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WACE Aviation practice questions

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Question 1Aviation Fundamentals and Aircraft Systems

Which component of a jet engine draws air into the engine and imparts an initial increase in velocity?

  1. The intake and fan/compressor assembly Correct answer.
  2. The exhaust nozzle
  3. The turbine section
  4. The combustion chamber

Explanation

The intake duct directs air smoothly into the engine, and the fan or low-pressure compressor then accelerates that air rearward, producing the bulk of thrust in a high-bypass turbofan. Downstream sections handle compression, combustion and expansion rather than initial air capture.

Question 2Aviation Fundamentals and Aircraft Systems

In a four-stroke piston engine, during which stroke does the intake valve open and the piston move downward?

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

Explanation

The intake stroke begins with the piston near top dead centre and the intake valve open, so the descending piston draws the fuel-air mixture into the cylinder. The other strokes involve compression, ignition-driven expansion, or expulsion of burnt gases.

Question 3Aviation Fundamentals and Aircraft Systems

What is the primary function of an aircraft's horizontal stabiliser?

  1. To provide longitudinal pitch stability Correct answer.
  2. To house the landing gear
  3. To generate lift for the aircraft
  4. To control yaw about the vertical axis

Explanation

The horizontal stabiliser is a small aerofoil mounted aft of the centre of gravity that produces a downward or trimming force, keeping the nose steady in pitch. Yaw control belongs to the vertical fin and rudder, while the wing provides the main lift.

Question 4Aviation Fundamentals and Aircraft Systems

Which instrument in a light aircraft directly indicates the aircraft's rate of climb or descent?

  1. The airspeed indicator
  2. The vertical speed indicator Correct answer.
  3. The altimeter
  4. The heading indicator

Explanation

The vertical speed indicator senses changes in static pressure and displays them as a rate, typically in feet per minute, so it shows climb or descent rate. The altimeter shows altitude and the airspeed indicator shows speed through the air.

Question 5Aviation Fundamentals and Aircraft Systems

Which control surface is primarily used to roll the aircraft about its longitudinal axis?

  1. The flaps
  2. The elevator
  3. The rudder
  4. The ailerons Correct answer.

Explanation

Ailerons are hinged at the trailing edge of each wing and move in opposite directions, increasing lift on one wing and decreasing it on the other to produce roll. The elevator and rudder control pitch and yaw respectively.

Question 6Aviation Fundamentals and Aircraft Systems

In aviation terminology, what does the term 'angle of attack' describe?

  1. The angle between the wing chord line and the relative airflow Correct answer.
  2. The angle at which the aircraft climbs after takeoff
  3. The angle between the fuselage and the horizon
  4. The angle between the wing and the ground during landing

Explanation

Angle of attack is the angle between the wing's chord line and the direction of the oncoming relative airflow. It governs lift generation and is distinct from pitch attitude, which is measured relative to the horizon.

Question 7Aviation Fundamentals and Aircraft Systems

What is the main purpose of an aircraft's empennage?

  1. To provide stability and control in pitch and yaw Correct answer.
  2. To generate most of the aircraft's lift
  3. To protect the engines from debris
  4. To store fuel for the engines

Explanation

The empennage, or tail section, comprises the horizontal and vertical stabilisers and their control surfaces, giving stability and control in pitch and yaw. Lift is mainly produced by the wing, and fuel is normally carried in the wings or fuselage.

Question 8Aviation Fundamentals and Aircraft Systems

Which of the following best describes the function of an aircraft's altimeter?

  1. To display the aircraft's height above a reference pressure level Correct answer.
  2. To indicate the aircraft's attitude relative to the horizon
  3. To measure the aircraft's speed relative to the air
  4. To show the rate at which altitude is changing

Explanation

A pressure altimeter converts static pressure from the static port into an indicated altitude referenced to a selected pressure setting such as mean sea level. Speed and rate of change are shown by other instruments.

Question 9Aviation Fundamentals and Aircraft Systems

An aircraft is flying at a constant indicated airspeed while climbing into thinner air. What happens to the true airspeed?

  1. It increases as altitude increases Correct answer.
  2. It remains equal to the indicated airspeed
  3. It becomes zero above 10 000 feet
  4. It decreases as altitude increases

Explanation

As altitude rises, air density falls, so the same dynamic pressure corresponds to a higher true airspeed. Indicated airspeed therefore under-reads true airspeed at high altitude, and the gap grows with height.

