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CAAB ATPL Theory study materials
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CAAB ATPL Theory practice questions

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Question 1Air Law

Under the Chicago Convention, each contracting State has ... over the airspace above its territory.

  1. Jurisdiction restricted to controlled airspace
  2. Sovereignty shared jointly with ICAO
  3. Complete and exclusive sovereignty Correct answer.
  4. Sovereignty limited to land areas only

Explanation

Article 1 of the Chicago Convention recognises that every State has complete and exclusive sovereignty over the airspace above its territory. Article 2 defines the territory of a State as including the land areas and territorial waters adjacent thereto. No delegation to ICAO or limitation by airspace type is implied.

Question 2Air Law

Which ICAO Annex contains the Standards and Recommended Practices for Rules of the Air?

  1. Annex 1
  2. Annex 2 Correct answer.
  3. Annex 11
  4. Annex 14

Explanation

Annex 2 to the Chicago Convention is titled Rules of the Air and contains the general rules governing flight, right of way, light signals and interception procedures. The other Annexes listed cover air traffic services, personnel licensing and aerodromes respectively.

Question 3Air Law

An aircraft registered in State A is destroyed in an accident at an aerodrome in State B. Which State is responsible for instituting the investigation?

  1. State B, as the State of Occurrence Correct answer.
  2. State A, as the State of Registry
  3. The State of the Operator, wherever it is located
  4. State B, as the State of Manufacture

Explanation

Annex 13 places the responsibility for instituting an investigation on the State of Occurrence, that is, the State in whose territory the accident happened. Other interested States, such as the State of Registry, Operator, Design and Manufacture, may participate but do not institute the investigation.

Question 4Air Law

Annex 17 to the Chicago Convention deals with ...

  1. The investigation of accidents and incidents
  2. The facilitation of international air transport
  3. The security of civil aviation against acts of unlawful interference Correct answer.
  4. The safe transport of dangerous goods by air

Explanation

Annex 17 contains the Standards and Recommended Practices for Security, aimed at safeguarding civil aviation against acts of unlawful interference. Dangerous goods are covered by Annex 18, accident investigation by Annex 13 and facilitation by Annex 9.

Question 5Air Law

Which ICAO Annex requires contracting States to establish search and rescue services within their territories?

  1. Annex 11
  2. Annex 15
  3. Annex 12 Correct answer.
  4. Annex 13

Explanation

Annex 12, Search and Rescue, obliges contracting States to arrange for search and rescue services to be established and provided within their territories. It also covers the organisation of search and rescue regions, rescue coordination centres and cooperation between States.

Question 6Air Law

The minimum age for the issue of an airline transport pilot licence (ATPL) under ICAO Annex 1 is ...

  1. 17 years
  2. 18 years
  3. 21 years Correct answer.
  4. 23 years

Explanation

Annex 1 specifies a minimum age of 21 years for an airline transport pilot licence. The corresponding minimum ages for a commercial pilot licence and a private pilot licence are 18 and 17 years respectively.

Question 7Air Law

A 34-year-old pilot engaged in single-pilot commercial passenger operations holds a Class 1 medical certificate. Under Annex 1, the certificate remains valid for a maximum of ...

  1. 3 months
  2. 12 months Correct answer.
  3. 6 months
  4. 24 months

Explanation

A Class 1 medical certificate is normally valid for 12 months. The reduced periodicity of 6 months applies only to licence holders who have reached the age of 40 and are engaged in single-pilot commercial passenger operations, which is not the case here.

Question 8Air Law

An aircraft is to be operated on international flights. Which State issues the certificate of airworthiness?

  1. The State of Registry Correct answer.
  2. The State of the Operator
  3. The State of Design
  4. The State of Manufacture

Explanation

Under Annex 8, the certificate of airworthiness is issued by the State of Registry, which is responsible for continuing airworthiness oversight of the individual aircraft. The States of Design and Manufacture provide the type certificate and supporting data rather than the individual certificate.

Question 9Air Law

An airline of State A wishes to carry passengers between two points within State B. Under the Chicago Convention, State B ...

