EASA Module 8 Exam Flashcards

Q: How many questions are on the EASA Module 8 exam, and what is the pass mark?

Under Commission Implementing Regulation (EU) 2023/989, applicable from 12 June 2024, Module 8 has 24 multiple-choice questions to complete in 30 minutes, for every licence category (A, B1, B2, B3). The pass mark is 75%, and there is no negative marking.

Q: What happens if I fail the Module 8 exam?

You may resit a failed module after a minimum 90-day wait, for up to three consecutive attempts. If you fail all three consecutive attempts, EASA examination rules require roughly a 12-month wait (at any linked examination centre) before a new set of three attempts can begin.

Q: How many answer options does the real Module 8 exam use, versus this practice bank?

The official EASA exam uses three-option multiple-choice questions, giving about 75 seconds per question. This OpenExamPrep flashcard set and practice question bank use four options per item to give tougher, more discriminating practice.

Q: What does 'Basic Aerodynamics' actually cover on Module 8?

Four areas: physics of the atmosphere (the ISA model, pressure/density/humidity with altitude), aerodynamics and airflow (boundary layer, aerofoil geometry, Bernoulli), lift and drag (the lift equation, drag types, the polar curve, and high-speed/Mach effects), and theory of flight plus flight stability and dynamics (turns, load factor, stall, and the three stability axes).

Q: Is Module 8 the same exam for Category A, B1, B2 and B3 licences?

Yes - since Regulation (EU) 2023/989 took effect on 12 June 2024, Module 8 is examined in the same 24-question, 30-minute, 75%-pass-mark format for every licence category, though the depth of underlying coursework leading up to it can differ by category.

Question 1

What are the ISA sea-level datum values for temperature and pressure?

Accepted Answer

15°C (288.15 K) and 1013.25 hPa. Every atmospheric calculation in Module 8 starts from this datum before applying the lapse rate.

Question 2

What is the ISA standard temperature lapse rate below the tropopause?

Accepted Answer

1.98°C per 1,000 ft (roughly 2°C/1,000 ft). Temperature falls steadily with altitude until the tropopause, where it stops changing.

Question 3

At what altitude does the tropopause occur in the ISA model, and what happens to temperature above it?

Accepted Answer

36,090 ft. Above this height, temperature stays constant at -56.5°C - the lapse rate stops in the layer ISA models above the troposphere.

Question 4

How does atmospheric pressure change with altitude?

Accepted Answer

Pressure decreases exponentially (not in a straight line) with altitude - fastest near sea level and more slowly higher up - while temperature falls linearly to the tropopause.

Question 5

What is density altitude, and why does it matter for performance?

Accepted Answer

Pressure altitude corrected for non-standard temperature. On a hot day the air is less dense than ISA predicts for that pressure altitude, so density altitude is higher than pressure altitude and aircraft/engine performance suffers.

Question 6

How does humidity affect air density?

Accepted Answer

Humid air is less dense than dry air at the same temperature and pressure, because water vapor molecules displace heavier nitrogen and oxygen molecules. Less dense air means less lift and less engine power for a given airspeed.

Question 7

What is the dew point, and how is it used?

Accepted Answer

The temperature at which air becomes saturated with water vapor and condensation begins. Comparing dew point to actual air temperature gives relative humidity - the ratio of actual to maximum possible water vapor content.

Question 8

What is the boundary layer?

Accepted Answer

A thin layer of air next to a surface where viscosity slows the airflow relative to the free stream - velocity ranges from zero at the surface (the no-slip condition) up to full free-stream speed at the layer's outer edge.

Question 9

Compare laminar and turbulent boundary-layer flow: which has lower skin friction, and which resists separation longer?

Accepted Answer

Laminar flow is smooth with lower skin friction but separates earlier. Turbulent flow has higher skin friction but mixes in energy from outside the layer, so it resists separation longer.

Question 10

What causes boundary-layer separation?

Accepted Answer

An adverse pressure gradient - air moving into a region of rising pressure loses momentum until it stops and reverses, separating from the surface. This is the root cause of an aerodynamic stall.

Question 11

Define chord line and camber for an aerofoil.

Accepted Answer

The chord line runs straight from the leading edge to the trailing edge. Camber is the curvature of the mean line (midway between the upper and lower surfaces) relative to the chord line - more camber generally raises lift at a given angle of attack.

Question 12

What is aspect ratio, and how is it calculated?

Accepted Answer

Wingspan squared divided by wing area (span² / area). A high-aspect-ratio wing (long and narrow, like a glider's) is more aerodynamically efficient, with lower induced drag, than a low-aspect-ratio wing (short and wide, like a fighter's).

Question 13

What is washout, and why is it built into a wing?

Accepted Answer

Washout twists the wing so the tip sits at a lower angle of incidence than the root. The root then stalls first, keeping the ailerons effective and giving the pilot a stall warning before the whole wing stops flying.