Question 10Aviation Fundamentals and Aircraft Systems

Why does induced drag decrease as an aircraft accelerates from just above stall speed toward its best glide speed?

  1. Because the wing area physically shrinks at higher speed
  2. Because the lift coefficient required falls, reducing the rearward tilt of lift Correct answer.
  3. Because parasite drag also decreases with speed
  4. Because engine thrust removes drag entirely

Explanation

Induced drag arises from the rearward component of lift, which is proportional to the square of the lift coefficient. At higher speed less lift coefficient is needed to support the same weight, so induced drag falls even though parasite drag rises.

Question 11Aviation Fundamentals and Aircraft Systems

A pilot selects flaps to the takeoff position before departure. Which combination of effects should the pilot expect?

  1. Increased lift with no change in drag or stall speed
  2. Increased lift and increased drag at a lower stall speed Correct answer.
  3. Decreased lift and decreased drag at a higher stall speed
  4. Decreased lift and increased drag at a higher stall speed

Explanation

Extending flaps increases wing camber and effective area, raising the lift coefficient and lowering the stall speed, but it also adds drag. The extra lift shortens the takeoff run while the extra drag must be accounted for in climb performance.

Question 12Aviation Fundamentals and Aircraft Systems

An aircraft is in a steady, level, unaccelerated flight. Which statement about the forces acting on it is correct?

  1. Weight exceeds lift and drag exceeds thrust
  2. Lift equals thrust and weight equals drag
  3. Lift equals weight and thrust equals drag Correct answer.
  4. Lift exceeds weight and thrust exceeds drag

Explanation

In steady level flight there is no acceleration, so the vertical forces balance with lift equal to weight and the horizontal forces balance with thrust equal to drag. Any imbalance would produce acceleration and a change in flight path or speed.

Question 13Aviation Fundamentals and Aircraft Systems

What is the primary reason modern high-bypass turbofans are more fuel-efficient than pure turbojets at typical airliner speeds?

  1. They burn fuel at a much higher combustion temperature only
  2. They eliminate the compressor stage entirely
  3. They accelerate a larger mass of air to a lower velocity Correct answer.
  4. They operate without any turbine section

Explanation

Propulsive efficiency improves when a large mass of air is accelerated by a modest amount rather than a small mass by a large amount. The bypass fan moves a large volume of air at relatively low velocity, which is well matched to subsonic cruise speeds.

Question 14Aviation Fundamentals and Aircraft Systems

During a constant-altitude turn, an aircraft banks to 60 degrees. Compared with level flight, what happens to the load factor?

  1. It becomes zero at the vertical component
  2. It doubles to approximately 2.0 Correct answer.
  3. It falls below 1.0
  4. It stays at 1.0 because altitude is constant

Explanation

Load factor in a level turn equals one divided by the cosine of the bank angle, so at 60 degrees it is about 2.0. The wing must produce twice the lift to support the weight while also providing the horizontal turning force.

Question 15Aviation Fundamentals and Aircraft Systems

Why must an aircraft's centre of gravity remain within specified forward and aft limits?

  1. To keep the engines within their temperature limits
  2. To ensure adequate stability and control authority Correct answer.
  3. To reduce the weight of the airframe
  4. To keep the fuel tanks balanced

Explanation

A centre of gravity too far forward demands excessive elevator force and lengthens takeoff distance, while one too far aft reduces static stability and can make the aircraft uncontrollable. The limits preserve a safe margin of stability and control.

Question 16Aviation Fundamentals and Aircraft Systems

What is the function of the static port on an aircraft's pitot-static system?

  1. To supply ambient pressure to the altimeter and vertical speed indicator Correct answer.
  2. To measure outside air temperature
  3. To drain water from the fuel system
  4. To supply ram air pressure to the airspeed indicator

Explanation

The static port samples undisturbed ambient pressure, which the altimeter and vertical speed indicator use, and which the airspeed indicator needs as a reference against pitot pressure. Blocking it corrupts all three instruments.

Question 17Aviation Fundamentals and Aircraft Systems

A pilot notices the airspeed indicator reads zero while the altimeter and vertical speed indicator appear normal during climb. Which blockage is most likely?

  1. The static port is blocked
  2. The turn coordinator is faulty
  3. The altimeter has failed
  4. The pitot tube is blocked Correct answer.

Explanation

If the pitot tube is blocked, ram pressure cannot reach the airspeed indicator, so it stops responding even though static pressure still feeds the other instruments normally. A blocked static port would instead disturb the altimeter and vertical speed indicator.

