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CARC PPL Theory study materials
CARC PPL Theory study resources

CARC PPL Theory practice questions

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Question 1Air Law and ATC Procedures

Under the CARC rules of the air, which minimum flight visibility applies to a VFR flight at and above 3 050 m (10 000 ft) AMSL in airspace classes C to G?

  1. 5 km
  2. 8 km Correct answer.
  3. 1.5 km
  4. 3 km

Explanation

At and above 3 050 m AMSL the VFR visibility minimum is 8 km, and the aircraft must also remain clear of cloud with the prescribed horizontal and vertical distance. Below that level the minimum drops to 5 km. Both figures assume the flight is not in a control zone where a special VFR clearance has been issued.

Question 2Air Law and ATC Procedures

In which airspace class may a VFR flight be conducted without a clearance, while still requiring the pilot to maintain two-way radio contact and comply with ATC instructions?

  1. Class C
  2. Class D Correct answer.
  3. Class A
  4. Class F

Explanation

Class D is controlled airspace in which IFR and VFR flights both receive a clearance, but the defining feature here is that VFR traffic is separated from IFR traffic only by ATC traffic information, not full separation. All flights must establish two-way radio communication before entering and follow ATC instructions. Class C requires a clearance and provides separation between VFR and IFR.

Question 3Air Law and ATC Procedures

What does a steady red light signal directed at an aircraft on the ground mean?

  1. Stop Correct answer.
  2. Return to starting point on the aerodrome
  3. Cleared for take-off
  4. Cleared to taxi

Explanation

A steady red light shown to an aircraft on the ground means stop. The signal is used by the aerodrome control tower when taxiing or movement must be halted immediately. A flashing red light on the ground has a different meaning, namely taxi clear of the landing area.

Question 4Air Law and ATC Procedures

An aircraft is on final approach and receives a series of red flashes from the precision approach path indicator. What does this indicate?

  1. The approach path indicator is unserviceable
  2. The aircraft is significantly above the correct approach path
  3. The aircraft is on the correct approach path
  4. The aircraft is significantly below the correct approach path Correct answer.

Explanation

A PAPI normally displays four light units; when all four show red the aircraft is well below the glidepath and must correct upwards. Two red and two white indicates on-slope. Three or four white units indicate the aircraft is too high.

Question 5Air Law and ATC Procedures

What is the standard altimeter setting used for flight above the transition altitude in most CARC states?

  1. Standard pressure 1 013.2 hPa Correct answer.
  2. QNE of the nearest reporting station
  3. QNH of the departure aerodrome
  4. QFE of the destination aerodrome

Explanation

Above the transition altitude, altimeters are set to standard pressure 1 013.2 hPa (29.92 inHg), and the resulting altitude is referred to as flight level. Below the transition altitude the local QNH is used so that the altimeter reads elevation above mean sea level. The transition level is the first flight level available above the transition altitude.

Question 6Air Law and ATC Procedures

When must a pilot file a flight plan for a VFR flight within controlled airspace?

  1. Only if the flight crosses an international border
  2. Before departure, so that ATC has the details for the flight Correct answer.
  3. At any time after departure, before entering controlled airspace
  4. Only when the flight exceeds 50 km from the departure aerodrome

Explanation

A flight plan must be submitted before departure for any flight in controlled airspace, so that ATC can coordinate the flight and provide the required services. It also underpins search and rescue alerting. Filing after departure defeats the purpose of pre-flight coordination.

Question 7Air Law and ATC Procedures

What is the minimum horizontal distance a VFR flight must maintain from cloud when flying at or above 3 050 m AMSL?

  1. 1 500 m Correct answer.
  2. 300 m
  3. 5 km
  4. 600 m

Explanation

At and above 3 050 m the VFR cloud clearance requirement is 1 500 m horizontally and 300 m vertically. Below that level the horizontal distance is reduced to 1 500 m as well, but the vertical clearance is 300 m. These figures assume the aircraft is not in a control zone with a special VFR clearance.

Question 8Air Law and ATC Procedures

An aircraft is intercepted by a military aircraft and receives the instruction to follow. What should the pilot do?

