SU2: Airplane Instruments, Engines, and Systems

If it is necessary to set the altimeter from 29.15 to 29.85, what change occurs?

700-foot increase in indicated altitude. The altimeter-indicated altitude moves in the same direction as the altimeter setting and changes about 1,000 feet for every 1" Hg in the altimeter setting.

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

Adjust for proper RPM and check for desired indications on the engine gauges. The oil pressure gauge is the most important gauge initially.

Which condition would cause the altimeter to indicate a lower altitude than true altitude?

Air temperature warmer than standard.

The pitot system provides impact pressure for which instrument?

Airspeed Indicator

Which instrument will become inoperative if the pitot tube becomes clogged?

Airspeed Indicator

You are flying and aircraft equipped with an electronic flight display (EFD) and the air data computer (ADC) fails. What instrument is affected?

Airspeed Indicator The ADC receives the pitot and static inputs and computes the difference between the total pressure and the static pressure. It then generates the information necessary to display the airspeed, altitude, and vertical speed on the PFD.

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

If the pitot tube and outside static vents become clogged, which instruments would be affected?

Altimeter, Airspeed Indicator, and Vertical Speed Indicator

Which instrument(s) will become inoperative if the static vents become clogged?

Altimeter, Airspeed Indicator, and Vertical Speed Indicator

Under what condition is pressure altitude and density altitude the same value?

At standard temperature (per ISA table).

How should a pilot determine the direction of bank from an attitude indicator such as the one illustrated?

By the relationship of the miniature airplane (fixed) to the deflected horizon bar (movable). Attitudes include nose high, nose low, left bank, and right bank.

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. At a high-elevation field, the air is less dense and the application of carburetor heat increases the already too rich fuel-to-air mixture. By leaning the mixture during the run-up, the condition should improve.

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

Enrich the fuel mixture.

Under what condition will true altitude be lower than indicated altitude?

In colder than standard air temperature. Altimeter readings are adjusted for changes in barometric pressure but not for changes in temperature. When one flies from warmer to cold air and keeps a constant indicated altitude at a constant altimeter setting, the plan has actually descended.

On aircraft equipped with fuel pumps, when is the auxiliary electric driven pump used?

In the event the engine-driven fuel pump fails. In a fuel pump system, two fuel pumps are used on most airplanes. The main fuel pump is engine-driven, and an auxiliary electric-driven pump is provided for use in the event the engine pump fails.

Which devices use the electrical system for power?

Lights, radios, and electrical fuel pumps.

Which color identifies the power-off stalling speed with wing flaps and landing gear in the landing configuration?

Lower limit of the white arc (V(S0))

What is an important airspeed limitation that is not color coded on airspeed indicators?

Maneuvering Speed (V(A)) - this speed or less should be held in turbulent air to prevent structural damage due to excessive loads

During flight, when are the indications of a magnetic compass accurate?

Only in straight-and-level, unaccelerated flight.

What is an advantage of a constant-speed propeller?

Permits the pilot to select the blade angle for the most effective performance. A controllable-pitch (constant speed) propeller permits the pilot to select the blade angle that will result in the most efficient performance given the flight conditions. A low blade angle and a decreased pitch reduces the propeller drag and allows more engine RPM (power) for takeoffs. After airspeed is attained during cruising flight, the propeller blade is changed to a higher angle to increase pitch. The blade takes a larger bite of air at a lower RPM and consequently increases the efficiency of the flight. This process is similar to shifting gears in a car from low to high.

How do variations in temperature affect the altimeter?

Pressure levels are raised on warm days and the indicated altitude is lower than true altitude. "Low to high, clear the sky."

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

Reduce the rate of climb and increase airspeed. The engine temperature will be decreased if the airspeed is increased.

What steps must be taken when flying with glass cockpits to ensure safe flight?

Regularly scan both inside (backup gauges) and outside (visually), use all appropriate checklists, and cross-check with other forms of information.

What is a benefit of flying with a glass cockpit?

Situational awareness is increased. Glass cockpits are designed to decrease pilot workload, enhance situational awareness, and increase the safety margin.

Which condition is most favorable to the development of carburetor icing?

Temperature between 20˚ F and 70˚F and high humidity. Due to the sudden cooling that takes place in the carburetor, icing can occur even with temperatures as high as 100˚ F and humidity as low as 50%. During low or closed throttle settings, an engine is particularly susceptible to carburetor icing.

What is pressure altitude?

The altitude indicated when the barometric pressure scale is set to 29.92.

What should be the indication on the magnetic compass as you roll into a standard rate turn to the right from a South heading in the Northern Hemisphere?

The compass will indicate a turn to the right, but at a faster rate than is actually occurring. The magnetic compass indication precedes the turn.

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

The fuel/air mixture becomes richer. Hot air is less dense than cold air, therefore, the decrease in air density with a constant amount of fuel makes a richer mixture.