Question 18Aviation Fundamentals and Aircraft Systems

Which of the following is the best description of a turbojet's Brayton cycle sequence?

  1. Intake, compression, combustion, expansion, exhaust Correct answer.
  2. Intake, combustion, compression, exhaust, expansion
  3. Compression, intake, expansion, combustion, exhaust
  4. Exhaust, expansion, combustion, compression, intake

Explanation

Air enters the intake, is compressed, mixed with fuel and burned at high pressure, expanded through the turbine, and finally expelled through the nozzle. Each stage prepares the working fluid for the next in this fixed order.

Question 19Aviation Fundamentals and Aircraft Systems

An aircraft with a maximum takeoff weight limitation is being loaded. Which action best preserves structural safety while maximising payload?

  1. Distributing load so that both weight and CG limits are satisfied Correct answer.
  2. Ignoring the CG envelope if the weight is below maximum
  3. Loading all cargo as far aft as possible
  4. Reducing fuel to zero to allow more cargo

Explanation

Both the maximum weight limit and the centre of gravity envelope must be satisfied simultaneously, so load must be distributed to keep the CG in range while total weight stays within limits. Meeting only one criterion leaves the aircraft unsafe.

Question 20Aviation Fundamentals and Aircraft Systems

What is the main advantage of a semi-monocoque fuselage construction over a pure monocoque design?

  1. It eliminates the need for bulkheads at the wing attachment
  2. It uses internal frames and stringers to share loads with the skin Correct answer.
  3. It removes the need for any skin covering
  4. It relies entirely on the skin for strength

Explanation

A semi-monocoque structure combines a stressed skin with longitudinal stringers and transverse frames, so loads are shared and the skin can be thinner. Pure monocoque relies on the skin alone and is less efficient for larger aircraft.

Question 21Aviation Fundamentals and Aircraft Systems

During descent an aircraft's vertical speed indicator shows a steady 500 feet per minute down. What does this indicate about the static pressure in the instrument case compared with the diaphragm?

  1. Case pressure is higher than diaphragm pressure
  2. Both pressures are falling at the same rate
  3. Diaphragm pressure is higher than case pressure Correct answer.
  4. They are equal and unchanging

Explanation

In a descent ambient static pressure rises, so the diaphragm pressure exceeds the case pressure, which is fed through a calibrated leak and lags behind. This differential drives the pointer to indicate a descent rate.

Question 22Aviation Fundamentals and Aircraft Systems

Why do swept wings help a high-speed jet aircraft at transonic speeds?

  1. They increase the wing area available for lift
  2. They allow the aircraft to fly without a vertical fin
  3. They delay the onset of shock waves by reducing the effective normal Mach number Correct answer.
  4. They eliminate the need for a horizontal stabiliser

Explanation

Sweeping the wing reduces the component of airflow perpendicular to the leading edge, lowering the effective Mach number experienced by the aerofoil. This delays local supersonic flow and shock-induced drag rise, improving high-speed performance.

Question 23Aviation Fundamentals and Aircraft Systems

An aircraft suffers a total loss of static pressure during cruise while the pitot tube remains clear. What will the airspeed indicator most likely show during a subsequent climb?

  1. A steadily decreasing airspeed toward zero
  2. A steadily increasing airspeed Correct answer.
  3. An airspeed that oscillates rapidly
  4. An airspeed that remains accurate

Explanation

With the static port blocked or lost, the trapped static pressure in the case remains at the cruise value while pitot pressure falls in the climb as true airspeed and dynamic pressure drop. The instrument interprets the growing difference as an increasing airspeed, a known trap for pilots.

Question 24Aviation Fundamentals and Aircraft Systems

In a level turn at constant altitude, an aircraft stalls at a higher indicated airspeed than in straight flight. What is the underlying reason?

  1. The increased load factor requires a higher lift coefficient, so the critical angle is reached at higher speed Correct answer.
  2. The wing area decreases in a bank
  3. Thrust is reduced in a turn
  4. The stall angle of attack decreases with bank angle

Explanation

Banking increases load factor, so more lift must be produced from the same wing, raising the required lift coefficient at any given speed. The critical angle of attack is therefore reached at a higher speed, so the aircraft stalls faster than in level flight.

Question 25Aviation Fundamentals and Aircraft Systems

A turbofan engine's bypass ratio is increased while core airflow is held constant. What is the expected effect on propulsive efficiency and specific thrust at subsonic cruise?