  1. Is obliged to permit it under Article 5 on non-scheduled flights
  2. Must permit it under the first freedom of the air
  3. May refuse permission for such cabotage traffic Correct answer.
  4. Must permit it if the airline holds an air operator certificate

Explanation

Article 7 of the Convention reserves cabotage, the carriage of traffic between two points within a State's own territory, to that State's aircraft and gives each State the right to refuse permission to foreign aircraft. Granting such traffic is a matter of bilateral agreement, not an obligation.

Question 10Air Law

For VFR flight at and above 10 000 ft AMSL, the minimum flight visibility required by Annex 2 is ...

  1. 5 km
  2. 1.5 km
  3. 10 km
  4. 8 km Correct answer.

Explanation

Above 10 000 ft AMSL the VMC minima are a flight visibility of 8 km and a distance from cloud of 1500 m horizontally and 1000 ft vertically. Below that level the visibility requirement is reduced to 5 km.

Question 11Air Law

An IFR flight is planned on a magnetic track of 275°. Which of the following cruising levels is appropriate?

  1. FL 350
  2. FL 330
  3. FL 320 Correct answer.
  4. FL 310

Explanation

The semicircular rule allocates magnetic tracks from 180° to 359° to even flight levels, so a track of 275° requires an even level. Of the options, only FL 320 is an even level.

Question 12Air Law

Two aircraft of the same category are converging at approximately the same level. Which aircraft has the right of way?

  1. The heavier aircraft
  2. The aircraft on the right Correct answer.
  3. The aircraft on the left
  4. The faster aircraft

Explanation

Annex 2 requires that when two aircraft of the same category converge at approximately the same level, the aircraft on the right has the right of way. The other aircraft must give way, normally by altering heading to the right and, if necessary, changing level.

Question 13Air Law

An aircraft is overtaking another aircraft in flight. The overtaking aircraft shall ...

  1. Keep clear by passing to the right Correct answer.
  2. Keep clear by passing to the left
  3. Maintain level and reduce speed
  4. Continue, since it has the right of way

Explanation

The aircraft being overtaken has the right of way, and the overtaking aircraft must keep clear by altering heading to the right until entirely past and clear. This applies whether the overtaking aircraft is climbing, descending or level.

Question 14Air Law

An aircraft is on final approach to land while another aircraft is taxiing on the runway. Which aircraft has the right of way?

  1. Whichever aircraft requests it first
  2. The aircraft on final approach Correct answer.
  3. The aircraft with the higher wake turbulence category
  4. The taxiing aircraft, because it is on the ground

Explanation

Annex 2 gives right of way to an aircraft on final approach to land, or landing, over aircraft in flight or operating on the ground. The taxiing aircraft must therefore vacate or hold clear of the runway.

Question 15Air Law

When flying over a congested area of a city, the minimum height at which an aircraft may be flown is ...

  1. 1500 ft above the highest obstacle within 600 m
  2. 1000 ft above the ground
  3. 500 ft above the highest obstacle within 150 m
  4. 1000 ft above the highest obstacle within 600 m Correct answer.

Explanation

Over congested areas of cities, towns or settlements, or over an open-air assembly of persons, flight must be at least 1000 ft above the highest obstacle located within a horizontal radius of 600 m from the aircraft. Elsewhere the requirement is 500 ft above the ground or obstacles.

Question 16Air Law

Unless otherwise authorised, the maximum indicated airspeed for an aircraft flying below 10 000 ft is ...

  1. 230 kt
  2. 250 kt Correct answer.
  3. 200 kt
  4. 280 kt

Explanation

Annex 2 prescribes a maximum indicated airspeed of 250 kt for all aircraft below 10 000 ft unless the appropriate authority has authorised a higher speed for specific classes of aircraft. Higher speeds may also be permitted in certain controlled airspace by the competent authority.

Question 17Air Law

Which radiotelephony signal indicates that an aircraft is in distress and requires immediate assistance?

