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Oman CAA ATPL(A) Theory study materials
Oman CAA ATPL(A) Theory study resources

Oman CAA ATPL(A) Theory practice questions

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Question 1Air Law and ATC Procedures

Under the ICAO Convention on International Civil Aviation, which body is the permanent legal and technical organ responsible for adopting International Standards and Recommended Practices?

  1. The Assembly
  2. The Secretariat
  3. The Air Navigation Commission
  4. The ICAO Council Correct answer.

Explanation

The Council is the permanent governing body of ICAO and is the organ that adopts Annexes containing Standards and Recommended Practices. The Assembly meets periodically and delegates adoption to the Council. The Air Navigation Commission only recommends technical standards to the Council.

Question 2Air Law and ATC Procedures

What is the primary purpose of a Standard in an ICAO Annex compared with a Recommended Practice?

  1. It is binding only on states that have signed the specific Annex
  2. It applies only to commercial air transport operations
  3. It is advisory guidance with no obligation on contracting states
  4. Uniform application is recognised as necessary for safety or regularity of international air navigation Correct answer.

Explanation

A Standard is any specification whose uniform application is recognised as necessary for the safety or regularity of international air navigation. States must notify ICAO of any differences from a Standard. Recommended Practices are desirable but not mandatory for uniform application.

Question 3Air Law and ATC Procedures

A pilot holds a licence issued by one contracting state and wishes to fly an aircraft registered in another contracting state on an international flight. Under the Convention, what is required?

  1. No action, since all contracting states recognise each other's licences automatically
  2. Conversion to a licence of the state of registry
  3. Re-issue of the licence by the state of registry
  4. Validation of the licence by the state of registry Correct answer.

Explanation

The Convention requires that licences issued by one contracting state be rendered valid by the state of registry for use on its aircraft. This validation ensures the state of registry accepts the competence of the licence holder. Automatic recognition without validation is not provided for.

Question 4Air Law and ATC Procedures

Which document must be carried on board an aircraft engaged in international navigation to record the identity and details of the aircraft and its registered owner?

  1. The certificate of airworthiness
  2. The certificate of registration Correct answer.
  3. The journey log book
  4. The crew licences

Explanation

The certificate of registration records the nationality and registration marks and the registered owner of the aircraft. It is one of the documents the Convention requires to be carried on board. The certificate of airworthiness certifies fitness for flight rather than ownership.

Question 5Air Law and ATC Procedures

A person has been refused a clearance or has received a clearance that appears unsafe. What does the correct phraseology and procedure require the pilot to do?

  1. File a report with the CAA before responding
  2. Read back the clearance correctly or request clarification before proceeding Correct answer.
  3. Ignore the clearance and continue on the previous routing
  4. Comply with the clearance and report the concern after landing

Explanation

When a clearance is not clearly understood or appears unsafe, the pilot must request clarification or read back the corrected clearance. Compliance with an unclear clearance is unacceptable. Concerns are resolved by communication at the time, not after the event.

Question 6Air Law and ATC Procedures

In radiotelephony, what does the phrase 'STANDBY' mean when transmitted by ATC?

  1. Your transmission was not understood
  2. Wait and I will call you Correct answer.
  3. Proceed with your request
  4. Change to another frequency

Explanation

STANDBY indicates that the controller acknowledges the call and asks the pilot to wait because a reply will follow. It is not an approval or clearance. The pilot should remain on frequency awaiting the call.

Question 7Air Law and ATC Procedures

An aircraft is on final approach and receives the instruction 'GO AROUND'. What is the correct initial action?

  1. Apply full power, establish climb and follow ATC instructions Correct answer.
  2. Reduce speed and extend the landing gear
  3. Hold position on the approach path until further clearance
  4. Continue the approach and land, then advise ATC

Explanation

A go-around instruction requires the pilot to abandon the approach, apply power, establish a positive climb and follow ATC instructions. Continuing to land against a go-around instruction is unsafe. Holding on the approach path is not a standard response.