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

The fuel/air mixture may become excessively lean. This could create higher cylinder temperature and may cause detonation.

Which color on the airspeed indicator identifies the power-off stalling speed in a specified configuration?

The lower limit of the green arc (V(S1))

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

The next higher octane aviation gas.

What is density altitude?

The pressure altitude corrected for nonstandard temperature.

Which line on the airspeed indicator identifies the never-exceed speed?

The red radial line (V(NE))

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. Airplanes equipped with controllable-pitch propellers have both a throttle control and a propeller control. Throttle = engine power, Propeller = engine RPM (registered on tachometer). The manifold pressure gauge is a barometer that measures the air pressure in the engine intake manifold in inches of Mercury.

What is the maximum flaps-extended speed?

The upper limit of the white arc (V(FE))

What is the maximum speed at which the airplane can be operated in smooth air?

The upper limit of the yellow arc / red radial line (V(NE))

What is true altitude?

The vertical distance of the aircraft above sea level; MSL - mean sea level

What is absolute altitude?

The vertical distance of the aircraft above the surface; AGL

Which color identifies the normal flap operating range?

The white arc (V(S0) to V(FE))

What is the full flap operating range for an airplane?

The white arc on the airspeed indicator (V(SO) to V(FE))

What is the caution range of the airplane?

The yellow arc on the airspeed indicator (V(NO) to V(NE))

What is the maximum structural cruising speed?

Upper limit of the green arc (V(NO))

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. This can cause many problems, including higher operating temperatures, detonation, etc.

What does the red line on an airspeed indicator represent?

V(NE) - Never-Exceed Speed

Under what condition is indicated altitude the same as true altitude?

When at sea level under standard conditions (per ISA table). Indicated altitude (what you read on your altimeter) approximates the true altitude (distance above mean sea level) when standard conditions exist and your altimeter is properly calibrated.

Under which condition will pressure altitude be equal to true altitude?

When standard atmospheric conditions exist. (29.92" Hg and 15 degrees C at sea level)

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 than a gradual increase in RPM. The decrease in RPM as heat is applied is caused by less dense hot air entering the engine and reducing power output. Also, if ice is present, melting water entering the engine may also cause a loss in performance. As the carburetor ice melts, however, the RPM gradually increases until it stabilizes when the ice is completely removed.

In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn to the East if...

a left turn is entered from a north heading.

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.

In the Northern Hemisphere, a magnetic compass will normally indicate a turn to the North if...

an aircraft is accelerated while on an East or West heading.

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. Manifold pressure is excessive for a given RPM when the cylinder design pressure is exceeded, placing undue stress on them. If repeated or extended, the stress would weaken the cylinder components and eventually cause engine failure.

Should it become necessary to handprop an airplane engine, it is extremely important that a competent pilot...

be at the controls on the flight deck.

Excessively high engine temperature will...

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

Excessively high engine temperatures, either in the air or on the ground, will...

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

Deviation error of the magnetic compass is caused by...

certain metals and electrical systems in the aircraft.

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. Errors only occur on East or West headings.

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...

decrease / loss of RPM.

Generally speaking, the use of carburetor heat tends to...

decrease engine performance. It also increases the operating temperature. Warmer air is less dense, and engine performance decreases with density. Thus, carburetor heat should not be used when full power is required (as during takeoff) or during normal engine operation except as a check for the presence or removal of carburetor ice.

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.

If the grade of fuel used in an aircraft engine is lower than specified for the engine, it will most likely cause...

detonation. Definition: an uncontrolled, explosive ignition of the fuel/air mixture within the cylinder's combustion chamber caused by a combination of excessively high temperature and pressure in the cylinder. Lower grade fuels ignite at lower temperatures. A higher temperature engine (which should use a higher grade of fuel) may cause lower grade fuel to explode (detonate) rather than burn evenly.

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

difference in air pressure at the venturi throat and the air inlet. In a float-type carburetor, air flows into the carburetor and through a venturi tube (a narrow throat in the carburetor). As the air flows more rapidly through the venturi, a low pressure area is created that draws the fuel from a main fuel jet located at the throat of the carburetor and into the airstream, where it is mixed with flowing air. It is called a float-type carburetor in that a ready supply of gasoline is kept in the float bowl by a float, which activates a fuel inlet valve.

Applying carburetor heat will...

enrich the fuel/air mixture. Warm air is less dense than cold air, hence the application of heat increases the fuel-to-air ratio.

An electrical system failure (battery and alternator) occurs during flight. In this situation, you would...

experience avionics equipment failure.

To properly purge water from the fuel system of an aircraft equipped with fuel tank sumps and a fuel strainer quick drain, it is necessary to drain fuel from the...

fuel strainer drain and (all of) the fuel tank sumps. Such drains are placed at low areas of the fuel system and should be drained prior to each flight.