  1. SECURITE
  2. MAYDAY Correct answer.
  3. STANDBY
  4. PAN PAN

Explanation

MAYDAY is the international distress signal, used when an aircraft is threatened by serious and imminent danger and requires immediate assistance. PAN PAN is the urgency signal for a condition concerning safety that does not yet require immediate assistance.

Question 18Air Law

An aircraft suffering a complete failure of two-way radio communication should set its SSR transponder to ...

  1. 7700
  2. 2000
  3. 7500
  4. 7600 Correct answer.

Explanation

The special purpose codes are 7500 for unlawful interference, 7600 for radio communication failure and 7700 for an emergency. Code 7600 should therefore be selected and maintained when communication cannot be established.

Question 19Air Law

An intercepting aircraft makes an abrupt break-away manoeuvre, consisting of a climbing turn away from the intercepted aircraft. This indicates that the intercepted aircraft ...

  1. Must reduce speed and await further instructions
  2. May proceed with its flight Correct answer.
  3. Must land at the nearest suitable aerodrome
  4. Must follow the interceptor to a designated aerodrome

Explanation

In the ICAO interception signal series, the abrupt break-away manoeuvre means that the intercepted aircraft is released and may continue its flight. The instruction to follow is given instead by rocking the wings, or by flashing navigation lights at night.

Question 20Air Law

Which of the following is included in the take-off distance available (TODA)?

  1. The take-off run available plus the stopway
  2. The take-off run available plus the clearway Correct answer.
  3. The landing distance available plus the clearway
  4. The take-off run available plus the runway end safety area

Explanation

The take-off distance available is the length of the take-off run available plus the length of the clearway, if a clearway is provided. Adding a stopway instead gives the accelerate-stop distance available.

Question 21Air Law

A steady red light directed at an aircraft on the ground from the aerodrome control tower means ...

  1. Stop Correct answer.
  2. Taxi clear of the landing area in use
  3. Cleared to taxi
  4. Cleared for take-off

Explanation

For an aircraft on the ground, a steady red light from the tower means stop. A flashing red light means taxi clear of the landing area in use, while a flashing green light means cleared to taxi.

Question 22Air Law

Under Annex 13, the preliminary report on an aircraft accident is to be dispatched by the investigating State ...

  1. Within 30 days of the accident Correct answer.
  2. Within 12 months of the accident
  3. Within 12 hours of the accident
  4. Within 60 days of the date of the accident

Explanation

Annex 13 requires the State conducting the investigation to send a preliminary report to ICAO and to the States entitled to participate within 30 days of the date of the accident. The final report is normally produced within 12 months.

Question 23Air Law

Under Annex 14, a full-scale aerodrome emergency exercise shall be conducted at least ...

  1. Once every five years
  2. Once every two years Correct answer.
  3. Once every six months
  4. Once every year

Explanation

Annex 14 requires a full-scale aerodrome emergency exercise at least once every two years, with partial or table-top exercises in the intervening period. The exercise is used to test the aerodrome emergency plan and to correct any deficiencies found.

Question 24Air Law

Under the Tokyo Convention of 1963, which State is competent to exercise jurisdiction over an offence committed on board an aircraft in flight?

  1. The State of Registry of the aircraft Correct answer.
  2. The State of Manufacture
  3. The State of the Operator only
  4. The State over which the aircraft happens to be flying

Explanation

The Tokyo Convention establishes the competence of the State of Registration of the aircraft to exercise jurisdiction over offences and acts committed on board. It also recognises limited concurrent jurisdiction, for example where the offence has effect on the territory of another State.

Question 25Air Law

In Class A airspace, which flights are permitted?

  1. IFR flights only, all separated from each other Correct answer.
  2. IFR and controlled VFR flights, separated from each other
  3. IFR and VFR flights, all separated from each other
  4. VFR flights only, all separated from each other

Explanation

Class A airspace is reserved for IFR flights only, and all flights within it are provided with air traffic control service and separated from each other. VFR flights are not permitted in Class A airspace.

