroid, moving the pointer upward, showing a climb and indicating the number of feet per minute the aircraft is ascending.

Hint 57

FAA-H-8083-15

Front 58

C. Pitot/Static Flight Instruments
12. What are the limitations of the vertical speed indicator?

Back 58

The VSI is not accurate until the aircraft is stabilized. Because of the restriction in airflow to the static line, a 6 to 9 second lag is required to equalize or stabilize the pressures. Sudden or abrupt changes in aircraft attitude will cause erroneous instrument readings as airflow fluctuates over the static port. Both rough control technique and turbulent air result in unreliable needle indications.

Hint 58

FAA-H-8083-25

Front 59

D. Gyroscopic Flight Instruments
1. What instruments contain gyroscopes?

Back 59

a. the turn coordinator
b. the heading coordinator
c. the attitude indicator

Hint 59

FAA-H-8083-25

Front 60

D. Gyroscopic Flight Instruments
2. What are the two fundamental properties of a gyroscope?

Back 60

Rigidity in space - a gyroscope remains in a fixed position in the plane in which it is spinning.

Precession - the tilting or turning of a gyro in response to a deflective force. The reaction to this force does not occur at the point where it was applied; rather, it occurs at a point that is 90* later in the direction of rotation. The rate at which the gyro precesses is inversely proportional to the speed of the rotor and proportional to the deflective force.

Hint 60

FAA-H-8083025

Front 61

D. Gyroscopic Flight Instruments
3. What are the various power sources that maybe used to power the gyroscopic instruments in an airplane?

Back 61

In some airplanes, all the gyros are vacuum, pressure, or electrically operated; in others, vacuum or pressure systems provide the power for the heading and attitude indicators, while the electrical system provides the power for the turn coordinator. Most airplanes have at least two sources of power to ensure at least one source of bank information if one power source fails.

Hint 61

FAA-H-8083-25

Front 62

D. Gyroscopic Flight Instruments
4. How does the vacuum system operate?

Back 62

Two redundent engine-driven vacuum pumps provide suction which pulls air from the instrument case. Normal pressure entering the case is directed against the rotor vanes to turn the rotor (gyro) at high speed, much like a water wheel or turbine operates. Air is drawn into the instrument through a filter from the cockpit and eventually vented outside. Vacuum values vary between manufacturers (usually between 4.5 and 5.5 in. Hg.), but provide rotor speeds from 8,000 to 18,000 RPM.

Hint 62

FAA-H-8083-25

Front 63

D. Gyroscopic Flight Instruments
5. How does the attitude indicator work?

Back 63

The gyro in the attitude indicator is mounted on a horizontal plane and depends upon rigidity in space for its operations. The horizon bar represents the true horizon. This bar is fixed to the gyro and remains in a horizontal plane as the airplane is pitched or banked about the lateral and longitudinal axis, indicating the attitude of the airplane relative to the true horizon.

Hint 63

FAA-H-8083-25

Front 64

D. Gyroscopic Flight Instruments
6. What are the limitations of the attitude indicator?

Back 64

The pitch and bank limits depend upon the make and model of the instrument. Limits in the the banking plane are usually from 100 to 110 degrees, and the pitch limits are usually from 60 to 70 degrees. If either limit is exceeded, the instrument will tumble or spill and will give incorrect indications until reset. A number of modern attitude indicators will not tumble.

Hint 64

FAA-H-8083-25

Front 65

D. Gyroscopic Flight Instruments
7. What are the errors of the attitude indicator?

Back 65

Attitude indicators are free from most errors, but depending upon the speed with which the erection system functions, there may be a slight nose-up indication during rapid acceleration and a nose-down indication during a rapid deceleration. There is also a possibility of a small bank angle and pitch error after a 180* turn. These inherent errors are small and correct themselves within a minute or so after returning to straight and level flight.

