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Canada IATRA practice questions

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Question 1Aeroplane systems and performance

In a normally aspirated piston engine, what happens to manifold pressure as the throttle is opened with the engine running at a constant rpm?

  1. Manifold pressure stays the same regardless of throttle position
  2. Manifold pressure decreases toward idle vacuum
  3. Manifold pressure increases toward ambient pressure Correct answer.
  4. Manifold pressure falls below ambient as altitude increases

Explanation

Manifold pressure measures the absolute pressure in the intake system downstream of the throttle. Closing the throttle creates a partial vacuum, so opening it lets the pressure rise toward the ambient value. At full throttle the gauge reads close to ambient pressure for a normally aspirated engine.

Question 2Aeroplane systems and performance

What is the primary purpose of the carburettor heat control in an aircraft piston engine?

  1. To cool the induction air during long climbs
  2. To prevent or clear ice forming in the carburettor venturi and throttle area Correct answer.
  3. To lean the mixture at high altitude airfields
  4. To increase manifold pressure at full throttle

Explanation

Fuel vaporisation and venturi pressure drop cool the induction air, allowing ice to form even at moderate outside temperatures. Carburettor heat routes warmed air from around the exhaust or oil cooler into the induction system to melt or prevent that ice. It is an anti-icing and de-icing control, not a mixture or power control.

Question 3Aeroplane systems and performance

During a magneto check at run-up, selecting the left magneto causes a drop of 150 rpm and selecting the right causes a drop of 175 rpm, both within limits. What does this indicate?

  1. Both magneto circuits are functioning normally Correct answer.
  2. The left magneto is faulty because its drop is smaller
  3. The engine is running too lean for the run-up
  4. The right magneto is faulty because its drop is larger

Explanation

A normal magneto check shows a small, similar rpm drop on each magneto because each is firing its own spark plugs. Drops within the manufacturer's limit and roughly comparable between sides indicate both circuits are working. A dead magneto would show a large drop or no drop at all.

Question 4Aeroplane systems and performance

What is the effect of a constant-speed propeller governor when the pilot selects a higher rpm setting?

  1. The governor increases oil pressure to the propeller hub to decrease blade angle Correct answer.
  2. The governor feathers the blades to reduce drag
  3. The governor closes the throttle valve to limit power
  4. The governor decreases oil pressure to the hub to increase blade angle

Explanation

In most light aircraft constant-speed systems, governor oil pressure acts to drive the blades toward fine pitch, which increases rpm. Selecting a higher rpm setting raises the governor's speed reference, so it admits more oil to the hub and reduces blade angle until the target rpm is reached. Feathering and throttle control are separate functions.

Question 5Aeroplane systems and performance

Compared with a lower altitude, what happens to true airspeed for a given indicated airspeed as altitude increases?

  1. True airspeed increases because air density decreases Correct answer.
  2. True airspeed remains the same because the pitot-static system is altitude-compensated
  3. True airspeed increases because the speed of sound increases
  4. True airspeed decreases because air density decreases

Explanation

The airspeed indicator responds to dynamic pressure, which depends on density as well as velocity. At higher altitude the same true speed produces less dynamic pressure, so the indicator under-reads relative to true airspeed. Roughly, true airspeed increases about two percent per thousand feet for a fixed indication.

Question 6Aeroplane systems and performance

An aircraft has a maximum certificated takeoff weight of 2300 lb and an empty weight of 1450 lb. With full fuel of 240 lb, what payload remains available for occupants and baggage?

  1. 850 lb
  2. 610 lb Correct answer.
  3. 370 lb
  4. 1090 lb

Explanation

Subtract empty weight and fuel from maximum takeoff weight: 2300 minus 1450 equals 850 lb, and 850 minus 240 equals 610 lb. This is the weight remaining for crew, passengers, and baggage. Exceeding it would place the aircraft over its certificated maximum weight.

Question 7Aeroplane systems and performance

If an aircraft is loaded so that its centre of gravity is forward of the forward limit, what handling characteristic is most likely?

