Final Test 1

Question 1

The application of carburettor heat when ice has formed in the carburettor will be accompanied by
[a] an increase in cylinder head temperature and an increase in manifold pressure
[b] an immediate drop in manifold pressure followed by an increase in manifold pressure and a richer
mixture
[c] a rise in cylinder head temperature due to a leaner mixture
[d] an immediate increase in manifold pressure and a rise in cylinder head temperature

Answer 1

B
Because ice takes time to melt, for a few seconds there is ice and hot air in the induction
system . As the ice is melted the manifold pressure will slowly increase, however it will
not return to normal even when all the ice has melted, since the heated air is still present.
When the carby heat is finally returned to “off”, the indications will return to normal.

Question 2

Symptoms of the formation of carburettor ice in an engine fitted with a CSU are
[a] dropping manifold pressure and rising cylinder head temperature
[b] dropping manifold pressure and dropping RPM
[c] dropping manifold pressure and indicated air speed with constant RPM
[d] dropping manifold pressure and increasing fuel flow

Answer 2

C
Fuel must be burnt to produce power. Fuel cannot be burnt without air. Ice restricts the
airflow in the induction system, and so reduces the power available. If power reduces, the
TAS must reduce. The propeller governor however, will move the blades into a finer pitch
setting to preserve the RPM.

Question 3

An engine is overheating during a climb. An appropriate action to remedy the situation would be
[a] open the cowl flaps, richen the mixture and increase the climbing indicated air speed
[b] increase power and adopt a higher indicated air speed
[c] decrease power and indicated air speed and richen the mixture
[d] open the cowl flaps, lean the mixture and increase the climbing indicated air speed

Answer 3

A
A richer mixture reduces the combustion temperatures in the cylinders thus getting
directly to the heart of the problem. Since the engine is aircooled, anything that increases
the airflow will assist cooling.

Question 4

If an engine running with the mixture leaned to peak EGT is richened to full rich
[a] power will increase continuously [b] power will decrease continuously
[c] power will decrease then increase [d] power will increase then decrease

Answer 4

D
Best power occurs between peak and full rich. As mixture is richened, power increases until best power is
achieved, then decreases as the mixture is moved towards full rich. This is true of most GA engines - not all.

Question 5

An engine is running with the mixture fully rich. Progressive leaning to peak EGT will produce
[a] best power first, followed by best economy then peak EGT
[b] best economy first, followed by best power then peak EGT
[c] best power at peak EGT
[d] best economy at peak EGT

Answer 5

A
Full rich provides extra fuel for better engine cooling when high power is used with low speed, such as at take off and max climb. When cooling is not a problem, ie in cruise, best power is obtained at a slightly leaner setting. Best
economy produces less power economy and therefore less TAS, but the lower fuel flow produces better miles per gallon. Further leaning produces peak combustion temperature, even though fuel flow is lower, the decrease in TAS results in a decrease in miles per gallon.

Question 6

A descent from high altitude where the engines have been leaned to peak EGT is made with no adjustment being
made to the mixture. As the descent is continued to sea level
[a] mixture will become too rich due to the increased air density
[b] cylinder head temperature will rise and back firing could occur
[c] the increasing air density will cool the air too rapidly
[d] a leaner mixture will be accompanied by decreasing manifold pressure

Answer 6

B
Descent into denser air causes the mixture to become too lean. Backfiring is a
characteristic of a lean mixture, as is overheating.

Question 7

Operating an engine with too low an oil quantity will produce
[a] rising oil temperature and pressure
[b] falling oil temperature and rising oil pressure
[c] falling oil pressure and falling oil temperature
[d] rising oil temperature and dropping oil pressure

Answer 7

D
One function of oil is to help cool the engine. If there is too little oil, the oil that is there
becomes too hot. Hot oil becomes less viscous and offers less resistance to the oil pump
eventually causing a drop in oil pressure.