Question 14

Distinguish free stream airflow from relative airflow.

Accepted Answer

Free stream is the undisturbed air ahead of the aircraft, unaffected by it. Relative airflow is airflow direction relative to the aircraft or aerofoil - it runs parallel to, and opposite, the flight path.

Question 15

What are wingtip vortices, and when are they strongest?

Accepted Answer

Spanwise flow at the wingtip, caused by higher-pressure air beneath the wing spilling around the tip toward the lower pressure above, rolling into a vortex. They are strongest for a slow, heavy aircraft in a clean configuration.

Question 16

What is a stagnation point?

Accepted Answer

The point on an aerofoil, usually near the leading edge, where local airflow velocity is zero and static pressure is at its maximum - the air has been brought fully to rest before splitting to flow over and under the surface.

Question 17

State Bernoulli's principle in terms of velocity and pressure.

Accepted Answer

As the velocity of a fluid increases, its static pressure decreases (and vice versa), provided total energy is conserved. This is the basic physical principle behind the pressure differences that develop over an aerofoil.

Question 18

What is dynamic pressure (q), and how is it calculated?

Accepted Answer

The pressure due to a moving airstream: q = 1/2 rho V squared. Added to static pressure it gives total pressure, and it is the term that appears directly in both the lift and drag equations.

Question 19

What happens to airflow velocity and static pressure through a venturi throat?

Accepted Answer

As the duct narrows, velocity increases and static pressure decreases - the venturi effect, a direct application of Bernoulli's principle used to explain accelerated airflow over the cambered upper surface of an aerofoil.

Question 20

State the lift equation and name its terms.

Accepted Answer

L = CL x 1/2 rho V squared x S, where CL is the lift coefficient, rho is air density, V is true airspeed, and S is wing area. Lift is directly proportional to density, wing area, and CL, but proportional to the SQUARE of airspeed.

Question 21

If true airspeed doubles with angle of attack and configuration unchanged, what happens to lift?

Accepted Answer

Lift increases by a factor of four, because lift varies with velocity squared in the lift equation - small speed changes have a large effect on the lift (and drag) produced.

Question 22

How does air density (rho) affect lift at a given true airspeed and angle of attack?

Accepted Answer

Lift is directly proportional to air density - less dense air (hot day, high altitude, humid air) produces less lift for the same true airspeed and angle of attack, so a higher true airspeed is needed to generate the same lift.

Question 23

What is CLmax, and when does it occur?

Accepted Answer

The maximum value of the lift coefficient, reached just before the critical angle of attack is exceeded. Beyond CLmax, further increases in angle of attack cause lift to fall away sharply as the wing stalls.

Question 24

Define angle of attack.

Accepted Answer

The angle between an aerofoil's chord line and the relative airflow, not the aircraft's longitudinal axis. It changes continuously in flight as the pilot pitches and as airspeed changes.

Question 25

How does angle of incidence differ from angle of attack?

Accepted Answer

Angle of incidence is the fixed rigging angle between the chord line and the aircraft's longitudinal axis, set during manufacture and unchanged in flight. Angle of attack is variable and measured against the relative airflow instead.

Question 26

Where is the aerodynamic centre located on a subsonic aerofoil?

Accepted Answer

Approximately 25% of the chord back from the leading edge (the quarter-chord point). The pitching moment about this point stays essentially constant as angle of attack changes, unlike the centre of pressure, which moves.

Question 27

What causes induced drag, and when is it greatest?

Accepted Answer

Induced drag is a by-product of generating lift, caused by wingtip vortices and the resulting downwash. It is greatest at low speed and high angle of attack, such as climb or landing approach, and falls as speed increases.

Question 28

How does induced drag change as airspeed increases?

Accepted Answer

It decreases - less angle of attack is needed to produce the required lift at higher speed, so vortex strength and induced drag both fall. This is the opposite trend to parasite drag.

Question 29

What is parasite drag, and what are its components?

Accepted Answer

Drag not directly related to producing lift: form (pressure) drag, skin-friction drag, and interference drag between components. It exists even at zero lift and rises with speed.

Question 30

How does parasite drag change as airspeed increases?

Accepted Answer

It rises, approximately with the square of airspeed - doubling speed roughly quadruples parasite drag. This is the opposite trend to induced drag, which falls as speed rises.

Question 31

What is profile drag?

Accepted Answer

The parasite drag generated specifically by a wing section - its form drag plus skin-friction drag - as distinct from the parasite drag produced by the fuselage, tail, and other components.

Question 32

At what point is total drag at a minimum, and why does that matter?

Accepted Answer

Total drag is minimum where induced drag equals parasite drag. This condition gives the best (maximum) lift-to-drag ratio, and therefore the best glide range or most efficient cruise speed.