Question 8Air Law and ATC Procedures

Which of the following is the correct read-back of the clearance 'Cleared to land runway 08'?

  1. Cleared to land runway 08, callsign Correct answer.
  2. Roger, callsign
  3. Wilco, callsign
  4. Affirm, callsign

Explanation

Safety-related clearances such as landing clearances must be read back in full, including the runway and the aircraft callsign. Roger and Wilco acknowledge receipt but do not confirm the content. Affirm is used to answer a question.

Question 9Air Law and ATC Procedures

When must an aircraft's altimeter be set to the standard pressure setting of 1013.2 hPa?

  1. Only when flying in controlled airspace
  2. Immediately after take-off
  3. When flying below the transition level
  4. When flying at or above the transition altitude Correct answer.

Explanation

The standard pressure setting is set when climbing through the transition altitude and maintained until descending through the transition level. This ensures all aircraft above the transition altitude use a common datum for flight levels. Below the transition altitude the local QNH is used.

Question 10Air Law and ATC Procedures

What does a steady red light directed at an aircraft in flight signify?

  1. Give way to other aircraft and continue circling Correct answer.
  2. Cleared to land
  3. Land at this aerodrome
  4. Stop immediately

Explanation

A steady red light to an aircraft in flight means give way to other aircraft and continue circling. It is a signal used when radio communication is not possible. A steady green light indicates cleared to land.

Question 11Air Law and ATC Procedures

In the event of a radio communication failure on an IFR flight, which action is appropriate?

  1. Descend immediately and land at the nearest aerodrome
  2. Squawk 7600 and continue at the last assigned level indefinitely
  3. Continue according to the published communication failure procedure and the last acknowledged clearance Correct answer.
  4. Turn back to the departure aerodrome

Explanation

On radio failure the pilot sets the appropriate SSR code and follows the published communication failure procedure, which includes the last acknowledged clearance and expected approach times. Immediate descent or indefinite continuation is not in accordance with the procedure.

Question 12Air Law and ATC Procedures

An aircraft is instructed to 'SQUAWK 7700'. What does this indicate?

  1. An emergency Correct answer.
  2. Radio communication failure
  3. Unlawful interference
  4. A test of the transponder

Explanation

Squawk 7700 is the general emergency code. It alerts ATC that the aircraft is in an emergency and requires priority. Codes 7600 and 7500 are used for radio failure and unlawful interference respectively.

Question 13Air Law and ATC Procedures

What is the meaning of the instruction 'LINE UP AND WAIT' given to an aircraft at a holding point?

  1. Begin the take-off roll immediately
  2. Enter the runway and remain in position, awaiting take-off clearance Correct answer.
  3. Vacate the runway and contact ground
  4. Hold at the holding point until further clearance

Explanation

LINE UP AND WAIT authorises the aircraft to enter the runway and position itself but does not authorise take-off. Take-off clearance must be issued separately. Remaining at the holding point would be the instruction HOLD POSITION.

Question 14Air Law and ATC Procedures

Which of the following correctly describes the requirement for a pilot to maintain a continuous listening watch on the appropriate frequency?

  1. It applies only during the approach phase
  2. It is required on the designated frequency for the airspace or service being used Correct answer.
  3. It is optional if the transponder is operating
  4. It is required only when flying in visual meteorological conditions

Explanation

Pilots must maintain a continuous listening watch on the appropriate ATC or designated frequency for the airspace or service in use. This ensures clearances and safety information are received promptly. The requirement is not limited to particular phases or weather conditions.

Question 15Air Law and ATC Procedures

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

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

Explanation

A flashing green light to an aircraft on the ground means cleared to taxi. A steady green light on the ground means cleared for take-off. A flashing red light means taxi clear of the runway in use.

