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Bahrain CAA PPL study materials
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Bahrain CAA PPL practice questions

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Question 1Air Law

Under the Bahrain Civil Aviation Regulations, which document primarily prescribes the rules of the air applicable to flights within Bahraini airspace?

  1. The airport authority's apron safety notice
  2. The ICAO Annex 2 only, without national effect
  3. The airline's own operations manual
  4. The Bahrain Civil Aviation Law and its implementing regulations Correct answer.

Explanation

National rules of the air in Bahrain are given force through the Bahrain Civil Aviation Law and the regulations issued under the Civil Aviation Affairs of the Ministry of Transportation and Telecommunications. ICAO Annexes provide the international standards that national regulations implement, but they do not by themselves create enforceable domestic rules. Company manuals and airport notices apply only within their own limited scope.

Question 2Air Law

A pilot is unsure whether a Bahraini regulation or an ICAO Annex Standard takes precedence for a flight within Bahrain. Which principle applies?

  1. The ICAO Annex always overrides national law
  2. National regulations take precedence, since the State implements and may differ from the Standard Correct answer.
  3. The older of the two documents prevails
  4. The pilot may choose whichever is more convenient

Explanation

A State gives effect to ICAO Standards through its own legislation, and where a State has filed a difference the national rule governs operations in that State. The Annex itself is not self-executing, so it cannot override the enacted national regulation. A pilot therefore follows the Bahraini rule, while noting any published difference.

Question 3Air Law

Which authority is responsible for issuing and administering pilot licences in Bahrain?

  1. The national carrier's training department
  2. The Gulf Cooperation Council secretariat
  3. The Bahrain Airport Company
  4. The Civil Aviation Affairs of the Ministry of Transportation and Telecommunications Correct answer.

Explanation

Licensing of flight crew in Bahrain falls under the Civil Aviation Affairs, the national civil aviation authority within the Ministry of Transportation and Telecommunications. It issues licences in accordance with the national regulations, which are aligned with ICAO Annex 1. Airport operators and airlines have operational roles but no licensing authority.

Question 4Air Law

What is the minimum age at which a person may be issued a Private Pilot Licence (Aeroplane) under the applicable standards?

  1. 16 years
  2. 21 years
  3. 18 years
  4. 17 years Correct answer.

Explanation

The internationally recognised standard for issue of a private pilot licence is a minimum age of 17 years, and Bahrain's licensing regulations follow this standard. The 16-year minimum applies to the student pilot or to licences such as the recreational or glider categories, not to the PPL. Higher ages such as 18 or 21 are required for other licences or ratings.

Question 5Air Law

Before acting as pilot in command of an aeroplane carrying passengers, a PPL holder must in principle hold which additional qualification?

  1. An instrument rating in all cases
  2. A commercial pilot licence
  3. A flight instructor certificate
  4. A valid class or type rating for the aircraft, current in accordance with the regulations Correct answer.

Explanation

A licence alone does not authorise flight in a specific aircraft; the pilot must also hold the appropriate class or type rating and keep it current. Passenger carriage does not require an instrument rating or a higher-grade licence for private operations in visual conditions. Instructor privileges are separate and not a prerequisite for carrying passengers.

Question 6Air Law

A PPL holder wishes to carry passengers. Which recent flight experience requirement must normally be met?

  1. One take-off and landing within the preceding 12 months
  2. A biennial check ride with the authority
  3. Three take-offs and landings within the preceding 90 days on the same class or type Correct answer.
  4. Ten hours of instrument time within the preceding 6 months

Explanation

To carry passengers, the pilot must have completed at least three take-offs and three landings within the preceding 90 days in the same class or type, and in aircraft requiring two pilots these must be performed in the pilot seat. This ensures recent handling experience before passengers are carried. Currency is separate from licence validity and from instrument recency.

Question 7Air Law

How long is a Class 1 medical certificate normally valid for a pilot under 40 years of age who is exercising commercial privileges?

