CAAS PPL Practice Tests

Questions & Explained Answers

CAAS PPL Principles of Flight Practice Questions, with Explained Answers

All 45 of our Principles of Flight practice questions, each shown with the correct answer and a short explanation of the reasoning behind it. Use it to revise, to check your working after a quiz, or to learn the theory the way the CAAS PPL exam tests it.

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  1. Q1. MET: WSSS 152230Z VRB02KT 9999 FEW018 BKN300 27/25 Q1010 NOSIG TAF: WSSS 151700Z 1518/1624 17008KT 9999 FEW018CB SCT020 TEMPO 1602/1606 3000 TSRA FEW012CB BKN015 What is the height of the lowest cloud base reported?

    • 120ft
    • 180ft
    • 1,200ft
    • 1,800ftCorrect answer
    Why: In a METAR cloud groups are reported in hundreds of feet above aerodrome level. FEW018 is the lowest layer at 18 x 100 = 1,800 ft; BKN300 sits much higher at 30,000 ft, so the lowest cloud base is 1,800 ft.

  2. Q2. Minimum fuel for single-piston/propeller engine:

    • 60 mins
    • 45 minsCorrect answer
    • 30 mins
    Why: For a single piston/propeller aeroplane the minimum final reserve to be carried on top of trip and contingency fuel is normally 45 minutes at holding speed, ensuring a safe margin should the approach or landing be delayed.

  3. Q3. In light aircraft, how is the centre of gravity defined?

    • Distance from aft limit
    • Distance from forward limit
    • Distance from datumCorrect answer
    Why: Centre of gravity is expressed as a distance (arm) measured from the datum, a fixed reference plane defined in the flight manual. Quoting it relative to the datum lets every loaded item's moment be summed against the published forward and aft CG limits.

  4. Q4. A propeller aircraft of weight <5700kg, passengers <9, falls under what category:

    • Performance Class A
    • Performance Class BCorrect answer
    • Performance Class C
    • No performance class
    Why: Single/multi piston-propeller aeroplanes of 5,700 kg or less carrying nine passengers or fewer fall under Performance Class B. The class is defined by aircraft type, mass and seating, not by the operation flown.
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  5. Q5. Document that needs to be signed to show mass and balance are complied with:

    • Technical log
    • Performance take-off calculation
    • DG sheet
    • Load and trim sheetCorrect answer
    Why: The load and trim sheet is the document certifying that the aircraft's mass and centre of gravity are within the certified limits for the flight. It is completed and signed before departure as the formal mass-and-balance record.

  6. Q6. Vertical plane which the CG and mass is referenced to:

    • DatumCorrect answer
    • Balance arm
    • Moment arm
    Why: The datum is the fixed vertical reference plane from which all balance arms, and hence the centre of gravity, are measured. It is chosen by the manufacturer and may lie anywhere convenient, such as the firewall or nose.

  7. Q7. Where will the pilot add CAS ETA?

    • VFR flight planCorrect answer
    • VFR navigation plan
    • VFR enroute plan
    Why: The flight plan (the ICAO/VFR flight plan filed with ATS) is where controlled-airspace estimates such as boundary ETAs are entered, because it is the document notified to air traffic services for coordination and search-and-rescue purposes.

  8. Q8. What mass of the aircraft refers to the mass of the airframe, engine, all standard, fixed equipment, unusable fuel, full oil contents, and the of any other item which is used on all flights of the aircraft concerned. This mass does not include the weight of the pilot and payload?

    • Basic massCorrect answer
    • Standard mass
    • Gross mass
    Why: Basic mass (basic empty mass) is the airframe, engine, fixed equipment, unusable fuel and full oil, plus items common to every flight, but excludes pilot and payload. It is the fixed starting weight from which loaded mass is built up.

  9. Q9. Max structural T/O weight:

    • Can never be exceeded
    • Can be exceeded after take-off
    • Can be exceeded a little during start-upCorrect answer
    Why: The maximum structural take-off mass is a certified structural limit, but a small momentary excess is tolerated during engine start and taxi because fuel will be burned before the aircraft actually becomes airborne and is subjected to flight loads.

