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CAAB PPL Theory study materials
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CAAB PPL Theory practice questions

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Question 1Air Law and ATC Procedures

Under ICAO rules, what is the primary purpose of a clearance issued by an air traffic control unit?

  1. To guarantee that no other traffic will be present
  2. To provide advisory information that the pilot may ignore
  3. To transfer responsibility for terrain separation to the pilot
  4. To authorise an aircraft to proceed under specified conditions Correct answer.

Explanation

An ATC clearance is an authorisation for an aircraft to proceed under conditions specified by the controlling unit. It provides separation and expedites traffic flow, but it does not relieve the pilot in command of responsibility for the safety of the flight. The pilot must still avoid collisions and terrain.

Question 2Air Law and ATC Procedures

Which of the following best describes a controlled aerodrome?

  1. An aerodrome that lies within Class G airspace
  2. An aerodrome where air traffic control service is provided to aerodrome traffic Correct answer.
  3. An aerodrome open only to scheduled airline operations
  4. An aerodrome with a mandatory radio listening watch but no ATC unit

Explanation

A controlled aerodrome is one at which air traffic control service is provided to aerodrome traffic, regardless of whether a control tower is physically present in all conditions. The defining feature is the provision of ATC service, not the type of traffic or the airspace class.

Question 3Air Law and ATC Procedures

When must a pilot reading back an ATC clearance always include the aircraft call sign?

  1. Only when instructed by the controller
  2. Only when the clearance contains an altitude
  3. On every readback of a clearance Correct answer.
  4. Only on the initial contact of the flight

Explanation

Each readback of a clearance must begin or end with the aircraft call sign so the controller can identify which aircraft is acknowledging. This applies to every clearance readback, not merely the first contact. Consistent identification prevents clearances being applied to the wrong aircraft.

Question 4Air Law and ATC Procedures

A pilot holds a clearance to enter a control zone. What does this clearance normally imply about the flight rules under which the flight must be conducted?

  1. The flight must remain VFR at all times
  2. The flight must change to IFR on entering the zone
  3. The flight may proceed under either VFR or IFR as cleared Correct answer.
  4. The flight must cancel its flight plan immediately

Explanation

A control zone entry clearance authorises the flight to enter under the flight rules specified in the clearance. ATC may clear an aircraft under VFR or IFR depending on the flight and traffic situation. The pilot must comply with the conditions attached to that clearance.

Question 5Air Law and ATC Procedures

What is the meaning of the transponder code 7700?

  1. Radio communication failure
  2. Unlawful interference
  3. General emergency Correct answer.
  4. Loss of navigation capability

Explanation

Code 7700 is the general emergency code and alerts ATC that the aircraft is in distress. It is distinct from 7600 for radio failure and 7500 for unlawful interference. Selecting the correct code allows controllers to give immediate priority.

Question 6Air Law and ATC Procedures

In the ICAO phonetic alphabet, which word represents the letter Q?

  1. Quota
  2. Quartz
  3. Quebec Correct answer.
  4. Queen

Explanation

The ICAO phonetic alphabet assigns Quebec to the letter Q. Standard spelling words are used to avoid confusion in radio transmissions. Using the approved word ensures clear identification across languages.

Question 7Air Law and ATC Procedures

Which body is responsible for establishing international standards and recommended practices for civil aviation?

  1. The airline operators' committee of the state of departure
  2. The International Air Transport Association
  3. The International Civil Aviation Organization Correct answer.
  4. The national civil aviation authority of the state of registry

Explanation

ICAO is the specialised United Nations agency that adopts Standards and Recommended Practices, published as Annexes to the Chicago Convention. National authorities then implement these standards in their own regulations. IATA is an industry trade association, not a regulatory standard-setter.

Question 8Air Law and ATC Procedures

An aircraft is on final approach and receives a landing clearance. What must the pilot do if the runway is subsequently occupied by another aircraft?

  1. Go around unless the controller confirms the runway is clear Correct answer.
  2. Land and then report the conflict after vacating
  3. Continue the approach because the clearance guarantees the runway is clear
  4. Reduce speed and continue to touchdown regardless

Explanation

A landing clearance does not relieve the pilot of the duty to ensure the runway is safe to use. If the runway appears occupied, the pilot should go around and inform ATC. The pilot in command retains final responsibility for the safety of the landing.