  1. 6 months
  2. 12 months Correct answer.
  3. 36 months
  4. 24 months

Explanation

A Class 1 medical certificate is generally valid for 12 months for holders under 40 years of age, with the validity reducing to 6 months once the holder reaches 40. Class 2 validity is longer, typically 24 months for younger holders. The validity also depends on the privileges exercised, so the applicable rule must be checked.

Question 8Air Law

A pilot's medical certificate expires during a flight. What is the status of the flight?

  1. The flight may be continued to completion if it began while the certificate was valid Correct answer.
  2. The flight becomes illegal immediately and must divert to the nearest aerodrome
  3. The certificate is automatically renewed on landing
  4. The pilot may continue for a further 30 days without action

Explanation

Where a medical certificate lapses during a flight, the flight may be completed, provided it commenced while the certificate was still valid. This avoids forcing an unsafe diversion for an administrative expiry. The pilot must not commence any further flight until the certificate is renewed.

Question 9Air Law

Under the rules of the air, which aircraft has the right of way when two aircraft of the same category are converging at approximately the same altitude?

  1. The aircraft on the right Correct answer.
  2. The faster aircraft
  3. The aircraft with the lower registration number
  4. The aircraft on the left

Explanation

When two aircraft of the same category converge at approximately the same level, the aircraft on the right has the right of way and the other must give way. The giving-way aircraft should avoid crossing ahead and, if necessary, alter heading to the right. Speed and registration are irrelevant to the right-of-way rule.

Question 10Air Law

An aircraft on final approach to land has the right of way over which other aircraft?

  1. Aircraft in flight at a higher altitude
  2. Aircraft already landed and vacating the runway
  3. Aircraft in the air or operating on the ground Correct answer.
  4. Aircraft on the ground taxiing

Explanation

An aircraft on final approach to land, or landing, has priority over all other aircraft in the air and on the ground. Other traffic must give way and must not impede the landing. This rule protects the most critical phase of flight, when manoeuvring options are limited.

Question 11Air Law

What is the minimum height above the highest obstacle within a horizontal radius of 600 metres that a VFR flight over a congested area of a city must normally maintain?

  1. 150 metres
  2. 1 000 feet above the surface only
  3. 300 metres Correct answer.
  4. 600 metres

Explanation

Over congested areas of cities, towns or settlements, or over an open-air assembly of persons, a VFR flight must not be operated below 300 metres above the highest obstacle within a horizontal radius of 600 metres of the aircraft. Elsewhere, a lower minimum such as 150 metres above the surface applies. These minima protect persons and property on the ground.

Question 12Air Law

For a VFR flight at or above 3 000 metres (10 000 feet) above mean sea level, what minimum flight visibility is normally required?

  1. 8 000 metres Correct answer.
  2. 1 500 metres
  3. No visibility requirement applies
  4. 5 000 metres

Explanation

At and above 3 000 metres above mean sea level, VFR flight requires a flight visibility of at least 8 000 metres, together with the specified distance from cloud. Below that level, lower visibility minima apply depending on airspace class. The higher requirement reflects the greater speeds and reduced reaction margins at altitude.

Question 13Air Law

Which of the following best describes the visibility and cloud distance criteria that must be met for flight under VFR in controlled airspace?

  1. Cloud clearance is required only when flying above 3 000 metres
  2. Only the reported ground visibility at the departure aerodrome matters
  3. Flight visibility and distance from cloud must equal or exceed the prescribed minima for the airspace class Correct answer.
  4. Visibility minima may be disregarded if the pilot holds an instrument rating

Explanation

VFR flight requires that both flight visibility and distance from cloud meet or exceed the minima prescribed for the class of airspace being used. Ground visibility at an aerodrome is used for take-off and landing minima, but it does not substitute for in-flight criteria. Holding an instrument rating does not permit VFR flight in conditions below the minima.

Question 14Air Law

Which of the following flights may be conducted under special VFR within a control zone?