  10. Q10. The CG of an aircraft is the point:

    • About which the trust of the aircraft acts
    • About which the total lift acts
    • About which all the aircraft’s weight is said to actCorrect answer
    • At the centre of the aircraft's axis
    Why: The centre of gravity is the single point through which the aircraft's entire weight is considered to act. Treating mass as concentrated there allows the aeroplane's balance and moments to be analysed about that point.

  11. Q11. Which of the following factors may limit the mass able to be loaded onto an aircraft?

    • Relative Humidity
    • Ambient PressureCorrect answer
    • Stability of the air
    • Forecast Crosswind
    Why: Ambient pressure (together with temperature and altitude) sets air density, which limits engine and aerodynamic performance and therefore the performance-limited take-off mass. Low pressure reduces available performance, capping the mass that can safely be loaded and flown.

  12. Q12. One method of contributing to safe in-flight fuel management is:

    • If a fuel boost pump is fitted, turn it on before changing fuel tanksCorrect answer
    • To plan to use the reserve fuel as well as flight fuel
    • To ensure the fuel tanks are completely full before departure
    • To add an extra percentage to your calculated fuel
    Why: Selecting the fuel boost pump on before switching tanks maintains positive fuel pressure during the changeover, guarding against an air lock or momentary fuel interruption that could cause the engine to stumble or stop.

  13. Q13. Primary purpose of calculating aircraft balance:

    • Ensure safe and sufficient performance Correct answer
    • Provide obstacle clearance
    • Ensure maximum control during emergency
    Why: Confirming the aircraft is correctly balanced keeps the centre of gravity within limits so that stability, control authority and predictable performance are assured throughout the flight. An out-of-balance aeroplane can be unstable or uncontrollable.

  14. Q14. A pilot plans a 60 nm route at a true airspeed of 120 kt. The planned ETA was worked out assuming a 10 kt headwind, but the actual flight had a 10 kt tailwind instead. Compared with the planned time, how much earlier or later does the aircraft actually arrive?

    • 5 mins more
    • 5 mins lessCorrect answer
    • 2.5 mins more
    • 2.5 mins less
    Why: With the planned 10 kt headwind the groundspeed is 110 kt, giving a planned time of 60/110 h = 32.7 min; with the actual 10 kt tailwind the groundspeed is 130 kt, giving an actual time of 60/130 h = 27.7 min. The aircraft therefore arrives about 5 minutes earlier (less) than planned.

  15. Q15. What speed should you fly at to achieve the maximum distance?

    • Max endurance speed
    • Max speed
    • Best lift/drag ratio Correct answer
    Why: Maximum still-air range is flown at the speed for the best lift/drag ratio, because that is where the aeroplane produces the required lift for the least total drag and therefore the least thrust and fuel for each mile travelled.

  16. Q16. One method of contributing to safe in-flight fuel management is:

    • If a fuel boost pump is fitted, select it on before changing fuel tanksCorrect answer
    • To plan to use the reserve fuel as well as flight fuel
    • To ensure the fuel tanks are completely full before departure
    • To add an extra percentage to your calculated fuel
    Why: Selecting the fuel boost pump on before changing tanks keeps fuel pressure up through the changeover, preventing an air lock or brief fuel interruption that might otherwise cause the engine to falter at the moment of selection.

  17. Q17. The CG of an aircraft is the point:

    • About which the trust of the aircraft acts
    • About which the total lift acts
    • About which all the aircraft’s weight is said to actCorrect answer
    • At the centre of the aircraft's axis
    Why: The centre of gravity is the point through which the whole weight of the aircraft is taken to act. Lift, thrust and the geometric centre are separate concepts; only weight is referenced to the CG.

  18. Q18. When must you submit a flight plan?

    • For IFR flights
    • For VFR flights
    • For all flights across international bordersCorrect answer
    • Domestic flight
    Why: A flight plan must always be filed for any flight crossing an international border, so that the receiving state's air traffic and customs/immigration services are notified. Many domestic VFR flights need none unless airspace rules require it.

  19. Q19. How long of a delay until a new flight plan must be submitted?

    • 30 minutesCorrect answer
    • 45 minutes
    • 1 hour
    • Delay ETD
    Why: If departure is delayed more than 30 minutes beyond the estimated off-block time, the filed flight plan must be amended or a new one submitted, so that ATS estimates and the activated plan remain valid for traffic and alerting.

