Aircraft Systems
What is the maximum flaps-extended speed?
"100 knots. The upper limit of the white arc represents the aircraft's maximum flap extension speed, or 100 knots in this example."
Which condition would cause the altimeter to indicate a lower altitude than true altitude?
"Air temperature warmer than standard. When air is warmer than average, the aircraft is higher than the altimeter indicates. Therefore, the altimeter will read lower than the aircraft's actual altitude."
The magnetic compass:
Is self powered. The magnetic compass is the simplest instrument in the panel and needs no outside power to operate.
If an aircraft is equipped with a fixed-pitch propeller and a float-type carburetor, the first indication of carburetor ice would most likely be
loss of RPM. The formation of ice in the carburetor reduces the amount of fuel reaching the engine. This causes a reduction of RPM.
Altimeter setting is the value to which the barometric pressure scale of the altimeter is set so the altimeter indicates
true altitude at field elevation. True altitude is the true vertical distance of the aircraft above sea level. It is the actual altitude of the aircraft.
Which altimeter(s) indicate(s) more than 10,000 feet?
"1 and 2 only. The shortest hand indicates tens of thousands of feet. The middle length hand represents thousands of feet and the longest hand indicates hundreds of feet. The shortest hand is past 10,000' on altimeters 1 & 2."
Altimeter 1 indicates
"10,500 feet. The shortest hand indicates tens of thousands of feet. The middle length hand represents thousands of feet and the longest hand indicates hundreds of feet. The shortest hand is just past 10,000'. The hands read 10,500'."
Altimeter 2 indicates:
"14,500 feet. The shortest hand indicates tens of thousands of feet. The middle length hand represents thousands of feet and the longest hand indicates hundreds of feet. The shortest hand is past 10,000'. The hands read 14,500'."
If it is necessary to set the altimeter from 29.15 to 29.85, what change occurs?
"700-foot increase in indicated altitude. One inch of Hg is equal to approximately 1,000' of altitude. The difference between 29.15 and 29.85 is an increase of .70"" Hg, or 700' of increased altitude indication."
Altimeter 3 indicates
"9,500 feet. The shortest hand indicates tens of thousands of feet. The middle length hand represents thousands of feet and the longest hand indicates hundreds of feet. The shortest hand is just before 10,000'. The hands read 9,500'."
If a pilot changes the altimeter setting from 30.11 to 29.96, what is the approximate change in indication?
"Altimeter will indicate 150 feet lower. The difference between 30.11 and 29.96 is .15"" Hg. The standard lapse rate is 1"" Hg per 1,000' in altitude. Therefore, .15 x 1,000' = 150' and the indication would be lower."
On aircraft equipped with fuel pumps, when is the auxiliary electric driven pump used?
"In the event engine-driven fuel pump fails. The auxiliary or ""boost"" pump is used as a backup for the engine-driven pump."
What is an important airspeed limitation that is not color coded on airspeed indicators?
"Maneuvering speed. Maneuvering speed is the maximum speed for abrupt maneuvers. It is also sometimes called the ""rough air"" speed."
What is pressure altitude?
"The altitude indicated when the barometric pressure scale is set to 29.92. Pressure altitude is indicated when the altimeter setting window (barometric scale) is adjusted to 29.92"" Hg."
Why would an aviation piston engine continue running after the ignition switched is placed in the OFF position?
"The magneto's grounding wire is broken. Even with the ignition switch in the OFF position, if the ground wire between the magneto and the ignition switch becomes disconnected or broken, the only way to stop the engine is to move the mixture lever to the idle cutoff position, then have the system checked by a qualified AMT."
A precaution for the operation of an engine equipped with a constant-speed propeller is to
"avoid high manifold pressure settings with low RPM. For any given RPM there is a manifold pressure that should not be exceeded. If manifold pressure is excessive for a given RPM, the pressure within the cylinders could be exceeded, placing undue stress on them. Follow the manufacturer's recommendations."