  1. Squawk 7700 and turn away from the intercepting aircraft
  2. Immediately descend to the lowest safe altitude and accelerate
  3. Continue on the current flight plan and ignore the intercepting aircraft
  4. Comply with the intercepting aircraft's instructions and attempt to establish radio contact on the emergency frequency Correct answer.

Explanation

The standard intercept procedure requires the intercepted aircraft to follow the intercepting aircraft's instructions, attempt radio contact on 121.5 MHz, and squawk 7700 if no communication is established. The intercepting crew will then guide the aircraft to a suitable aerodrome. Deviating from the instructions can endanger both aircraft.

Question 9Air Law and ATC Procedures

What does an SSR code of 7600 indicate?

  1. Radio communication failure Correct answer.
  2. Emergency
  3. Aircraft in distress
  4. Unlawful interference

Explanation

The special SSR codes are 7500 for unlawful interference, 7600 for radio communication failure, and 7700 for emergency. Setting 7600 alerts ATC that the aircraft cannot communicate normally. ATC will then apply the appropriate procedures for a radio failure, including the use of light signals.

Question 10Air Law and ATC Procedures

A pilot flying VFR in Class G airspace at 1 200 ft AMSL encounters deteriorating visibility. What is the most appropriate action under the CARC rules of the air?

  1. Continue at the same altitude because Class G has no visibility requirements
  2. Climb into cloud to reach VMC on top
  3. Turn back or divert to maintain the required VFR visibility and cloud clearance Correct answer.
  4. Squawk 7600 and continue to destination

Explanation

In Class G airspace the VFR minima still apply; the pilot must maintain the prescribed visibility and cloud clearance for the altitude band. If these cannot be maintained, the flight must be changed to remain in VMC, for example by turning back or diverting. Continuing in deteriorating conditions risks loss of visual reference.

Question 11Air Law and ATC Procedures

What is the purpose of a Mandatory Occurrence Report under the CARC occurrence reporting scheme?

  1. To report specified safety-related occurrences to the competent authority for safety analysis Correct answer.
  2. To report only occurrences involving commercial air transport
  3. To report occurrences to the aircraft manufacturer only
  4. To report only accidents that cause injury or damage

Explanation

The mandatory occurrence reporting scheme requires the reporting of specified safety-related occurrences, not just accidents, so that the authority can analyse trends and take preventive action. Reports are made to the competent authority. The scheme is a safety tool and is not limited to commercial operations.

Question 12Air Law and ATC Procedures

When is a pilot required to activate the aircraft's emergency locator transmitter manually?

  1. During every pre-flight inspection
  2. Before every take-off from a controlled aerodrome
  3. After a forced landing or ditching when the automatic activation has not occurred Correct answer.
  4. Whenever the aircraft enters controlled airspace

Explanation

The ELT activates automatically on impact or immersion, but the pilot should activate it manually if the automatic activation has not occurred after a forced landing or ditching. This helps search and rescue locate the aircraft. Routine activation during normal operations is not appropriate.

Question 13Air Law and ATC Procedures

What is the minimum fuel a VFR flight must carry to be able to divert to an alternate aerodrome?

  1. Enough fuel to reach the destination only
  2. Enough fuel for 10 minutes of flight at maximum continuous power
  3. Enough fuel for 45 minutes of holding at 1 500 ft
  4. Enough fuel to reach the destination and then fly for a further 30 minutes at cruising speed Correct answer.

Explanation

For VFR flights the required fuel must cover the flight to the destination plus a reserve of 30 minutes at cruising speed. This reserve allows for a diversion to an alternate aerodrome if landing at the destination is not possible. The reserve is not intended for holding at a fixed altitude.

Question 14Air Law and ATC Procedures

An aircraft is on the ground and receives a flashing green light from the tower. What does this authorise?

  1. Stop
  2. Take-off
  3. Return to the starting point
  4. Taxi Correct answer.

Explanation

A flashing green light to an aircraft on the ground means cleared to taxi. The same signal to an aircraft in flight means cleared to land. A steady green light to an aircraft on the ground means cleared for take-off.