Question 16Air Law and ATC Procedures

When a controlled flight is about to enter controlled airspace, at what point should the pilot request the clearance?

  1. After entering the airspace
  2. At the boundary of the airspace
  3. Only when instructed by the previous controller
  4. Sufficiently in advance to allow the clearance to be received before entering the airspace Correct answer.

Explanation

The pilot must request clearance sufficiently in advance so that it can be obtained before entering controlled airspace. Entering without a clearance is not permitted. Waiting until the boundary or after entry risks a breach of the clearance requirement.

Question 17Aircraft General Knowledge: Airframe, Systems and Powerplant

In a semimonocoque fuselage, the primary function of the stringers is to:

  1. Carry the longitudinal bending loads together with the skin Correct answer.
  2. Provide attachment points for the engine mounts
  3. Resist only torsional loads transmitted by the frames
  4. Seal the pressure cabin at the door frames

Explanation

Stringers run longitudinally and share the bending loads with the stressed skin, stiffening it against buckling. Frames maintain the cross-sectional shape and, in pressurized aircraft, help carry pressure loads.

Question 18Aircraft General Knowledge: Airframe, Systems and Powerplant

A wing spar that is machined from a single billet of aluminium alloy is best described as:

  1. A truss spar
  2. An integral spar Correct answer.
  3. A built-up spar
  4. An I-section wooden spar

Explanation

An integral spar is machined from solid material so that caps and web form one continuous piece, reducing part count and fastener holes. Built-up spars are assembled from separate caps and web.

Question 19Aircraft General Knowledge: Airframe, Systems and Powerplant

The purpose of a wing spoiler when deployed in flight is to:

  1. Provide nose-down pitch trim only
  2. Increase lift at low speed
  3. Increase the critical Mach number
  4. Reduce lift and increase drag Correct answer.

Explanation

Spoilers disrupt the smooth airflow over the upper surface, destroying lift and adding drag, which is used for roll control, descent, or speedbrake functions. They do not increase lift.

Question 20Aircraft General Knowledge: Airframe, Systems and Powerplant

In a typical hydraulic system, the function of the accumulator is to:

  1. Convert hydraulic pressure into mechanical force
  2. Filter contamination from the return line
  3. Cool the hydraulic fluid after it leaves the pump
  4. Store pressurized fluid to handle transient demands and damp pressure surges Correct answer.

Explanation

An accumulator contains a gas charge separated from the fluid and stores energy, smoothing pump demand peaks and absorbing pressure pulses. It does not filter, cool, or actuate loads.

Question 21Aircraft General Knowledge: Airframe, Systems and Powerplant

Aircraft tyres are inflated with dry nitrogen rather than air mainly because nitrogen:

  1. Eliminates the need for a pressure relief valve
  2. Increases the tyre's load rating
  3. Reduces the risk of internal combustion and pressure variation from moisture Correct answer.
  4. Has a higher density and lowers wheel weight

Explanation

Dry nitrogen is inert and moisture-free, reducing the risk of an internal fire in the wheel and minimizing pressure changes caused by water vapour freezing or expanding. It does not change the structural load rating.

Question 22Aircraft General Knowledge: Airframe, Systems and Powerplant

In a gas turbine engine, the compressor is driven by:

  1. An electric starter motor throughout all phases of operation
  2. The accessory gearbox through a reduction gear
  3. The turbine through a common shaft Correct answer.
  4. Bleed air taken from the compressor outlet

Explanation

The turbine extracts energy from the exhaust gas and transmits it forward through a shaft to rotate the compressor. The starter only assists during starting.

Question 23Aircraft General Knowledge: Airframe, Systems and Powerplant

An aircraft with a constant-speed propeller is in level flight when power is increased and the propeller governor maintains the same RPM. The blade angle will:

  1. Increase, then immediately feather
  2. Decrease, maintaining a constant angle of attack
  3. Remain unchanged because RPM is constant
  4. Increase, absorbing the additional power at a higher blade angle Correct answer.