  1. Propulsive efficiency falls and specific thrust rises
  2. Both propulsive efficiency and specific thrust rise
  3. Both propulsive efficiency and specific thrust fall to zero
  4. Propulsive efficiency rises and specific thrust falls Correct answer.

Explanation

A higher bypass ratio means more air is accelerated by a smaller velocity increment for the same total thrust, which raises propulsive efficiency at subsonic speeds. Because each unit of airflow produces less thrust, specific thrust falls, leading to larger but more efficient engines.

Question 26Aviation Fundamentals and Aircraft Systems

Which control surface is used to control an aircraft about its longitudinal axis?

  1. The elevators
  2. The flaps
  3. The rudder
  4. The ailerons Correct answer.

Explanation

The longitudinal axis runs from nose to tail, and rolling motion around this axis is produced by the ailerons, which move in opposite directions to raise one wing and lower the other. The elevators act about the lateral axis and the rudder about the vertical axis.

Question 27Aviation Fundamentals and Aircraft Systems

What is the primary function of a wing's dihedral angle?

  1. To increase the maximum cruising speed
  2. To reduce the stalling speed of the wing
  3. To increase the rate of climb at low speed
  4. To provide lateral stability in a sideslip Correct answer.

Explanation

Dihedral is the upward angle of the wings from the root. When the aircraft slips sideways, the lower wing meets the airflow at a greater angle of attack and generates more lift, producing a rolling moment that tends to level the wings and so gives lateral stability.

Question 28Aviation Fundamentals and Aircraft Systems

Which structural component of a wing carries the main bending loads from the wing root to the fuselage?

  1. The skin
  2. The spar Correct answer.
  3. The ribs
  4. The stringers

Explanation

The spar is the deep beam running spanwise through the wing and is designed to resist the bending and shear loads generated by lift. Ribs give the wing its aerofoil shape and support the skin, while stringers stiffen the skin against buckling.

Question 29Aviation Fundamentals and Aircraft Systems

In a piston engine, what is the purpose of the magneto?

  1. To supply high-voltage current to the spark plugs Correct answer.
  2. To drive the propeller through a reduction gear
  3. To cool the cylinder heads during operation
  4. To regulate the fuel-air mixture entering the cylinders

Explanation

A magneto is a self-contained generator that produces the high-voltage pulses needed to fire the spark plugs. Because it generates its own electricity, it keeps the ignition working even if the aircraft's electrical system fails.

Question 30Aviation Fundamentals and Aircraft Systems

An aircraft is climbing at a constant indicated airspeed while the pilot maintains a fixed power setting. What happens to the rate of climb as altitude increases?

  1. It increases because the air is thinner
  2. It becomes zero once above 10 000 feet
  3. It decreases as engine power available falls Correct answer.
  4. It stays constant because power is fixed

Explanation

As altitude rises, air density falls, so the engine produces less power and the propeller or fan absorbs less thrust. Because power available decreases while power required for a given climb remains similar, the excess power shrinks and the rate of climb reduces with height.

Question 31Aviation Fundamentals and Aircraft Systems

Why is a swept wing used on many high-speed aircraft?

  1. To increase the wing area available for lift
  2. To delay the onset of shock-wave drag Correct answer.
  3. To reduce the weight of the wing structure
  4. To improve low-speed handling near the stall

Explanation

Sweeping the wing reduces the component of airflow acting perpendicular to the leading edge, which raises the critical Mach number. This delays the formation of shock waves and the associated drag rise as the aircraft approaches the speed of sound.

Question 32Aviation Fundamentals and Aircraft Systems

An aircraft is descending at a constant indicated airspeed without changing power. What tends to happen to true airspeed as it descends into denser air?

  1. True airspeed and indicated airspeed both increase equally
  2. True airspeed remains unchanged regardless of altitude
  3. True airspeed increases while indicated airspeed stays constant
  4. True airspeed decreases while indicated airspeed stays constant Correct answer.

Explanation

Indicated airspeed depends on dynamic pressure, which reflects the density of the air. In denser air at lower altitude, the same indicated airspeed corresponds to a lower true airspeed, because fewer units of true speed are needed to produce the same dynamic pressure.

Question 33Aviation Fundamentals and Aircraft Systems

What is the purpose of the bypass duct in a turbofan engine?