  20. Q20. How do you check the aircraft CG?

    • Aircraft flight manualCorrect answer
    • ICAO load and balance sheet
    • AIP
    Why: The aircraft flight manual contains the certified centre-of-gravity limits and loading data for that specific aeroplane, making it the authoritative source for checking that the CG is within range for the planned load.

  21. Q21. Maximum structural take-off mass may:

    • Be exceeded if passengers are not carried
    • Never be exceeded
    • Be exceeded provided the aeroplane performance limited take-off mass within limits
    • Be exceeded by a small amount, but only during start up and taxiCorrect answer
    Why: Maximum structural take-off mass is a certified limit that may be exceeded only by a small amount, and only during start-up and taxi, because fuel burned on the ground brings the mass within limits before the aircraft is subjected to flight loads.

  22. Q22. Forward position of CG is limited to ensure:

    • Aircraft is not tail heavy
    • Aircraft sufficiently stable to hold steady nose attitude
    • Elevator maintain sufficient nose up pitch authority at low airspeeds as required on landingCorrect answer
    • Aircraft does not stall easily
    Why: A forward CG increases the nose-down moment, so the elevator must work harder to raise the nose. The forward limit ensures enough nose-up pitch authority remains at low airspeed, such as during the landing flare, when elevator effectiveness is least.

  23. Q23. What may be affected if aircraft CG is outside the limit?

    • Nothing
    • Control forces, stability, manoeuvrability and performanceCorrect answer
    • Passenger comfort and susceptibility to turbulence
    • Structural lift
    Why: An out-of-limits centre of gravity degrades control forces, longitudinal stability, manoeuvrability and performance. A CG too far aft reduces stability, while too far forward increases stick forces and may leave insufficient elevator authority.

  24. Q24. Centre of Gravity is defined as:

    • Calculated point through which the lift vector acts
    • Point at which all individual weight components are measured from
    • Theoretical point on the wing at which the coefficient of drag will be at its least value
    • Theoretical point at which the entire weight of the aircraft is assumed to be concentratedCorrect answer
    Why: The centre of gravity is the theoretical point at which the aeroplane's entire weight is assumed to be concentrated. It is the balance point about which the aircraft would be in equilibrium if suspended.

  25. Q25. For an aircraft to be in a state of equilibrium during straight and level flight:

    • Total thrust must balance total weight and total lift must balance total drag
    • Total lift must balance total weight and total thrust must balance total dragCorrect answer
    • Lift and drag must balance weight and thrust
    • Lift and thrust couple must balance weight and drag couple
    Why: In steady straight-and-level flight the four forces are in equilibrium in opposing pairs: lift balances weight in the vertical sense and thrust balances drag along the flight path, so there is no net force and the aeroplane is unaccelerated.

  26. Q26. Which of the following options lists the items to include when calculating that maximum zero fuel mass is within limits?

    • Crew, passengers and operating fuel, but not baggage
    • Crew, unusable fuel and baggage, but not passengers
    • Crew, passengers, baggage and unusable fuelCorrect answer
    • Crew, passengers, baggage and operating fuel
    Why: Maximum zero-fuel mass is everything aboard except usable fuel, so it includes crew, passengers, baggage/cargo and unusable fuel. Usable (operating) fuel is excluded because the limit guards the structure against bending loads relieved by fuel carried in the wings.

  27. Q27. Max endurance in straight and level flight is achieved when power is set to:

    • Cruise power, max lean
    • Full power, max rich
    • Full power, max lean
    • Minimum power requiredCorrect answer
    Why: Maximum endurance, the longest time airborne, is achieved at the speed and configuration requiring the minimum power, because minimum power equals minimum fuel flow per unit time, letting the aeroplane stay aloft longest on a given quantity of fuel.

  28. Q28. In which aircraft performance class would a single-engine aeroplane weighing less than 5700kg, with four seats be classified in?

    • Performance Class A
    • Performance Class BCorrect answer
    • Performance Class C
    • Performance Class D
    Why: A single-engine aeroplane below 5,700 kg with four seats is classified Performance Class B, the category for smaller piston-propeller aeroplanes of 5,700 kg or less carrying nine or fewer passengers.