Explanation

At constant RPM, extra power must be absorbed by a larger blade angle so the propeller takes a bigger bite of air. The governor increases blade angle to prevent RPM rise.

Question 24Aircraft General Knowledge: Airframe, Systems and Powerplant

During a climb at constant indicated airspeed, the true airspeed increases because:

  1. The static pressure rises with altitude
  2. The aircraft's mass decreases during the climb
  3. The dynamic pressure required for a given IAS corresponds to a higher TAS at lower air density Correct answer.
  4. The Mach number is held constant

Explanation

Indicated airspeed reflects dynamic pressure; as density falls with altitude, a higher true airspeed is needed to produce the same dynamic pressure. The relationship comes from the density ratio between sea level and the flight level.

Question 25Aircraft General Knowledge: Airframe, Systems and Powerplant

A pressurization system controller schedules cabin altitude so that the cabin rate of climb is limited. This protects the occupants from:

  1. Rapid pressure changes causing discomfort and barotrauma Correct answer.
  2. Overheating of the air-conditioning packs
  3. Carbon dioxide accumulation in the cabin
  4. Hypoxia caused by a high cabin altitude

Explanation

Rate limiting keeps the cabin pressure change per unit time within comfortable limits, preventing ear and sinus discomfort. Cabin altitude itself is limited by the pressure schedule, not the rate.

Question 26Aircraft General Knowledge: Airframe, Systems and Powerplant

A landing gear oleo strut with insufficient fluid (low oil level) will most likely:

  1. Settle lower on the ground and bottom out easily on landing Correct answer.
  2. Cause the wheel brakes to fail
  3. Extend fully and remain rigid in flight
  4. Feel excessively stiff and transmit high loads on landing

Explanation

The oil provides the damping and also occupies volume; with too little oil, less energy is absorbed and the strut sits lower and can bottom out. Correct servicing is by gas pressure and fluid level per the maintenance manual.

Question 27Aircraft General Knowledge: Airframe, Systems and Powerplant

In a DC electrical system, the purpose of the reverse-current cut-out associated with a generator is to:

  1. Limit the generator output current to a safe value
  2. Convert AC to DC for the battery bus
  3. Regulate the generator voltage to a constant value
  4. Prevent the battery from discharging through the generator when generator voltage falls below battery voltage Correct answer.

Explanation

The reverse-current cut-out disconnects the generator when its voltage drops below the bus voltage, preventing current from flowing back through the generator. Voltage regulation and current limiting are separate functions.

Question 28Aircraft General Knowledge: Airframe, Systems and Powerplant

A fire in an engine compartment is detected by a continuous-loop system. The main advantage of this type over spot detectors is that it:

  1. Requires no power supply to operate
  2. Covers the whole protected volume and responds to both local overheating and flame Correct answer.
  3. Responds only after the fire has reached a fixed temperature threshold
  4. Cannot produce false warnings

Explanation

A continuous-loop element runs throughout the compartment and reacts along its length to overheat or flame, giving broader coverage than a point detector. It still needs electrical power and can produce false warnings.

Question 29Aircraft General Knowledge: Airframe, Systems and Powerplant

The function of the thrust reverser on a turbofan engine is to:

  1. Reduce engine noise on approach
  2. Redirect fan or exhaust efflux forward to produce a decelerating force after touchdown Correct answer.
  3. Provide additional lift during the flare
  4. Increase forward thrust during take-off

Explanation

Reversers redirect the fan or exhaust stream so that a component of thrust acts rearwards, helping to decelerate the aircraft on the ground. They do not increase forward thrust or lift.