Question 15Air Law and ATC Procedures

What does the abbreviation ATIS stand for in aeronautical communications?

  1. Automatic Terminal Information Service Correct answer.
  2. Automatic Traffic Identification System
  3. Air Traffic Information Service
  4. Aerodrome Traffic Information System

Explanation

ATIS is the Automatic Terminal Information Service, a continuous broadcast of recorded non-control information such as weather, runway in use, and altimeter setting. Pilots normally include the ATIS letter in their first call to the approach or tower frequency. It reduces frequency congestion by removing routine information from voice exchanges.

Question 16Air Law and ATC Procedures

What is the standard phraseology used by a pilot to acknowledge an ATC clearance?

  1. Say only 'Wilco'
  2. Say only 'Roger'
  3. Say nothing and proceed with the clearance
  4. Read back the clearance in full or use the prescribed abbreviated read-back Correct answer.

Explanation

A clearance must be read back in full, or in the prescribed abbreviated form, so that ATC can verify the pilot has understood it correctly. 'Roger' only acknowledges receipt and 'Wilco' only indicates compliance; neither confirms the content. Silence is never an acceptable acknowledgement of a clearance.

Question 17Air Law and ATC Procedures

Under the CARC rules, when may an aircraft be flown at a height below 150 m over a congested area of a city?

  1. Only when flying at night with navigation lights on
  2. Whenever the aircraft is within 5 km of an aerodrome
  3. At any time, provided the pilot maintains 150 m horizontal distance from buildings
  4. Only with the permission of the competent authority and when the flight is necessary for take-off, landing, or a specified purpose Correct answer.

Explanation

Flight over congested areas is restricted to protect people and property on the ground. Below 150 m, flight over a congested area is permitted only with the permission of the competent authority and for specified purposes such as take-off or landing. The horizontal distance from buildings does not by itself authorise low flight.

Question 18Air Law and ATC Procedures

What is the standard minimum vertical separation applied by ATC between IFR flights in controlled airspace above 8 850 m?

  1. 300 m
  2. 150 m
  3. 1 000 m
  4. 600 m Correct answer.

Explanation

Above 8 850 m the standard vertical separation minimum is 600 m (2 000 ft), reflecting the reduced accuracy of altimetry at high altitude. Below that level the standard is 300 m (1 000 ft). Reduced vertical separation minima of 300 m may apply in designated airspace where the required equipment is carried.

Question 19Air Law and ATC Procedures

A pilot wishes to enter a control zone. What is the correct sequence of actions before entry?

  1. Obtain the ATIS, establish two-way radio contact with ATC, and obtain a clearance before entering Correct answer.
  2. Enter the zone first and then call ATC for a clearance
  3. File a flight plan after entering the zone
  4. Call ATC on the emergency frequency and enter without a clearance

Explanation

Entry into a control zone requires a clearance, which must be obtained before crossing the boundary. The pilot should first obtain the ATIS to reduce frequency congestion, then establish two-way radio contact with ATC and request the clearance. Entering first and calling later is a serious infringement.

Question 20Air Law and ATC Procedures

What does a white cross displayed in the aerodrome signal square indicate?

  1. The aerodrome is closed to all traffic
  2. Parachuting is in progress
  3. The runway is unserviceable
  4. Gliding is in progress Correct answer.

Explanation

A white cross in the signal square indicates that gliding is in progress, warning pilots of unpowered traffic in the vicinity. Other signals include a white dumbbell for glider launching, a red square with a diagonal for parachuting, and a horizontal white bar for a closed runway. Pilots should expect gliders and adjust their approach accordingly.

Question 21Air Law and ATC Procedures

An aircraft experiences a radio failure in VMC while in controlled airspace. What is the most appropriate initial action?

  1. Squawk 7500 and continue to destination
  2. Continue in VMC, land at the nearest suitable aerodrome, and report arrival to ATC Correct answer.
  3. Climb into IMC and follow the last assigned route
  4. Descend immediately to 500 ft above ground level

Explanation

In VMC with a radio failure, the pilot should continue visually, land at the nearest suitable aerodrome, and report arrival to ATC as soon as possible. This keeps the aircraft clear of IFR traffic and avoids entering IMC without a clearance. Squawking 7600 and following the published radio failure procedures applies in IMC.