Question 8

Vaporising of fuel in the fuel lines can be caused by
[a] high engine temperature and high power [b] excessively lean mixtures
[c] overuse of the boost pump at low engine power [d] using rich mixtures at high altitudes

Answer 8

A
At high power the high demand for fuel requires fuel to be pulled through the fuel lines
more quickly. This increases the likelihood of the fuel breaking down into vapour. If the
fuel is hot, the risk is further increased. Low ambient atmospheric pressure also
contributes.

Question 9

If a heat soaked engine will not start due to fuel vaporisation, an appropriate action would be
[a] crank the engine with mixture lean until it fires
[b] continue cranking the engine with mixture rich and prime pump on
[c] operate the prime pump with the mixture in idle cut off to purge the vapour
[d] wait about 15 minutes then try again with the mixture lean

Answer 9

C
This circulates cool fuel through the system and helps to cool down the fuel lines. Since
the problem is caused by excessive heat, it will help prevent further vaporisation.

Question 10

If an engine begins to run roughly due to vaporisation of fuel during flight the appropriate pilot action would be
[a] operate the boost pump
[b] richen the mixture
[c] check the boost pump is turned off and reduce power
[d] place the mixture in the idle cut off and turn the boost pump on

Answer 10

A
The boost pump assists the engine fuel pump in moving fuel through the lines. This
prevents the fuel from breaking down into vapour.

Question 11

When increasing power on an engine fitted with a CSU it is good practice to
[a] increase RPM before manifold pressure to prevent overboosting
[b] increase manifold pressure before RPM to prevent overboosting
[c] increase manifold pressure and RPM together
[d] increase manifold pressure only as RPM do not affect power

Answer 11

A
When high manifold pressure is combined with low RPM the mass of charge induced can
become excessive. The heat that results from compression of the charge can raise the
temperature of combustion to the point where detonation occurs.

Question 12

Throttle operation during take off with an engine fitted with a supercharger should be
[a] slow opening of the throttle to fully opened position
[b] rapid movement of the throttle to the fully open position
[c] careful operation of the throttle with care not to exceed rated boost
[d] rapid movement to rated boost then slowly to fully open position

Answer 12

C
The high manifold pressure produced with supercharging at low altitude can cause the
mass of charge induced to become excessive.
When high manifold pressure is combined with low RPM the mass of charge induced can
become excessive. The heat that results from compression of the charge can raise the
temperature of combustion to the point where detonation occurs.

Question 13

The purpose of a supercharger fitted to an engine is
[a] to increase power by pumping extra fuel into the cylinders
[b] to increase power by increasing the mass air flow
[c] to increase power by producing an increase in RPM
[d] to increase power by allowing richer mixtures to be used

Answer 13

B
Combustion requires both fuel and air. There is no point introducing more fuel into the
engine if there is not enough air to burn it. Supercharging increases the amount of air
induced to allow more fuel to be burnt thus producing more power.

Question 14

If a centre zero ammeter indicates an unusually high charge rate during flight the cause could be
[a] a faulty battery
[b] the alternator has failed
[c] the electrical system is overloaded
[d] the indication would be normal if all electrical loads are turned on

Answer 14

A
In a healthy electrical system during flight, the battery should be receiving a small current
to maintain its charge. If the battery is not accepting its charge, a higher than normal
charge rate is indicated continuously.

Question 15

Excessive use of the starter motor on an engine which is difficult to start can cause
[a] a burn out of the alternator [b] will damage the battery
[c] can cause damage to the starter motor solenoid [d] overheating of the starter motor

Answer 15

D
The starter motor requires an extremely high current. This causes rapid heating.

Question 16

The use of a lower grade of fuel than specified for an engine can
[a] promote detonation at high power [b] cause lead fouling of the spark plugs
[c] result in an over lean mixture [d] increase the risk of vapour locking

Answer 16

A
A lower grade of fuel has a lower resistance to detonation when subject to the higher
temperatures of a higher compression engine. The octane rating of fuel used should
never be less than specified. Detonation can cause serious engine damage.