Question 9Air Law and ATC Procedures

A VFR flight in Class D airspace requests a special VFR clearance because the visibility has fallen below the normal minimum. Which condition must normally be met before ATC may issue it?

  1. The flight must be conducted at night only
  2. The flight must remain clear of cloud and in sight of the surface Correct answer.
  3. The aircraft must be equipped with a serviceable transponder
  4. The pilot must hold an instrument rating

Explanation

Special VFR allows flight below normal VMC minima provided the aircraft remains clear of cloud and in sight of the surface. It is normally subject to ATC authorisation and traffic separation. It is generally available to appropriately rated pilots during the day or night as permitted locally.

Question 10Air Law and ATC Procedures

An aircraft is instructed to hold at a VOR. Which of the following correctly describes the standard holding pattern direction?

  1. Left turns, with the inbound leg away from the holding fix
  2. Left turns, with the outbound leg toward the holding fix
  3. Right turns, with the inbound leg toward the holding fix Correct answer.
  4. Right turns, with the outbound leg away from the holding fix

Explanation

Standard holding patterns use right-hand turns, and the aircraft flies inbound toward the holding fix on the inbound leg. The outbound leg is flown away from the fix before turning back. Non-standard left-hand holds must be specified explicitly.

Question 11Air Law and ATC Procedures

A pilot receives the instruction 'descend to 3000 feet, report reaching'. What does this instruction require?

  1. Report when the aircraft begins the descent
  2. Report only if unable to reach 3000 feet
  3. Report passing each 1000 feet during the descent
  4. Report when the aircraft has levelled at 3000 feet Correct answer.

Explanation

'Report reaching' requires the pilot to advise ATC when the aircraft has arrived at the assigned level. It is not a request to report passing intermediate levels. This allows the controller to know when the level is occupied for separation purposes.

Question 12Air Law and ATC Procedures

What does the term 'estimated time of arrival' mean in the context of a flight plan?

  1. The time the aircraft will leave the departure gate
  2. The time the aircraft will begin its approach
  3. The time the aircraft will enter the destination control zone
  4. The time the aircraft is expected to arrive over the destination aerodrome Correct answer.

Explanation

In flight plan terminology, estimated time of arrival is the estimated time the aircraft will arrive over the destination aerodrome. It is used by ATC and search and rescue services to monitor the flight. It is not the approach commencement time or the gate departure time.

Question 13Air Law and ATC Procedures

An aircraft is cleared to cross an active runway. What should the pilot do before entering the runway?

  1. Switch off the landing lights to avoid distracting other pilots
  2. Wait for a second clearance before crossing
  3. Enter immediately because the clearance guarantees the runway is clear
  4. Look out for conflicting traffic and confirm the runway is clear before entering Correct answer.

Explanation

A crossing clearance authorises the aircraft to cross but does not guarantee that the runway is free of traffic. The pilot must visually check for conflicting traffic before entering the runway. Landing lights should normally be on to increase conspicuity.

Question 14Air Law and ATC Procedures

Which of the following is a characteristic of Class C airspace under ICAO classification?

  1. Only IFR flights are permitted to operate in the airspace
  2. IFR flights are separated from all traffic and VFR flights are separated from IFR flights Correct answer.
  3. No air traffic control service is provided to VFR flights
  4. IFR and VFR flights are both separated from all other traffic

Explanation

In Class C airspace, IFR flights are separated from all other traffic, while VFR flights are separated from IFR flights but receive traffic information about other VFR flights. VFR flights are permitted subject to clearance. This differs from Class B, where all flights are separated from each other.

Question 15Air Law and ATC Procedures

A pilot on an IFR flight is given a clearance to descend at the pilot's discretion. What does this authorise?

  1. The pilot may leave the cleared route while descending
  2. The pilot may descend below the cleared level if visual conditions permit
  3. The pilot must begin descent immediately at the standard rate
  4. The pilot may descend at any time and at any rate until the cleared level Correct answer.

Explanation

A descent at the pilot's discretion allows the aircraft to leave the current level when convenient and descend at a chosen rate. The aircraft must still remain at or above the cleared level. It does not authorise deviation from the cleared route or descent below the cleared level.

Question 16Air Law and ATC Procedures

What is the purpose of a 'line up and wait' instruction issued to an aircraft at a controlled aerodrome?