  1. Shorter takeoff distance and lighter control forces
  2. Increased elevator forces and a longer takeoff distance Correct answer.
  3. Reduced longitudinal stability and a tendency to stall abruptly
  4. Increased tendency to enter a spin

Explanation

A forward centre of gravity increases the nose-down moment that the tailplane must counter, so more up-elevator force is needed. This lengthens the takeoff run and raises stick forces, and may limit rotation at low speeds. Stability generally increases, but control authority and performance suffer.

Question 8Aeroplane systems and performance

What is the function of the alternate static source in a light aircraft pitot-static system?

  1. It provides a backup source of pitot pressure if the pitot tube ices over
  2. It automatically corrects airspeed indications for altitude
  3. It supplies vacuum pressure to the gyroscopic instruments
  4. It supplies static pressure from the cabin when the external static port is blocked Correct answer.

Explanation

A blocked static port freezes the altimeter, airspeed indicator, and vertical speed indicator at misleading values. The alternate static source draws pressure from inside the cabin so those instruments can still give usable information. Cabin pressure is usually slightly lower than ambient, so the readings carry a small error.

Question 9Aeroplane systems and performance

An aircraft stalls at an indicated airspeed of 45 knots in level flight at 1 g. Approximately what is the stall speed in a level 60-degree banked turn?

  1. About 55 knots
  2. About 64 knots Correct answer.
  3. About 90 knots
  4. About 45 knots

Explanation

In a 60-degree bank the load factor is 1 divided by cosine 60 degrees, which equals 2. Stall speed rises with the square root of the load factor, so 45 knots multiplied by about 1.41 gives roughly 64 knots. The wing reaches its critical angle of attack at a higher speed because it must produce twice the lift.

Question 10Aeroplane systems and performance

What is the primary hazard of operating an engine at high manifold pressure with low rpm, sometimes called overboosting?

  1. Excessive oil temperature caused by high rpm
  2. Detonation caused by an over-rich mixture
  3. Carburettor icing caused by low manifold pressure
  4. Excessive cylinder pressures that can damage the engine Correct answer.

Explanation

High manifold pressure with low rpm produces very high peak cylinder pressures because the charge is compressed and burns against a slowly moving piston. This can cause detonation and mechanical damage. Pilots avoid it by keeping manifold pressure within the charted limits for each rpm.

Question 11Aeroplane systems and performance

In a turbocharged engine, what limits the maximum manifold pressure at high altitude compared with a normally aspirated engine?

  1. The absence of a mixture control
  2. The fixed size of the throttle butterfly
  3. The carburettor venturi diameter
  4. A wastegate or overboost valve that regulates turbine output Correct answer.

Explanation

A turbocharger compresses induction air using exhaust energy, so without a limit it could raise manifold pressure beyond the engine's structural limits. A wastegate bypasses exhaust gas around the turbine, and an overboost valve provides a safety limit. This regulation allows rated power to be held to higher altitudes.

Question 12Aeroplane systems and performance

What does the best-glide speed represent for a light aeroplane?

  1. The speed giving the minimum rate of descent
  2. The speed giving the maximum endurance in the air
  3. The speed giving the greatest horizontal distance per unit of altitude lost Correct answer.
  4. The speed giving the lowest stalling margin

Explanation

Best glide is the speed at which the ratio of lift to drag is greatest, so the aircraft covers the most ground for each foot of altitude lost. It differs from minimum-sink speed, which maximises time aloft rather than distance. Best glide is normally published for maximum weight and must be adjusted for other weights.

Question 13Aeroplane systems and performance

An aircraft's published takeoff distance over a 50-foot obstacle is 1500 feet at sea level and 2500 feet at 5000 feet pressure altitude, all other factors equal. What does this show about the effect of altitude?

  1. Takeoff distance is unaffected by altitude when weight is constant
  2. Takeoff distance decreases because the air is thinner
  3. Takeoff distance increases substantially as density altitude rises Correct answer.
  4. Takeoff distance increases only because of the obstacle height

Explanation

Thinner air reduces both engine power and propeller thrust, and it requires a higher true airspeed for the same lift. The result is a longer ground roll and a shallower initial climb, so the total distance to clear an obstacle grows. The figures show roughly a 67 percent increase over 5000 feet.