Question 22Air Law and ATC Procedures

An aircraft on an IFR flight in controlled airspace is given a clearance to descend to 3 000 ft. The pilot's altimeter is set to QNH. What does the clearance mean?

  1. The aircraft may descend below 3 000 ft if visual with the ground
  2. The aircraft must not descend below 3 000 ft above mean sea level until further clearance Correct answer.
  3. The aircraft must descend to 3 000 ft above ground level
  4. The aircraft must descend to 3 000 ft above the aerodrome

Explanation

With QNH set, the altimeter reads altitude above mean sea level, so a clearance to 3 000 ft means 3 000 ft AMSL. The pilot must not descend below that level until a further clearance is received. Descending below the cleared level without authorisation is a serious infringement.

Question 23Air Law and ATC Procedures

An aircraft is flying VFR at night in Class G airspace. Which additional requirement applies compared with a daytime VFR flight?

  1. The aircraft must be equipped with the required lighting and the pilot must maintain the night VFR minima Correct answer.
  2. The flight must be conducted under IFR
  3. The pilot must obtain an ATC clearance before departure
  4. No additional requirement applies at night

Explanation

Night VFR requires the aircraft to carry the prescribed lighting and the pilot to comply with the night VFR minima, which differ from the day minima. An IFR clearance is not required in Class G, but the flight must remain in VMC. The additional equipment and visibility requirements reflect the reduced visual cues at night.

Question 24Air Law and ATC Procedures

An aircraft is cleared to land on runway 27. The tower later transmits a steady red light. What does this mean and what should the pilot do?

  1. Give way to other aircraft and continue circling; the landing clearance is cancelled Correct answer.
  2. Land immediately; the red light confirms the clearance
  3. Return to the starting point on the aerodrome
  4. Stop on the runway after landing

Explanation

A steady red light to an aircraft in flight means give way to other aircraft and continue circling. It cancels the landing clearance and requires the pilot to remain clear of the runway. A steady red light to an aircraft on the ground means stop, which is a different situation.

Question 25Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

In a four-stroke reciprocating aircraft engine, which stroke immediately follows the power (combustion) stroke?

  1. The exhaust stroke Correct answer.
  2. The compression stroke
  3. The ignition stroke
  4. The induction stroke

Explanation

The four strokes occur in the fixed order induction, compression, power, exhaust. After the burning mixture has driven the piston down on the power stroke, the exhaust valve opens and the piston rises to expel the gases. The cycle then restarts with induction.

Question 26Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

The purpose of the magneto in a piston aero engine is to:

  1. Regulate the fuel pressure delivered to the carburettor
  2. Provide a self-contained high-tension supply for the spark plugs Correct answer.
  3. Cool the cylinder heads at high power
  4. Drive the propeller reduction gear

Explanation

A magneto is a self-exciting generator that produces the high voltage needed to fire the spark plugs without dependence on the aircraft battery. This independence is why magnetos remain the standard ignition source on light aircraft engines.

Question 27Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

During a magneto check at run-up, selecting one magneto causes a small acceptable RPM drop. What does this drop indicate?

  1. The mixture is far too rich for ground operation
  2. Both magnetos have failed simultaneously
  3. The propeller is out of balance
  4. The engine is now running on one magneto and its associated plugs only Correct answer.

Explanation

When one magneto is grounded out during the check, combustion is sustained only by the plugs fired by the remaining magneto. A modest drop shows that the live magneto and its plugs are working; an excessive drop or rough running suggests a faulty plug or lead.

Question 28Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

A carburettor is fitted to a piston engine. Which condition most strongly favours carburettor icing?

  1. Hot, dry air above 30°C
  2. High humidity with outside air temperature between about -5°C and +15°C Correct answer.
  3. Very cold, dry air well below freezing
  4. High altitude with extremely low humidity

Explanation

Carburettor icing occurs because fuel vaporisation and the venturi pressure drop cool the air further, so ice can form even at outside temperatures well above freezing. High humidity in the moderate temperature band provides both the moisture and the cooling margin for ice to accumulate.