  1. To authorise the aircraft to enter the runway and hold in position without taking off Correct answer.
  2. To instruct the aircraft to vacate the runway at the next exit
  3. To authorise the aircraft to begin its take-off roll immediately
  4. To hold the aircraft on the taxiway short of the holding point

Explanation

'Line up and wait' authorises the aircraft to enter the runway and position itself for departure but not to begin the take-off roll. A separate take-off clearance is required before commencing the roll. The instruction is used to position aircraft efficiently while the runway is being cleared.

Question 17Air Law and ATC Procedures

An aircraft is unable to maintain the assigned altitude because of turbulence. What is the correct action according to standard ATC procedures?

  1. Change level without notifying ATC to maintain safety
  2. Advise ATC immediately and request a different level Correct answer.
  3. Reduce speed only and remain at the assigned level
  4. Continue at the assigned level and report after landing

Explanation

When unable to maintain an assigned level, the pilot must inform ATC promptly and request an amended clearance. Unannounced level changes can compromise separation with other traffic. ATC can then adjust other clearances to maintain safe separation.

Question 18Air Law and ATC Procedures

Which of the following correctly describes the readback requirement for a conditional clearance?

  1. No readback is required for conditional clearances
  2. The condition and the clearance must both be read back Correct answer.
  3. Only the condition needs to be read back
  4. Only the clearance itself needs to be read back

Explanation

For a conditional clearance, the pilot must read back the condition as well as the clearance itself. This confirms that the pilot has understood both the triggering event and the action to be taken. Omitting the condition risks the clearance being applied at the wrong time.

Question 19Air Law and ATC Procedures

An aircraft is intercepted by a military aircraft and the pilot is unsure of the intercepting aircraft's intentions. According to ICAO procedures, what should the intercepted aircraft do first?

  1. Attempt to establish radio communication and follow the intercepting aircraft's signals Correct answer.
  2. Turn away from the intercepting aircraft and continue the flight
  3. Immediately descend and land at the nearest aerodrome
  4. Climb to the highest available level and accelerate

Explanation

The intercepted aircraft should try to establish radio communication with the intercepting aircraft or the appropriate ATC unit. If radio contact cannot be established, the pilot should follow the visual signals given by the intercepting aircraft. Deviating without following signals could escalate the situation.

Question 20Air Law and ATC Procedures

An aircraft on approach is instructed to 'go around'. Which action is required?

  1. Abandon the approach and follow the published or instructed go-around procedure Correct answer.
  2. Reduce speed and continue to touchdown
  3. Hold at the current position on the approach path
  4. Continue the approach and land at the pilot's discretion

Explanation

A go-around instruction requires the pilot to abandon the approach and follow the published missed approach or the procedure specified by ATC. The aircraft must be climbed and configured appropriately for the go-around. Continuing the approach would conflict with the instruction.

Question 21Air Law and ATC Procedures

An aircraft is flying VFR in Class E airspace. Which statement about ATC service is correct?

  1. VFR flights are provided with traffic information as far as practicable Correct answer.
  2. VFR flights are provided with separation from all other traffic
  3. VFR flights are not permitted in Class E airspace
  4. VFR flights must obtain a clearance before entering Class E airspace

Explanation

In Class E airspace, IFR flights are separated from each other and from VFR flights as far as practicable, and VFR flights receive traffic information. VFR flights are not separated from other VFR flights. Class E is controlled airspace but VFR entry normally does not require a clearance.

Question 22Air Law and ATC Procedures

A pilot receives a clearance that appears to conflict with a previously issued clearance. What is the correct course of action?

  1. Choose the clearance that appears safest and proceed
  2. Seek clarification from ATC before acting on either clearance Correct answer.
  3. Comply with the later clearance without comment
  4. Comply with the earlier clearance and ignore the new one

Explanation

When a clearance is unclear or appears to conflict with an earlier instruction, the pilot must seek clarification before acting. Acting on an ambiguous clearance could compromise separation. The controller is responsible for resolving the conflict.

Question 23Air Law and ATC Procedures

Which of the following statements about the responsibility for collision avoidance in VMC is correct?

  1. Responsibility passes to the controller once the aircraft is in controlled airspace
  2. Responsibility is shared equally between pilot and controller at all times
  3. ATC is solely responsible for collision avoidance for all flights
  4. The pilot in command is responsible for collision avoidance, even when a clearance has been issued Correct answer.

Explanation

The pilot in command is always responsible for collision avoidance, including when operating under an ATC clearance in VMC. ATC provides separation between controlled flights but cannot guarantee see-and-avoid. The pilot must remain vigilant for other traffic.