Question 14Aeroplane systems and performance

What is the significance of the maximum structural cruising speed, Vno, on an airspeed indicator?

  1. Above this speed the aircraft should only be flown in smooth air Correct answer.
  2. It is the speed at which flaps may be fully extended
  3. It is the speed at which the landing gear may be retracted
  4. It is the never-exceed speed for all operations

Explanation

Vno marks the top of the normal operating range, shown by the upper limit of the green arc. Above it, up to the never-exceed speed, the aircraft is permitted only in smooth air and with caution because gust loads can overstress the structure. The yellow arc indicates that cautionary range.

Question 15Aeroplane systems and performance

Why does an aircraft's landing ground roll increase when landing with a tailwind compared with the same approach into a headwind?

  1. The groundspeed at touchdown is higher for the same airspeed Correct answer.
  2. The brakes become less effective with a tailwind
  3. The indicated airspeed is lower for the same approach
  4. The wing generates less lift in a tailwind

Explanation

The aircraft flies at a given airspeed, so a tailwind adds to the groundspeed at touchdown. The aircraft must therefore dissipate more kinetic energy during the landing roll, lengthening the distance required. Headwind components have the opposite, beneficial effect.

Question 16Aeroplane systems and performance

What is the purpose of the mixture control in a piston engine at high-altitude cruise?

  1. To reduce fuel flow as air density falls so the fuel-air ratio stays correct Correct answer.
  2. To prime the engine before start
  3. To increase fuel flow to cool the engine during climb
  4. To control manifold pressure independently of the throttle

Explanation

As altitude increases, air density falls, so a fixed fuel metering setting would produce an increasingly rich mixture. Leaning restores the correct fuel-air ratio, improving power, economy, and plug life. The mixture control adjusts fuel flow relative to the air entering the engine.

Question 17Aeroplane systems and performance

During a climb at a constant indicated airspeed, why does the true airspeed increase as altitude rises?

  1. The angle of attack must increase to maintain the climb
  2. The pitot tube heats up and reads higher
  3. Air density decreases, so a higher true speed is needed to produce the same dynamic pressure Correct answer.
  4. Engine power increases with altitude, accelerating the aircraft

Explanation

Indicated airspeed reflects dynamic pressure, which equals one-half density times velocity squared. As density drops with altitude, velocity must rise to keep the same dynamic pressure and thus the same indicated airspeed. This is why true airspeed and groundspeed climb steadily during a constant-indicated-airspeed ascent.

Question 18Aeroplane systems and performance

What is the function of the voltage regulator in an aircraft electrical system?

  1. It converts alternating current to direct current
  2. It controls generator or alternator output to a steady voltage Correct answer.
  3. It limits the current drawn by the starter motor
  4. It protects the battery from over-discharge on the ground

Explanation

The voltage regulator modulates the field current of the generator or alternator so that system voltage stays within a narrow band regardless of load or rpm. This protects avionics and the battery from over-voltage. Current-limiting and reverse-current protection are related but separate functions.

Question 19Aeroplane systems and performance

An aircraft alternator fails in flight and the ammeter shows a discharge. Which action best conserves electrical power?

  1. Select the battery master off and continue the flight
  2. Reset the alternator field breaker repeatedly in flight
  3. Turn off non-essential electrical equipment and land as soon as practicable Correct answer.
  4. Increase engine rpm to full power to restore the alternator

Explanation

With the alternator offline, the battery is the only source and its endurance is limited. Shedding non-essential loads extends that endurance and preserves power for essential equipment and radio calls. The pilot should plan to land before the battery is depleted.

Question 20Aeroplane systems and performance

What is indicated by the yellow arc on a light aircraft's airspeed indicator?

  1. The normal operating range
  2. The flap operating range
  3. The caution range in which the aircraft should be flown only in smooth air Correct answer.
  4. The range in which the landing gear may be extended

Explanation

The yellow arc lies between the maximum structural cruising speed and the never-exceed speed. Flight in this range is permitted only in smooth air, because gusts can impose loads that approach the design limits. The green arc marks normal operations and the white arc marks the flap range.