Question 26Air Law

A pilot sets the aircraft's SSR transponder to code 7500. What does this signify?

  1. Two-way radio communication failure
  2. Unlawful interference Correct answer.
  3. Loss of navigation capability
  4. A general emergency

Explanation

Annex 10 allocates three discrete codes for special situations: 7500 for unlawful interference, 7600 for radio communication failure and 7700 for a general emergency. Code 7500 therefore tells the ground that the flight is subject to an act of unlawful interference.

Question 27Air Law

Under ICAO Annex 2, when must an aircraft in flight display anti-collision lights?

  1. Only between sunset and sunrise, unless in IMC
  2. At all times, day and night Correct answer.
  3. Only when the aircraft is operated under IFR
  4. Only when flying within controlled airspace

Explanation

Annex 2 requires anti-collision lights intended to attract attention to the aircraft to be displayed day and night. They may be switched off only when their use would adversely affect the performance of the crew's duties or when it is in the interest of safety.

Question 28Air Law

In VMC at 5 000 ft AMSL in Class D airspace, ICAO Annex 2 requires the aircraft to remain clear of cloud by at least ...

  1. 1 000 ft vertically and 1 500 m horizontally Correct answer.
  2. 300 ft vertically and 1 500 m horizontally
  3. 1 000 ft vertically and 2 000 m horizontally
  4. 500 ft vertically and 1 000 m horizontally

Explanation

For VMC below 10 000 ft, Annex 2 requires a distance from cloud of at least 1 500 m horizontally and 1 000 ft vertically. The same cloud-clearance criteria apply above 10 000 ft, where only the visibility requirement changes.

Question 29Air Law

An aircraft is intercepted by another aircraft. Which action should the intercepted aircraft take in the first instance?

  1. Squawk 7700 and continue on the current track
  2. Descend and land at the nearest aerodrome
  3. Switch off the transponder to avoid interference
  4. Establish radio contact on 121.5 MHz Correct answer.

Explanation

Annex 2 interception procedures require the intercepted aircraft to attempt to establish radio communication with the intercepting aircraft or the appropriate intercept control unit on the emergency frequency 121.5 MHz. It should also try to attract attention, for example by rocking the wings or flashing landing lights.

Question 30Air Law

Under Article 15 of the Chicago Convention, charges imposed by a State on an aircraft of another Contracting State for the use of an airport must not exceed those paid by ...

  1. national aircraft engaged in similar international operations Correct answer.
  2. any foreign aircraft making use of the same airport facilities
  3. national aircraft of a greater maximum mass on the same route
  4. aircraft of the State that has concluded a bilateral air service agreement

Explanation

Article 15 requires airport and air navigation facility charges to be non-discriminatory: they may not be higher for the aircraft of another Contracting State than those paid by national aircraft engaged in similar international air services. The charges must also be published and notified to ICAO.

Question 31Aircraft General Knowledge

In a semi-monocoque fuselage, which members primarily carry the bending loads?

  1. Longitudinal stringers Correct answer.
  2. Outer skin panels
  3. Transverse frames
  4. Pressure bulkheads

Explanation

Stringers, or longerons, run fore and aft and together with the skin resist the bending moments acting on the fuselage. Frames maintain the cross-sectional shape and support the skin but contribute little to bending strength.

Question 32Aircraft General Knowledge

What is the main function of a hydraulic accumulator in an aircraft system?

  1. It raises pump output at low engine speed
  2. It cools the fluid returning to the reservoir
  3. It filters contaminants from the fluid
  4. It stores fluid to absorb pressure surges Correct answer.

Explanation

An accumulator contains fluid under gas pressure and acts as a cushion, absorbing pressure peaks and smoothing pump pulsations. It also provides a limited supply of fluid for emergency or transient demands.

Question 33Aircraft General Knowledge

What is the purpose of the voltage regulator in a DC generating system?

  1. To limit the generator output current
  2. To keep generator voltage within set limits Correct answer.
  3. To disconnect the battery during start
  4. To convert AC into DC for the battery

Explanation

The voltage regulator varies the generator field excitation so that the output voltage stays at the design value as load and engine speed change. Current limitation and reverse-current protection are separate functions.