Question 17

Battery compartments are vented because
[a] heat from the battery can cause pressure build up in the compartment
[b] the battery needs air to help keep it cool
[c] dangerous gases such as hydrogen are released when the battery is charged
[d] vents allow water to drain away from the battery compartment

Answer 17

C
A battery produces electricity through a chemical reaction. When a battery is being
charged, the chemical reaction is reversed. One of the by-products of this process is
hydrogen - a highly inflammable gas.

Question 18

Fuel tank vents should be inspected before flight because
[a] a blockage in the vent can interrupt the fuel supply to the engine
[b] the vent allows excess fuel to escape if the tank is full
[c] a blocked vent increases the risk in the event of fire
[d] the vent must allow dangerous fumes to escape from the tank

Answer 18

A
If no air can enter the tank to replace the fuel being removed, a vacuum is created which
restricts the flow. In the case of gravity fed systems, this will quickly lead to fuel
starvation. In a pump fed system, structural damage to the tank can occur as well.

Question 19

If the gas pressure is too low in a hydraulic accumulator you would expect
[a] a reduction in system pressure
[b] a reduction in emergency pressure and slower operation of some services
[c] an increased risk of air entering the system
[d] difficulty in using the emergency hand pump

Answer 19

B
The accumulator in a hydraulic system can be likened to a battery in an electrical
system, it provides emergency power and assists the pump to maintain pressure when
system demand is high.

Question 20

The purpose of a shimmy damper is
[a] to prevent the wheels from locking if too much brake is applied
[b] to stop the wheels from rotating after lift off
[c] to absorb undercarriage shocks on rough strips
[d] to prevent nose wheel vibration during ground operation

Answer 20

D
Good old Cessna 152!

Question 21

Unintentional retraction of the undercarriage while on the ground is prevented by
[a] a microswitch on the undercarriage selector [b] a microswitch on the instrument panel
[c] a microswitch on one of the undercarriage legs [d] a microswitch on the throttle linkage

Answer 21

C
This prevents the undercarriage retraction cycle from starting even if the selector is
placed in the “up” position [but don’t count on itl!

Question 22

An aircraft is parked on a strip with the engine stopped. If the elevation of the strip is 2000 ft above mean sea
level, what would the manifold pressure gauge be expected to read?
[a] approximately 30 Hg” [b] approximately 28 Hg”
[c] approximately 10 13 hPa [d] approximately 25 Hg”

Answer 22

B
The standard pressure drop of I hPa for each 30 ft converts to about I Hg” for each
1000ft. When an engine is stopped, the manifold pressure gauge simply reads the
ambient atmospheric pressure.

Question 23

The effect of a blocked static vent during a long climb would be
[a] the airspeed indicator under reading [b] the airspeed indicator over reading
[c] the altimeter under reading [d] the altimeter over reading

Answer 23

A
As the aircraft climbs, the lower ambient air density produces a decreasing total pressure inside the
capsule. This is measured against the higher pressure trapped inside the case. The instrument
indicates a lower reading than it should.
The altimeter simply measures the ambient pressure, compares it with the pressure set on the
subscale and expresses the difference as a height equivalent.

Question 24

An altimeter reads the aircraft’s vertical displacement from
[a] mean sea level in ISA
[b] mean sea level
[c] the ground
[d] that pressure which is selected on the sub scale of the instrument

Answer 24

D
The altimeter simply measures the ambient pressure, compares it with the pressure set
on the subscale and expresses the difference as a height equivalent.

Question 25

Following the toppling of a directional gyro in flight the instrument will [a] remain serviceable but must be reset to the correct heading [b] be unserviceable for the rest of the flight [c] reset itself automatically [d] require servicing after landing

Answer 25

A Typically the card will spin rapidly. Once it is reset, it will be serviceable again.