Question 21Aeroplane systems and performance

An aircraft is loaded with its centre of gravity at the aft limit. How does this affect stall recovery?

  1. The stall speed will be significantly higher
  2. The aircraft will recover more readily because the nose drops faster
  3. The aircraft may be harder to recover from a stall and spin Correct answer.
  4. The aircraft will require more back pressure to raise the nose

Explanation

An aft centre of gravity reduces longitudinal static stability and can allow a wing to remain stalled with little natural nose-down tendency. Recovery from a stall or spin may then require more positive and prompt control input. Forward loading gives the opposite characteristic.

Question 22Aeroplane systems and performance

Why is the landing distance chart normally based on a specified approach speed and configuration?

  1. Because deviations from the reference speed or flap setting change the touchdown energy and braking distance Correct answer.
  2. Because the chart assumes maximum braking on a dry runway only
  3. Because the aircraft weight is fixed for all landings
  4. Because the chart already includes the effect of any wind

Explanation

Published landing distances are computed for a defined approach speed, flap setting, and braking action. Carrying extra speed or less flap increases the energy that must be dissipated after touchdown and lengthens the roll. Pilots should add a margin when conditions differ from the reference case.

Question 23Aeroplane systems and performance

What is the primary purpose of the cylinder head temperature gauge in an air-cooled engine?

  1. To warn of overheating that could lead to detonation or engine damage Correct answer.
  2. To indicate the oil pressure available to the bearings
  3. To show the manifold pressure in the induction system
  4. To measure the exhaust gas temperature for leaning

Explanation

Air-cooled cylinders depend on airflow for cooling, and excessive head temperature can cause detonation, pre-ignition, and warped or cracked components. The gauge lets the pilot adjust mixture, power, and climb attitude to keep temperatures within limits. Exhaust gas temperature is a separate gauge used for leaning.

Question 24Aeroplane systems and performance

A pilot notes that the altimeter reads 4500 feet while the subscale is set to the local altimeter setting, but the aircraft is actually at 4700 feet pressure altitude. What is the most likely cause?

  1. The airspeed indicator is reading too high
  2. The subscale was set to a value different from the current local setting Correct answer.
  3. The vertical speed indicator is faulty
  4. The static port is completely blocked

Explanation

The altimeter converts static pressure into altitude using the reference pressure set in the Kollsman window. If the subscale is not set to the current local altimeter setting, the indicated altitude will differ from the true altitude by a predictable amount. A blocked static port would freeze the indication rather than shift it by a fixed offset.

Question 25Aeroplane systems and performance

What is the effect of extending flaps on the stall speed and on the approach path angle for a given airspeed?

  1. Stall speed decreases and the approach path becomes steeper Correct answer.
  2. Stall speed increases and the approach path becomes shallower
  3. Stall speed is unchanged and the approach path is unchanged
  4. Stall speed decreases and the approach path becomes shallower

Explanation

Flaps increase camber and lift coefficient, which lowers the stall speed and allows a slower approach. They also add drag, so for a given airspeed the aircraft descends more steeply. This combination is why flaps are used for landing.

Question 26Aeroplane systems and performance

Which instrument in a light aircraft is driven directly by the engine through a mechanical tachometer cable in many older designs?

  1. The vertical speed indicator
  2. The airspeed indicator
  3. The engine rpm indicator Correct answer.
  4. The fuel pressure gauge

Explanation

The tachometer displays engine crankshaft speed, and in many older light aircraft it is driven by a mechanical cable from the engine accessory case. Other engine gauges such as fuel pressure are usually electrical or direct-pressure instruments.

Question 27Aeroplane systems and performance

What is the purpose of the carburettor heat control in a float-type carburettor engine?

  1. To enrich the mixture during climb
  2. To increase manifold pressure on takeoff
  3. To supply warmed air to the carburettor to prevent or clear ice Correct answer.
  4. To cool the induction air in hot weather

Explanation

Carburettor heat routes air through a shroud around the exhaust or a heat muff, warming the induction air. This melts or prevents ice in the venturi and throttle area. It also enriches the mixture slightly because warm air is less dense.