Question 29Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

In a light aircraft electrical system, the function of the voltage regulator is to:

  1. Limit the current in the starter motor circuit
  2. Hold the generator or alternator output within a set range as load and RPM vary Correct answer.
  3. Convert AC to DC for the avionics bus
  4. Prevent the battery from discharging on the ground

Explanation

The voltage regulator controls the field current of the generator or alternator so that system voltage stays within limits regardless of engine RPM or electrical load. Without it, voltage would rise and fall with engine speed and could damage avionics or overcharge the battery.

Question 30Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

What is the primary purpose of the master switch in a light aircraft electrical system?

  1. To connect or isolate the battery and alternator/generator from the main bus Correct answer.
  2. To trim the aircraft about the pitch axis
  3. To open and close the cabin heat valve
  4. To select which fuel tank is feeding the engine

Explanation

The master switch is the main contactor control that connects the battery and the generating source to the electrical bus. Turning it off removes power from most systems and is a key action in electrical fire or smoke drills.

Question 31Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

An aircraft alternator warning light illuminates in flight and the ammeter shows a discharge. What is the most appropriate immediate interpretation?

  1. The battery is fully charged and the system is normal
  2. The fuel pump has failed
  3. The generating source has failed and the battery is supplying the electrical load Correct answer.
  4. The starter motor is still engaged

Explanation

A warning light with a discharge indication means the alternator/generator is no longer supplying the bus, so the battery is carrying the load and will steadily deplete. The pilot should reduce electrical load and plan to land, since electrical power is time-limited.

Question 32Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

The main structural advantage of a semi-monocoque fuselage compared with a pure monocoque design is that:

  1. It allows the skin to be made of fabric
  2. The load is shared between the skin and internal frames and stringers, allowing a lighter structure Correct answer.
  3. It eliminates the need for rivets
  4. It removes the need for any internal structure

Explanation

In semi-monocoque construction, longitudinal stringers and transverse frames stiffen the skin and share the loads, so the skin can be thinner and the structure lighter than a pure monocoque that relies on the skin alone. Pure monocoque is inefficient because the unstiffened skin would need to be thick to resist buckling.

Question 33Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Which control surface is normally used to control the aircraft about its longitudinal axis?

  1. The elevators
  2. The flaps
  3. The ailerons Correct answer.
  4. The rudder

Explanation

The longitudinal axis runs fore and aft through the fuselage, and roll about this axis is controlled by the ailerons. Elevators control pitch about the lateral axis and the rudder controls yaw about the vertical axis.

Question 34Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

A wing spar carries the main bending loads. Which statement best describes the role of the wing ribs?

  1. They provide the hinge for the aileron only
  2. They contain the fuel tanks in all aircraft
  3. They carry all the bending loads to the fuselage
  4. They maintain the aerofoil shape and transfer loads between skin and spars Correct answer.

Explanation

Ribs are transverse members that hold the aerofoil section and support the skin, transferring local air loads to the spars. The spars, not the ribs, are the primary bending members that carry loads inboard to the fuselage.

Question 35Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Why are aircraft fuel tanks in light aircraft normally vented to atmosphere?

  1. To increase the fuel octane rating
  2. To allow water to drain into the tank
  3. To allow fuel to flow to the engine as the tank level falls and to prevent overpressure Correct answer.
  4. To cool the fuel before combustion

Explanation

As fuel is used, the space above it must be replenished with air, otherwise a partial vacuum would form and restrict fuel flow. The vent also prevents excessive pressure build-up as fuel expands with heat, and a blocked vent can cause fuel starvation.

Question 36Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

The fuel selector valve in a light twin-engine aircraft is set to the LEFT tank. What is the primary consequence if the pilot forgets to manage fuel and the left tank runs dry?

  1. Only the left engine will stop
  2. Both engines may stop because both are fed from the selected tank Correct answer.
  3. The aircraft will automatically transfer fuel from right to left
  4. The right engine will automatically switch to the right tank

Explanation

In many light twins both engines draw from the tank chosen on the selector, so running a selected tank dry starves both engines. Fuel management must ensure the selected tank has adequate contents for the phase of flight.