  1. A flight cleared by ATC, with the pilot remaining clear of cloud and with the surface in sight Correct answer.
  2. A flight without any ATC clearance when visibility is at least 1 500 metres
  3. Any flight, provided the pilot holds an instrument rating
  4. A flight only when the aircraft is equipped for instrument flight

Explanation

Special VFR allows flight within a control zone in conditions below the normal VFR minima, but only with an explicit ATC clearance and while the pilot remains clear of cloud and with the surface in sight. It is not available merely because the pilot is instrument rated. The clearance and the see-and-avoid conditions are both essential.

Question 15Air Law

What does a steady red light directed at an aircraft in flight by ATC mean?

  1. Give way to other aircraft and continue circling Correct answer.
  2. Return to the aerodrome and land
  3. Stop the aircraft and hold position
  4. Continue the approach and land

Explanation

A steady red light shown to an aircraft in flight means the pilot must give way to other aircraft and continue circling. It is not an instruction to land or to stop in the air. The signal sequence differs from those used for aircraft on the ground.

Question 16Air Law

An aircraft on the ground receives a flashing white light from the aerodrome control tower. What action is required?

  1. Stop immediately
  2. Return to the starting point on the aerodrome Correct answer.
  3. Continue taxiing as cleared
  4. Vacate the runway without delay

Explanation

A flashing white light directed at an aircraft on the ground means the aircraft should return to its starting point on the aerodrome. It is distinct from a flashing red light, which instructs the aircraft to vacate the runway in use. Pilots must recognise these signals in case of radio failure.

Question 17Air Law

When must position lights on an aircraft be displayed?

  1. Only when the aircraft is on the ground
  2. Only when flying at night
  3. At night and during any other period when visibility is reduced Correct answer.
  4. Only when flying in controlled airspace

Explanation

Navigation or position lights must be displayed at night and during any other period when visibility is reduced, such as in poor daylight conditions. They indicate the aircraft's position and heading to other traffic. Display is not limited to controlled airspace or to ground operations.

Question 18Air Law

An aircraft is being overtaken by another aircraft. Which aircraft must keep out of the way?

  1. The aircraft with the slower speed
  2. The overtaking aircraft Correct answer.
  3. The aircraft being overtaken
  4. The aircraft flying at the lower altitude

Explanation

The aircraft that is overtaking must keep out of the way of the aircraft being overtaken, whether climbing, descending or level. The overtaking aircraft should alter heading to the right until entirely clear. The overtaken aircraft maintains its course and speed.

Question 19Air Law

Two aircraft are approaching head-on or nearly so and there is risk of collision. What should each pilot do?

  1. The faster aircraft slows down
  2. Both alter heading to the left
  3. The lower aircraft climbs
  4. Both alter heading to the right Correct answer.

Explanation

When two aircraft approach head-on or nearly head-on and risk of collision exists, both pilots should alter heading to the right. This produces a predictable separation to the left of each aircraft. Altering to the left would turn the aircraft towards each other.

Question 20Air Law

What is the meaning of the term 'ceiling' when used in aviation weather and operational planning?

  1. The height of the highest cloud layer observed
  2. The maximum altitude at which the aircraft may be operated
  3. The height of the tropopause
  4. The height above ground or water of the base of the lowest layer of cloud below 6 000 metres covering more than half the sky Correct answer.

Explanation

Ceiling is defined as the height above the ground or water of the base of the lowest layer of cloud below 6 000 metres covering more than half of the sky. It is a key element for VFR planning because a low ceiling restricts visual flight. It is not the highest cloud layer or an aircraft performance limit.

Question 21Air Law

An aircraft is compelled to land at an aerodrome other than of intended landing because of weather. What is the primary obligation of the pilot in command?

  1. Abandon the aircraft and travel to the destination
  2. Report the landing to the appropriate authority and comply with local requirements Correct answer.
  3. Wait for the weather to improve before contacting anyone
  4. Continue to the destination under special VFR

Explanation

When a flight lands at an aerodrome other than that of intended landing, the pilot in command must report the landing without delay to the appropriate authority and comply with any local customs, immigration and health requirements. This ensures the authorities know the aircraft's whereabouts and status. The aircraft should not simply be abandoned.

Question 22Air Law

What is the general rule on the carriage of dangerous goods by a private pilot operating a non-commercial flight?