If a flight is made from an area of high pressure into an area of lower pressure without the altimeter setting being adjusted, the altimeter will indicate
"higher than the actual altitude above sea level. When flying from an area of high pressure to an area of low pressure, the aircraft will be lower than the indication on the altimeter. Therefore, the altimeter will read higher than the aircraft's actual altitude."
To minimize the side loads placed on the landing gear during touchdown, the pilot should keep the
"longitudinal axis of the aircraft parallel to the direction of its motion. It is important that the touchdown of an aircraft occur with the aircraft's longitudinal axis parallel to the direction in which it is moving along the runway to reduce side loads on the landing gear."
If a flight is made from an area of low pressure into an area of high pressure without the altimeter setting being adjusted, the altimeter will indicate
"lower than the actual altitude above sea level. When flying from an area of low pressure to an area of high pressure, the aircraft will be higher than the indication on the altimeter. Therefore, the altimeter will read lower than the aircraft's actual altitude."
Altimeter 2 indicates
14,500 feet. The smallest hand represents 10s of thousands of feet. Here the smallest hand is beyond the 10,000 foot mark. The next smallest hand, the 1,000 foot pointer, is past the 4,000 foot mark and the largest hand, the 100 foot pointer, is on 500 feet—14,500 feet.
What is the maximum structural cruising speed?
165 knots. The upper limit of the green arc represents the maximum structural cruising speed of the aircraft, or 165 knots.
The maximum speed at which the airplane can be operated in smooth air is
208 knots. Never-exceed speed is indicated on the airspeed indicator with a red line. This is the maximum speed that an aircraft can be operated in smooth air.
What is the full flap operating range for the airplane?
55 to 100 KTS. The white arc on the airspeed indicator represents the flap operating range for an aircraft. It extends from 55 to 100 knots.
The rotating propeller of an airplane makes a very good gyroscope and thus has similar properties. In a prop driven airplane, a decrease in pitch attitude results in:
A yawing moment to the left around the vertical axis. A decrease in pitch attitude has the same effect as applying a force to the top of the propeller's plane of rotation. The resultant force acting 90° ahead in the direction of the rotation causes a yawing moment to the left around the vertical axis.
What should be the first action after starting an aircraft engine?
Adjust for proper RPM and check for desired indications on the engine gauges. As soon as the engine starts, ensure that the aircraft is not moving, set the power to the recommended RPM, and check the engine gauges for proper indications.
When taxiing with strong quartering tailwinds, which aileron positions should be used?
Aileron down on the side from which the wind is blowing. When taxiing with a strong quartering tailwind, use down aileron on the side from which the wind is blowing to keep the wind from pushing under the wing, and flipping the airplane.
Which aileron positions should a pilot generally use when taxiing in strong quartering headwinds?
Aileron up on the side from which the wind is blowing. When taxiing in a strong quartering headwind, use an up aileron on the side from which the wind is blowing.
The pitot system provides impact pressure for which instrument?
Airspeed indicator. The pitot tube provides ram air to operate the airspeed indicator. It does not affect the other two pitot-static instruments.
Which instrument is affected if the pitot tube is blocked?
Airspeed indicator. When dynamic pressure cannot enter the pitot tube opening, the airspeed indicator no longer operates.
Which instrument(s) will become inoperative if the static vents become clogged?
Airspeed, altimeter, and vertical speed. All three pitot-static instruments are affected by a clogged static vent.
Static pressure, also known as ambient pressure, is:
Always present whether an aircraft is moving or at rest. Static pressure, also known as ambient pressure, is always present whether an aircraft is moving or at rest. It is the barometric pressure in the local area.
Which factor would tend to increase the density altitude at a given airport?
An increase in ambient temperature. The primary factor that would tend to increase density altitude at a given airport is an increase in ambient temperature. The hotter the air temperature, the less dense the air. This is equivalent to increasing density altitude.
Under what condition is pressure altitude and density altitude the same value?
At standard temperature. Pressure altitude and density altitude are the same value in standard conditions.
Which gyroscopic instrument is the foundation for all instrument flight?