  1. To cool the turbine blades with fuel
  2. To direct fan air around the core to produce thrust Correct answer.
  3. To compress the air before it reaches the fan
  4. To mix exhaust gas with the incoming air

Explanation

In a turbofan, the fan sends part of the incoming air through the core and part through the bypass duct. The bypassed air is accelerated by the fan and produces thrust without passing through the combustor, which improves efficiency and reduces noise.

Question 34Aviation Fundamentals and Aircraft Systems

An aircraft is in a steady level turn with a load factor of 2. If the stall speed in straight flight is 60 knots, what is the approximate stall speed in the turn?

  1. 120 knots
  2. 30 knots
  3. 85 knots Correct answer.
  4. 60 knots

Explanation

Stall speed varies with the square root of the load factor. For a load factor of 2, the multiplier is about 1.41, so 60 knots multiplied by 1.41 gives roughly 85 knots.

Question 35Aviation Fundamentals and Aircraft Systems

What is the function of the aircraft's horizontal stabiliser trim system?

  1. To hold a selected pitch attitude with reduced control force Correct answer.
  2. To lock the landing gear in the down position
  3. To limit the maximum deflection of the rudder
  4. To balance fuel between the left and right tanks

Explanation

Trim systems apply a small aerodynamic or mechanical force that offsets the control force needed to hold a chosen attitude. This lets the pilot release pressure on the controls while the aircraft maintains the selected pitch, reducing workload during cruise or climb.

Question 36Aviation Fundamentals and Aircraft Systems

A pilot flying at high altitude notices the cabin altitude warning has activated. Which system is primarily responsible for maintaining a safe cabin altitude?

  1. The pressurisation outflow valve Correct answer.
  2. The hydraulic pressure regulator
  3. The air-conditioning bypass valve
  4. The anti-ice bleed valve

Explanation

Cabin pressure is maintained by controlling how fast air leaves the pressurised fuselage. The outflow valve modulates the escape of air so that cabin altitude stays within limits, and it opens fully if the cabin altitude exceeds a safe value.

Question 37Aviation Fundamentals and Aircraft Systems

Which of the following best describes the function of an aircraft's anti-skid system during braking?

  1. It transfers braking force to the nose wheel
  2. It increases brake pressure whenever the wheels slow down
  3. It applies the parking brake automatically after landing
  4. It prevents the wheels from locking and skidding Correct answer.

Explanation

Anti-skid systems sense when a wheel is about to lock and momentarily release brake pressure so the tyre keeps rolling and retains steering and friction. This shortens stopping distance and protects tyres from flat spots, particularly on wet or contaminated runways.

Question 38Aviation Fundamentals and Aircraft Systems

An aircraft is loaded such that its centre of gravity is close to the aft limit. Compared with a forward centre of gravity, what is the effect on longitudinal stability?

  1. Longitudinal stability is reduced Correct answer.
  2. Longitudinal stability becomes neutral at all speeds
  3. Longitudinal stability is increased
  4. Longitudinal stability is unchanged

Explanation

Moving the centre of gravity aft reduces the distance between the centre of gravity and the tail, which reduces the restoring moment produced by the horizontal stabiliser. The aircraft becomes less resistant to pitch disturbances and may require more careful handling.

Question 39Aviation Fundamentals and Aircraft Systems

A turbojet engine is fitted with a convergent exhaust nozzle. What happens to the exhaust gas as it passes through the nozzle?

  1. Pressure rises and velocity falls
  2. Pressure and velocity both remain constant
  3. Pressure falls and velocity rises Correct answer.
  4. Pressure and velocity both fall

Explanation

In a convergent duct, the flow area decreases, so the gas accelerates and its velocity increases. By conservation of energy, the static pressure falls as the velocity rises, and the resulting momentum change produces thrust.

Question 40Aviation Fundamentals and Aircraft Systems

An aircraft is flying straight and level at a constant true airspeed. If the pilot increases the angle of attack slightly without changing power, what is the immediate result?

  1. Drag decreases and the aircraft accelerates
  2. Lift decreases and the aircraft begins to descend
  3. Thrust increases and the aircraft climbs
  4. Lift increases and the aircraft begins to climb Correct answer.

Explanation

Increasing the angle of attack raises the lift coefficient, so lift temporarily exceeds weight and the aircraft accelerates upward. Drag also rises, so the aircraft will settle into a climb only if power is available to match the new condition.

Question 41Aerodynamics and Principles of Flight

Which force directly opposes the forward motion of an aircraft through the air?