  1. Dangerous goods may never be carried in any aircraft
  2. Dangerous goods may be carried freely if the quantity is small
  3. Dangerous goods may be carried if the pilot considers them safe
  4. Dangerous goods may be carried only in accordance with the applicable regulations and any required approvals Correct answer.

Explanation

Carriage of dangerous goods is governed by the applicable dangerous goods regulations, which specify permitted items, packaging, marking and documentation. Some items are forbidden entirely, while others may be carried under defined conditions and approvals. The pilot's personal opinion of safety does not authorise carriage.

Question 23Air Law

What is the purpose of an Airworthiness Directive issued by the State of Registry?

  1. To mandate corrective action on aircraft or components to restore or maintain airworthiness Correct answer.
  2. To recommend optional improvements to aircraft comfort
  3. To approve the pilot's licence renewal
  4. To set the airspace classification at an aerodrome

Explanation

An Airworthiness Directive is a mandatory requirement issued to correct an unsafe condition found in a type design, aircraft or component. Compliance is compulsory and must be recorded in the aircraft maintenance records. It is not advisory and is unrelated to licensing or airspace matters.

Question 24Air Law

An aircraft's Certificate of Airworthiness has become invalid because a required inspection was not completed. What is the correct course of action?

  1. Do not fly the aircraft until the inspection is completed and the certificate is valid Correct answer.
  2. Fly the aircraft to a maintenance base for the inspection
  3. Fly only if no passengers are carried
  4. Fly only in daylight and clear weather

Explanation

A flight may only be made when the aircraft is airworthy and holds a valid Certificate of Airworthiness. If a required inspection or maintenance action has lapsed, the aircraft must not be flown until the work is completed. Neither the absence of passengers nor favourable weather cures an invalid certificate.

Question 25Air Law

Which of the following is a required element of a flight plan submitted for a flight under instrument flight rules in controlled airspace?

  1. The colour scheme of the aircraft
  2. The aircraft identification and type, together with the route and cruising level Correct answer.
  3. The pilot's home address
  4. The name of the aircraft owner's insurer

Explanation

A flight plan must contain the information necessary for air traffic services, including aircraft identification, type, departure and destination aerodromes, route, cruising level and speed, and endurance. Personal or commercial details such as insurance or aircraft colour are not part of the operational content. Complete information allows ATC to provide separation and alerting services.

Question 26Air Law

Under the Convention on International Civil Aviation, which document normally certifies that an aircraft is airworthy and is recognised by other contracting States?

  1. The Certificate of Registration issued by the State of Registry
  2. The pilot licence endorsed by the State of the Operator
  3. The radio station licence issued by the State of the Operator
  4. The Certificate of Airworthiness issued by the State of Registry Correct answer.

Explanation

The Certificate of Airworthiness is issued by the State of Registry after the aircraft is shown to comply with the applicable airworthiness requirements, and other contracting States accept it provided the aircraft remains maintained to those standards. The registration certificate only establishes nationality, while licences and radio documents relate to personnel and equipment rather than airworthiness.

Question 27Air Law

What is the primary purpose of the Certificate of Registration of an aircraft?

  1. To authorise the aircraft to carry passengers for remuneration
  2. To confirm that the aircraft's maintenance programme has been approved
  3. To record the aircraft's nationality and registration mark Correct answer.
  4. To specify the maximum take-off mass permitted for the aircraft

Explanation

Registration establishes the aircraft's nationality and its unique registration mark, and the certificate is the documentary evidence of that registration. It does not by itself confer operating permission or confirm maintenance status.

Question 28Air Law

An aircraft is landing and another aircraft is taxiing on the manoeuvring area. Which aircraft has the right of way?

  1. The landing aircraft, because aircraft on final approach or landing have priority Correct answer.
  2. The taxiing aircraft, because it is already established on the ground
  3. Neither aircraft, because both must stop and await instructions
  4. The aircraft with the higher maximum take-off mass

Explanation

Aircraft on final approach to land or already landing have the right of way over aircraft manoeuvring on the ground, which must give way and keep clear of the runway in use. This protects the landing aircraft, which has limited ability to go around at short notice.