The possibility of carburetor icing exists even when the ambient air temperature is as...

high as 70˚ F and the relative humidity is high.

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.

To keep a battery charged, the alternator voltage output should be...

higher than the battery voltage.

During preflight in cold weather, crankcase breather lines should receive special attention because they are susceptible to being clogged by...

ice from crankcase vapors that have condensed and subsequently frozen (after the engine is turned off). Frozen crankcase breather lines prevent oil from circulating adequately in the engine and may even result in broken oil lines or oil being pumped out of the crankcase.

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

improved engine performance. Most airplane engines are equipped with dual ignition systems, which have two magnetos to supply the electrical current to two spark plugs for each combustion chamber. The main advantages of the dual system are increased safety and improved burning and combustion of the mixture, which results in improved performance.

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 the altimeter setting is at a lower value than the correct setting, the altimeter is indicating less than it should and thus would be showing lower than the actual altitude above sea level.

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. This would allow for more cooling and decrease the load on the engine. Detonation is usually caused by a poor grade of fuel or an excessive engine temperature. Leaning the mixture is the wrong answer because doing so would cause an increase in engine temperature and an increase in detonation.

Deviation in a magnetic compass is caused by the...

magnetic fields within the aircraft distorting the lines of magnetic force. The metals and electrical accessories in the airplane disturb the compass needles and produce errors. The errors are referred to as compass deviations.

If the ignition switch ground wire becomes disconnected, the magneto...

may continue to fire. Loose or broken wires in the ignition system can cause problems. For example, if the ignition switch is OFF, the magneto may continue to fire if the ignition switch ground wire is disconnected. If this continues, the only way to stop the engine is to move the mixture lever to the idle cut-off position, then have the system checked by a qualified aviation maintenance technician.

The proper adjustment to make on the attitude indicator during level flight is to align the...

miniature airplane to the horizon bar. The horizon bar represents the true horizon. It is fixed to the gyro and remains on a horizontal plane as the airplane is pitched or banks about its lateral or longitudinal axis, indicating the attitude of the airplane relative to the true horizon.

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 carburetor systems are generally more susceptible to icing than fuel-injection engines due to the cooling effect resulting from fuel vaporization and a decrease in air pressure at the venturi in a carburetor. When there is high humidity and the temperature is between 20˚ F and 70˚ F, there is a high potential for carburetor icing particularly at low power settings.

A turn coordinator provides an indication of the...

movement of the aircraft about the yaw and roll axes (vertical and longitudinal axes, respectively).

An aircraft which is equipped with an Electronic Flight Display (EFD) can...

offer new capabilities and simplify the basic flying task. EFDs offer enhanced situational awareness and simplify basic flying tasks, such as traditional cross-country flight planning and fuel management.

To receive accurate indications during flight from a heading indicator, the instrument must be...

periodically realigned with the magnetic compass as the gyro precesses. Friction is a major cause of it drifting from the correct heading.

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

pre-ignition. Definition: the ignition of the fuel prior to normal ignition or ignition before the electrical arcing occurs at the spark plug. It may be caused by excessively hot exhaust valves, carbon particles, or spark plugs and electrodes heated to an incandescent state. These hot spots are usually caused by high temperatures encountered during detonation. If the conditions for detonation exist in one cylinder, they usually exist in all cylinders, but pre-ignition often takes place in only one or two cylinders.

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

prevent moisture condensation by eliminating airspace in the tanks. Humid air may result in condensation at night when the airplane cools.

A positive indication on an ammeter...

shows the rate of charge on the battery.

In the Northern Hemisphere, the magnetic compass will normally indicate a turn toward the South when...

the aircraft is decelerated while on an East or West heading.

For internal cooling, air cooled engines are especially dependent on...

the circulation of lubricating oil. An engine accomplishes much of its cooling by the flow of oil through the lubrication system. The lubrication system aids in cooling by reducing friction and absorbing heat from internal engine parts. Many airplane engines use an oil cooler, a small radiator device that will cool the oil before it is recirculated through the engine.

Detonation may occur at high-power settings when...

the fuel mixture ignites instantaneously instead of burning progressively and evenly.

An abnormally high engine oil temperature indication may be caused by...

the oil level being too low. Operating with an excessively low oil level prevents the oil from being cooled adequately, and it won't be able to transfer engine heat to the engine's oil cooler. It could also damage an engine from excessive friction within the cylinders and on other metal-to-metal contact parts.

Detonation occurs in a reciprocating aircraft engine when...

the unburned charge in the cylinders explodes instead of burning normally. This more rapid force slams the piston down instead of pushing it.

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. This can cause engine overheating.

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. Altimeter setting is the value to which the scale of the pressure altimeter is set so that the altimeter indicates true altitude at field elevation.

Fuel/air ratio is the ratio between the...

weight of fuel and weight of air entering the cylinder.