  1. Lift
  2. Thrust
  3. Drag Correct answer.
  4. Weight

Explanation

Drag is the aerodynamic resistance acting parallel to the relative airflow and opposite to the direction of motion. Thrust acts forward to overcome it, while lift and weight act roughly perpendicular to the flight path.

Question 42Aerodynamics and Principles of Flight

In steady, unaccelerated level flight, which relationship between the four forces is correct?

  1. Lift is less than weight and thrust is less than drag
  2. Lift equals weight and thrust equals drag Correct answer.
  3. Lift equals thrust and weight equals drag
  4. Lift exceeds weight and thrust exceeds drag

Explanation

Steady level flight means no acceleration, so the vertical forces must balance and the horizontal forces must balance. Therefore lift equals weight and thrust equals drag, giving a net force of zero.

Question 43Aerodynamics and Principles of Flight

According to Bernoulli's principle, what happens to static pressure in a region where airflow speed increases?

  1. Static pressure falls Correct answer.
  2. Static pressure rises
  3. Static pressure stays constant
  4. Static pressure becomes equal to dynamic pressure

Explanation

For streamline flow of an incompressible fluid, an increase in velocity is accompanied by a decrease in static pressure, because total pressure remains constant. This pressure drop is the basis of lift generation over a cambered wing.

Question 44Aerodynamics and Principles of Flight

What is the angle of attack of an aerofoil?

  1. The angle between the longitudinal axis and the flight path
  2. The angle between the upper and lower surfaces at the trailing edge
  3. The angle between the chord line and the horizontal
  4. The angle between the chord line and the relative airflow Correct answer.

Explanation

Angle of attack is defined as the angle between the chord line of the aerofoil and the direction of the relative airflow. It is the primary variable controlling the lift coefficient.

Question 45Aerodynamics and Principles of Flight

What is the primary function of wing dihedral?

  1. To reduce induced drag at high speed
  2. To increase the critical angle of attack
  3. To provide lateral stability in a sideslip Correct answer.
  4. To increase the maximum lift coefficient

Explanation

With dihedral, a wing lowered in a sideslip meets the airflow at a greater angle of attack and generates more lift, producing a rolling moment that restores the wings level. This gives lateral (roll) stability.

Question 46Aerodynamics and Principles of Flight

Which statement best describes the centre of pressure of an aerofoil?

  1. It is fixed at the quarter-chord point for all angles of attack
  2. It coincides with the centre of gravity in all flight conditions
  3. It is the point of maximum wing thickness
  4. It is the point where the resultant aerodynamic force acts Correct answer.

Explanation

The centre of pressure is the point on the chord through which the resultant of pressure forces acts. As angle of attack increases it generally moves forward, which is why it is not fixed.

Question 47Aerodynamics and Principles of Flight

What causes an aircraft to stall?

  1. Exceeding the maximum structural load factor
  2. Flying with the centre of gravity too far forward
  3. Exceeding the critical angle of attack Correct answer.
  4. Flying faster than the never-exceed speed

Explanation

A stall occurs when the angle of attack exceeds the critical value and the airflow separates from the upper surface, causing a sudden loss of lift. It can happen at any speed, weight or attitude.

Question 48Aerodynamics and Principles of Flight

What is the effect of increasing altitude on true airspeed for a given indicated airspeed?

  1. True airspeed varies randomly with altitude
  2. True airspeed decreases
  3. True airspeed remains the same
  4. True airspeed increases Correct answer.

Explanation

As altitude increases, air density decreases, so a given dynamic pressure corresponds to a higher true airspeed. Indicated airspeed reflects dynamic pressure, so TAS rises above IAS as altitude increases.

Question 49Aerodynamics and Principles of Flight

Which of the following best describes form drag?

  1. Drag that is a by-product of generating lift
  2. Drag caused by compressibility effects at high Mach number
  3. Drag caused by skin friction along the surface
  4. Drag caused by the pressure difference between the front and rear of a body Correct answer.

Explanation

Form drag, also called pressure drag, arises from the pressure imbalance between the high-pressure forward region and the low-pressure wake behind a body. Streamlining reduces it by delaying separation.

Question 50Aerodynamics and Principles of Flight

Induced drag is greatest under which condition?

  1. Descending with idle power
  2. High speed, low altitude
  3. High speed, low angle of attack
  4. Low speed, high angle of attack Correct answer.

Explanation

Induced drag is proportional to the square of the lift coefficient, so it is greatest when the wing must generate a high lift coefficient. That occurs at low speed and high angle of attack, such as during slow flight.