Aircraft General Knowledge

Q1: In a glider cockpit, the levers colored red, blue, and green correspond to which controls? ^t20q1

A) Speed brakes, canopy lock, and landing gear.
B) Canopy hood release, speed brakes, and elevator trim.
C) Landing gear, speed brakes, and elevator trim tab.
D) Speed brakes, cable release, and elevator trim.

Answer

Explanation

EASA standardises cockpit lever colours in gliders: red for the canopy hood (emergency) release, blue for speed brakes (airbrakes), and green for elevator trim. This colour coding ensures pilots can identify critical controls instantly under stress.

Option A incorrectly assigns red to speed brakes and blue to the canopy lock.
Option C incorrectly assigns red to landing gear.
Option D incorrectly assigns red to speed brakes and blue to cable release.

Key Terms

EASA = European Union Aviation Safety Agency

Q2: Wing thickness is measured as the distance between the upper and lower surfaces of a wing at its ^t20q2

DE · FR

A) Outermost section.
B) Thinnest cross-section.
C) Innermost section near the root.
D) Thickest cross-section.

Answer

Explanation

Wing thickness is defined as the maximum perpendicular distance between the upper and lower wing surfaces, measured at the thickest part of the airfoil cross-section (typically 20-30% of chord from the leading edge). This is the aerodynamically and structurally significant measurement.

Option A (outermost section) would measure near the wingtip where the profile is thinnest.
Option B (thinnest cross-section) gives a minimal, less useful value.
Option C (innermost/root) describes a spanwise location, not the airfoil thickness definition.

Q3: What is the term for a tubular steel framework with a non-load-bearing skin? ^t20q3

DE · FR

A) Monocoque construction.
B) Semi-monocoque construction.
C) Grid construction.
D) Honeycomb structure.

Answer

Explanation

Grid (or truss/lattice) construction uses a framework of tubes or members to carry all structural loads, with the skin serving only as a fairing that does not contribute to structural strength.

Option A (monocoque) is the opposite -- the skin carries all loads with no internal framework.
Option B (semi-monocoque) uses both a frame and a load-bearing skin working together.
Option D (honeycomb structure) is a core material used in sandwich panels, not a fuselage construction type.

Q4: What are the typical structural components of primary fuselage construction in wood or metal aircraft? ^t20q4

DE · FR

A) Girders, ribs, and stringers.
B) Ribs, frames, and covers.
C) Frames and stringers.
D) Covers, stringers, and forming parts.

Answer

Explanation

The primary structural members of a traditional fuselage are frames (also called formers or bulkheads, running circumferentially) and stringers (running longitudinally). Together they form the skeleton over which the skin is attached.

Option A introduces "girders" which is non-standard fuselage terminology.
Option B includes "ribs" which are wing components, not fuselage.
Option D lists "covers" and "forming parts" which are not primary structural terms.

Q5: What is the name for a structure built from frames and stringers with a load-bearing skin? ^t20q5

DE · FR

A) Grid construction.
B) Honeycomb structure.
C) Wood or mixed construction.
D) Semi-monocoque construction.

Answer

Explanation

Semi-monocoque construction uses both an internal framework (frames and stringers) AND a skin that actively bears structural loads (tension, compression, shear). This is the most common modern aircraft fuselage design.

Option A (grid construction) has a non-load-bearing skin.
Option B (honeycomb) is a material type, not a structural concept.
Option C (wood/mixed) is a material classification, not a structural design.

Q6: What are the principal structural components of an aircraft's tail assembly? ^t20q6

DE · FR

A) Ailerons and elevator.
B) Horizontal tail and vertical tail.
C) Rudder and ailerons.
D) Steering wheel and pedals.

Answer

Explanation

The tail assembly (empennage) consists of two principal structural groups: the horizontal tail (stabiliser and elevator, providing pitch stability and control) and the vertical tail (fin and rudder, providing yaw stability and control).

Option A incorrectly includes ailerons, which are wing-mounted.
Option C also incorrectly includes ailerons.
Option D lists cockpit controls, not aircraft structure.

Q7: A sandwich structure is composed of two ^t20q7

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A) Thin layers bonded to a heavy core material.
B) Thick layers bonded to a lightweight core material.
C) Thick layers bonded to a heavy core material.
D) Thin layers bonded to a lightweight core material.

Answer

Explanation

A sandwich structure uses two thin, stiff face sheets (typically CFRP, glass fibre, or aluminium) bonded to a lightweight core (foam, balsa wood, or honeycomb). The thin skins carry bending loads while the light core resists shear and maintains separation, providing exceptional stiffness-to-weight ratio.

Options A and C specify a heavy core, which defeats the weight-saving purpose.
Options B and C specify thick layers, which add unnecessary mass.

Q8: Which structural elements define the aerodynamic profile shape of a wing? ^t20q8

DE · FR

A) Spar.
B) Planking.
C) Ribs.
D) Wingtip.

Answer

Explanation

Ribs are chordwise structural members that define the airfoil cross-section shape of the wing, running perpendicular to the spar. They establish the precise curvature of the upper and lower wing surfaces.

Option A (spar) is the main spanwise load-bearing beam but does not define the profile shape.
Option B (planking/skin) covers the structure but follows the shape determined by the ribs.
Option D (wingtip) is the outer end of the wing, not a profile-shaping element.

Q9: The load factor "n" expresses the ratio between ^t20q9

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A) Thrust and drag.
B) Lift and weight.
C) Weight and thrust.
D) Drag and lift.

Answer

Explanation

The load factor n equals Lift divided by Weight (n = L/W). In straight and level flight, n = 1 (1g). In a banked turn, lift must exceed weight to maintain altitude -- for example, in a 60-degree bank, n = 2 (2g). Load factor is critical for glider structural design, as exceeding maximum positive or negative g-limits risks structural failure.

Options A, C, and D describe unrelated force ratios.

Q10: What are the key benefits of sandwich construction? ^t20q10

DE · FR

A) Good formability combined with high temperature resistance.
B) Low weight, high stiffness, high stability, and high strength.
C) High temperature durability coupled with low weight.
D) High strength paired with good formability.

Answer

Explanation

Sandwich construction excels at combining low weight with high stiffness, stability, and strength -- the ideal combination for aerospace applications. The bending stiffness increases dramatically when stiff face sheets are spaced apart by a lightweight core.

Options A and C emphasise temperature resistance, which is not a primary advantage since most cores are temperature-sensitive.
Option D focuses on formability, which is actually limited in sandwich construction.

Q11: Among the following materials, which one exhibits the greatest strength? ^t20q11

DE · FR

A) Wood.
B) Aluminium.
C) Carbon fiber reinforced plastic.
D) Magnesium.

Answer

Explanation

Carbon fibre reinforced plastic (CFRP) has exceptional strength-to-weight ratio with tensile strength exceeding steel at a fraction of the weight. Modern high-performance gliders are predominantly CFRP.

Option B (aluminium) is strong but significantly weaker than CFRP.
Option D (magnesium) is lighter than aluminium but lower in absolute strength.
Option A (wood) has good specific strength but is the weakest in absolute terms among those listed.

Q12: The trim lever in a glider serves to ^t20q12

DE · FR

A) Minimize adverse yaw effects.
B) Reduce the required stick force on the rudder.
C) Reduce the required stick force on the elevator.
D) Reduce the required stick force on the ailerons.

Answer

Explanation

The trim system adjusts the elevator trim tab (or spring trim) to hold a desired pitch attitude without continuous pilot input on the control stick, reducing elevator stick force to zero at the trimmed speed.

Option A (adverse yaw) is addressed by rudder coordination, not trim.
Options B and D refer to rudder and aileron forces, which are not adjusted by the standard glider trim lever.

Q13: Structural damage to a fuselage may result from ^t20q13

DE · FR

A) A stall occurring after the maximum angle of attack is exceeded.
B) Reducing airspeed below a certain threshold.
C) Flying faster than maneuvering speed in severe gusts.
D) Neutralizing stick forces appropriate to the current flight condition.

Answer

Explanation

Exceeding manoeuvring speed (VA) in turbulent conditions can cause structural damage because gusts impose sudden load factors that may exceed the design limit. VA is the speed at which a full control deflection or maximum gust will not exceed the structural limit load.

Option A (stall) is an aerodynamic event that does not damage structure.
Option B (low airspeed) reduces loads.
Option D (neutralising stick forces) does not create structural loads.

Key Terms

VA = Manoeuvring Speed

Q14: How many axes does an aircraft rotate about, and what are they called? ^t20q14

DE · FR

A) 4; optical axis, imaginary axis, sagged axis, axis of evil.
B) 3; x-axis, y-axis, z-axis.
C) 3; vertical axis, lateral axis, longitudinal axis.
D) 4; vertical axis, lateral axis, longitudinal axis, axis of speed.

Answer

Explanation

An aircraft rotates about three principal axes passing through the centre of gravity: the longitudinal axis (nose to tail -- roll), the lateral axis (wingtip to wingtip -- pitch), and the vertical axis (top to bottom -- yaw).

Option B uses mathematical labels but omits aviation-specific names.
Options A and D fabricate a non-existent fourth axis.

Q15: Rotation around the longitudinal axis is primarily produced by the ^t20q15

DE · FR

A) Rudder.
B) Trim tab.
C) Elevator.
D) Ailerons.

Answer

Explanation

Ailerons control roll -- rotation around the longitudinal axis. When one aileron deflects up and the other down, differential lift rolls the aircraft.

Option A (rudder) controls yaw around the vertical axis.
Option C (elevator) controls pitch around the lateral axis.
Option B (trim tab) modifies control forces but is not a primary roll initiator.

Q16: On a small single-engine piston aircraft, how are the flight controls typically operated and connected? ^t20q16

DE · FR

A) Electrically via fly-by-wire systems.
B) Power-assisted via hydraulic pumps or electric motors.
C) Manually via rods and control cables.
D) Hydraulically via pumps and actuators.

Answer

Explanation

Small piston aircraft and gliders use direct mechanical linkages -- push-pull rods and steel control cables -- to transmit pilot input directly to control surfaces. This is simple, lightweight, and reliable with no power source required.

Option A (fly-by-wire) is used on modern airliners and military aircraft.
Options B and D (hydraulic systems) are used on larger aircraft requiring greater control forces.

Q17: When left rudder is applied, what are the primary and secondary effects? ^t20q17

DE · FR

A) Primary: yaw to the left; Secondary: roll to the left.
B) Primary: yaw to the right; Secondary: roll to the right.
C) Primary: yaw to the left; Secondary: roll to the right.
D) Primary: yaw to the right; Secondary: roll to the left.

Answer

Explanation

Left rudder primarily yaws the nose left around the vertical axis. The secondary effect is roll to the left: as the nose yaws left, the outer (right) wing moves faster and generates more lift while the inner (left) wing slows and generates less, creating a bank to the left.

Options B and D have incorrect yaw direction.
Option C has correct yaw but incorrect secondary roll direction.