Question 30Aircraft General Knowledge: Airframe, Systems and Powerplant

An aircraft is in cruising flight when the pilot selects a lower thrust setting. Considering the engine's spool-up behaviour, a rapid reduction in thrust is generally:

  1. Impossible because the fuel control prevents throttle movement
  2. Achieved instantly by closing the fuel shut-off valve
  3. Limited by the rate at which the compressor can decelerate without surging Correct answer.
  4. Only possible with reverser deployment

Explanation

Engine deceleration is limited by the fuel control to avoid compressor surge and flameout as rotor speed falls. Acceleration is similarly rate-limited to stay clear of the surge line.

Question 31Aircraft General Knowledge: Airframe, Systems and Powerplant

A wing is designed with washout (geometric twist). The effect at high angles of attack is that:

  1. The whole wing stalls simultaneously for a sharper break
  2. The stall speed is reduced without any change in stall pattern
  3. The tip stalls before the root, improving aileron effectiveness
  4. The root stalls before the tip, preserving aileron effectiveness Correct answer.

Explanation

Washout gives the tip a lower angle of attack than the root, so the root reaches the critical angle first and the tips remain flying longer. This preserves aileron control and gives better stall warning.

Question 32Aircraft General Knowledge: Airframe, Systems and Powerplant

In a fuel system, the purpose of a fuel/oil heat exchanger is to:

  1. Separate water from the fuel by centrifugal action
  2. Increase the fuel pressure for the high-pressure pump
  3. Use cold fuel to cool the engine oil while warming the fuel to prevent ice formation Correct answer.
  4. Warm the fuel so that it vaporizes before reaching the combustion chamber

Explanation

The heat exchanger transfers heat from the oil to the fuel, cooling the oil and warming the fuel so that dissolved or free water does not freeze in the fuel lines. It does not vaporize fuel or pressurize it.

Question 33Aircraft General Knowledge: Instrumentation

In a light aircraft, the primary purpose of the pitot-static system is to provide inputs for the airspeed indicator, the altimeter and which other instrument?

  1. The attitude indicator
  2. The turn coordinator
  3. The directional gyro
  4. The vertical speed indicator Correct answer.

Explanation

The pitot-static system supplies pitot pressure and static pressure. Static pressure feeds the altimeter, the vertical speed indicator and the airspeed indicator. Gyroscopic instruments such as the attitude indicator and directional gyro are not driven by the pitot-static system.

Question 34Aircraft General Knowledge: Instrumentation

An aircraft climbs at a constant indicated altitude while the ambient static pressure falls. If the subscale is not adjusted, what does the altimeter indicate?

  1. An altitude higher than the true altitude
  2. A constant true altitude regardless of pressure
  3. An altitude lower than the true altitude Correct answer.
  4. The true altitude exactly

Explanation

The altimeter is calibrated to the pressure set in the subscale window. If ambient pressure falls while the subscale is left unchanged, the altimeter senses a pressure corresponding to a lower altitude than the aircraft is actually at. The aircraft is therefore higher than the instrument shows.

Question 35Aircraft General Knowledge: Instrumentation

In a steady climb, what does the vertical speed indicator indicate immediately after the climb is established?

  1. Zero until the aircraft levels off
  2. A rate of climb slightly lower than the actual rate Correct answer.
  3. A rate of climb equal to the true rate with no lag
  4. A rate of climb slightly higher than the actual rate

Explanation

The VSI responds to the pressure difference between the static source and a calibrated choke inside the case. This difference takes a few seconds to stabilise, so once established the indication lags slightly and reads a little lower than the true rate of climb.

Question 36Aircraft General Knowledge: Instrumentation

What is the effect on the indicated airspeed if the pitot head becomes completely blocked while the static source remains clear?

  1. The indicator behaves like an altimeter, reading higher in a climb and lower in a descent Correct answer.
  2. The indicator over-reads in a climb and under-reads in a descent
  3. The indicator falls steadily to zero
  4. The indicator remains fixed at the airspeed at the moment of blockage

Explanation

With a blocked pitot and a clear static source, the trapped pitot pressure stays constant while static pressure changes with altitude. In a climb static pressure falls, so the differential rises and the instrument over-reads; in a descent it under-reads. The instrument therefore behaves like an altimeter in reverse.