  29. Q29. In the event of a delay in estimated off-block time, flight plan is to be amended or new flight plan is to be submitted if delay exceeds:

    • The advised ETD
    • 30 minutesCorrect answer
    • 45 minutes
    • 60 minutes
    Why: When the off-block time slips by more than 30 minutes, the flight plan must be amended or refiled. This keeps the activated plan and ATS estimates accurate for separation and search-and-rescue alerting.

  30. Q30. Why is Forward Position centre of gravity limited?

    • Safe nose up pitch authority at low airspeed during landingCorrect answer
    • Does not stall /spin easily
    • Not too tail heavy
    • Stable to hold nose attitude
    Why: The forward CG limit guarantees the elevator retains enough nose-up pitch authority at low airspeed, particularly in the landing flare. A CG too far forward could leave insufficient elevator power to raise the nose and check the descent.

  31. Q31. For an aircraft to be in a state of equilibrium during straight and level flight:

    • Total thrust must balance total weight and total lift must balance total drag
    • Total lift must balance total weight and total thrust must balance total dragCorrect answer
    • Lift and drag must balance weight and thrust
    • Lift and thrust couple must balance weight and drag couple
    Why: Equilibrium in straight-and-level flight means the forces balance in opposing pairs: lift equals weight vertically and thrust equals drag horizontally. With no net force the aeroplane maintains a constant speed, altitude and heading.

  32. Q32. One method of contributing to safe in-flight fuel management is:

    • If a fuel boost pump is fitted, select it on before changing fuel tanksCorrect answer
    • To plan to use the reserve fuel as well as flight fuel
    • To ensure the fuel tanks are completely full before departure
    • To add an extra percentage to your calculated fuel
    Why: Turning the fuel boost pump on before changing tanks sustains fuel pressure through the selection, preventing a vapour lock or brief supply interruption that could make the engine hesitate just as the new tank is selected.

  33. Q33. TAF: WSSS 151700Z 1518/1624 17008KT 9999 FEW018CB SCT020 TEMPO 1602/1606 3000 TSRA FEW012CB BKN015. What is the height of the lowest cloud base reported?

    • 120ft
    • 180ft
    • 1200ft
    • 1800ftCorrect answer
    Why: Cloud heights in a TAF are given in hundreds of feet above aerodrome level. FEW018 is the lowest layer at 18 x 100 = 1,800 ft, well below SCT020 and the convective layers, so the lowest reported base is 1,800 ft.

  34. Q34. What mass of the aircraft refers to the mass of the airframe, engine, all standard, fixed equipment, unusable fuel, full oil contents, and any other item which is used on all flights of the aircraft concerned? This mass does not include the weight of the pilot and payload.

    • Basic massCorrect answer
    • Standard mass
    • Gross mass
    Why: Basic mass (basic empty mass) comprises the airframe, engine, fixed equipment, unusable fuel and full oil plus items carried on every flight, but not the pilot or payload. It is the fixed base weight on which loading is built.

  35. Q35. A pilot will be able to expect to find details of an aircraft’s allowable CG range in the:

    • Aeronautical Information Publication
    • Aircraft Flight ManualCorrect answer
    • ICAO Mass and Balance public
    • Visual flight guide
    Why: The aircraft flight manual lists that specific aeroplane's certified centre-of-gravity range and loading limits, so it is where a pilot finds the allowable CG envelope for mass-and-balance calculations.

  36. Q36. Why is it important to confirm mass and balance and ensure that they are within limits?

    • Aircraft can be uncontrollable at slow speedCorrect answer
    • Aircraft control will be less responsive
    • Aircraft might float and have a longer landing run when landing
    • Aircraft might overspeed during descent
    Why: If mass and balance are outside limits the aeroplane can become uncontrollable, especially at slow speed where control surfaces are least effective. An aft CG in particular can reduce stability to the point of loss of control near the stall.

  37. Q37. Gross weight of a/c is 2432lb, CG 98inch aft burns 125 at station 96 and drops 20lb at station 103. Where is the CG of the aircraft?