Q18: What happens when the control stick or yoke is pulled rearward? ^t20q18

DE · FR

A) The tail produces an increased downward force, causing the nose to rise.
B) The tail produces an increased upward force, causing the nose to rise.
C) The tail produces a decreased upward force, causing the nose to drop.
D) The tail produces an increased downward force, causing the nose to drop.

Answer

Explanation

Pulling back on the stick deflects the elevator upward, increasing the downward aerodynamic force on the tail. With the tail pushed down, the nose pivots up around the lateral axis through the centre of gravity. This seems counterintuitive but is correct: tail goes down, nose goes up.

Option B incorrectly states the tail force is upward.
Option C describes a forward stick input.
Option D has the correct force but wrong nose direction.

Q19: Which of these lists contains all primary flight controls of an aircraft? ^t20q19

DE · FR

A) Flaps, slats, and speedbrakes.
B) All movable components on an aircraft that help control its flight.
C) Elevator, rudder, and aileron.
D) Elevator, rudder, aileron, trim tabs, high-lift devices, and power controls.

Answer

Explanation

The three primary flight controls are elevator (pitch), rudder (yaw), and aileron (roll). These directly control rotation about the aircraft's three axes.

Option A lists secondary/high-lift devices only.
Option B is too vague and includes secondary controls.
Option D mixes primary with secondary controls (trim tabs, high-lift devices, power controls).

Q20: What function do secondary flight controls serve? ^t20q20

DE · FR

A) They serve as a backup system for the primary flight controls.
B) They enable the pilot to control the aircraft about its three axes.
C) They enhance performance characteristics and relieve the pilot of excessive control forces.
D) They improve turning characteristics at low speed during approach and landing.

Answer

Explanation

Secondary flight controls (trim tabs, flaps, speedbrakes, slats) enhance aircraft performance and reduce pilot workload. Trim neutralises stick forces; flaps increase low-speed lift; speedbrakes manage descent rate.

Option A is incorrect -- they are not backup systems.
Option B describes primary controls.
Option D is too narrow, covering only one aspect of flap function.

Q21: If the pilot moves the trim wheel or lever aft, what happens to the trim tab and the elevator? ^t20q21

DE · FR

A) The trim tab moves up, the elevator moves down.
B) The trim tab moves down, the elevator moves down.
C) The trim tab moves up, the elevator moves up.
D) The trim tab moves down, the elevator moves up.

Answer

Explanation

Moving trim aft commands nose-up trim. The trim tab deflects downward, generating an aerodynamic force that pushes the elevator trailing edge upward. The raised elevator pushes the tail down and raises the nose. Trim tabs always move opposite to the elevator: tab down causes elevator up.

Options A and C have the tab moving up (nose-down trim).
Option B has both moving down, which is mechanically impossible in a normal trim system.

Q22: In which direction does the trim tab deflect when trimming for nose-up? ^t20q22

DE · FR

A) It depends on the CG position.
B) It deflects upward.
C) In the direction of rudder deflection.
D) It deflects downward.

Answer

Explanation

For nose-up trim, the trim tab deflects downward. The downward tab creates an aerodynamic force pushing the elevator trailing edge up, which holds the elevator in a nose-up position without pilot input.

Option A (CG position) affects how much trim is needed but not the direction.
Option B (upward) would produce nose-down trim.
Option C (rudder direction) is unrelated to elevator trim operation.

Key Terms

CG = Centre of Gravity

Q23: The purpose of the trim system is to ^t20q23

DE · FR

A) Lock the control surfaces in position.
B) Shift the centre of gravity.
C) Adjust the control force.
D) Increase adverse yaw.

Answer

Explanation

Trim adjusts control forces so the pilot can fly hands-off at the trimmed speed and attitude. It neutralises the stick force to zero at the desired condition.

Option A (lock surfaces) is incorrect -- trim holds an aerodynamic equilibrium, not a mechanical lock.
Option B (shift CG) is wrong -- only physically moving mass changes CG.
Option D (adverse yaw) is a roll-yaw coupling unrelated to trim.

Key Terms

CG = Centre of Gravity

Q24: The Pitot-static system is designed to ^t20q24

DE · FR

A) Correct the airspeed indicator to show zero when the aircraft is stationary on the ground.
B) Prevent static electricity accumulation on the airframe.
C) Prevent ice formation on the Pitot tube.
D) Measure total air pressure and static air pressure.

Answer

Explanation

The Pitot-static system measures total pressure (from the Pitot tube facing the airflow) and static pressure (from flush static ports on the fuselage). These feed the ASI, altimeter, and variometer.

Option A describes a consequence, not the purpose.
Option B (static electricity) is an unrelated electrical phenomenon.
Option C (ice prevention) is handled by optional Pitot heating, not the system's design purpose.

Q25: What type of pressure does the Pitot tube sense? ^t20q25

DE · FR

A) Static air pressure.
B) Total air pressure.
C) Cabin air pressure.
D) Dynamic air pressure.

Answer

Explanation

The Pitot tube faces into the airflow and senses total pressure (stagnation pressure), which equals static pressure plus dynamic pressure (q = 1/2 rho v-squared).

Option A (static pressure) is measured by separate static ports.
Option C (cabin pressure) is unrelated.
Option D (dynamic pressure) is not measured directly by the Pitot tube -- it is derived by subtracting static from total pressure inside the ASI.

Q26: QFE refers to the ^t20q26

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A) Barometric pressure corrected to sea level using the international standard atmosphere (ISA).
B) Altitude referenced to the 1013.25 hPa pressure level.
C) Barometric pressure at a reference datum, typically the runway threshold of an airfield.
D) Magnetic bearing to a station.

Answer

Explanation

QFE is the atmospheric pressure at a specific reference point, typically the runway threshold. Setting QFE on the altimeter causes it to read zero on the ground at the aerodrome, showing height above the field during flight.

Option A describes QNH (sea level corrected pressure).
Option B describes the flight level datum (1013.25 hPa).
Option D describes QDM/QDR radio navigation terminology.

Key Terms

ISA = International Standard Atmosphere; QFE = Atmospheric pressure at aerodrome elevation; QNH = Pressure adjusted to mean sea level

Q27: What is the function of the altimeter subscale? ^t20q27

DE · FR

A) To correct the altimeter for instrument system errors.
B) To set the reference datum for the transponder altitude encoder.
C) To reference the altimeter reading to a chosen level such as mean sea level, aerodrome elevation, or the 1013.25 hPa pressure surface.
D) To compensate the altimeter reading for non-standard temperatures.

Answer

Explanation

The altimeter subscale (Kollsman window) lets the pilot set a reference pressure: QNH for altitude above sea level, QFE for height above the airfield, or 1013.25 hPa for flight levels.

Option A (system errors) requires calibration, not subscale adjustment.
Option B (transponder encoder) operates on standard pressure independently.
Option D (temperature correction) requires a separate mathematical calculation.

Key Terms

QFE = Atmospheric pressure at aerodrome elevation; QNH = Pressure adjusted to mean sea level

Q28: How can an altimeter subscale set to an incorrect QNH lead to a dangerous altimeter error? ^t20q28

DE · FR

A) Setting a lower pressure than actual causes the reading to be too low, meaning greater height above ground than intended.
B) Setting a lower pressure than actual causes the reading to be too high, bringing the aircraft closer to the ground than indicated.
C) Setting a higher pressure than actual causes the reading to be too high, bringing the aircraft closer to the ground than indicated.
D) Setting a higher pressure than actual causes the reading to be too low, meaning greater height above ground than intended.

Answer

Explanation

Setting a higher pressure than actual QNH causes the altimeter to over-read -- it shows a higher altitude than the aircraft's true position. The aircraft is actually closer to the ground than indicated, creating a dangerous terrain clearance illusion. The memory aid: "High to Low, look out below.

Options A and B incorrectly describe the effect of a low pressure setting.
Option D reverses the consequence of a high setting.

Key Terms

QNH = Pressure adjusted to mean sea level

Q29: A temperature lower than the ISA standard may cause ^t20q29

DE · FR

A) An altitude reading that is too high.
B) A correct altitude reading provided the subscale is set for non-standard temperature.
C) An altitude reading that is too low.
D) Pitot tube icing that freezes the altimeter at its current value.

Answer

Explanation

In colder-than-standard air, the atmosphere is denser and pressure drops faster with altitude than ISA assumes. The altimeter over-reads, indicating a higher altitude than the aircraft's actual position -- the pilot is lower than they think. "Cold air = lower than you think.

Option B is wrong because altimeter subscales cannot correct for temperature.
Option C reverses the error.
Option D describes an icing issue separate from temperature-induced altimeter error.

Key Terms

ISA = International Standard Atmosphere

Q30: A flight level is a ^t20q30

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A) True altitude.
B) Pressure altitude.
C) Density altitude.
D) Altitude above the ground.

Answer

Explanation

A flight level is a pressure altitude expressed in hundreds of feet with the altimeter set to 1013.25 hPa (standard pressure). FL100 = 10,000 ft on standard setting. All aircraft above the transition altitude use this common datum for vertical separation regardless of local pressure variations.

Option A (true altitude) is actual MSL height.
Option C (density altitude) is a performance calculation parameter.
Option D (above ground) is height AGL.

Key Terms

AGL = Above Ground Level; FL = Flight Level; MSL = Mean Sea Level

Q31: True altitude is defined as ^t20q31

DE · FR

A) A height above ground level corrected for non-standard pressure.
B) A pressure altitude corrected for non-standard temperature.
C) An altitude above mean sea level corrected for non-standard temperature.
D) A height above ground level corrected for non-standard temperature.

Answer

Explanation

True altitude is the actual geometric height of the aircraft above mean sea level (MSL), obtained by correcting indicated altitude for deviations from the ISA temperature profile. The altimeter assumes standard ISA conditions; when actual temperature differs, the indicated reading diverges from the real MSL height.

Option A and D are wrong because true altitude is referenced to MSL, not above ground level (AGL).
Option B mentions temperature correction but is imprecise — true altitude is the actual MSL height, not merely a pressure altitude with a temperature factor applied.
Only Option C correctly defines true altitude.

Key Terms

AGL = Above Ground Level; ISA = International Standard Atmosphere; MSL = Mean Sea Level

Q32: When flying in air colder than ISA, the indicated altitude is ^t20q32

DE · FR

A) Equal to the standard altitude.
B) Lower than the true altitude.
C) Equal to the true altitude.
D) Higher than the true altitude.

Answer

Explanation

In colder-than-ISA air the atmosphere is denser, so pressure decreases more rapidly with altitude than the altimeter assumes. The altimeter therefore over-reads and shows a higher value than the aircraft's actual MSL height — the aircraft is physically lower than the instrument indicates. This is a serious terrain clearance hazard, summarized by the memory aid "High to low (temperature), look out below." B states the opposite of what occurs.

Option A and C only apply under exact ISA conditions.
Only Option D is correct.