Question 24Air Law and ATC Procedures

An aircraft is cleared to descend from FL 350 to FL 200. During the descent, the pilot observes that the aircraft will pass through a level occupied by another aircraft according to the traffic display. What should the pilot do?

  1. Continue the descent because the clearance guarantees separation
  2. Change to a different frequency and continue descending
  3. Accelerate to pass through the level more quickly
  4. Level off and advise ATC of the observed traffic Correct answer.

Explanation

Although ATC is responsible for separation, the pilot must inform ATC if a potential conflict is observed. Levelling off and advising the controller allows separation to be re-established. Continuing blindly relies on an assumption that the clearance guarantees separation.

Question 25Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

In a four-stroke aircraft piston engine, during which stroke is the intake valve open and the piston moving toward the crankshaft?

  1. Exhaust stroke
  2. Power stroke
  3. Compression stroke
  4. Intake stroke Correct answer.

Explanation

The intake stroke draws the fuel-air mixture into the cylinder. The piston travels downward toward the crankshaft while the intake valve is open, increasing cylinder volume and reducing pressure so the mixture flows in.

Question 26Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What is the primary function of the magneto in an aircraft ignition system?

  1. It regulates the charging voltage to the battery
  2. It drives the propeller governor
  3. It meters fuel into the intake manifold
  4. It generates the high-tension voltage that fires the spark plugs Correct answer.

Explanation

A magneto is a self-contained generator that produces high voltage for the spark plugs without relying on the aircraft battery. Because it creates its own current from a rotating magnet, the engine keeps firing even if the electrical system fails.

Question 27Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

A pilot observes that the oil pressure gauge reads zero shortly after start. What is the most appropriate immediate action?

  1. Continue the run-up and monitor the gauge
  2. Increase power to raise oil pressure
  3. Ignore it because the gauge is often slow to respond
  4. Shut down the engine and investigate before further running Correct answer.

Explanation

Zero oil pressure means lubrication may have failed, and continued running can destroy the engine within seconds. The safe response is to stop the engine promptly and have the indication investigated.

Question 28Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

In a simple carburettor, what is the purpose of the venturi?

  1. To filter contaminants from the fuel
  2. To warm the incoming air
  3. To store fuel for abrupt power changes
  4. To lower the pressure so fuel is drawn from the discharge nozzle Correct answer.

Explanation

As air accelerates through the narrowed venturi, its velocity rises and its static pressure falls. This reduced pressure draws fuel out of the main discharge nozzle and into the airstream, forming the combustible mixture.

Question 29Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Which control surface produces movement about the aircraft's longitudinal axis?

  1. Rudder
  2. Flaps
  3. Ailerons Correct answer.
  4. Elevators

Explanation

The longitudinal axis runs fore and aft through the fuselage, and roll occurs about it. Ailerons move differentially to raise one wing and lower the other, producing that roll.

Question 30Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

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

  1. To vary blade pitch so engine RPM stays at the selected value Correct answer.
  2. To feather the propeller automatically at shutdown
  3. To synchronise two engines' RPM
  4. To limit manifold pressure at high altitude

Explanation

The governor senses engine RPM and adjusts oil pressure to the propeller hub, changing blade angle to hold the selected RPM as load or power varies. This keeps the engine at an efficient speed regardless of throttle changes.

Question 31Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Which statement best describes the function of the aircraft electrical bus bar?

  1. It stores electrical energy for engine starting
  2. It distributes electrical power from the source to the various circuits Correct answer.
  3. It limits current to the starter motor only
  4. It converts alternating current to direct current

Explanation

A bus bar is a common connection point that receives power from the battery or alternator and feeds it to the individual circuit breakers and loads. It simplifies wiring by providing a single distribution node.

Question 32Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

During a climb at full throttle, a fixed-pitch propeller aircraft shows rising cylinder head temperature. Which factor most directly explains this?

  1. Increased fuel octane at altitude
  2. Higher oil viscosity in cold air
  3. Reduced cooling airflow and richer mixture demand at lower airspeed Correct answer.
  4. Greater alternator output at high RPM

Explanation

In a climb, airspeed is lower so less air passes over the cylinders, reducing cooling. At the same time the engine is working hard, so heat production is high, and the mixture must be managed to avoid overheating.

Question 33Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What happens to the fuel-air mixture if carburettor heat is applied during cruise?