Question 26

In the southern hemisphere, an aircraft's actual heading will lag behind the compass indication when the aircraft is turning onto [a] north [b] south [c] east [d] west

Answer 26

A The combination of forces that act on a compass during a turn is such that the compass reading runs ahead of the aircraft's true heading when turning onto north in the southern hemisphere. It lags behind the aircraft's true heading when turning onto south. The compass is "NIPPY ON NORTH - SLUGGISH ON SOUTH" The pilot should "OVERSHOOT NORTH -UNDERSHOOT SOUTH"

Question 27

If the outside air temperature is +5'C, and the relative humidity is 60%, which of the situations described below would be most likely to produce carburettor icing? [a] cruising at maximum continuous power [b] climbing at full power [c] cruising at 65% power [d] descending at 35% power

Answer 27

D A partly closed throttle produces a bigger pressure drop across inside the throat of the carburettor. This adds to the cooling effect already present due to the evaporation of fuel and increases the likelihood of ice formation.

Question 28

During a dive, if power is not reduced, constant speed propellers may move onto the [a] fine pitch stops and then slow down [b] fine pitch stops and then overspeed [c] coarse pitch stops and then slow down [d] coarse pitch stops and then overspeed

Answer 28

D As the aircraft dives the propeller governor moves the blades towards coarse pitch to prevent the RPM from increasing. If the speed gets high enough, the propeller hits the coarse pitch stops. From then on it behaves as a fixed pitch propeller and begins to overspeed. [Most aircraft would have reached VNE before this happens].

Question 29

Using fuel of a lower octane rating than is recommended for an engine can result in [a] exhaust valve erosion [b] afterburning [c] backfiring [d] detonation

Answer 29

D Octane rating is a measure of the fuel's ability to tolerate compression without detonating. A low octane fuel in a high compression engine is more likely to detonate.

Question 30

A shimmy damper is a device designed to control vibration of the [a] rudder control surface [b] main wheels during retraction [c] nose wheel [d] elevator control surface

Answer 30

C Common in light training aeroplanes.

Question 31

On a colour coded ASI, the maximum landing gear extended speed [VLE], is [a] marked at the end of a green arc [b] marked at the top of the white arc [c] not marked [d] marked by a radial red line

Answer 31

C It is often found placarded near the landing gear selector lever.

Question 32

The engine operating conditions most likely to produce fouling of the spark plugs are [a] high power and lean mixture [b] high power and rich mixture [c] low power and lean mixture [d] low power and rich mixture

Answer 32

D Low combustion temperatures allow oil to accumulate on the plug gaps without burning.

Question 33

With regard to CHT and EGT gauges, which of the following is true [a] CHT gauges react more quickly to sudden combustion temperature changes [b] EGT gauges and CHT gauges do not register sudden temperature changes [c] both gauges register sudden changes in combustion temperature [d] EGT gauges register sudden changes in combustion temperature more quickly than CHT gauges

Answer 33

D Large bodies of metal such as cylinders cannot suddenly change temperature.

Question 34

In the southern hemisphere the heading indicated by a direct reading magnetic compass will lead an aeroplane's actual heading when turning onto [a] east [b] south [c] north [d] west

Answer 34

C The compass is 'nippy on north'.

Question 35

During a climb a high cylinder head temperature can be reduced by [a] leaning the mixture [b] increasing the IAS [c] closing the cowl flaps [d] decreasing the IAS

Answer 35

B Since the engine is aircooled, an increase in airspeed across it assists in cooling.

Question 36

The function of a pressure relief valve [PRV] in a hydraulic system is to: [a] maintain a constant pressure in the hydraulic accumulator [b] prevent the system pressure from falling below a pre-set minimum value [c] prevent a build up of pressure in the system should the pressure regulator fail [d] regulate the pressure in the system during normal operation.

Answer 36

C It is the pressure regulator that normally maintains the pressure in the system. The pressure relief valve is a stand-by in case the regulator ever fails. Regulator failure could cause the system pressure to rise to a dangerous level with the risk of failing leads. Also the pump would be operating under an unnecessarily high back pressure. The PRV is set to a higher pressure than the normal regulator, and normally is inoperative.