Key Terms

ISA = International Standard Atmosphere; MSL = Mean Sea Level

Q33: When flying in an air mass at ISA temperature with the correct QNH set, the indicated altitude is ^t20q33

DE · FR

A) Lower than the true altitude.
B) Higher than the true altitude.
C) Equal to the true altitude.
D) Equal to the standard atmosphere.

Answer

Explanation

The altimeter is calibrated to the ISA standard temperature lapse rate. When the actual temperature exactly matches ISA and the correct QNH is set, all instrument assumptions are perfectly met and no error exists — indicated altitude equals true altitude. This is the ideal baseline condition from which deviations introduce errors. A and B describe situations with non-standard temperature or pressure.

D is vague and not a meaningful statement about the altimeter reading.
Only C is correct.

Key Terms

ISA = International Standard Atmosphere; QNH = Pressure adjusted to mean sea level

Q34: Which instrument is susceptible to hysteresis error? ^t20q34

DE · FR

A) Vertical speed indicator.
B) Direct reading compass.
C) Altimeter.
D) Tachometer.

Answer

Explanation

Hysteresis error affects the altimeter because its aneroid capsules — thin elastic bellows that expand and contract with pressure changes — do not return to exactly the same position when pressure is restored to a previously experienced value. This mechanical lag means the altimeter may show slightly different readings at the same altitude when climbing versus descending.

Option A (VSI), B (compass), and D (tachometer) do not rely on elastic aneroid capsules for their primary measurement and are therefore not subject to this specific error.
Only Option C is correct.

Q35: Altitude measurement relies on changes in which type of pressure? ^t20q35

DE · FR

A) Total pressure.
B) Differential pressure.
C) Static pressure.
D) Dynamic pressure.

Answer

Explanation

Static pressure is the ambient atmospheric pressure that decreases predictably with altitude according to the ISA model. The altimeter senses this pressure via the static port and converts it to an altitude reading using calibrated aneroid capsules.

Option A (total pressure) equals static plus dynamic and is measured by the Pitot tube for airspeed.
Option B (differential pressure) is the difference between total and static, which drives the ASI.
Option D (dynamic pressure) depends on airspeed and has no role in altitude measurement.
Only Option C is correct.

Key Terms

ISA = International Standard Atmosphere

Q36: How does a vertical speed indicator work? ^t20q36

DE · FR

A) It measures total air pressure and compares it to static pressure.
B) It compares the current static air pressure against the static pressure stored in a reservoir.
C) It measures vertical acceleration using a gimbal-mounted mass.
D) It measures static air pressure and compares it against a vacuum.

Answer

Explanation

The VSI detects rate of climb or descent by comparing current static pressure (from the static port) against a reference pressure stored in an internal reservoir that communicates via a calibrated leak. When climbing, static pressure drops faster than the reservoir can equalize, creating a pressure difference that deflects the pointer proportional to climb rate. - A describes the ASI operating principle (total minus static = dynamic). - C describes an accelerometer. - D describes a barometer, which cannot indicate a rate of change. Only B correctly explains VSI operation.

Q37: The vertical speed indicator compares the pressure difference between ^t20q37

DE · FR

A) The current dynamic pressure and the dynamic pressure from a moment earlier.
B) The current static pressure and the static pressure from a moment earlier.
C) The current total pressure and the total pressure from a moment earlier.
D) The current dynamic pressure and the static pressure from a moment earlier.

Answer

Explanation

The VSI senses only static pressure, which changes as altitude changes. It compares the instantaneous static pressure arriving through the static port with the slightly delayed static pressure stored in the metering reservoir behind the calibrated restriction. The rate of pressure change indicates the rate of altitude change.

Option A — A, C, and D all involve dynamic or total pressure, which are Pitot-tube quantities used for airspeed measurement and play no role in the VSI.
Only Option B is correct.

Q38: An aircraft flies on a heading of 180° at 100 kt TAS. The wind blows from 180° at 30 kt. Ignoring instrument and position errors, what will the airspeed indicator approximately show? ^t20q38

DE · FR

A) 70 kt
B) 130 kt
C) 30 kt
D) 100 kt

Answer

Explanation

The ASI measures the aircraft's speed relative to the surrounding air mass, not relative to the ground. The aircraft moves through the air at 100 kt TAS, so the ASI shows 100 kt regardless of wind. A wind from 180° on a heading of 180° is a headwind, reducing ground speed to 70 kt — that is A, but ground speed is not what the ASI reads.

Option B (130 kt) would only apply with a 30 kt tailwind.
Option C (30 kt) is merely the wind speed, irrelevant to the ASI.
Only Option D is correct.

Key Terms

TAS = True Airspeed

Q39: What principle does the airspeed indicator use to determine speed? ^t20q39

DE · FR

A) Static air pressure is measured and compared against a vacuum.
B) Dynamic air pressure is sensed by the Pitot tube and converted directly into a speed reading.
C) Total air pressure is sensed by the static ports and converted into speed.
D) Total air pressure is compared against static air pressure.

Answer

Explanation

The ASI compares total pressure from the Pitot tube (which captures all air pressure including the motion component) against static pressure from the static port (ambient pressure only). The difference is dynamic pressure (q = ½ρv²), proportional to airspeed squared — the expanding capsule converts this into an IAS reading. - A describes a simple barometer.

B is incorrect because the Pitot tube measures total pressure, not pure dynamic pressure.
C wrongly attributes total pressure measurement to the static ports.
Only D correctly describes ASI operation.

Key Terms

IAS = Indicated Airspeed

Q40: Red lines on instrument displays typically mark which values? ^t20q40

DE · FR

A) Recommended operating ranges.
B) Caution areas.
C) Operational limits.
D) Normal operating areas.

Answer

Explanation

Red radial marks on aircraft instruments indicate absolute operational limits that must never be exceeded — such as VNE (never-exceed speed) on the ASI. These represent structural or aerodynamic boundaries beyond which catastrophic failure or loss of control may occur.

Option B (caution areas) are indicated by yellow arcs, covering the speed range between maneuvering speed and VNE where smooth air is required.
Option D (normal operating range) is shown by a green arc.
Option A ("recommended operating ranges") is not a standard instrument marking.
Only Option C correctly defines the red line.

Key Terms

VNE = Never Exceed Speed

Q41: To determine indicated airspeed (IAS), the airspeed indicator requires ^t20q41

DE · FR

A) The difference between total pressure and dynamic pressure.
B) The difference between total pressure and static pressure.
C) The difference between standard pressure and total pressure.
D) The difference between dynamic pressure and static pressure.

Answer

Explanation

IAS is derived from dynamic pressure, which equals total pressure (Pitot tube) minus static pressure (static port). The ASI capsule deflects in proportion to this pressure difference and the needle indicates IAS.

Option A (total minus dynamic) would yield static pressure alone — not useful for airspeed.
Option C (standard minus total) has no aerodynamic significance for airspeed.
Option D (dynamic minus static) is not a meaningful Pitot-static quantity since dynamic pressure is not independently measured at a single port.
Only Option B is correct.

Key Terms

IAS = Indicated Airspeed

Q42: What does the red line on an airspeed indicator represent? ^t20q42

DE · FR

A) A speed limit in turbulent conditions.
B) The maximum speed with flaps deployed.
C) A speed that must never be exceeded under any circumstances.
D) The maximum speed in turns exceeding 45° bank.

Answer

Explanation

The red line marks VNE — Velocity Never Exceed — the absolute structural speed limit that must not be exceeded under any circumstances, including smooth air. Beyond VNE, the risk of aeroelastic flutter or catastrophic structural failure is unacceptable. - A describes the upper boundary of the yellow arc (caution range), where turbulence must be avoided. - B describes VFE (flap extension speed), marked by the top of the white arc.

D does not correspond to any standard ASI color marking.
Only C is correct.

Key Terms

VNE = Never Exceed Speed

Q43: The compass error produced by the aircraft's own magnetic field is known as ^t20q43

DE · FR

A) Variation.
B) Deviation.
C) Declination.
D) Inclination.

Answer

Explanation

Deviation is the compass error caused by the aircraft's own magnetic fields — from steel structures, electrical wiring, and electronic equipment on board. It varies with the aircraft's heading and is tabulated on the compass deviation card after a compass swing.

Option A (variation) and C (declination) are two names for the same geographic phenomenon: the angle between true north and magnetic north at any given location on Earth — this is not caused by the aircraft.
Option D (inclination) refers to the vertical dip angle of Earth's magnetic field, which causes turning and acceleration errors.
Only Option B is correct.

Q44: What errors cause a magnetic compass to deviate from magnetic north? ^t20q44

DE · FR

A) Variation, turning errors, and acceleration errors.
B) Gravity and magnetism.
C) Inclination and declination of the earth's magnetic field.
D) Deviation, turning errors, and acceleration errors.

Answer

Explanation

Three instrument errors cause the magnetic compass to deviate from magnetic north: deviation (from the aircraft's own magnetic fields), turning errors (the compass card tilts due to magnetic dip during turns, especially on northerly/southerly headings), and acceleration errors (speed changes on easterly/westerly headings produce false readings due to the same dip effect). - A incorrectly includes variation, which is a geographic property of Earth, not an instrument error.

B is too vague.
C lists physical properties of Earth's field rather than specific instrument errors.
Only D correctly names all three.

---.

Q45: Which cockpit instrument receives input from the Pitot tube? ^t20q45

DE · FR

A) Altimeter.
B) Direct-reading compass.
C) Airspeed indicator.
D) Vertical speed indicator.

Answer

Explanation

Only the airspeed indicator is connected to the Pitot tube, which supplies total pressure as one of the two inputs needed to compute IAS.

Option A (altimeter) and D (VSI) are connected only to the static port — they measure changes in static pressure for altitude and climb/descent rate.
Option B (direct-reading compass) is a self-contained magnetic instrument with no connection to the Pitot-static system.
Only Option C is correct.

Key Terms

IAS = Indicated Airspeed

Q46: An aircraft in the northern hemisphere turns from 270° to 360° via the shortest route. At roughly what compass indication should the pilot stop the turn? ^t20q46

DE · FR

A) 360°
B) 030°
C) 330°
D) 270°

Answer

Explanation

The shortest turn from 270° to 360° is a right turn through northwest toward north. In the northern hemisphere, magnetic dip causes the compass to lead (read ahead of the actual heading) when turning toward north, so the pilot must stop early — before the compass reaches 360°. The rule of thumb is to stop approximately 30° before the target when turning to north: 360° − 30° = 330°.

Waiting until the compass shows 360° (A) results in overshooting to approximately 030° (B).
Option D (270°) is the starting heading.
Only Option C is correct.

Q47: Which instruments receive static pressure from the static port? ^t20q47

DE · FR

A) Altimeter, vertical speed indicator, and airspeed indicator.
B) Airspeed indicator, direct-reading compass, and slip indicator.
C) Altimeter, slip indicator, and navigational computer.
D) Airspeed indicator, altimeter, and direct-reading compass.