Question 34Aircraft General Knowledge

Water and sediment are normally removed from an aircraft fuel system by...

  1. the main fuel filter
  2. the fuel boost pumps
  3. the fuel control unit
  4. the tank sump drains Correct answer.

Explanation

Water is denser than fuel and collects at the lowest points of each tank, where sump drains allow it to be sampled and drained before flight. Filters remove solid particles but do not provide a routine way of removing settled water.

Question 35Aircraft General Knowledge

A propeller blade is in the feathered position when its chord line is...

  1. set to give maximum thrust
  2. approximately aligned with the relative airflow Correct answer.
  3. set to the finest pitch angle
  4. at right angles to the relative airflow

Explanation

Feathering turns the blade to a very coarse angle so that it lies almost edge-on to the relative airflow, giving minimum drag and resisting windmilling after an engine failure.

Question 36Aircraft General Knowledge

What is the purpose of creep marks on an aircraft wheel and tyre?

  1. To balance the wheel assembly
  2. To show the tyre inflation pressure
  3. To show whether the tyre has slipped on the rim Correct answer.
  4. To indicate the tyre wear limit

Explanation

Creep marks are aligned lines painted across the tyre sidewall and the wheel rim. If the marks become misaligned, the tyre has rotated on the rim, usually as a result of heavy braking or under-inflation.

Question 37Aircraft General Knowledge

Which extinguishing agent is commonly used for aircraft engine and cargo compartment fires?

  1. Dry powder
  2. Halon Correct answer.
  3. Carbon dioxide only
  4. Water spray

Explanation

Halon is the standard fixed-fire-extinguishing agent for engines, APUs and cargo compartments because it interrupts the combustion reaction and leaves no residue. It is effective in relatively low concentrations and does not damage equipment.

Question 38Aircraft General Knowledge

In the ideal Otto cycle, thermal efficiency increases primarily with...

  1. increasing compression ratio Correct answer.
  2. increasing manifold pressure
  3. decreasing compression ratio
  4. increasing fuel/air ratio

Explanation

The ideal Otto cycle efficiency is given by 1 minus 1 divided by the compression ratio raised to the power gamma minus one. Increasing the compression ratio raises the efficiency; manifold pressure and mixture ratio affect power output rather than ideal cycle efficiency.

Question 39Aircraft General Knowledge

Carburettor ice is most likely to form when the outside air temperature is between...

  1. 0 degrees C and +5 degrees C only at full throttle
  2. +20 degrees C and +30 degrees C with any humidity
  3. -5 degrees C and +15 degrees C with high humidity Correct answer.
  4. -30 degrees C and -10 degrees C with low humidity

Explanation

Carburettor icing is most likely in cool, moist air because the fuel vaporisation and venturi pressure drop cool the charge by a further 20 degrees C or more. The risk is greatest in the range of roughly minus five to plus fifteen degrees Celsius with high relative humidity.

Question 40Aircraft General Knowledge

Which condition is most likely to cause detonation in a piston engine?

  1. A rich mixture at low power
  2. A low intake air temperature
  3. A high octane fuel
  4. A weak mixture at high power Correct answer.

Explanation

Detonation occurs when the end gas in the cylinder ignites spontaneously ahead of the flame front, producing the characteristic knock. A weak mixture at high power raises combustion temperatures and pressures, which makes detonation far more likely.

Question 41Aircraft General Knowledge

What is the effect of using hydraulic fluid with too high a viscosity?

  1. The system pressure falls to zero
  2. The fluid becomes more compressible
  3. Seals wear more rapidly
  4. Pressure losses in the lines increase Correct answer.

Explanation

A high-viscosity fluid flows less easily, so the pressure drop through pipes, valves and filters increases and system response becomes sluggish. Excessive pressure losses can also reduce the pressure available at the actuators.

Question 42Aircraft General Knowledge

In a typical cabin pressurisation system, cabin altitude is controlled by...