Question 29Air Law

During a flight, an aircraft receives a series of green flashes from the aerodrome control tower. What does this signal mean?

  1. Cleared to land
  2. Aerodrome unsafe, do not land
  3. Return for landing, to be followed by a steady green at the appropriate time Correct answer.
  4. Give way to other aircraft and continue circling

Explanation

A succession of green flashes directed at an aircraft in flight means the aircraft is cleared to return for landing and should expect a steady green light at the proper moment. It is a conditional clearance, not an immediate landing clearance.

Question 30Air Law

An aircraft in flight receives a series of red flashes from the aerodrome control tower. What is the correct interpretation?

  1. Cleared to land immediately
  2. Continue circling and await further instructions
  3. Aerodrome unsafe, do not land Correct answer.
  4. Land and proceed to the apron

Explanation

In the international light-signal table, a series of red flashes directed at an aircraft in flight warns that the aerodrome is unsafe and that landing must not be attempted. The pilot should consider diverting to a suitable alternate.

Question 31Air Law

At night, when must an aircraft display its navigation lights?

  1. Only when operating within controlled airspace
  2. During the whole period between sunset and sunrise, and at other times when the State prescribes Correct answer.
  3. Only when the aircraft is on the ground and engines are running
  4. Only when flying in instrument meteorological conditions

Explanation

Navigation lights must be shown at night, generally from sunset to sunrise, and also at any other time the responsible authority may prescribe to ensure the aircraft is visible. The requirement is not limited to controlled airspace or particular weather conditions.

Question 32Air Law

An aircraft is flying in a control zone and the pilot wishes to change from IFR to VFR. What condition must normally be satisfied?

  1. The pilot must obtain an explicit clearance from the appropriate ATC unit before changing
  2. The pilot must wait until leaving the control zone before changing flight rules
  3. The pilot may change without any notification provided the aircraft remains in radio contact
  4. The pilot must advise ATC of the change and the change must be made in meteorological conditions that meet VFR criteria Correct answer.

Explanation

When a flight is conducted under IFR in controlled airspace and the pilot wishes to continue under VFR, the pilot must notify the appropriate ATC unit and the change may only be made when the meteorological conditions permit flight under visual flight rules. Cancelling IFR without notification can create a serious traffic conflict.

Question 33Air Law

A controlled flight is about to enter an area where it will be beyond the range of the ground radio station with which it has been communicating. What is the correct action?

  1. Continue without action, because radio failure procedures apply only in the event of an actual failure
  2. Advise ATC, and if possible obtain a transfer of communication to the next appropriate unit before losing contact Correct answer.
  3. Descend below 1 000 feet to re-establish contact with the previous station
  4. Squawk 7600 and continue on the current clearance without informing anyone

Explanation

Before a controlled flight leaves the range of a ground station, the pilot should notify ATC and, where practicable, arrange for communication to be transferred to the next appropriate unit. This ensures the flight remains in contact with the responsible unit and that separation is maintained.

Question 34Air Law

What does the term 'movement area' mean in aerodrome terminology?

  1. The apron only, including aircraft stands
  2. The whole of the aerodrome, including runways, taxiways and aprons
  3. The part of an aerodrome to be used for the take-off, landing and taxiing of aircraft, excluding aprons Correct answer.
  4. The runway strip and the clearway together

Explanation

The movement area comprises the manoeuvring area plus the aprons, but the term is often contrasted with the manoeuvring area, which excludes aprons. Careful use of these definitions matters for right-of-way and access rules.

Question 35Air Law

Which of the following best describes the 'manoeuvring area' of an aerodrome?

  1. The area used for the maintenance of aircraft
  2. The terminal building and its road access
  3. The part of the aerodrome used for take-off, landing and taxiing of aircraft, excluding aprons Correct answer.
  4. The apron and the aircraft parking positions

Explanation

The manoeuvring area is that part of the aerodrome used for the take-off, landing and taxiing of aircraft, excluding aprons. The distinction matters because ATC clearance requirements and ground movement rules differ between the manoeuvring area and the apron.