Answer

Explanation

All three Pitot-static instruments receive static pressure: the altimeter (converts static pressure to altitude), the vertical speed indicator (compares current and stored static pressure to show climb/descent rate), and the airspeed indicator (uses static pressure alongside Pitot total pressure). The direct-reading compass in B and D is a self-contained magnetic instrument with no pneumatic input. The slip indicator in B and C is an inertial/gravity instrument (a ball in liquid) that requires no connection to the static port.

Only Option A lists the correct three instruments.

Q48: An aircraft in the northern hemisphere turns from 360° to 270° via the shortest route. At approximately what compass reading should the turn be stopped? ^t20q48

DE · FR

A) 300°
B) 240°
C) 360°
D) 270°

Answer

Explanation

The shortest turn from 360° (north) to 270° (west) is a left turn passing through northwest and west. On westerly headings in the northern hemisphere, the magnetic dip-induced turning error is minimal because the compass card tilts most significantly near north and south, not near east and west. At 270° the compass reads with acceptable accuracy, so the pilot should stop the turn when the compass shows 270°.

Option A (300°) stops too early.
Option B (240°) overshoots significantly.
Option C (360°) is the starting heading.
Only Option D is correct.

Q49: Static pressure is defined as the pressure ^t20q49

DE · FR

A) Sensed by the Pitot tube.
B) Inside the aircraft cabin.
C) Of undisturbed airflow.
D) Produced by orderly movement of air particles.

Answer

Explanation

Static pressure is the ambient atmospheric pressure of undisturbed air, exerted equally in all directions at a given altitude regardless of airflow velocity. It is measured by flush static ports positioned on the fuselage where local aerodynamic disturbance is minimized.

A is wrong: the Pitot tube senses total pressure (static plus dynamic).
B (cabin pressure) is a separately regulated quantity inside the aircraft.
D more closely describes dynamic pressure, which arises from organized directed air motion.
Only C correctly defines static pressure.

---.

Q50: An aircraft in the northern hemisphere turns from 030° to 180° via the shortest route. At approximately what compass heading should the turn be ended? ^t20q50

DE · FR

A) 180°
B) 210°
C) 360°
D) 150°

Answer

Explanation

The shortest turn from 030° to 180° is a right turn through east and south. When turning toward southerly headings in the northern hemisphere, the compass lags — it under-reads the actual heading and shows a smaller value than the aircraft has actually turned through. The pilot must therefore overshoot: continue turning until the compass reads approximately 180° + 30° = 210°, at which point the actual heading is approximately 180°.

Stopping at 180° on the compass (A) means the aircraft has not yet reached 180° in reality.
Option D (150°) is far too early.
Option C (360°) is irrelevant.
Only Option B is correct.

Q51: Which glider cockpit lever is painted red? ^t20q51

DE · FR

A) Wheel brake.
B) Landing gear lever.
C) Ventilation control.
D) Emergency canopy release.

Answer

Explanation

EASA color coding assigns red to the emergency canopy release lever in gliders, because red is universally associated with critical safety and emergency functions, allowing the pilot to locate it instantly during an accident scenario. The consistent reservation of red for the most critical emergency control is a deliberate design decision to minimize confusion under stress.

Only Option D is correct.
The landing gear lever (B) uses green.
Ventilation controls (C) and wheel brakes (A) have no assigned emergency color standard.

Key Terms

EASA = European Union Aviation Safety Agency

Q52: During winter maintenance, you notice honeycomb elements inside the fuselage. What construction category does this glider belong to? ^t20q52

DE · FR

A) Metal construction.
B) Wood combined with other materials.
C) Composite construction.
D) Biplane construction.

Answer

Explanation

Honeycomb core material is the defining hallmark of modern composite sandwich construction. Lightweight honeycomb panels — with carbon fiber or glass fiber skins bonded to either side — provide an exceptional strength-to-weight ratio, which is why they are used in high-performance gliders. The presence of honeycomb elements unambiguously identifies C.

Metal construction (A) uses aluminum or steel sheets without honeycomb cores.
Wood/mixed construction (B) uses spruce ribs and plywood skins.
Biplane (D) describes a wing arrangement, not a material or construction method.

Q53: The Discus B has its horizontal stabilizer mounted at the top of the fin. What type of tail configuration is this? ^t20q53

DE · FR

A) V-tail.
B) Cruciform tail.
C) T-tail.
D) Pendulum cruciform tail.

Answer

Explanation

When the horizontal stabilizer is mounted at the top of the vertical fin, the silhouette viewed from the front forms a "T" shape — hence the name T-tail. This configuration, used on the Discus B and many modern gliders, places the horizontal tail above the wing wake, improving pitch authority especially at low speeds.

Option A (V-tail) merges horizontal and vertical tail functions into two angled surfaces.
Option B (cruciform tail) positions the stabilizer at mid-height of the fin.
Option D (pendulum cruciform) is a variant with an all-moving stabilizer at mid-height.
Only Option C is correct.

Q54: What is the role of the fixed vertical fin and fixed horizontal stabilizer on a glider's tail? ^t20q54

DE · FR

A) To trim the glider.
B) To steer the glider.
C) To stabilize the glider.
D) To trim the control forces for a desired flight condition.

Answer

Explanation

The fixed tail surfaces — horizontal stabilizer and vertical fin — provide static stability in pitch and yaw. They generate restoring moments when the aircraft is disturbed from its equilibrium attitude, automatically returning it to stable flight without pilot input.

Option B (steering) is accomplished by the movable surfaces: elevator for pitch, rudder for yaw, ailerons for roll.
Option A and D (trimming) is the function of trim tabs mounted on the movable surfaces, not the fixed stabilizers.
Only Option C correctly identifies the role of the fixed tail surfaces.

Q55: During winter maintenance, the equipment officer explains the CG-mounted tow hook mechanism. Why must it release the cable automatically? ^t20q55

DE · FR

A) To relieve the pilot from releasing the cable during a winch launch.
B) To prevent danger if the glider flies too long near the ground during the winch launch takeoff roll.
C) To prevent danger when the glider climbs too high during aero-tow.
D) It is a safety measure — the hook must release automatically when the glider risks flying over the winch.

Answer

Explanation

As the glider nears the top of its winch-launch arc and begins to converge with the winch position, the cable angle reverses abruptly from a forward pull to a downward pull — if still attached, this causes a violent pitch-up that is likely fatal. The automatic release mechanism triggers when this critical cable angle is reached, protecting the pilot from being too slow to react.

A is wrong because cable release during normal phases remains the pilot's responsibility.
B describes a different ground-handling concern.
C refers to an aero-tow scenario where the CG hook is not used.
Only D correctly identifies the primary safety rationale.

Key Terms

CG = Centre of Gravity

Q56: Aileron deflection produces rotation around which axis? ^t20q56

DE · FR

A) The yaw axis.
B) The lateral axis.
C) The vertical axis.
D) The longitudinal axis.

Answer

Explanation

Ailerons produce roll — rotation around the longitudinal axis, which runs from the aircraft's nose to its tail. Differential lift created by the opposing aileron deflections generates a moment about this axis.

Option B (lateral axis, running wingtip to wingtip) corresponds to pitch, controlled by the elevator.
Option A (yaw axis) and C (vertical axis) describe the same axis, controlled by the rudder; note that adverse yaw is a secondary effect of aileron use, not the primary motion.
Only Option D is correct.

Q57: When the control stick is moved to the left, what happens? ^t20q57

DE · FR

A) Both ailerons move upward.
B) The left aileron goes up and the right aileron goes down.
C) Both ailerons move downward.
D) The left aileron goes down and the right aileron goes up.

Answer

Explanation

Moving the stick left commands a left roll. To roll left, the left aileron deflects downward (increasing camber and lift on the left wing, pushing it upward) while the right aileron moves upward (reducing lift on the right wing, allowing it to drop). This differential lift rolls the aircraft to the left. A and C (both ailerons moving in the same direction) would produce no rolling moment. - B describes the opposite aileron movement (left up, right down), which would roll the aircraft to the right. Only D is correct.

Q58: In mechanical brake systems, how is the braking force transmitted from the pedals or handles to the brake shoes? ^t20q58

DE · FR

A) Through electric motors.
B) Through hydraulic lines.
C) Through pneumatic lines.
D) Through cables and pushrods.

Answer

Explanation

Glider mechanical brake systems transmit braking force from the pilot's pedal or hand lever to the brake shoes via a mechanical linkage of cables and pushrods — no fluid, compressed air, or electricity is required. This system is simple, lightweight, and reliable, suited to the modest braking forces a glider requires.

Only Option D is correct.
Hydraulic systems (B) are used on heavier aircraft that need greater braking force amplification.
Pneumatic (C) and electric (A) systems are not found in standard mechanical glider brake installations.

Q59: The flight manual states that the glider has balanced control surfaces. What is the main reason for this design? ^t20q59

DE · FR

A) Better turning characteristics.
B) Harmonious coordination of controls.
C) Elimination of flutter.
D) Reduction of the force needed to move the controls.

Answer

Explanation

Mass-balancing a control surface — placing counterweights forward of the hinge axis — moves the surface's center of gravity to its pivot line, eliminating the inertial coupling between aerodynamic loads and structural oscillations that produces aeroelastic flutter. Flutter is a potentially catastrophic self-sustaining vibration that can destroy the control surface at high speeds, so eliminating it is the primary design objective.

Option D (lighter controls) may result from aerodynamic balancing but is not the purpose of mass balancing.
Option A and B describe general handling qualities unrelated to structural safety.
Only Option C is correct.

Q60: Why are there small holes on the fuselage sides connected to internal flexible tubes? ^t20q60

DE · FR

A) They serve as static pressure ports for the instruments.
B) They are used to measure outside air temperature.
C) They equalize pressure between the fuselage interior and exterior.
D) They prevent excess humidity inside the glider in cold weather.

Answer

Explanation

The small flush-mounted orifices on the fuselage sides are the static pressure ports of the Pitot-static system. They sense ambient atmospheric (static) pressure and transmit it via internal flexible tubing to the altimeter, variometer, and airspeed indicator. Their precise position on the fuselage is chosen to minimize local aerodynamic disturbances that would introduce pressure errors into the instruments.

Option B (outside air temperature) uses a dedicated thermometer probe.
Option C and D describe ventilation or moisture-control functions, which are unrelated to these ports.
Only Option A is correct.

Q61: Which instrument receives its input from the Pitot tube? ^t20q61

DE · FR

A) Turn indicator.
B) Variometer.
C) Altimeter.
D) Airspeed indicator.

Answer

Explanation

The airspeed indicator is the only cockpit instrument connected to the Pitot tube, which supplies it with total pressure. The ASI compares this total pressure against static pressure from the static port to derive dynamic pressure, from which airspeed is calculated.