Question 37Aircraft General Knowledge: Instrumentation

What is the purpose of the drain valve fitted at the lowest point of a pitot-static system?

  1. To calibrate the static source on the ground
  2. To remove accumulated moisture from the system Correct answer.
  3. To isolate the static ports during flight
  4. To release excess pressure during a rapid climb

Explanation

Moisture can condense or enter the lines, and water in the lines causes erroneous indications. The drain valve at the low point allows this moisture to be removed during pre-flight checks. It is not used to vent pressure or to isolate ports in flight.

Question 38Aircraft General Knowledge: Instrumentation

A gyroscope used in an attitude indicator is best described as having which property that keeps its spin axis fixed in space?

  1. Precession
  2. Gimballing
  3. Erection
  4. Rigidity in space Correct answer.

Explanation

Rigidity in space is the property whereby a spinning gyroscope maintains the direction of its spin axis in inertial space. Precession is the apparent tilting of the axis when a force is applied. Erection mechanisms are used to align the gyro with gravity.

Question 39Aircraft General Knowledge: Instrumentation

How does a real gyroscope respond when a force is applied to its spin axis?

  1. It precesses in a direction at right angles to the applied force Correct answer.
  2. It moves directly in the direction of the applied force
  3. It accelerates its spin rate
  4. It immediately stops spinning

Explanation

When a torque is applied to a spinning gyroscope, the resulting motion (precession) occurs about an axis perpendicular to both the spin axis and the applied force. This right-angle response is fundamental to gyroscopic instruments and to apparent drift corrections.

Question 40Aircraft General Knowledge: Instrumentation

What causes apparent drift of a directional gyro when an aircraft operates at a constant latitude away from the poles?

  1. Aircraft acceleration along the flight path
  2. The Earth's rotation relative to the fixed spin axis Correct answer.
  3. Unbalanced rotor mass
  4. Friction in the gimbal bearings

Explanation

Apparent drift results from the Earth rotating beneath a gyro whose spin axis remains fixed in space. The magnitude depends on latitude, being greatest at the poles and zero at the equator. Bearing friction and rotor imbalance cause real drift, not apparent drift.

Question 41Aircraft General Knowledge: Instrumentation

During a coordinated turn, which instrument indicates the rate of turn independently of bank angle?

  1. The attitude indicator
  2. The turn coordinator Correct answer.
  3. The altimeter
  4. The heading indicator

Explanation

The turn coordinator uses a rate gyro to display rate of turn about the yaw axis. Its presentation is largely independent of bank angle, which is why it is used as a reference for standard-rate turns. The attitude indicator shows bank and pitch, not rate of turn.

Question 42Aircraft General Knowledge: Instrumentation

An aircraft in level flight at 120 kt is to be turned at the standard rate of 3 degrees per second. Approximately how long will it take to complete a 90 degree turn?

  1. 60 seconds
  2. 45 seconds
  3. 30 seconds Correct answer.
  4. 15 seconds

Explanation

A standard-rate turn of 3 degrees per second covers 90 degrees in 90 divided by 3, which is 30 seconds. This timing allows pilots to use the turn coordinator for timed turns onto a heading.

Question 43Aircraft General Knowledge: Instrumentation

What is the fundamental sensing principle of a modern electrically driven attitude indicator that uses no spinning rotor?

  1. Vibrating or ring-laser sensing of angular rate and acceleration Correct answer.
  2. Magnetic flux detection
  3. Static pressure differential measurement
  4. Pitot pressure comparison

Explanation

Solid-state attitude and heading reference systems use vibrating-structure gyroscopes and accelerometers, or ring-laser gyros, to sense angular rate and acceleration. These signals are integrated to provide attitude without a spinning mass. Pitot and static pressures are unrelated to attitude sensing.