Question 37Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

What is the function of the oil in a piston aero engine?

  1. To increase the compression ratio
  2. To ignite the mixture in the cylinders
  3. To lubricate, cool and help seal and clean internal components Correct answer.
  4. To provide the fuel for combustion

Explanation

Oil forms a film between moving surfaces to reduce friction and wear, carries heat away from bearings and pistons, helps seal the piston rings and suspends contaminants for filtration. It is not consumed as fuel or involved in ignition.

Question 38Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

During a pre-flight check the oil level is at the minimum mark and the dipstick shows milky, emulsified oil. What does the milky appearance most likely indicate?

  1. The oil filter is new
  2. The oil has been overfilled
  3. The oil is at the correct operating temperature
  4. Water contamination, often from condensation, requiring investigation before flight Correct answer.

Explanation

Milky or mayonnaise-like oil indicates water emulsified in the oil, commonly from condensation in a little-used engine or a failed seal. Water reduces lubrication and can cause corrosion, so the cause should be investigated and the oil changed before flight.

Question 39Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

In a constant-speed propeller system, the propeller governor controls blade angle in order to:

  1. Limit the maximum manifold pressure
  2. Control the mixture strength
  3. Keep the propeller at a fixed blade angle at all times
  4. Maintain a selected engine/propeller RPM as load and airspeed change Correct answer.

Explanation

The governor senses RPM and adjusts oil pressure to change blade angle so that the selected RPM is held. If RPM tends to rise, blade angle increases to absorb more power; if it falls, blade angle decreases.

Question 40Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

On take-off in a constant-speed propeller aircraft, the pilot selects full RPM. What does this selection cause?

  1. The blades move to a finer pitch to allow the engine to reach high RPM Correct answer.
  2. The propeller stops rotating
  3. The blades move to a coarse pitch to reduce RPM
  4. The propeller feathers automatically

Explanation

Fine pitch presents less blade area to the airflow, reducing the load on the engine so it can accelerate to high RPM and produce take-off power. Coarse pitch would increase load and reduce RPM, which is used for cruise efficiency.

Question 41Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Which instrument directly indicates the pressure in the engine induction manifold and is used to set power on a constant-speed propeller aircraft?

  1. The manifold pressure gauge Correct answer.
  2. The vertical speed indicator
  3. The oil pressure gauge
  4. The tachometer

Explanation

The manifold pressure gauge shows the absolute pressure in the induction system, which reflects the power being developed at a given RPM. On aircraft with constant-speed propellers, power is set using manifold pressure in combination with RPM.

Question 42Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

An engine has a compression ratio of 8:1. What does this mean?

  1. The engine has eight cylinders
  2. The engine produces eight times the power of a normally aspirated engine
  3. The fuel/air mixture is compressed to eight atmospheres absolute
  4. The cylinder volume with the piston at bottom dead centre is eight times the volume at top dead centre Correct answer.

Explanation

Compression ratio is the ratio of total cylinder volume at bottom dead centre to the clearance volume at top dead centre. A ratio of 8:1 means the charge is squeezed into one eighth of its original volume, raising its pressure and temperature before ignition.

Question 43Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Detonation in a piston aero engine is best described as:

  1. Explosive, uncontrolled burning of the charge after normal ignition, causing a pressure spike and possible damage Correct answer.
  2. Normal progressive flame travel across the combustion chamber
  3. A failure of the oil pump
  4. Pre-ignition caused by a hot spot before the spark

Explanation

Detonation occurs when the unburned charge auto-ignites explosively after the spark, producing very high local pressures and temperatures that can damage pistons and valves. It is distinct from pre-ignition, which is ignition before the spark by a hot spot.

Question 44Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Which action best reduces the risk of detonation during a climb in a high-compression engine?

  1. Lean the mixture aggressively at high power
  2. Use the recommended fuel grade, keep cylinder head temperatures within limits and avoid over-lean mixtures Correct answer.
  3. Select a lower octane fuel to reduce cost
  4. Reduce airspeed to reduce cooling airflow

Explanation

Detonation is promoted by low octane fuel, high cylinder head temperature and over-lean mixtures at high power. Using the correct grade, managing temperatures and avoiding excessive leanness keeps combustion within design limits.