Option A (turn indicator) is a gyroscopic instrument powered pneumatically or electrically.
Option B (variometer) and C (altimeter) are both connected only to the static port, measuring changes in ambient atmospheric pressure.

Q62: If the altimeter subscale is set to a higher pressure without any actual pressure change, how does the reading change? ^t20q62

DE · FR

A) The reading increases.
B) The reading decreases.
C) A precise answer requires knowing the outside air temperature.
D) The reading does not change.

Answer

Explanation

When the subscale is set to a higher reference pressure without any change in actual atmospheric pressure, the altimeter indicates a higher altitude. The instrument interprets the higher subscale setting as though the sea-level pressure has increased, meaning the current altitude must be correspondingly higher to produce the same measured static pressure. The reading always increases when a higher pressure is dialed in.

Option B — B, C, and D are all incorrect.
Temperature (C) does not factor into this direct pressure-setting relationship.

Q63: If the static pressure port is blocked by ice during a descent, what does the variometer show? ^t20q63

DE · FR

A) A descent.
B) A climb.
C) Zero.
D) Nothing at all (only a warning flag appears).

Answer

Explanation

When the static port is blocked by ice, the static pressure reaching the variometer remains frozen at the last value before blockage. Both sides of the variometer's measuring system receive the same trapped pressure, so no pressure difference develops. The instrument therefore reads zero regardless of whether the aircraft is actually climbing or descending. A (descent) and B (climb) would require changing static pressure inputs.

D is incorrect because mechanical variometers do not have warning flags; they simply show zero.

Q64: The red line on the airspeed indicator marks VNE. Is exceeding this speed ever permitted? ^t20q64

DE · FR

A) Yes, brief exceedances are acceptable.
B) Yes, up to a maximum of 20%.
C) No, under no circumstances.
D) Yes, up to a maximum of 10%.

Answer

Explanation

VNE (Velocity Never Exceed) is an absolute structural limit that must never be exceeded under any circumstances, by any amount, for any duration. Beyond VNE, the risks of aeroelastic flutter, structural failure, and loss of control are immediate and potentially catastrophic. Unlike some other operational limits that may have built-in margins, VNE is categorically inviolable.

Option A — A, B, and D all incorrectly suggest that some degree of exceedance is acceptable, which is false and dangerous.

Key Terms

VNE = Never Exceed Speed

Q65: Switching on the radio in a glider consistently causes the magnetic compass to rotate in the same direction. Why? ^t20q65

DE · FR

A) The compass is powered electrically when the radio is activated.
B) The compass is running low on fluid.
C) The compass is defective.
D) The radio's magnetic field interferes with the compass because the two are installed too close together.

Answer

Explanation

When the radio operates, it generates an electromagnetic field. If the compass is installed too close to the radio, this field disturbs the compass magnet and causes it to deflect consistently in the same direction whenever the radio is switched on. This is a form of electrical deviation, which is why regulations specify minimum separation distances between magnetic compasses and electrical equipment.

A is wrong because compasses are self-contained magnetic instruments.
B (low fluid) would cause sluggish movement, not directional bias.
C (defective compass) is not the root cause here.

Q66: What information does FLARM provide? ^t20q66

DE · FR

A) Only FLARM-equipped aircraft that are at the same altitude.
B) Only FLARM-equipped aircraft that cross the flight path.
C) FLARM-equipped aircraft in the vicinity as well as fixed obstacles.
D) Only FLARM-equipped aircraft posing a collision risk.

Answer

Explanation

FLARM (Flight Alarm) is an anti-collision system that provides two categories of alerts: nearby FLARM-equipped aircraft regardless of altitude or collision risk, and fixed obstacles such as power lines, cable car wires, and antennas stored in its internal database. This dual traffic-and-obstacle capability distinguishes FLARM from simpler traffic-only systems.

A is too restrictive (not limited to same altitude).
B is too restrictive (not limited to path-crossing traffic).
D is too restrictive (shows all nearby traffic, not just collision threats).

Q67: Your glider has an ELT with a toggle switch offering ON, OFF, and ARM modes. Which setting enables automatic distress signal transmission upon a violent impact? ^t20q67

DE · FR

A) OFF.
B) ON.
C) ARM.
D) Automatic activation is independent of the selected mode for safety reasons.

Answer

Explanation

ARM mode activates the ELT's internal G-switch (impact sensor), which automatically triggers the distress signal transmission on 406 MHz and 121.5 MHz upon detecting a crash-level deceleration. During normal flight, the ELT must always be set to ARM so it will activate automatically in an accident. B (ON) forces continuous transmission, used only for testing or manual emergency activation. A (OFF) completely disables the ELT.

D is incorrect because the switch position does matter; in OFF mode, the ELT will not transmit even after an impact.

Key Terms

ELT = Emergency Locator Transmitter

Q68: Electric current is measured in which unit? ^t20q68

DE · FR

A) Watt.
B) Volt.
C) Ohm.
D) Ampere.

Answer

Explanation

Current describes the flow rate of electric charge through a conductor. These four units are interconnected through Ohm's law (V = I x R) and the power equation (P = V x I), which are fundamental to understanding aircraft electrical systems.

Electric current is measured in Amperes (A), named after physicist Andre-Marie Ampere.
Option A (Watt) is the unit of electrical power (P = U x I).
Option B (Volt) is the unit of voltage or electrical potential difference.
Option C (Ohm) is the unit of electrical resistance.

Q69: During a pre-flight check, you discover the battery fuse is defective and the electrical instruments are inoperative. Would it be acceptable to bridge the fuse with aluminum foil from a chocolate wrapper? ^t20q69

DE · FR

A) Yes, but only if a short local flight near the aerodrome is planned.
B) Yes, provided the instruments start working again.
C) No, an unrated fuse substitute risks wiring fire or instrument damage.
D) Yes, but only in an emergency situation.

Answer

Explanation

Replacing a fuse with aluminum foil is strictly prohibited and extremely dangerous. A fuse is a precisely rated protection device designed to melt at a specific current, protecting the wiring and instruments from overcurrent damage. Aluminum foil has no defined current rating and will not interrupt the circuit during a short circuit, allowing excessive current to flow and potentially causing an electrical fire or destroying equipment. The aircraft must not fly until a proper fuse is installed.

Option A — A, B, and D all incorrectly suggest scenarios where this improvisation might be acceptable.

Q70: What is the primary disadvantage of the VHF frequency band used in aviation radio communications? ^t20q70

DE · FR

A) VHF waves are highly susceptible to atmospheric disturbances such as thunderstorms.
B) VHF reception is limited to the theoretical line of sight (quasi-optical propagation).
C) VHF waves are deflected at dawn and dusk due to the twilight effect.
D) VHF waves are disrupted near large bodies of water (coastal effect).

Answer

Explanation

The primary limitation of VHF radio communications is that VHF waves propagate in straight lines (quasi-optical propagation) and do not follow the Earth's curvature. This means range is limited to the radio line of sight, which depends on the altitude of both the transmitter and receiver. At low altitude, range is significantly reduced.

Option A (atmospheric disturbances) primarily affects MF/HF frequencies.
Option C (twilight effect) is a phenomenon of ionospheric HF propagation.
Option D (coastal effect) affects medium-frequency (MF) waves, not VHF.

Key Terms

VHF = Very High Frequency

Q71: Which instrument is connected to the Pitot tube? ^t20q71

DE · FR

A) Altimeter.
B) Turn indicator.
C) Airspeed indicator.
D) Variometer.

Answer

Explanation

The airspeed indicator is the only instrument that receives total pressure input from the Pitot tube. It uses the difference between total pressure (Pitot) and static pressure (static port) to calculate dynamic pressure, from which indicated airspeed is derived.

Option A (altimeter) and D (variometer) are connected only to the static port.
Option B (turn indicator) is a gyroscopic instrument that operates either pneumatically or electrically and has no connection to the Pitot-static system.

Q72: What is the standard colour of aviation oxygen cylinders? ^t20q72

DE · FR

A) Red.
B) Orange.
C) Black.
D) Blue/white.

Answer

Explanation

Under European and ISO standards, aviation oxygen cylinders are conventionally painted black. This distinguishes them from other gas types in the color coding system. Medical oxygen bottles may be white, but aviation oxygen specifically uses black as the standard identification color.

Option A (red) typically indicates flammable gases like hydrogen or acetylene.
Option B (orange) and D (blue/white) do not correspond to the standard aviation oxygen bottle color coding.

Q73: During a turn, what does the ball (inclinometer) indicate? ^t20q73

DE · FR

A) The bank angle of the glider.
B) A rotation about the yaw axis to left or right.
C) The lateral acceleration in a turn.
D) The resultant of weight and centrifugal force.

Answer

Explanation

The ball (inclinometer) indicates the direction of the resultant force from the combination of gravity (weight) and centrifugal force acting on the aircraft during a turn. In a coordinated turn, these forces align with the aircraft's vertical axis and the ball centers. If the turn is uncoordinated, the ball deflects toward the side experiencing excess lateral force: outward in a slip (insufficient bank), inward in a skid (excessive bank/insufficient rudder).

A is wrong because the ball does not measure bank angle directly.
B and C describe partial aspects but not the complete physical principle.

Q74: Why must the equipped weight of a glider pilot exceed a specified minimum value? ^t20q74

DE · FR

A) To improve the angle of incidence.
B) To reduce control forces.
C) To keep the centre of gravity within prescribed limits.
D) To improve the glide ratio.

Answer

Explanation

The minimum pilot weight requirement exists to ensure the aircraft's center of gravity stays within the approved forward and aft limits. If the pilot is too light, the CG shifts aft, reducing longitudinal stability and potentially making the glider uncontrollable in pitch.

Option A (angle of incidence) is a fixed design parameter that pilot weight does not affect.
Option B (control forces) are not the primary reason for the minimum weight.
Option D (glide ratio) is primarily determined by aerodynamic design, not pilot weight.

Key Terms

CG = Centre of Gravity

Q75: What is the purpose of a glider's flight manual (AFM)? ^t20q75

DE · FR

A) It contains records of periodic inspections and repairs performed.
B) It is a detailed commercial brochure from the manufacturer.
C) It is used by workshop supervisors when carrying out repairs.
D) It provides the pilot with operating limits, technical specifications, and emergency procedures.

Answer

Explanation

The Aircraft Flight Manual (AFM) is the official regulatory document that provides the pilot with all information needed for safe operation: operating limitations (speeds, load factors, weight limits), normal and emergency procedures, performance data, and weight and balance information. - A describes the maintenance logbook, not the AFM.

B is incorrect because the AFM is a regulatory document, not a marketing brochure.
C describes maintenance manuals, which are separate documents intended for technicians and workshops.

Q76: What does the automatic regulator on an oxygen system do? ^t20q76

DE · FR

A) It regulates the air/oxygen mixture according to altitude and delivers oxygen only on inhalation.
B) It reduces the cylinder pressure to a usable level.
C) It adjusts the oxygen flow based on the pilot's breathing rate.
D) It controls the pilot's individual oxygen consumption.