Question 28Aeroplane systems and performance

In a light aircraft electrical system, what is the function of the master switch?

  1. It connects and disconnects the battery and alternator from the main bus Correct answer.
  2. It selects which magneto fires during start
  3. It regulates fuel flow to the engine
  4. It controls the pitch of the propeller

Explanation

The master switch is the main contactor control that ties the battery and the alternator/generator feed to the electrical bus. Turning it off isolates the electrical system from its sources. Magneto and fuel systems are controlled separately.

Question 29Aeroplane systems and performance

What does the green arc on a light aircraft airspeed indicator represent?

  1. The flap operating range
  2. The never-exceed speed
  3. The caution range
  4. The normal operating range Correct answer.

Explanation

The green arc marks the normal operating speed range, from the power-off stall speed to the maximum structural cruising speed. Flight within this band is approved for normal operations.

Question 30Aeroplane systems and performance

Which of the following best describes the purpose of the fuel selector valve in a light twin-engine aircraft?

  1. It allows the pilot to draw fuel from and shut off any selected tank Correct answer.
  2. It pumps fuel from the tip tanks
  3. It meters fuel into the carburettor
  4. It automatically balances fuel between tanks

Explanation

The fuel selector lets the pilot choose which tank feeds the engine and provides an OFF position for shutting off fuel. This gives control over fuel management and a means of stopping fuel flow in an emergency.

Question 31Aeroplane systems and performance

What happens to the indicated airspeed reading if the pitot tube becomes blocked while the static port remains clear?

  1. It reads the true airspeed accurately
  2. It reads consistently low by a fixed amount
  3. It behaves like an altimeter, rising in a climb and falling in a descent Correct answer.
  4. It reads zero immediately

Explanation

With the pitot blocked, pressure trapped in the pitot line stays constant while static pressure changes with altitude. In a climb the static pressure falls, so the indicated airspeed rises; in a descent it falls.

Question 32Aeroplane systems and performance

Why does an aircraft's service ceiling occur where the maximum rate of climb has fallen to a low value such as 100 feet per minute?

  1. Because thrust or power available decreases with altitude while power required for a given climb remains similar Correct answer.
  2. Because the fuel flow becomes excessive
  3. Because the wing reaches its critical angle of attack
  4. Because the propeller reaches supersonic tip speed

Explanation

As altitude increases, engine power available generally decreases while the power required to climb at a given speed stays roughly similar. The excess power shrinks, so the achievable rate of climb falls until it reaches the defined low value.

Question 33Aeroplane systems and performance

An aircraft has a published landing distance of 1200 feet at 2000 lb and 1500 feet at 2300 lb under the same conditions. What does this illustrate?

  1. Landing distance is independent of weight
  2. Landing distance decreases with increased weight
  3. Landing distance increases with increased landing weight Correct answer.
  4. Landing distance depends only on runway slope

Explanation

A heavier aircraft must be flown faster to generate the same lift, so it touches down at higher speed and carries more kinetic energy to dissipate. Both effects lengthen the landing roll and total distance.

Question 34Aeroplane systems and performance

What is the effect of density altitude on engine power output for a normally aspirated piston engine?

  1. Power decreases as density altitude increases Correct answer.
  2. Power remains constant regardless of density altitude
  3. Power is affected only by fuel octane rating
  4. Power increases as density altitude increases

Explanation

A normally aspirated engine takes in a fixed volume of air per cycle, so the mass of air inducted falls as air density decreases with altitude or heat. Less air mass means less fuel can be burned and less power produced.

Question 35Aeroplane systems and performance

What is the purpose of the propeller governor in a constant-speed propeller system?

  1. It sets the ignition timing
  2. It limits the maximum manifold pressure
  3. It regulates oil flow to the propeller hub to maintain a selected rpm Correct answer.
  4. It controls the mixture entering the cylinders

Explanation

The governor senses engine rpm and adjusts oil pressure to the propeller hub to change blade angle. This keeps the selected rpm constant as load or airspeed changes. Mixture and ignition are separate systems.