Question 45Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

The purpose of the exhaust system in a piston aero engine is to:

  1. Store fuel for the engine
  2. Provide the electrical ground return
  3. Supply filtered air to the carburettor
  4. Carry combustion gases away from the engine and, in some installations, provide cabin heat and turbocharging drive Correct answer.

Explanation

The exhaust system routes hot gases overboard and away from the airframe, and in many aircraft a heat exchanger on the exhaust provides cabin heat; turbocharged engines also use exhaust gas to drive the turbocharger. Leaks are hazardous because they can allow carbon monoxide into cabin heat.

Question 46Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

A pilot notices the cabin heat smells of exhaust and a passenger develops a headache. What is the most appropriate action?

  1. Open the heat valve fully to clear the smell
  2. Select cabin cold air, shut off cabin heat and land as soon as practicable Correct answer.
  3. Continue the flight and monitor the passenger
  4. Increase engine power to burn off the contamination

Explanation

Exhaust smell with symptoms suggests carbon monoxide entering the cabin through a leaking heat exchanger or exhaust joint. The immediate response is to shut off the heat source, ventilate with cold air and land so the leak can be inspected; CO is odourless and can incapacitate.

Question 47Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Which statement correctly describes the operation of a turbocharger on a light aircraft engine?

  1. The turbocharger replaces the magneto for ignition
  2. The turbocharger cools the oil before it returns to the sump
  3. A compressor is driven directly by the crankshaft through a belt
  4. Exhaust gas drives a turbine that drives a compressor to raise induction manifold pressure Correct answer.

Explanation

A turbocharger uses the energy of the exhaust gases to spin a turbine on a common shaft with a compressor, which raises the pressure of the induction air. This restores manifold pressure at altitude, allowing the engine to maintain power as air density falls.

Question 48Aircraft General Knowledge - Airframe, Systems, Electrics and Powerplant

Why must a pilot avoid rapid throttle movements on a turbocharged engine?

  1. The propeller will feather automatically
  2. The fuel tanks will vent excessively
  3. Abrupt changes can cause overboost or compressor surge and thermal stress on the turbocharger Correct answer.
  4. The magnetos will lose their timing permanently

Explanation

Rapid throttle changes on a turbocharged engine can produce a manifold pressure overshoot (overboost) and surge loads on the compressor, as well as thermal shock to the turbine. Smooth, progressive movements allow the wastegate and induction system to respond without exceeding limits.

Question 49Flight Performance and Planning - Mass and Balance, Performance, Flight Planning and Monitoring

In light aircraft mass and balance, what does the term 'empty mass' normally include?

  1. The airframe and engines only, with all fluids drained and equipment removed
  2. The airframe, crew, usable fuel and baggage loaded for a specific flight
  3. The maximum mass at which the aircraft may be operated in the utility category
  4. The airframe, engines, systems and fixed equipment, plus unusable fuel and full engine oil Correct answer.

Explanation

Empty mass is the basic mass of the aircraft as delivered, including fixed equipment and operating fluids that cannot be drained, notably unusable fuel and full oil. It excludes crew, usable fuel, payload and baggage, which are added to give the actual take-off mass.

Question 50Flight Performance and Planning - Mass and Balance, Performance, Flight Planning and Monitoring

An aircraft has a maximum structural take-off mass of 1150 kg and a maximum landing mass of 1050 kg. For a flight of 3 hours, trip fuel is 120 kg and it is planned to land with 80 kg of fuel remaining. What is the maximum traffic load that may be carried at take-off?

  1. 50 kg Correct answer.
  2. 130 kg
  3. 30 kg
  4. 150 kg

Explanation

Take-off mass is limited by both the take-off limit and the landing limit plus trip fuel. The landing limit allows 1050 + 120 = 1170 kg at take-off, so the take-off limit of 1150 kg governs. With empty mass plus fuel at take-off equal to 1100 kg, the remaining traffic load is 50 kg.