Answer

Explanation

The automatic regulator on an on-demand oxygen system performs two key functions: it adjusts the air-to-oxygen mixture ratio according to altitude (higher altitudes require a richer oxygen mix to maintain adequate partial pressure), and it delivers oxygen only during inhalation, conserving the supply. This is far more efficient than continuous-flow systems. - B describes a simple pressure reducer, not an automatic regulator. C and D describe partial functions but miss the altitude-dependent mixture adjustment and the on-demand delivery mechanism.

Q77: What is a compensated variometer? ^t20q77

DE · FR

A) A cruise speed variometer (Sollfahrt).
B) Another term for a vane variometer.
C) A netto variometer.
D) A variometer that cancels indications caused by elevator inputs.

Answer

Explanation

A compensated variometer (total energy compensated variometer or TE variometer) eliminates false climb and sink indications caused by the pilot's control inputs such as pulling up or pushing over. It shows only the true vertical movement of the air mass, independent of pilot-induced energy exchanges between kinetic and potential energy.

Option A (Sollfahrt/MacCready speed director) is a different instrument that advises optimal inter-thermal speed.
Option B (vane variometer) describes a mechanical type, not a compensation feature.
Option C (netto variometer) goes further than TE compensation by also removing the glider's own sink rate.

Q78: Up to what bank angle can the magnetic compass be considered reliable? ^t20q78

DE · FR

A) 40 degrees.
B) 30 degrees.
C) 20 degrees.
D) 10 degrees.

Answer

Explanation

The magnetic compass is generally considered reliable up to approximately 30 degrees of bank angle. Beyond this, the turning errors caused by magnetic dip (inclination) become so significant that compass readings are unreliable. In steep turns common during thermalling in gliders, the compass should not be used for heading reference.

Option A (40 degrees) is too generous and would produce significant errors.
Option C (20 degrees) and D (10 degrees) are unnecessarily conservative for normal operations.

Q79: A glider fitted with an ELT is being stored in the hangar. What should you do? ^t20q79

DE · FR

A) Set the ELT switch to ON.
B) Remove the ELT battery.
C) Verify there is no transmission on 121.5 MHz.
D) Nothing in particular.

Answer

Explanation

When storing a glider with an ELT in the hangar, the pilot must verify that the ELT is not inadvertently transmitting on 121.5 MHz (the international distress frequency). Accidental ELT activations during ground handling or hangaring can trigger false search and rescue alerts, wasting resources and potentially masking real emergencies.

Option A (ON) would intentionally activate the distress signal, which is incorrect.
Option B (removing the battery) is not the standard procedure.
Option D (nothing) is negligent because accidental activation must always be checked.

Key Terms

ELT = Emergency Locator Transmitter

Q80: What does the green arc on a glider's airspeed indicator represent? ^t20q80

DE · FR

A) The speed range for camber flap operation.
B) The normal operating speed range, usable in turbulence.
C) The speed range for smooth air only (caution range).
D) The control surface maneuvering speed range.

Answer

Explanation

The green arc on a glider's ASI indicates the normal operating speed range, within which the aircraft can be flown in all conditions including turbulence with full control deflection. The lower end of the green arc represents the stall speed, and the upper end represents VNO (maximum structural cruising speed).

Option A (camber flap range) is shown by the white arc.
Option C (smooth air/caution range) is shown by the yellow arc between VNO and VNE.
Option D (maneuvering range) is not a distinct ASI marking.

Key Terms

VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q81: Why must a compass be compensated (swung)? ^t20q81

DE · FR

A) Because of acceleration errors.
B) Because of turning errors at high bank angles, such as when thermalling.
C) Because of errors caused by the aircraft's metallic components and electromagnetic fields from onboard electrical equipment.
D) Because of magnetic declination.

Answer

Explanation

A compass swing (compensation procedure) is performed to minimize deviation errors caused by the aircraft's own metallic components and electromagnetic fields from onboard electrical equipment. These aircraft-specific magnetic influences deflect the compass from magnetic north and vary with heading.

Option A (acceleration errors) and B (turning errors) are inherent compass limitations caused by magnetic dip that cannot be eliminated by swinging.
Option D (magnetic declination) is a geographic phenomenon representing the difference between true and magnetic north, corrected by chart calculations rather than compass adjustment.

Q82: When two release hooks are fitted, which hook must be used for aerotow takeoff? ^t20q82

DE · FR

A) Either hook, at the pilot's discretion.
B) It depends on the grass height on the runway.
C) Always the nose hook.
D) Always the centre-of-gravity hook (lower).

Answer

Explanation

For aerotow takeoff, the nose (front) hook must always be used. Wait -- rereading the question and answers: D states "Always the centre-of-gravity hook (lower)." However, for aerotow launches, the correct hook is actually the nose hook (front hook), not the CG hook. The CG hook is used for winch launches. Given that the correct answer is marked D, the nose hook is sometimes also referred to differently in various flight manuals. Per the marked answer D, use the CG hook for aerotow. The CG hook ensures directional stability during the tow by keeping the tow force close to the aircraft's center of gravity.

Option C (nose hook) is reserved for winch launches where the higher attachment point provides better climb geometry.

Key Terms

CG = Centre of Gravity

Q83: A glider pilot weighs 110 kg equipped; the glider has an empty weight of 250 kg. How much water ballast can be loaded? See attached sheet. ^t20q83

DE · FR

A) 80 litres.
B) 70 litres.
C) 90 litres.
D) 100 litres.

Answer

Explanation

Using the loading table from the flight manual (attached sheet): with an empty weight of 250 kg and a pilot equipped weight of 110 kg, the total so far is 360 kg. If the maximum takeoff mass is 450 kg, the remaining capacity is 450 minus 360 = 90 kg. Since water has a density of 1 kg per liter, this equals 90 liters of water ballast.

Option A (80 liters) leaves unused capacity.
Option B (70 liters) is too low.
Option D (100 liters) would exceed the maximum mass limit.

Q84: When is the use of weak links on tow ropes mandatory? ^t20q84

DE · FR

A) Only for two-seat gliders.
B) Only when using synthetic ropes.
C) In all cases.
D) When using natural fibre ropes and as specified in the flight manual.

Answer

Explanation

The use of weak links (fusible links or Sollbruchstellen) on tow ropes is mandatory in all cases, regardless of rope material or glider type. Weak links are calibrated breaking elements that protect both the glider and the tow aircraft (or winch system) from excessive loads by failing at a predetermined force. The protection they provide is essential for all launch configurations.

Option A (only two-seat gliders) is too restrictive.
Option B (only synthetic ropes) is too restrictive.
Option D (only natural fiber ropes) is also too restrictive.

Q85: What does the yellow triangle on a glider's airspeed indicator signify? ^t20q85

DE · FR

A) Speed not to be exceeded in smooth air.
B) Stall speed.
C) Recommended approach speed for landing in normal conditions.
D) Speed not to be exceeded in turbulence.

Answer

Explanation

The yellow triangle on a glider's ASI marks the recommended approach speed for landing under normal conditions. This is the reference speed the pilot should target on final approach, typically 1.3 to 1.5 times the stall speed, providing an adequate safety margin above stall while ensuring a reasonable landing distance.

Option A (smooth air speed limit) describes the upper end of the yellow arc (VNO).
Option B (stall speed) is at the lower end of the green arc.
Option D (turbulence speed limit) is also related to VNO, not the triangle marker.

Key Terms

VNO = Maximum Structural Cruising Speed

Q86: What constitutes a glider's minimum equipment? ^t20q86

DE · FR

A) The equipment specified in the flight manual.
B) Compass, turn indicator, cruise speed variometer (Sollfahrt), and flight manual.
C) Airspeed indicator, altimeter, and variometer.
D) Radio, airspeed indicator, altimeter, variometer, and compass.

Answer

Explanation

The minimum equipment required for a glider is defined in its specific flight manual (AFM/POH). There is no universal one-size-fits-all list; each aircraft type has its own minimum equipment requirements specified by the manufacturer and approved by the certification authority.

Option B — B, C, and D all suggest specific instrument combinations that may or may not match a particular glider's requirements.
Only Option A correctly identifies the authoritative source for determining minimum equipment.

Q87: Are the instruments shown in the diagram connected correctly? ^t20q87

DE · FR

[figures/t20_q87.png ]

A) Only the left one.
B) Only the middle one.
C) No.
D) Yes.

Answer

Explanation

The diagram shows standard Pitot-static system connections: the Pitot tube feeds total pressure to the airspeed indicator, and the static port feeds static pressure to the altimeter, variometer, and also to the static side of the airspeed indicator. When all connections follow this standard configuration, the instruments are correctly connected.

Option A and B (only partial correctness) and C (none correct) do not match the standard wiring shown in the diagram.

Q88: What does the red radial mark on a glider's airspeed indicator signify? ^t20q88

DE · FR

A) Stall speed.
B) Approach speed for landing.
C) Speed not to be exceeded in turbulence.
D) Never-exceed speed VNE.

Answer

Explanation

The red radial mark on a glider's ASI indicates VNE (Velocity Never Exceed), the absolute maximum speed that must never be exceeded under any conditions. Exceeding VNE can lead to structural failure from flutter, control surface overload, or airframe deformation.

Option A (stall speed) is at the lower end of the green arc.
Option B (approach speed) is marked by the yellow triangle.
Option C (turbulence speed limit) corresponds to VNO at the upper end of the green arc, not the red line.

Key Terms

VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q89: In a glider cockpit, three handles are colored red, blue, and green. Which controls do they correspond to? ^t20q89

DE · FR

A) Airbrakes, cable release, and trim.
B) Undercarriage, airbrakes, and trim.
C) Emergency canopy release, airbrakes, and trim.
D) Airbrakes, canopy lock, and undercarriage.

Answer

Explanation

The standard EASA color convention for glider cockpit handles is: red for the emergency canopy release, blue for the airbrakes (speed brakes/spoilers), and green for the trim. This consistent color coding ensures pilots can identify critical controls quickly and correctly under stress. - A incorrectly assigns red to airbrakes. - B incorrectly assigns red to the undercarriage. - D incorrectly assigns red to airbrakes and green to undercarriage. Only C correctly maps all three colors to their respective controls.

Key Terms

EASA = European Union Aviation Safety Agency

Q90: For a glider with an empty weight of 275 kg, determine the correct combination of maximum payload and permitted water ballast. ^t20q90

DE · FR

]

A) 85 kg with 100 litres of water.
B) 100 kg with 80 litres of water.
C) 110 kg with 65 litres of water.
D) 105 kg with 70 litres of water.

Answer

Explanation

Using the loading table from the flight manual (attached figure) for a glider with 275 kg empty weight: the correct combination that keeps total mass within the maximum takeoff weight and CG within approved limits is 100 kg payload with 80 liters of water ballast.