Hint 65

FAA-H-8083-15

Front 66

D. Gyroscopic Flight Instruments
8. How does the heading indicator operate?

Back 66

The operation of the heading indicator uses the principle of rigidity in space. The rotor turns in a vertical plane, and the compass card is fixed to the rotor. Since the rotor remains rigid in space, the points on the card hold the same position in space relative to the vertical plane. As the instrument case and the airplane revolve around the vertical axis, the card provides clear and accurate heading information.

Hint 66

FAA-H-8083-25

Front 67

D. Gyroscopic Flight Instruments
9. What are the limitations of the heading indicator?

Back 67

The bank and pitch limits of the heading indicator vary with the particular design and make of the instrument. On some heading indicators found in light airplanes, the limits are approximately 55 degrees of pitch and 55 degrees of bank. When either of these attitude limits is exceeded, the instrument "tumbles" or "spills" and no longer gives the correct indication until reset. After spilling, it may be reset with the caging knob. Many of the modern instruments used are designed in such a manner that they will not tumble.

Hint 67

FAA-H-8083-25

Front 68

D. Gyroscopic Flight Instruments
10. What error is the heading indicator subject to?

Back 68

Because of precession, caused chiefly by friction, the heading indicator will creep or drift from a heading to which it is set. Among other factors, the amount of drift depends largely upon the conditions of the instrument. The heading indicator may indicate as much as 15 degrees error per every hour of operation.

Hint 68

FAA-H-8083-25

Front 69

D. Gyroscopic Flight Instruments
11. How does the turn coordinator operate?

Back 69

The turn part of the instrument uses precession to indicate direction and approximate rate of turn. A gyro reacts by trying to move in reaction to the force applied thus moving the needle or miniature aircraft in proportion to the rate of turn. The slip/skid indicator is a liquid filled tube with a ball that reacts to the centrifugal force and gravity.

Hint 69

FAA-H-8083-15

Front 70

D. Gyroscopic Flight Instruments
12. What information does the turn coordinator provide?

Back 70

The turn coordinator shows the yaw and roll of the aircraft around the vertical and longitudinal axes.

The miniature airplane will indicate direction of the turn as well as rate of turn. When aligned with the turn index, it represents a standard rate turn of 3 degrees per second. The inclinometer of the turn coordinator indicates the coordination of the aileron and rudder. The ball indicates whether the airplane is in coordinated flight or is in a slip or skid.

Hint 70

FAA-H-8083-25

Front 71

D. Gyroscopic Flight Instruments
13. What will the turn indicator indicate when the aircraft is in a "skidding" or a "slipping" turn?

Back 71

Slip - the ball in the tube will be on the inside of the turn; not enough rate of turn for the amount of bank.

Skid - the ball in the tube will be on the outside of the turn; too much rate of turn for the amount of bank.

Hint 71

FAA-H-8083-25

Front 72

E. Magnetic Compass
1. How does the magnetic compass work?

Back 72

Magnetized needles fastened to a float assembly, around which is mounted a compass card, align themselves parallel to the earth's lines of magnetic force. The float assembly is housed in a bowl filled with acid-free white kerosene.

Hint 72

FAA-H-8083-25

Front 73

E. Magnetic Compass
2. What limitations does the magnetic compass have?

Back 73

The float assembly of the compass is balanced on a pivot, which allows free rotation of the card, and allows it to tilt at an angle up to 18 degrees.

Hint 73

FAA-H-8083-15

Front 74

E. Magnetic Compass
3. What are the various compass errors?

Back 74

Oscillation error - erratic movement of the compass card caused by turbulence or rough control technique.

Deviation error - due to electrical and magnetic disturbances in the aircraft.

Variation error - angular difference between true and magnetic north; reference isogonic lines of variation.

Dip Errors:
Acceleration error - on east or west heading, while accelerating, the magnetic compass shows a turn to the north, and when decelerating, it shows a turn to the south.

Remember: ANDS
A ccelerate
N orth
D ecelerate
S outh

Northerly turning error - the compass leads in the south half of a turn, and lags in the north half of a turn.

Remember: UNOS
U ndershoot
N orth
O vershoot
S outh

Hint 74

FAA-H-8083-15