Question 36Air Law

An aircraft is on the ground and the tower signals it with a steady red light. What does this mean?

  1. Return to the starting point
  2. Stop Correct answer.
  3. Cleared to taxi
  4. Taxi clear of the runway in use

Explanation

For an aircraft on the ground, a steady red light from the tower means stop. Further movement requires a subsequent clearance, usually given by another light signal.

Question 37Air Law

Which condition must be met before a pilot may operate an aircraft as pilot-in-command carrying passengers?

  1. The pilot must hold a valid licence with the appropriate rating for the aircraft and be medically fit in accordance with the applicable medical certificate Correct answer.
  2. The pilot must have logged at least 100 hours of total flight time in any aircraft type
  3. The pilot must have flown the aircraft type within the previous 12 months
  4. The pilot must hold an instrument rating for the aircraft type

Explanation

Carrying passengers requires a valid pilot licence with the appropriate type or class rating and a current medical certificate appropriate to the privileges being exercised. Additional hours, an instrument rating or recent type experience may be required in particular cases but are not universal conditions for all private flights.

Question 38Air Law

A pilot holds a PPL and wishes to act as pilot-in-command of an aircraft carrying passengers at night. What must the pilot hold?

  1. A multi-engine class rating only
  2. A night rating or the appropriate night flying privileges endorsed on the licence Correct answer.
  3. A flight instructor rating
  4. An airline transport pilot licence

Explanation

Carrying passengers at night requires the pilot to hold night flying privileges, normally evidenced by a night rating or an equivalent endorsement. Without those privileges the pilot may not act as pilot-in-command at night, even if otherwise qualified by day.

Question 39Air Law

An aircraft is being operated in the vicinity of an aerodrome and the pilot observes another aircraft approaching to land. What is the pilot's obligation?

  1. Increase speed to pass ahead of the landing aircraft
  2. Give way to the landing aircraft and avoid cutting in front of it or overtaking it on final approach Correct answer.
  3. Maintain the current flight path because the other aircraft must give way
  4. Land first because the pilot is already established in the circuit

Explanation

Aircraft in the vicinity of an aerodrome must give way to aircraft landing or on final approach, and must not cut in front of or overtake them on final approach. This prevents conflicts at the most critical phase of flight.

Question 40Air Law

Which of the following is a general requirement for a pilot to act as pilot-in-command of an aircraft on a flight that crosses an international border?

  1. The pilot must hold a licence and medical certificate valid under the regulations, and the aircraft must carry the required documents Correct answer.
  2. The pilot must hold a licence issued by the State being overflown
  3. The pilot must file a flight plan only if flying under IFR
  4. The pilot must obtain a new Certificate of Airworthiness in each State overflown

Explanation

International flights require a valid licence and medical certificate and the carriage of prescribed documents, including the registration and airworthiness certificates and the journey log. The licences and certificates issued by the State of Registry are recognised by other contracting States.

Question 41Aircraft General Knowledge

Which component of a four-stroke piston engine opens to admit the fuel-air mixture into the cylinder?

  1. The exhaust valve
  2. The inlet valve Correct answer.
  3. The piston ring
  4. The spark plug

Explanation

The inlet (intake) valve is timed to open during the induction stroke so the fuel-air charge can be drawn into the cylinder as the piston descends. The exhaust valve remains closed during this stroke. Valve opening is controlled by the camshaft.

Question 42Aircraft General Knowledge

In a four-stroke cycle, during which stroke does the piston move upward with both valves closed, compressing the mixture?

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

Explanation

During compression both valves are shut and the rising piston reduces the cylinder volume, raising pressure and temperature before ignition. This prepares the charge for efficient combustion. Ignition occurs near the top of this stroke.

Question 43Aircraft General Knowledge

What is the primary purpose of the carburettor in a piston engine induction system?