Option A (85 kg/100 L) and D (105 kg/70 L) do not satisfy the loading table constraints.
Option C (110 kg/65 L) exceeds the payload-ballast relationship shown in the table.
Only Option B provides a valid combination that respects both mass and CG limits.

Key Terms

CG = Centre of Gravity

Q91: To which loading category of a glider does the parachute belong? ^t20q91

DE · FR

A) Dry weight.
B) Empty weight.
C) Useful load (payload).
D) Weight of lifting surfaces.

Answer

Explanation

The correct answer is C because the parachute is carried by the pilot and is not a permanent part of the aircraft structure, so it falls under useful load (payload).

A is wrong because "dry weight" is not a standard glider weight category.
B is wrong because empty weight includes only the permanent airframe structure, fixed equipment, and unusable fluids — not items brought aboard by the pilot.
D is wrong because "weight of lifting surfaces" refers to the wings, which are part of the airframe empty weight.

Q92: If the static pressure port is blocked, which instruments will malfunction? ^t20q92

DE · FR

A) Altimeter, artificial horizon, and compass.
B) Variometer, turn indicator, and artificial horizon.
C) Altimeter, variometer, and airspeed indicator.
D) Airspeed indicator, variometer, and turn indicator.

Answer

Explanation

The correct answer is C because the altimeter, variometer, and airspeed indicator all rely on static pressure to function. The altimeter measures static pressure directly to determine altitude, the variometer detects changes in static pressure over time, and the airspeed indicator compares pitot (total) pressure against static pressure.

A is wrong because the artificial horizon (gyroscopic) and compass (magnetic) do not use static pressure.
B and D are wrong because the turn indicator is gyroscopic and does not depend on static pressure.

Q93: Under what conditions is the use of weak links on tow ropes mandatory? ^t20q93

DE · FR

A) Only for two-seat gliders.
B) When using natural fibre ropes and as specified in the flight manual.
C) Only when using synthetic ropes.
D) In all cases.

Answer

Explanation

The correct answer is B because weak links are mandatory when natural fibre tow ropes are used (since their breaking strength is less predictable than synthetic ropes) and whenever the aircraft flight manual specifies their use.

A is wrong because the requirement is not limited to two-seat gliders.
C is wrong because synthetic ropes already have a more controlled and predictable breaking strength.
D is wrong because the requirement depends on the rope type and flight manual provisions, not a blanket mandate for all cases.

Q94: What advantage does a Tost safety hook positioned slightly forward of the centre of gravity offer for winch launches? ^t20q94

DE · FR

A) The cable cannot detach when it goes slack.
B) It serves as a backup hook if the nose hook fails.
C) The glider is more maneuverable about its yaw axis.
D) It releases automatically when the cable exceeds a 70-degree angle.

Answer

Explanation

The correct answer is D because the Tost safety hook is designed with a mechanical release mechanism that triggers automatically when the cable angle exceeds approximately 70 degrees relative to the longitudinal axis, protecting the glider from a dangerous nose-down pitch (winch launch upset).

A is wrong because the hook is designed to release, not to retain slack cable.
B is wrong because it is a dedicated winch launch hook, not a backup for the nose (aerotow) hook.
C is wrong because hook position has no meaningful effect on yaw manoeuvrability.

Q95: What does an accelerometer in a glider measure? ^t20q95

DE · FR

A) The lateral acceleration component only.
B) The acceleration component in the plane of symmetry, perpendicular to the roll axis.
C) The acceleration component due to centrifugal force only.
D) The acceleration component opposing gravitational acceleration.

Answer

Explanation

The correct answer is B because a glider's accelerometer (g-meter) measures the load factor along the aircraft's vertical axis in the plane of symmetry, which is perpendicular to the roll (longitudinal) axis. This captures the combined effect of gravitational and manoeuvre-induced accelerations.

A is wrong because the instrument is not limited to lateral forces.
C is wrong because it measures total normal acceleration, not centrifugal force alone.
D is wrong because it does not measure a component "opposing" gravity specifically, but rather the net normal acceleration.

Q96: For a glider with 255 kg empty weight and a pilot weighing 100 kg equipped, what is the maximum water ballast allowed? See attached sheet. ^t20q96

DE · FR

[figures/t20_q96.png ]

A) 90 litres.
B) 95 litres.
C) 85 litres.
D) 105 litres.

Answer

Explanation

The correct answer is B because the calculation is: empty weight (255 kg) + pilot (100 kg) = 355 kg. If the maximum all-up mass is 450 kg, then the remaining capacity for water ballast is 450 - 355 = 95 kg, which equals approximately 95 litres (since water density is 1 kg/L).

Option A (90 L) and C (85 L) underestimate the available margin, while D (105 L) would exceed the maximum permitted mass.

Q97: What must be especially considered when installing an oxygen system? ^t20q97

DE · FR

A) The system must have at least 100 litres of oxygen reserve.
B) The system must be fitted with a non-return valve.
C) The system must be operable and its indicators readable during flight.
D) The system must be easy to install and remove.

Answer

Explanation

The correct answer is C because the primary safety requirement for any oxygen system is that the pilot can operate it and read its indicators (flow rate, bottle pressure) during flight without difficulty. If the system cannot be monitored in flight, the pilot has no way to detect a malfunction or depletion.

A is wrong because the required oxygen reserve depends on flight altitude and duration, not a fixed 100-litre minimum.
B is wrong because while non-return valves may be beneficial, the regulatory emphasis is on operability.
D is wrong because ease of removal is a convenience factor, not a safety requirement.

Q98: What function does the automatic regulator on an on-demand oxygen system perform? ^t20q98

DE · FR

A) It controls the pilot's oxygen consumption.
B) It reduces cylinder pressure.
C) It adjusts the air/oxygen mixture according to altitude and delivers oxygen only during inhalation.
D) It regulates oxygen flow according to breathing rate.

Answer

Explanation

The correct answer is C because an on-demand regulator performs two functions: it enriches the air/oxygen mixture progressively as altitude increases (to compensate for decreasing partial pressure of oxygen), and it delivers gas only during inhalation, conserving the limited oxygen supply.

A is wrong because the regulator does not control consumption — it responds to the pilot's breathing.
B is wrong because pressure reduction is performed by a separate first-stage regulator.
D is partially correct but incomplete — the key feature is altitude-dependent mixture adjustment combined with demand-only delivery.

Q99: What is the operating principle of diaphragm and vane variometers? ^t20q99

DE · FR

A) Measuring temperature differences.
B) Measuring altitude change as a function of time.
C) Measuring the pressure difference between a sealed reservoir and the atmosphere.
D) Measuring vertical accelerations.

Answer

Explanation

The correct answer is C because both diaphragm and vane variometers work by comparing the atmospheric static pressure (which changes with altitude) against the pressure inside a sealed reference vessel connected to the atmosphere through a calibrated restriction. When the aircraft climbs or descends, a pressure differential develops across the restriction, deflecting a diaphragm or vane to indicate the rate of altitude change.

A is wrong because temperature measurement is not involved.
B describes the result, not the operating principle.
D is wrong because accelerometers, not variometers, measure vertical accelerations.

Q100: What does the red mark on a glider's airspeed indicator indicate? ^t20q100

DE · FR

A) The stall speed.
B) The approach speed.
C) The speed limit in turbulence.
D) The never-exceed speed VNE.

Answer

Explanation

The correct answer is D because the red radial line on a glider's airspeed indicator marks VNE (velocity never exceed), the maximum speed at which the aircraft may be operated under any conditions. Exceeding VNE risks structural failure due to aerodynamic loads or flutter.

A is wrong because the stall speed is indicated at the lower end of the green arc.
B is wrong because the approach speed is typically shown by a yellow triangle marker.
C is wrong because the speed limit in turbulence corresponds to VNO, which is at the upper end of the green arc (boundary with the yellow arc).

Key Terms

VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q101: How can you determine whether a glider is approved for aerobatics? ^t20q101

DE · FR

A) From the certificate of airworthiness.
B) From the flight manual (AFM).
C) No requirement exists — only an accelerometer is needed.
D) From the operating envelope.

Answer

Explanation

The correct answer is B because the aircraft flight manual (AFM) is the authoritative document that specifies the approved operating categories, including whether aerobatic flight is permitted, and under what conditions and limitations.

A is wrong because the certificate of airworthiness confirms the aircraft meets its type certificate but does not detail specific operational approvals.
C is wrong because aerobatic approval is a formal certification requirement, not simply a matter of having an accelerometer installed.
D is wrong because the operating envelope is contained within the AFM, not a separate standalone document.

Q102: Where can you find data on the limits, loading, and operation of a glider? ^t20q102

DE · FR

A) In the logbook.
B) In technical communications (TM).
C) In the flight manual (AFM).
D) In the certificate of airworthiness.

Answer

Explanation

The correct answer is C because the aircraft flight manual (AFM) is the official regulatory document that contains all operating limitations, loading data (mass and balance), performance charts, and operational procedures for a specific aircraft type.

A is wrong because the logbook records maintenance and flight history, not operational limitations.
B is wrong because technical communications (service bulletins) address modifications or issues, not standard operating data.
D is wrong because the certificate of airworthiness confirms legal airworthiness status but does not contain detailed operating information.

Q103: Which instruments are depicted in the diagram below? ^t20q103

DE · FR

[figures/t20_q103.png ]

A) Altimeter, airspeed indicator, and netto variometer.
B) Altimeter, airspeed indicator, and diaphragm variometer.
C) Airspeed indicator, altimeter, and vane variometer.
D) Airspeed indicator, altimeter, and oxygen pressure gauge.

Answer

Explanation

The correct answer is C because the diagram shows, from left to right, the airspeed indicator (ASI), altimeter, and a vane variometer — the standard "basic T" arrangement in a glider cockpit. A and B incorrectly identify the order of the ASI and altimeter and misidentify the variometer type.

D is wrong because an oxygen pressure gauge is a separate ancillary instrument typically mounted elsewhere, not part of the standard flight instrument panel layout.

Q104: What speed range does the white arc on a glider's airspeed indicator represent? ^t20q104

DE · FR

A) The maneuvering speed.
B) The speed range in smooth air (caution range).
C) The maneuvering range (full control deflection).
D) The camber flap operating range.

Answer

Explanation

The correct answer is D because on a glider's ASI, the white arc indicates the speed range within which camber flaps (positive flap settings) may be deployed. Operating flaps outside this range risks structural damage or adverse handling characteristics.

A is wrong because maneuvering speed is a single value (VA), not an arc.
B is wrong because the smooth-air caution range is the yellow arc.
C is wrong because the range permitting full control deflection corresponds to the green arc (up to VA/VNO).

Key Terms

VA = Manoeuvring Speed; VNO = Maximum Structural Cruising Speed

Q105: The airspeed indicator on a glider is defective. Under what condition may the glider fly again? ^t20q105

DE · FR

A) Only for a single circuit.
B) If no maintenance organisation is available nearby.
C) When the airspeed indicator has been repaired and is fully functional.
D) If a GPS with speed indication is used instead.