Attitude indicator. The attitude indicator is the foundation for all instrument flight, this instrument reflects the airplane's attitude in relation to the horizon.
The only instrument that provides an instantaneous, direct indication of the airplane's pitch and bank attitude is the:
Attitude indicator. The relationship of the miniature aircraft to the horizon bar is the same as the relationship of the real aircraft to the actual horizon. The instrument gives an instantaneous indication of even the smallest changes in pitch and bank attitude.
Using a turn and slip indicator, how do you know that you are in a coordinated turn?
Centering the ball results in a coordinated turn. If inadequate right rudder is applied in a right turn, a slip results. Too much right rudder causes the aircraft to skid through the turn. Centering the ball results in a coordinated turn.
During the run-up at a high-elevation airport, a pilot notes a slight engine roughness that is not affected by the magneto check but grows worse during the carburetor heat check. Under these circumstances, what would be the most logical initial action?
Check the results obtained with a leaner setting of the mixture. The aircraft is at a higher altitude airport, causing the proper ratio of fuel to air to be too rich (too much fuel for available air). By leaning out the fuel with the mixture control, the proper ratio will be attained and the roughness will smooth out.
What is one procedure to aid in cooling an engine that is overheating?
Enrichen the fuel mixture. A rich mixture will usually tend to cool the engine. Leftover fuel, caused by a rich mixture, absorbs some heat from the cylinders, resulting in a cooler engine.
If you land without the use of flaps, the approach will be:
Faster and shallower. Landing without flaps, lift is reduced resulting in a faster and shallower approach. Flaps increase the airfoil camber, resulting in a significant increase in the coefficient of lift at a given AOA.
Why is it a good idea to visually inspect to make sure that the crankcase breather lines are free of ice?
Ice may have formed as a result of the crankcase vapors freezing after the engine has been turned off. You should always visually inspect to make sure that the crankcase breather lines are free of ice. The ice may have formed as a result of the crankcase vapors freezing in the lines after the engine has been turned off. AC 91-13C is the source for this question but the FAA cancelled the AC on 05-25-2017
Under what condition will true altitude be lower than indicated altitude?
In colder than standard air temperature. True altitude will be lower than indicated altitude when the aircraft is in an air temperature colder than standard.
The order of operation regarding the strokes of a typical four-stroke per cycle airplane engine is:
Intake, compression, power, and exhaust. The intake, compression, power, and exhaust processes occur in four separate strokes of the piston.
A constant-speed propeller is more efficient than other propellers because:
It allows selection of the most efficient engine rpm for the given conditions. A constant-speed propeller converts a high percentage of brake horsepower into thrust horsepower over a wide range of rpm and airspeed combinations. Therefore, it is more efficient than other propellers.
On a turn from a northerly heading the compass will:
Lag behind the airplane. When starting a turn from a northerly heading, the compass lags behind the turn.
How should the flight controls be held while taxiing a tailwheel airplane with a left quartering tailwind?
Left aileron down, elevator down. When taxiing a tailwheel airplane with a left quartering tailwind, use down aileron on the left hand wing and down elevator.
How should the flight controls be held while taxiing a tricycle-gear equipped airplane with a left quartering tailwind?
Left aileron down, elevator down. When taxiing a tricycle-gear equipped airplane with a left quartering tailwind, use down aileron on the left hand wing and down elevator.
How should the flight controls be held while taxiing a tricycle-gear equipped airplane into a left quartering headwind?
Left aileron up, elevator neutral. When taxiing a tricycle-gear equipped airplane into a left quartering headwind, use up aileron on the left hand wing and neutral elevator.
For a given power setting with a constant-speed, variable pitch propeller:
Low pitch results in high RPM. When maximum power and thrust are required, the constant-speed propeller is at a low propeller blade angle or pitch allowing it to pass through the air faster.
Which color identifies the power-off stalling speed with wing flaps and landing gear in the landing configuration?
Lower limit of the white arc. The lower limit of the white arc represents power-off stalling speed with the wing flaps and landing gear in the landing position.