  1. The mixture becomes richer because warmed air is less dense Correct answer.
  2. The mixture is unchanged because only fuel temperature changes
  3. The mixture becomes leaner because warmed air expands
  4. The mixture becomes richer because fuel flow increases

Explanation

Warming the intake air lowers its density, so each intake stroke draws in less air mass while fuel metering stays roughly constant. The result is a richer mixture, which is why carburettor heat is used cautiously and the mixture may need leaning.

Question 34Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

An aircraft has a 24-volt battery and a 50-ampere alternator. What does the ammeter reading primarily indicate in flight?

  1. The charge state of the magnetos
  2. The voltage across the battery terminals
  3. The total power consumed by the avionics
  4. The current flowing into or out of the battery Correct answer.

Explanation

The ammeter shows current direction and magnitude in the battery circuit, indicating whether the alternator is charging the battery or the battery is supplying loads. A discharge reading warns that the alternator is not keeping up.

Question 35Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Why are aircraft piston engines usually fitted with two independent magnetos?

  1. To allow the engine to run on two fuels
  2. To double the engine's maximum RPM
  3. To provide redundancy and more complete combustion Correct answer.
  4. To reduce the weight of the ignition harness

Explanation

Two magnetos give redundancy so a single ignition failure does not stop the engine, and two spark plugs per cylinder improve combustion and power. The dual system also shortens flame travel for more efficient burning.

Question 36Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What is the purpose of the exhaust gas temperature gauge in a piston engine?

  1. To show manifold pressure
  2. To help the pilot set the fuel-air mixture accurately Correct answer.
  3. To measure cylinder head cooling efficiency
  4. To indicate oil temperature

Explanation

Exhaust gas temperature peaks near the stoichiometric mixture ratio, so the gauge lets the pilot lean or enrich the mixture to a chosen setting. It is a key leaning instrument, especially at cruise.

Question 37Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

A pilot notices the fuel pressure gauge fluctuating and the engine running rough at altitude. Which condition is most consistent with these symptoms?

  1. Vapour lock in the fuel lines Correct answer.
  2. Low oil pressure
  3. A failed magneto
  4. A stuck exhaust valve

Explanation

At altitude the lower ambient pressure encourages fuel to vaporise in the lines, creating vapour lock that causes pressure fluctuations and rough running. Keeping the fuel cool and using the boost pump help prevent it.

Question 38Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What is the effect of increasing blade angle on a constant-speed propeller at a fixed power setting?

  1. The propeller stops rotating
  2. The engine RPM is unaffected
  3. The engine RPM tends to increase
  4. The engine RPM tends to decrease Correct answer.

Explanation

A larger blade angle presents more blade area to the airflow, increasing the load on the engine. At constant power the extra load slows the engine until the governor restores the selected RPM by adjusting oil pressure.

Question 39Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

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

  1. It connects the battery and alternator to the main bus Correct answer.
  2. It starts the engine directly
  3. It selects which magneto is active
  4. It controls the fuel pump

Explanation

The master switch closes the main contactors that link the battery and the alternator to the electrical bus, energising the distribution system. Individual circuits are then controlled by their own switches and breakers.

Question 40Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Why is a rich mixture used during takeoff in a piston engine?

  1. To lower the octane requirement of the fuel
  2. To provide extra fuel for cooling and to ensure full power Correct answer.
  3. To reduce fuel consumption
  4. To increase exhaust gas temperature

Explanation

A richer-than-ideal mixture adds evaporative cooling in the cylinders and guards against detonation while ensuring all air is burned for maximum power. The excess fuel also helps control peak combustion temperatures during the high-power phase.

Question 41Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What does a sudden drop in oil pressure accompanied by rising oil temperature most likely indicate?

  1. A blocked fuel line
  2. A misrigged aileron
  3. An oil leak or pump failure Correct answer.
  4. A failed alternator

Explanation

Loss of oil pressure with rising temperature suggests the oil is not circulating properly, often from a leak or pump problem. Continued operation risks overheating and seizure, so the engine should be shut down safely.

Question 42Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Which statement correctly describes the relationship between manifold pressure and engine power at constant RPM?

  1. Manifold pressure has no relation to power
  2. Manifold pressure equals oil pressure
  3. Higher manifold pressure means less power
  4. Higher manifold pressure generally means more power Correct answer.

Explanation

Manifold pressure reflects how much air-fuel charge enters the cylinders, so a higher value at constant RPM means a larger charge and more power. This is why the throttle is described as controlling manifold pressure.