Question 36Aeroplane systems and performance

Why does a turbocharged engine require careful monitoring of turbine inlet temperature?

  1. Low temperature causes detonation
  2. High temperature indicates low oil pressure
  3. High temperature always means a rich mixture
  4. Excessive temperature can damage the turbine and exhaust components Correct answer.

Explanation

Turbine inlet temperature reflects the heat load on the turbocharger and exhaust valves. Exceeding limits can crack or warp these components, so the pilot manages mixture and power to stay within limits.

Question 37Aeroplane systems and performance

What is the primary function of the aircraft's static wick dischargers?

  1. To measure static pressure for the altimeter
  2. To bleed static electricity from the airframe into the atmosphere Correct answer.
  3. To reduce drag on the wingtips
  4. To provide a backup static source

Explanation

Static dischargers, or wicks, provide a path for accumulated static charge to leave the airframe gradually. This reduces radio interference caused by corona discharge. They do not affect pitot-static pressure measurement.

Question 38Aeroplane systems and performance

An aircraft is cruising at 8000 feet with the mixture leaned for best power. The pilot enriches the mixture without changing throttle or rpm. What immediate effect occurs?

  1. Fuel flow decreases
  2. Cylinder head temperature increases sharply
  3. Engine rpm rises significantly in a fixed-pitch installation
  4. Cylinder head temperature decreases and power may decrease slightly Correct answer.

Explanation

Enriching the mixture adds fuel, which cools combustion and lowers cylinder head temperature. Because the mixture moves away from best power, power typically decreases slightly and fuel flow increases.

Question 39Aeroplane systems and performance

What is the effect of a headwind on the takeoff ground roll compared with still air?

  1. The ground roll is longer because the aircraft accelerates more slowly
  2. The ground roll is unchanged because airspeed determines lift
  3. The ground roll is shorter because the aircraft reaches flying speed at a lower groundspeed Correct answer.
  4. The ground roll is shorter only if flaps are retracted

Explanation

A headwind gives the aircraft airspeed before it has gained groundspeed, so it reaches flying speed after covering less ground. The air distance to the obstacle is less affected, but the ground roll shortens.

Question 40Aeroplane systems and performance

Why is the use of full carburettor heat on takeoff generally avoided?

  1. It causes the engine to run too lean
  2. It reduces available power because warmed air is less dense Correct answer.
  3. It increases the risk of carburettor icing
  4. It raises manifold pressure beyond limits

Explanation

Carburettor heat lowers the density of the induction air, reducing the mass of air and therefore the power the engine can produce. For takeoff, full power is needed, so heat is normally selected off unless ice is suspected.

Question 41Aeroplane systems and performance

What does the maximum landing weight limitation primarily protect?

  1. The airframe and landing gear from excessive loads at touchdown Correct answer.
  2. The engine from overboosting on approach
  3. The propeller from exceeding its rpm limit
  4. The fuel tanks from overfilling

Explanation

Landing weight limits are set by the structural loads imposed on the landing gear and airframe at touchdown. Exceeding them reduces the margin against structural damage.

Question 42Aeroplane systems and performance

An aircraft's centre of gravity is at the forward limit. How does this affect the elevator force needed to flare for landing?

  1. The flare requires no elevator input
  2. Less aft elevator force is required, making the flare easy
  3. The aircraft tends to pitch up strongly on flare
  4. More aft elevator force is required, increasing the risk of a nose-down arrival Correct answer.

Explanation

A forward centre of gravity increases the nose-down moment that the tail must counter. The pilot needs more aft elevator authority and force to raise the nose for the flare, and the margin may be limited.

Question 43Aeroplane systems and performance

Why does the maximum range cruise speed differ from the maximum endurance speed for a piston-engine aircraft?