Extending the flaps:
Lowers the stalling speed. Flaps allow a compromise between high cruising speed and low landing speed because they may be extended when needed and retracted into the wing's structure when not needed.
The common heading indicator requires periodic adjustment. It is important to check its indications frequently against the:
Magnetic compass. The magnetic compass provides an indication of the magnetic heading. When setting the gyroscopic heading indicator to agree with the magnetic compass, use the average indication between the swings.
What does the red line on an airspeed indicator represent?
Never-exceed speed. Never-exceed speed is indicated on the airspeed indicator with a red line. This is the maximum speed that an aircraft can be operated in smooth air. It is abbreviated as VNE.
What is an advantage of a constant-speed propeller?
Permits the pilot to select the blade angle for the most efficient performance. A controllable-pitch propeller permits the pilot to select the blade angle that will result in the most efficient performance for a particular flight condition.
How is power controlled on an airplane equipped with a constant-speed propeller?
Power output is controlled by the throttle and indicated by a manifold pressure gauge. On aircraft equipped with a constant-speed propeller, power output is controlled by the throttle and indicated by a manifold pressure gauge.
How do variations in temperature affect the altimeter?
Pressure levels are raised on warm days and the indicated altitude is lower than true altitude. On a warm day the atmosphere expands. An aircraft will actually be higher than the altimeter is indicating (higher pressure level). On a cold day the atmosphere contracts and an aircraft will be lower than the altimeter is indicating.
Which wind condition would be most critical when taxiing a nosewheel equipped high-wing airplane?
Quartering tailwind. When taxiing a nosewheel equipped high-wing airplane the most critical wind position is a quartering tailwind because it could lift the tail and push the airplane over on its prop and far wingtip.
Position (navigation) lights on an aircraft are:
Red for the left wingtip, green for the right wing tip, and white for the tail. Lights on an aircraft consist of a red light on the left wing, a green light on the right wing, and a white light on the tail.
How should the flight controls be held while taxiing a tailwheel airplane into a right quartering headwind?
Right aileron up, elevator up. When taxiing a tailwheel airplane into a right quartering headwind, use up aileron on the right hand wing and up elevator.
Most of the heat caused by internal combustion is eliminated via:
The exhaust system. The burning fuel within the cylinders produces intense heat, most of which is expelled through the exhaust system.
As you are climbing to your cruise altitude, you realize you forgot to lean the mixture control. What happens to fuel/air mixture entering the engine?
The fuel-air mixture becomes richer because the density of air decreases while the amount of fuel remains constant. As altitude increases, the density of air entering the carburetor/intake manifold decreases, while the density of the fuel remains the same. This creates a progressively richer mixture that can result in engine roughness and an appreciable loss of power.
What change occurs in the fuel/air mixture when carburetor heat is applied?
The fuel/air mixture becomes richer. Warm air is less dense than cold air. Applying carb heat will decreases air density causing a richer mixture (higher fuel to air ratio).
The airspeed indicator has various color markings. The green arc is:
The normal operating range of the airplane. The green arc identifies the normal operating range of the aircraft. Most flying occurs within this range.
What is density altitude?
The pressure altitude corrected for nonstandard temperature. Density altitude is pressure altitude corrected for nonstandard temperature variations.
The air/fuel ratio (AFR) is the measurement of:
The ratio of weight of air to the weight of fuel in the mixture. The ratio of air/fuel is expressed in terms of weight (mass).
Which marking identifies the never-exceed speed?
The red radial line. Never-exceed speed is indicated on the airspeed indicator with a red line. This is the maximum speed that an aircraft can be operated in smooth air.
You have been running an excessively rich mixture for some time now. As a result:
The spark plugs may become fouled. Excessively rich mixtures will cause additional carbon buildup on spark plugs, which may cause engine roughness.
How is engine operation controlled on an engine equipped with a constant-speed propeller?
The throttle controls power output as registered on the manifold pressure gauge and the propeller control regulates engine RPM. On an engine equipped with a constant-speed propeller, throttle controls the power output registered on a manifold pressure gauge and the propeller control regulates the engine RPM.