  1. To meter and mix fuel with air in the correct proportion Correct answer.
  2. To regulate the ignition timing
  3. To increase the octane rating of the fuel
  4. To cool the engine oil during flight

Explanation

The carburettor proportions fuel and air to produce a combustible mixture suitable for the engine across its operating range. Mixture strength is controlled by the mixture lever, and the throttle controls the quantity admitted. It does not alter fuel chemistry or ignition timing.

Question 44Aircraft General Knowledge

Which instrument indicates the rotational speed of the engine crankshaft?

  1. The tachometer Correct answer.
  2. The fuel flow indicator
  3. The manifold pressure gauge
  4. The oil pressure gauge

Explanation

The tachometer displays engine speed, usually in revolutions per minute, which the pilot uses to set and monitor power. For a fixed-pitch propeller, rpm is the principal power indication. Manifold pressure is used mainly with constant-speed propellers.

Question 45Aircraft General Knowledge

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

  1. To drive the vacuum pump for the gyroscopic instruments
  2. To generate the high-tension voltage that fires the spark plugs Correct answer.
  3. To charge the aircraft battery in flight
  4. To supply pressurised fuel to the injectors

Explanation

Magnets rotate past coils to induce a high voltage that is distributed to the spark plugs at the correct moment. Two independent magnetos are fitted so that ignition continues if one fails. The engine-driven nature means ignition does not depend on the aircraft battery.

Question 46Aircraft General Knowledge

Which of these is the purpose of the engine oil in a piston aero engine?

  1. To act as the primary source of cabin heat
  2. To increase the octane rating of the fuel
  3. To lubricate moving parts, assist cooling and hold contaminants in suspension Correct answer.
  4. To raise the compression ratio of the cylinders

Explanation

Oil reduces friction between moving surfaces, carries heat away from hot components and suspends dirt and metal particles for removal by the filter. It also helps seal and protect against corrosion. These combined functions are essential for reliable engine operation.

Question 47Aircraft General Knowledge

An aircraft is fitted with a fixed-pitch propeller. Which combination best describes how engine power is controlled in cruise?

  1. By the throttle, which changes rpm and therefore power Correct answer.
  2. By the mixture lever alone, with the throttle fully open
  3. By the cowl flaps, which set the power output
  4. By the propeller pitch lever, which changes blade angle

Explanation

With a fixed-pitch propeller, blade angle cannot change, so engine speed varies directly with throttle setting and manifold pressure. The pilot sets power mainly by reference to rpm. There is no propeller control lever on such an installation.

Question 48Aircraft General Knowledge

Why does a constant-speed propeller unit vary blade angle as airspeed changes at a fixed power setting?

  1. To maintain a fixed fuel-air ratio automatically
  2. To keep manifold pressure constant regardless of throttle position
  3. To prevent carburettor icing at high altitude
  4. To keep the engine rpm at the selected value despite changing airspeed Correct answer.

Explanation

The propeller governor senses rpm and adjusts blade angle: coarser at high airspeed to absorb power, finer at low airspeed. This keeps engine speed at the value selected by the pilot. It allows efficient operation without continual throttle adjustment.

Question 49Aircraft General Knowledge

What is detonation in a piston aero engine?

  1. Pre-ignition caused by a glowing spark plug electrode
  2. The normal rapid combustion that produces the power stroke
  3. Explosive, uncontrolled burning of the fuel-air charge after normal ignition Correct answer.
  4. The sudden loss of oil pressure at high rpm

Explanation

Detonation occurs when part of the charge ignites spontaneously ahead of the flame front, producing a rapid pressure rise and high cylinder temperatures. It can cause overheating and structural damage. It is distinct from pre-ignition, which is ignition before the spark.

Question 50Aircraft General Knowledge

A pilot suspects pre-ignition. Which action is the most appropriate immediate response?

  1. Reduce power and enrich the mixture, then investigate on the ground Correct answer.
  2. Increase power to clear the fault
  3. Switch off the fuel pump and continue the flight
  4. Lean the mixture aggressively to cool the charge

Explanation

Pre-ignition raises cylinder temperatures and can rapidly damage the engine, so power should be reduced and the mixture enriched to lower temperatures. A landing and engineering inspection should follow. Continuing at high power risks severe damage.