  1. The two speeds are always identical for piston aircraft
  2. Maximum range occurs at the lowest possible airspeed
  3. Maximum range accounts for speed as well as fuel flow, while maximum endurance minimises fuel flow per hour Correct answer.
  4. Endurance is maximised at the highest safe airspeed

Explanation

Endurance is greatest where fuel flow per hour is least, which occurs at low power settings. Range depends on fuel flow per unit distance, so a higher speed improves distance covered per unit of fuel and gives a different optimum speed.

Question 44Aeroplane systems and performance

During a constant-speed propeller run-up, the pilot cycles the propeller control and observes no change in rpm. Which interpretation is most appropriate?

  1. The tachometer is definitely accurate
  2. The engine is producing too much power
  3. The propeller governor or control linkage may be faulty and the aircraft should not be flown Correct answer.
  4. The propeller is operating normally

Explanation

Cycling the propeller control should produce a noticeable rpm change as blade angle changes. No response suggests a governor or linkage fault, which could prevent the propeller from governing properly in flight, so the aircraft should be grounded for maintenance.

Question 45Aeroplane systems and performance

Why does a rapid throttle opening on a float-type carburettor engine risk a temporary lean condition or stumble?

  1. The fuel pump pressure rises instantly
  2. Fuel is heavier than air and lags behind the sudden increase in airflow Correct answer.
  3. The carburettor heat valve opens automatically
  4. The mixture control moves toward rich

Explanation

When the throttle opens quickly, airflow into the engine increases almost immediately, but fuel must be accelerated and vaporised. The brief lag leaves a temporarily lean mixture until fuel flow catches up, causing a stumble.

Question 46Aeroplane systems and performance

What is the significance of the manoeuvring speed, Va, in structural terms?

  1. At or below it, full control deflection will stall the wing before overstressing the airframe Correct answer.
  2. It is the speed for best angle of climb
  3. Above it, the aircraft can be manoeuvred at any speed without structural risk
  4. It is the speed at which flaps must be retracted

Explanation

Va is the speed at which the wing reaches its stalling angle of attack at the limit load factor. At or below Va, full abrupt control input stalls the wing before the structure is overstressed, so severe turbulence is best handled near this speed.

Question 47Aeroplane systems and performance

What is the purpose of the fuel boost pump in a light twin-engine aircraft?

  1. To provide positive fuel pressure for starting and as a backup if the engine-driven pump fails Correct answer.
  2. To transfer fuel between wing tanks automatically
  3. To increase the octane rating of the fuel
  4. To cool the fuel before it reaches the carburettor

Explanation

The boost pump supplies fuel pressure during engine start and provides redundancy if the engine-driven pump fails. It is typically used for takeoff and landing and in some cross-feed situations.

Question 48Aeroplane systems and performance

What does the exhaust gas temperature gauge primarily help the pilot do?

  1. Measure cylinder head temperature directly
  2. Monitor oil pressure
  3. Set the mixture for a desired operating condition Correct answer.
  4. Indicate manifold pressure

Explanation

Exhaust gas temperature peaks near the stoichiometric mixture ratio, so pilots use it to lean to a chosen point relative to peak. This helps achieve best power or best economy while respecting engine limits.

Question 49Aeroplane systems and performance

Why does an aircraft require a longer takeoff distance on a grass runway than on a paved runway of the same length and slope?

  1. The wings generate less lift over grass
  2. The air is denser over grass
  3. Rolling friction and surface resistance are higher on grass Correct answer.
  4. The engine produces less power on grass

Explanation

Grass increases rolling resistance and reduces acceleration, so more runway is needed to reach flying speed. The published performance figures are normally for paved surfaces and must be adjusted for soft or grassy conditions.

Question 50Aeroplane systems and performance

A pilot flying at 10 000 feet notices the manifold pressure gauge reads lower than the throttle position suggests. Which factor most directly explains this on a normally aspirated engine?

  1. The throttle valve is stuck closed
  2. The fuel mixture is too lean
  3. Ambient pressure is lower at altitude, so full throttle yields less manifold pressure Correct answer.
  4. The magnetos are misfiring

Explanation

Manifold pressure reflects the absolute pressure in the induction system, which is limited by ambient pressure. At altitude, ambient pressure is lower, so even wide-open throttle cannot produce sea-level manifold pressure.