    • 92.22 inch
    • 98.07 inchCorrect answer
    • 104.21 inch
    • 110.36 inch
    Why: Total moment starts at 2432 x 98 = 238,336 lb-in. Removing 125 lb at 96 in and 20 lb at 103 in leaves 2287 lb and a moment of 224,276 lb-in, giving a new CG of 224,276 / 2287 = 98.07 in aft of datum.

  38. Q38. What is Zero Fuel Mass?

    • Mass with cargo, passengers, crew, operating oil but not fuel
    • Mass with operating oil, unusable fuel, but not passengers, crew or cargo
    • Mass with cargo, passengers, crew, operating oil and unusable fuelCorrect answer
    • Mass with passengers, crew, unusable fuel but not cargo or operating oil
    Why: Zero-fuel mass is the aeroplane fully loaded with cargo, passengers, crew, operating oil and unusable fuel but with no usable fuel. Any mass above it must consist only of usable fuel, which relieves wing bending loads in flight.

  39. Q39. When can the Maximum Structural Landing Weight be exceeded?

    • Can never be exceededCorrect answer
    • Can be exceeded in an emergency
    • Can be exceeded if the crew allows
    • Can be exceeded if no passengers are carried
    Why: Maximum structural landing mass is a certified structural limit and must never be deliberately exceeded, because landing imposes high vertical loads on the airframe and undercarriage that the structure is only stressed to absorb up to that mass.

  40. Q40. How does an increase in take-off weight affect the take-off run?

    • It shortens the take-off run
    • It does not affect the take-off run
    • It increases the take-off runCorrect answer
    Why: A heavier aeroplane has a higher stalling and lift-off speed and accelerates more slowly, so it must travel further to reach flying speed. Increasing take-off weight therefore lengthens the take-off run.

  41. Q41. What does NOTAM stands for?

    • Note To Airmen
    • Notice To Aircraft
    • Notice To AirmenCorrect answer
    • Notice To Aircrew
    Why: NOTAM stands for Notice To Airmen, a notice distributed to alert pilots to the establishment, condition or change of any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to flight safety.

  42. Q42. A flight involving a single propeller 4-seater aircraft of less than 5700kg, which performance class does the aircraft belong in?

    • Performance Class A
    • Performance Class BCorrect answer
    • Performance Class C
    • Performance Class D
    Why: A single propeller four-seat aeroplane of less than 5,700 kg is in Performance Class B, the category covering piston-propeller aeroplanes of 5,700 kg or less with nine or fewer passenger seats.

  43. Q43. WSSS 270430Z 18006KT 150V210 9999 FEW018 FEW020TCU BKN300 26/24 Q1011 NOSIG. What is the temperature and dewpoint recorded?

    • Temperature 24 degrees celsius, Dewpoint 26 degrees celsius
    • Temperature 26 degrees celsius, Dewpoint 24 degrees celsiusCorrect answer
    • Temperature 21 degrees celsius, Dewpoint 15 degrees celsius
    • Temperature 20 degrees celsius, Dewpoint 18 degrees celsius
    Why: In a METAR the temperature and dewpoint are reported as two figures separated by a slash, air temperature first. Here 26/24 means an air temperature of 26 degrees C and a dewpoint of 24 degrees C.

  44. Q44. WSSS 270700Z 21005KT 180V240 9999 FEW020 BKN300 32/23 Q1009 NOSIG. TAF WSSS 270500Z 2706/2812 17008KT 9999 FEW015 SCT020. What is the forecasted winds?

    • 210°T, 5Kts
    • 210°M, 5Kts
    • 170°T, 8KtsCorrect answer
    • 170°M, 8Kts
    Why: The question asks for the forecast wind, which comes from the TAF rather than the METAR. The TAF group 17008KT means wind from 170° at 8 kt, and all METAR and TAF winds are referenced to true north — so the answer is 170°T, 8 kt, not the METAR’s 21005KT.

  45. Q45. What may be affected if aircraft CG is outside the limit?

    • Nothing
    • Control forces, stability, manoeuvrability and performanceCorrect answer
    • Passenger comfort and susceptibility to turbulence
    • Structural lift
    Why: A centre of gravity outside limits adversely affects control forces, stability, manoeuvrability and performance. An aft CG reduces longitudinal stability while a forward CG raises stick forces and can limit elevator authority, both degrading handling.

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