Question 44Aircraft General Knowledge: Instrumentation

In a remote-reading (servo) air data system, what is the function of the air data computer?

  1. To display raw pressure values directly to the pilot
  2. To drive the gyroscopic instruments
  3. To control the aircraft's flight controls
  4. To convert pitot and static pressures into computed airspeed, altitude and temperature-corrected outputs Correct answer.

Explanation

The air data computer receives pitot and static pressures and other inputs and computes airspeed, altitude, vertical speed and temperature-corrected data for display and for other systems. Its outputs are computed values rather than raw pressures.

Question 45Aircraft General Knowledge: Instrumentation

What does the 'baro' setting on an electronic flight instrument system adjust?

  1. The reference pressure used to compute displayed altitude Correct answer.
  2. The airspeed calibration factor
  3. The temperature used for true airspeed
  4. The brightness of the display

Explanation

The barometric setting supplies the reference pressure against which static pressure is compared to compute altitude. Changing it shifts the displayed altitude to the selected pressure datum. It does not affect display brightness or airspeed computation.

Question 46Aircraft General Knowledge: Instrumentation

What is the function of the air data module in an integrated avionics system?

  1. To convert pneumatic pressures into digital electrical signals Correct answer.
  2. To provide standby gyroscopic attitude
  3. To store navigation waypoints
  4. To control the autopilot servos

Explanation

The air data module contains pressure transducers that convert pitot and static pressures into digital electrical outputs for use by the air data computer and displays. It does not perform navigation or autopilot functions, and standby attitude is provided by separate instruments.

Question 47Aircraft General Knowledge: Instrumentation

An aircraft flies from an area of high pressure to an area of low pressure without changing the altimeter subscale. If the aircraft maintains a constant indicated altitude, what happens to its true altitude?

  1. It varies only with temperature
  2. It increases
  3. It remains constant
  4. It decreases Correct answer.

Explanation

The altimeter uses the subscale pressure to interpret static pressure as altitude. Flying into lower pressure makes the instrument sense a pressure corresponding to a higher altitude, so the aircraft descends to hold the indicated altitude. True altitude therefore decreases.

Question 48Aircraft General Knowledge: Instrumentation

How does a Machmeter derive Mach number from its inputs?

  1. By measuring the angle of attack
  2. By comparing indicated airspeed with true airspeed
  3. By measuring outside air temperature directly
  4. By comparing pitot-static pressure differential with static pressure Correct answer.

Explanation

Mach number is the ratio of true airspeed to the local speed of sound. The Machmeter computes this from the ratio of pitot pressure to static pressure, which depends on the compression of the airflow. It does not require a direct temperature input.

Question 49Mass and Balance

The maximum zero-fuel mass of an aircraft is the maximum mass permitted with which of the following contents on board?

  1. Crew, passengers, baggage and cargo but excluding usable fuel
  2. Crew, passengers, baggage, cargo and all fuel including reserve
  3. Fuel and payload only, excluding crew
  4. Crew, passengers, baggage, cargo and unusable fuel Correct answer.

Explanation

Maximum zero-fuel mass is the maximum mass of the aircraft with everything loaded except usable fuel. Unusable fuel and oil are part of the empty mass and therefore remain included. Any usable fuel on board must be added on top of the zero-fuel mass.

Question 50Mass and Balance

An aircraft has a basic empty mass of 4200 kg at an arm of 6.50 m and takes 800 kg of payload at an arm of 7.25 m. What is the combined moment about the datum?

  1. 28 500 kg·m
  2. 36 300 kg·m
  3. 33 100 kg·m Correct answer.
  4. 32 500 kg·m

Explanation

Moment is mass multiplied by arm. Empty moment = 4200 × 6.50 = 27 300 kg·m; payload moment = 800 × 7.25 = 5800 kg·m. Adding gives 33 100 kg·m.