Question 33

What does the polar curve (drag polar) plot, and what does it reveal?

Accepted Answer

It plots lift coefficient (CL) against drag coefficient (CD). The point of maximum lift-to-drag ratio, the most efficient angle of attack, is found where a line from the origin is tangent to the curve.

Question 34

How is Mach number defined?

Accepted Answer

The ratio of the aircraft's true airspeed to the local speed of sound. Mach 1.0 means the aircraft is traveling exactly at the speed of sound for the surrounding conditions.

Question 35

What is critical Mach number (Mcrit), and why does it matter?

Accepted Answer

The aircraft's flight Mach number at which airflow over part of the airframe, usually the accelerated flow over the wing's upper surface, first reaches Mach 1.0, even though the aircraft itself still flies below the speed of sound. Beyond Mcrit, shock waves and extra compressibility drag appear.

Question 36

Name the four forces acting on an aircraft in flight.

Accepted Answer

Lift, weight, thrust, and drag. In steady, straight-and-level, unaccelerated flight, lift equals weight and thrust equals drag.

Question 37

In a glide with no thrust, what balances drag along the flight path?

Accepted Answer

A component of weight acting along the descending flight path balances drag, while the component of weight perpendicular to the flight path balances lift - this is how an unpowered aircraft flies steadily downhill.

Question 38

What does a 10:1 glide ratio mean?

Accepted Answer

The aircraft travels 10 feet forward for every 1 foot of altitude lost, with no wind. A higher glide ratio means better unpowered range for the same height loss.

Question 39

What is load factor?

Accepted Answer

The ratio of lift to weight (the 'g' loading on the aircraft and its structure). In level, unaccelerated flight, load factor is 1g; in a turn or pull-up it rises above 1g because lift must exceed weight to also supply centripetal force.

Question 40

How does load factor in a turn affect stall speed?

Accepted Answer

Stall speed rises with the square root of load factor, because more lift is needed to support the increased apparent weight. A 2g turn raises stall speed to about 1.41 times (the square root of 2) the normal 1g value.

Question 41

What does a V-n (flight envelope) diagram show?

Accepted Answer

The structural and aerodynamic limits of an aircraft, plotting load factor (n) against airspeed (V) - the maximum positive and negative g the structure can withstand, and the speed at which the wing stalls before those structural limits are reached.

Question 42

What causes a wing to stall?

Accepted Answer

Exceeding the critical angle of attack, which causes the boundary layer to separate from the upper surface and lift to collapse. Stall is an angle-of-attack event, not simply a low-airspeed event.

Question 43

How do flaps and slats each help delay or lower the stall?

Accepted Answer

Flaps increase camber, raising CLmax so the wing produces the needed lift at a lower angle of attack and speed. Slats and slots re-energize the boundary layer over the upper surface with high-energy air, delaying separation to a higher angle of attack.

Question 44

What is an aerodynamic spin, and what triggers it?

Accepted Answer

Autorotation following a stall in which one wing is more deeply stalled than the other, producing less lift and more drag on that side, so the aircraft yaws and rolls continuously about a vertical axis while descending.

Question 45

What provides longitudinal (pitch) stability, and about which axis does it act?

Accepted Answer

The tailplane (horizontal stabilizer), acting about the lateral axis. If a gust pitches the nose up, an increased tailplane download restores the aircraft toward its trimmed attitude.

Question 46

What provides lateral (roll) stability, and what design feature reinforces it?

Accepted Answer

Dihedral - the upward angle of the wings from root to tip - generates a restoring rolling moment during a sideslip. Wing sweepback adds a similar dihedral-like effect, boosting lateral stability further.

Question 47

What provides directional (yaw) stability?

Accepted Answer

The vertical fin, acting about the normal (vertical) axis - it 'weathercocks' the nose back into the relative airflow if the aircraft yaws off its flight path.

Question 48

Distinguish static stability from dynamic stability.

Accepted Answer

Static stability describes only the aircraft's initial tendency after a disturbance - whether it first moves back toward equilibrium. Dynamic stability describes how that motion develops over time, whether the resulting oscillation damps out, stays constant, or grows.

Question 49

What does a negative dynamic stability response look like?

Accepted Answer

Oscillations that increase in amplitude over time instead of damping out. An aircraft can be statically stable, with an initial tendency to return, yet dynamically unstable if the resulting oscillation grows rather than decays.

Question 50

How does moving the centre of gravity aft affect longitudinal stability, and what is Dutch roll?

Accepted Answer

An aft CG shortens the tailplane's effective moment arm and weakens longitudinal (pitch) stability, potentially reversing it beyond the aft limit. Dutch roll is a combined yaw-roll oscillation, seen especially on swept-wing aircraft that have strong lateral stability but weaker directional stability.

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