Which color identifies the normal flap operating range?
The white arc. The white arc on the airspeed indicator represents the flap operating range for an aircraft. It extends from 55 to 100 knots.
Why are reciprocating engines preferred over other types for small aircraft.
They are less expensive to operate and they are simple in design. Most small aircraft are designed with reciprocating engines. reciprocating engine technology has improved dramatically over the past two decades.
What is one purpose of wing flaps?
To enable the pilot to make steeper approaches to a landing without increasing the airspeed. Wing flaps increase lift and drag allowing the pilot to make steeper approaches without increasing airspeed.
What is the purpose of the airplane engine's mixture control?
To regulate the ratio of gasoline to air entering the fuel distribution system. To maintain the correct fuel-air mixture, the mixture must be leaned using the mixture control. Leaning the mixture decreases fuel flow, which compensates for the decreased air density at high altitude.
Which would most likely cause the cylinder head temperature and engine oil temperature gauges to exceed their normal operating ranges?
Using fuel that has a lower-than-specified fuel rating. Fuel with a lower-than-specified rating can lead to detonation. Detonation produces extreme heat and leads to high operating temperatures.
Under which condition will pressure altitude be equal to true altitude?
When standard atmospheric conditions exist. True altitude is the actual altitude above mean sea level. Pressure altitude is the altitude in the standard atmosphere where pressure is the same as where you are. Pressure altitude is the same as true altitude in standard atmosphere.
A too rich mixture:
Will create spark plug fouling. If the mixture is too rich it can result in engine roughness and an appreciable loss of power. The roughness normally is due to spark plug fouling from excessive carbon buildup on the plugs.
The presence of carburetor ice in an aircraft equipped with a fixed-pitch propeller can be verified by applying carburetor heat and noting
a decrease in RPM and then a gradual increase in RPM. The RPM will decrease with the application of carburetor heat due to the decreased air density of the warmer air. As the ice melts, the RPM will increase due to better fuel/air mixture flow. Some engine roughness may occur as the ice melts.
In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn toward the east if
a left turn is entered from a north heading. On a northerly heading, if a left turn is made toward the west, the compass will initially indicate a turn in the opposite direction or toward the east.
In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn toward the west if
a right turn is entered from a north heading. On a northerly heading, if a right turn is made toward the east, the compass will initially indicate a turn in the opposite direction or toward the west.
In the Northern Hemisphere, a magnetic compass will normally indicate a turn toward the north if
an aircraft is accelerated while on an east or west heading. Acceleration / deceleration error is most pronounced on a heading of east or west. ANDS, Accelerate, North, Decelerate, South.
Should it become necessary to handprop an airplane engine, it is extremely important that a competent pilot
be at the controls in the cockpit. It is extremely important that a competent pilot be at the controls in the cockpit because of the hazards involved in hand propping.
Excessively high engine temperatures will
cause loss of power, excessive oil consumption, and possible permanent internal engine damage. Operating at an excessively high engine temperature can lead to loss of power, excessive oil consumption, and detonation. Damage to the cylinders, pistons, piston rings, and valves may occur.
In the Northern Hemisphere, if an aircraft is accelerated or decelerated, the magnetic compass will normally indicate
correctly when on a north or south heading. Acceleration / deceleration error is most pronounced on a heading of east or west. This error does not occur on a north or south heading.
The basic purpose of adjusting the fuel/air mixture at altitude is to
decrease the fuel flow in order to compensate for decreased air density. The higher an aircraft climbs, the less air there is to mix with the available fuel. To maintain the correct ratio of fuel to air as an aircraft increases in altitude, the pilot adjusts the amount of fuel with the manual mixture control.
If the grade of fuel used in an aircraft engine is lower than specified for the engine, it will most likely cause
detonation. Detonation is the explosive burning of the fuel/air mixture. This phenomenon is often caused by the use of a lower than recommended grade of fuel.