  1. the air cycle machine
  2. the cabin pressure relief valve
  3. the outflow valve Correct answer.
  4. the bleed air shut-off valve

Explanation

The outflow valve regulates the rate at which air leaves the cabin. By opening or closing it, the pressure controller sets the cabin altitude and its rate of change.

Question 43Aircraft General Knowledge

In an air cycle air conditioning system, the air is cooled by...

  1. expansion through a turbine Correct answer.
  2. passing through a heat exchanger only
  3. mixing with recirculated cabin air
  4. compression in the compressor

Explanation

In a bootstrap air cycle machine, bleed air is compressed, cooled in a heat exchanger and then expanded through a turbine. The expansion does work on the turbine, which drops the air temperature sharply.

Question 44Aircraft General Knowledge

Which method is used to protect the leading edges of a wing from ice accretion on many transport aircraft?

  1. Electro-thermal mats on the upper surface
  2. Spraying de-icing fluid in flight
  3. Hot bleed air heating the leading edge Correct answer.
  4. Pneumatic boots inflating

Explanation

Thermal anti-icing uses hot engine bleed air ducted through the leading edge to keep the surface above freezing so that ice cannot form. Pneumatic boots are more common on smaller aircraft and remove ice after it has formed.

Question 45Aircraft General Knowledge

What is the purpose of a shimmy damper on a nose landing gear?

  1. To suppress nose wheel oscillations Correct answer.
  2. To lock the gear in the down position
  3. To damp landing impact loads
  4. To centre the wheel after steering

Explanation

A shimmy damper adds hydraulic or friction damping to the nose wheel steering axis. It prevents the rapid side-to-side oscillation known as shimmy that can occur at certain speeds.

Question 46Aircraft General Knowledge

An anti-skid system prevents wheel lock by...

  1. Releasing pressure at a fixed cyclic rate
  2. Applying the parking brake automatically
  3. Increasing pressure as the wheel decelerates
  4. Modulating pressure to limit wheel slip Correct answer.

Explanation

The anti-skid system compares wheel speed with aircraft speed and modulates brake pressure to keep the tyre near its optimum slip ratio. This preserves cornering grip and prevents a locked wheel from skidding.

Question 47Aircraft General Knowledge

On a transport aircraft, the AC generators are normally driven through a constant speed drive because...

  1. the engine speed is too low for generation
  2. the generator needs oil cooling
  3. generator frequency must remain constant Correct answer.
  4. generator voltage must remain constant

Explanation

The frequency produced by an AC generator depends directly on its rotational speed. A constant speed drive keeps the generator at a constant rpm, and therefore at a constant frequency, despite variations in engine speed.

Question 48Aircraft General Knowledge

What is the main purpose of fuel boost pumps in an aircraft fuel system?

  1. To raise the fuel temperature before combustion
  2. To transfer fuel between the wing tanks
  3. To meter the fuel flow to the engine
  4. To feed the engine pump at positive pressure Correct answer.

Explanation

Boost pumps deliver fuel from the tank to the engine-driven pump at a positive pressure. This suppresses vapour locking at altitude and ensures a continuous supply at high engine demand.

Question 49Aircraft General Knowledge

In a piston engine, the primary function of the oil cooler is to...

  1. increase oil viscosity
  2. keep oil temperature within limits Correct answer.
  3. clean the oil
  4. prevent oil foaming

Explanation

The oil cooler transfers heat from the oil to the air or fuel so that the oil stays within its designed temperature range. This keeps viscosity suitable and prevents breakdown of the oil.

Question 50Aircraft General Knowledge

In a high-bypass-ratio turbofan engine, most of the thrust at take-off is produced by...

  1. the hot core exhaust gases
  2. the high-pressure compressor
  3. the low-pressure turbine
  4. the fan-driven bypass air Correct answer.

Explanation

In a high-bypass turbofan, the fan accelerates a large mass of air through the bypass duct, and this stream produces the majority of the thrust. The core exhaust contributes a smaller share.