Question 43Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

A pilot selects carburettor heat and the RPM rises slightly. What does this indicate?

  1. The mixture is too lean
  2. Ice was present and is being cleared Correct answer.
  3. The magnetos are failing
  4. The fuel pump is overboosting

Explanation

Carburettor ice restricts the airflow and causes a lean, rough-running engine. Applying heat melts the ice, restoring airflow and often producing a slight RPM rise as the restriction clears.

Question 44Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What is the primary purpose of the aircraft structure's stressed skin?

  1. It insulates the cabin from noise
  2. It carries part of the structural load as well as forming the surface Correct answer.
  3. It stores fuel in all aircraft
  4. It houses the electrical bus

Explanation

In a stressed-skin design, the outer skin is bonded or riveted to the framework and shares the bending and shear loads with it. This allows a lighter, stiffer structure than a fabric-covered frame carrying all loads internally.

Question 45Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Why does a turbocharged engine require a wastegate?

  1. To feather the propeller
  2. To enrich the mixture at altitude
  3. To cool the oil after shutdown
  4. To limit manifold pressure by bypassing exhaust gas around the turbine Correct answer.

Explanation

A turbocharger can overboost the engine if exhaust flow to the turbine is not controlled. The wastegate opens to divert exhaust around the turbine, limiting compressor speed and manifold pressure to a safe value.

Question 46Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

What is the effect of detonation on an aircraft engine?

  1. Smooth even burning that improves efficiency
  2. A gradual loss of oil pressure
  3. Uncontrolled rapid burning that raises pressures and can damage the engine Correct answer.
  4. A complete failure of the ignition system

Explanation

Detonation is explosive burning of the end gas after normal ignition, producing very high peak pressures and temperatures. It can crack pistons and cylinders, so it must be stopped by enriching the mixture or reducing power.

Question 47Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

Why is a pre-flight magneto check performed at a specified RPM?

  1. To warm the engine oil
  2. To set the propeller pitch
  3. To test the alternator output
  4. To verify each magneto operates within an acceptable RPM drop Correct answer.

Explanation

At a set RPM, switching to each magneto in turn should produce a small, similar RPM drop if both are working. An excessive drop or rough running indicates a faulty magneto or plug, so the check confirms ignition health before flight.

Question 48Aircraft General Knowledge (Airframe, Systems, Powerplant, Electrics)

In a fuel-injected engine, what is the function of the fuel control unit?

  1. It cools the cylinder heads
  2. It drives the propeller governor
  3. It meters fuel to match the air entering the engine across the operating range Correct answer.
  4. It filters water from the fuel tanks

Explanation

The fuel control unit senses airflow and engine conditions and meters the correct fuel quantity to the injectors. This maintains a suitable mixture from idle to full power without the venturi-based limitations of a carburettor.

Question 49Flight Performance and Planning (Mass and Balance, Performance)

An aircraft has an empty mass of 700 kg and an empty-arm moment of 2,450 kg·m. A pilot (80 kg) sits at an arm of 1.0 m and 60 kg of baggage is loaded at an arm of 2.0 m. What is the centre of gravity position relative to the datum?

  1. 1.25 m Correct answer.
  2. 1.50 m
  3. 1.35 m
  4. 1.10 m

Explanation

Total mass = 700 + 80 + 60 = 840 kg. Total moment = 2450 + 80 + 120 = 2650 kg·m. Dividing moment by mass gives 2650 / 840 ≈ 3.155 m only if the empty moment is used directly; the empty arm is 2450/700 = 3.5 m, so the correct combined arm is (2450 + 80 + 120)/840 ≈ 3.15 m. Care is needed: the CG is obtained by dividing the total moment by the total mass, never by averaging the individual arms.

Question 50Flight Performance and Planning (Mass and Balance, Performance)

Which statement best describes the purpose of the maximum zero-fuel mass limitation?

  1. It protects the wing structure from excessive bending while fuel in the wings relieves that load. Correct answer.
  2. It guarantees the aircraft can climb with one engine inoperative.
  3. It sets the maximum mass permitted for take-off on a wet runway.
  4. It limits the baggage compartment floor loading.

Explanation

Maximum zero-fuel mass caps the mass of the aircraft without usable fuel. Fuel carried in the wings produces an upward relieving load that reduces wing-root bending, so the structural limit is applied to the fuel-free condition. It is a structural limit rather than a climb or runway performance limit.