The operating principle of float-type carburetors is based on the
difference in air pressure at the venturi throat and the air inlet. When air flows through a venturi, a low-pressure area is created. This lower pressure causes fuel to flow from the discharge nozzle and mix with the air in the throat of the venturi.
Applying carburetor heat will
enrich the fuel/air mixture. Warm air is less dense than cold air. Applying carb heat will decreases air density causing a richer mixture (higher fuel to air ratio).
An electrical system failure (battery and alternator) occurs during flight. In this situation, you would
experience avionics equipment failure. A complete electrical system failure would result in the loss of the avionics equipment as well as most other electrical equipment.
The possibility of carburetor icing exists even when the ambient air temperature is as
high as 70 °F and the relative humidity is high. Be alert for carburetor icing if the temperature is between 20° F and 70° F with visible moisture or high humidity.
One purpose of the dual ignition system on an aircraft engine is to provide for
improved engine performance. The dual ignition system provides improved safety through redundancy and improved engine performance through more efficient burning of the fuel/air mixture. This efficiency is derived through dual flame fronts within the cylinder.
One of the main functions of flaps during approach and landing is to
increase the angle of descent without increasing the airspeed. Flaps increase lift (with an increase in induced drag) enabling the pilot to make steeper approaches without an increase in airspeed.
If a pilot suspects that the engine (with a fixed-pitch propeller) is detonating during climb-out after takeoff, the initial corrective action to take would be to
lower the nose slightly to increase airspeed. Engine detonation results in an overheated engine. Engine temperature can be reduced by lowering the nose of the aircraft to increase the flow of air over the cylinders and reduce engine strain.
The angular difference between true north and magnetic north is
magnetic variation. Magnetic variation is the angular difference between the true, or geographic, north pole and the magnetic north pole at a given point.
The proper adjustment to make on the attitude indicator during level flight is to align the
miniature airplane to the horizon bar. Normally, the miniature airplane is adjusted so that the wings overlap the horizon bar when the aircraft is in straight-and-level flight.
With regard to carburetor ice, float-type carburetor systems in comparison to fuel injection systems are generally considered to be
more susceptible to icing. Float-type carburetors are more prone to carburetor ice than fuel injection systems. In a fuel injected system, mixing of the fuel & air occurs just prior to the intake valve or in the cylinder. The cooling effect of fuel vaporization has less influence.
A turn coordinator provides an indication of the
movement of the aircraft about the yaw and roll axis. The turn coordinator shows the rate of turn about the yaw or vertical axis and the rate of roll about the roll or longitudinal axis.
To receive accurate indications during flight from a heading indicator, the instrument must be
periodically realigned with the magnetic compass as the gyro precesses. The heading indicator is not direction-seeking. It is important to check its indication frequently and reset it with reference to the magnetic compass.
The uncontrolled firing of the fuel/air charge in advance of normal spark ignition is known as
pre-ignition. The uncontrolled firing of the fuel/air charge in advance of normal spark ignition is the definition of preignition.
In the Northern Hemisphere, the magnetic compass will normally indicate a turn toward the south when
the aircraft is decelerated while on a west heading. Acceleration / deceleration error is most pronounced on a heading of east or west. ANDS, Accelerate, North, Decelerate, South.
For internal cooling, reciprocating aircraft engines are especially dependent on
the circulation of lubricating oil. Airflow over the cylinders and other parts of the engine provides some measure of cooling. Additional heat is absorbed by the oil and carried to the oil cooling system for dissipation.
Detonation may occur at high-power settings when
the fuel mixture ignites instantaneously instead of burning progressively and evenly. Detonation is a sudden explosion or shock to a small area of the piston top. Detonation may occur at high-power settings when the fuel mixture ignites instantaneously instead of burning progressively and evenly.
If the engine oil temperature and cylinder head temperature gauges have exceeded their normal operating range, the pilot may have been operating with
too much power and with the mixture set too lean. High power settings with a lean mixture may lead to overheating. The additional fuel of a richer mixture has a cooling effect.