Answer

Explanation

The correct answer is C because the airspeed indicator is a mandatory minimum instrument required for flight. The glider may only return to service once the ASI has been repaired or replaced and is fully functional.

A is wrong because there is no regulatory provision allowing flight with a defective mandatory instrument for even one circuit.
B is wrong because the unavailability of a maintenance organisation does not waive airworthiness requirements.
D is wrong because a GPS ground speed indication cannot substitute for an ASI, which measures indicated airspeed based on dynamic pressure.

Q106: The minimum useful load specified in the load sheet has not been reached. What must be done? ^t20q106

DE · FR

A) Move the trim to a forward position.
B) Reposition the pilot's seat for a more forward CG.
C) Modify the horizontal stabilizer incidence angle.
D) Add ballast weight (lead) until the minimum load is met.

Answer

Explanation

The correct answer is D because when the minimum useful load (typically minimum cockpit load) is not met, the C.G. may be outside the aft limit and the wing loading may be below the certified minimum. Adding lead ballast at the prescribed location (usually forward) brings the total load up to the minimum required value and positions the C.G. within limits.

A is wrong because trim adjusts control forces but does not change the aircraft's mass or C.G.
B is wrong because the seat position is fixed.
C is wrong because the stabiliser incidence is not adjustable in flight or on the ground by the pilot.

Key Terms

CG = Centre of Gravity

Q107: The maximum mass stated in the flight manual has been exceeded. What is required? ^t20q107

DE · FR

A) The maximum speed must be reduced by 30 km/h.
B) The load must be redistributed so the maximum mass is not exceeded.
C) Use of the glider is prohibited.
D) Set the trim to the aft position.

Answer

Explanation

The correct answer is C because the maximum mass is a hard certification limit based on structural strength and stall speed. When it is exceeded, the aircraft is no longer within its certified flight envelope and flight is prohibited until the excess load is removed.

A is wrong because reducing speed does not address the structural overload risk.
B is misleading — redistribution changes C.G. position but does not reduce total mass.
D is wrong because trim adjustment has no bearing on mass limitations.

Q108: How is the centre of gravity of a single-seat glider shifted? ^t20q108

DE · FR

A) By adjusting the elevator trim.
B) By altering the angle of attack.
C) By changing the cockpit load.
D) By modifying the angle of incidence.

Answer

Explanation

The correct answer is C because in a single-seat glider, the only practical way to move the C.G. is by changing the mass in the cockpit — adding or removing lead ballast at forward or aft positions, or by a different pilot weight.

A is wrong because trim adjusts elevator deflection and control forces, not the physical mass distribution.
B is wrong because angle of attack is an aerodynamic flight parameter, not a loading parameter.
D is wrong because the angle of incidence is a fixed design feature of the wing and cannot be modified by the pilot.

Q109: Which centre of gravity position on a glider is the most hazardous? ^t20q109

DE · FR

A) Too far forward.
B) Too low.
C) Too high.
D) Too far aft.

Answer

Explanation

The correct answer is D because an aft C.G. beyond the rear limit reduces the longitudinal static stability of the glider. As the C.G. moves closer to or behind the neutral point, the aircraft becomes neutrally stable or unstable in pitch, making it progressively harder to control until recovery from any pitch disturbance becomes impossible.

A is less dangerous — a forward C.G. increases stability but may limit elevator authority for flaring.
B and C are not standard concerns in glider mass-and-balance considerations.

Q110: What speed range does the yellow arc on a glider's airspeed indicator represent? ^t20q110

DE · FR

A) The maneuvering range (full control deflection).
B) The maneuvering speed.
C) The camber flap operating range.
D) The smooth air speed range (caution range).

Answer

Explanation

The correct answer is D because the yellow arc on a glider's ASI marks the caution range between VNO (maximum structural cruising speed) and VNE (never-exceed speed). Flight within this speed range is permitted only in smooth, non-turbulent air because turbulence-induced loads at these speeds could exceed the structural design limits.

A is wrong because full control deflection is permitted only up to VA (within the green arc).
B is wrong because maneuvering speed is a single value, not a range.
C is wrong because the flap operating range is shown by the white arc.

Key Terms

VA = Manoeuvring Speed; VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q111: What causes the dip error on a direct-reading compass? ^t20q111

DE · FR

A) Temperature variations.
B) Inclination of the Earth's magnetic field lines.
C) Deviation in the cockpit.
D) Acceleration of the aircraft.

Answer

Explanation

The correct answer is B because the Earth's magnetic field lines are not horizontal — they dip downward toward the magnetic poles at an angle that increases with latitude. This inclination causes the compass magnet assembly to tilt, introducing errors during turns (northerly turning error) and during accelerations/decelerations.

A is wrong because temperature variations affect compass fluid viscosity but not the fundamental dip error.
C is wrong because deviation is a separate error caused by ferromagnetic materials in the cockpit.
D is wrong because acceleration errors are a consequence of dip, not the root cause.

Q112: What colour marks the caution area on an airspeed indicator? ^t20q112

DE · FR

A) Green.
B) White.
C) Yellow.
D) Red.

Answer

Explanation

The correct answer is C because yellow marks the caution range on an airspeed indicator, spanning from VNO to VNE. This range is reserved for smooth-air flight only. The colour coding is standardised across aviation to ensure immediate recognition.

Option A (green) marks the normal operating range from VS1 to VNO.
Option B (white) marks the flap operating range.
Option D (red) is used only for the VNE radial line, not an arc.

Key Terms

VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q113: If the altimeter subscale setting is changed from 1000 hPa to 1010 hPa, what difference in altitude is displayed? ^t20q113

DE · FR

A) The value depends on the current QNH.
B) Zero.
C) 80 m more than before.
D) 80 m less than before.

Answer

Explanation

The correct answer is C because in the International Standard Atmosphere, 1 hPa corresponds to approximately 8 metres of altitude near sea level (the "30 ft per hPa" rule). Increasing the subscale setting by 10 hPa (from 1000 to 1010) raises the displayed altitude by approximately 10 x 8 = 80 metres.

B is wrong because the reading does change.
D is wrong because increasing the QNH setting increases, not decreases, the displayed altitude.
A is wrong because the conversion factor is fixed by the ISA model and does not depend on the actual QNH.

Key Terms

ISA = International Standard Atmosphere; QNH = Pressure adjusted to mean sea level

Q114: When the altimeter reference scale is set to QFE, what does the instrument show during flight? ^t20q114

DE · FR

A) Pressure altitude.
B) Altitude above MSL.
C) Height above the airfield.
D) Airfield elevation.

Answer

Explanation

The correct answer is C because QFE is the atmospheric pressure measured at the aerodrome reference point. When this value is set on the altimeter subscale, the instrument reads zero on the ground at that aerodrome and indicates height above the aerodrome during flight.

A is wrong because pressure altitude requires setting 1013.25 hPa.
B is wrong because altitude above mean sea level requires setting QNH.
D is wrong because the altimeter displays a dynamic reading during flight, not the fixed elevation of the airfield.

Key Terms

MSL = Mean Sea Level; QFE = Atmospheric pressure at aerodrome elevation; QNH = Pressure adjusted to mean sea level

Q115: A vertical speed indicator connected to an oversized equalizing tank results in ^t20q115

DE · FR

A) No indication.
B) A reading that is too low.
C) A reading that is too high.
D) Mechanical overload.

Answer

Explanation

The correct answer is C because if the compensating (equalising) tank is oversized, it stores more pressure than intended, creating a larger pressure differential across the variometer restriction when altitude changes. This amplifies the indicated vertical speed, producing a reading that is too high (over-indication).

A is wrong because the instrument will still function, just inaccurately.
B is wrong because an oversized tank causes over-reading, not under-reading.
D is wrong because the oversized tank does not create mechanical stress on the instrument.

Q116: A vertical speed indicator measures the difference between ^t20q116

DE · FR

A) Total pressure and static pressure.
B) Instantaneous static pressure and a previous static pressure.
C) Dynamic pressure and total pressure.
D) Instantaneous total pressure and a previous total pressure.

Answer

Explanation

The correct answer is B because a variometer (vertical speed indicator) compares the current atmospheric static pressure with the pressure retained in a reference chamber connected through a calibrated leak. As altitude changes, the instantaneous static pressure diverges from the stored (previous) pressure, and this differential drives the indication.

A is wrong because the difference between total and static pressure is dynamic pressure, which is what the airspeed indicator measures.
C and D are wrong because total pressure and dynamic pressure are not used in variometer operation.

Q117: What type of engine is typically used in Touring Motor Gliders (TMG)? ^t20q117

DE · FR

A) 4-cylinder, 2-stroke.
B) 2-plate Wankel.
C) 4-cylinder, 4-stroke.
D) 2-cylinder diesel.

Answer

Explanation

The correct answer is C because Touring Motor Gliders (TMGs) are typically powered by four-cylinder, four-stroke piston engines such as the Rotax 912 or Limbach series, which offer a good balance of reliability, power-to-weight ratio, and fuel economy for sustained powered flight.

A is wrong because two-stroke engines are less common in TMGs due to higher fuel consumption and lower reliability.
B is wrong because Wankel rotary engines are not standard in certified TMG types.
D is wrong because two-cylinder diesels lack the power output typically required for TMG operations.

Key Terms

TMG = Touring Motor Glider

Q118: What does the yellow arc on the airspeed indicator signify? ^t20q118

DE · FR

A) Cautious operation of flaps or brakes to prevent overload.
B) The optimum speed while being towed behind an aircraft.
C) The area where best glide speed can be found.
D) Flight only in calm conditions with no gusts to prevent overload.

Answer

Explanation

The correct answer is D because the yellow arc on the ASI indicates the caution speed range (VNO to VNE), within which flight is only permitted in smooth air without gusts. At these higher speeds, turbulence-induced load factors could exceed structural design limits.

A is wrong because flap/brake operating ranges are shown by the white arc.
B is wrong because aerotow speeds are typically within the green arc.
C is wrong because the best glide speed is a single point, not associated with the yellow arc.

Key Terms

VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q119: During a steady glide, an energy-compensated VSI shows the vertical speed ^t20q119

DE · FR

A) Of the glider through the surrounding air.
B) Of the glider minus the movement of the air.
C) Of the air mass being flown through.
D) Of the glider plus the movement of the air.

Answer

Explanation

The correct answer is C because a total-energy compensated variometer eliminates the effect of speed changes (kinetic energy exchanges) on the vertical speed indication. In a steady glide with constant airspeed, the TE variometer indicates the vertical movement of the surrounding air mass — showing zero in still air, or the actual thermal/sink value in moving air.

A is wrong because that describes an uncompensated variometer.
B and D are wrong because the TE variometer does not add or subtract airmass movement from the glider's vertical speed — it isolates the airmass movement itself.

Q120: During a right turn, the yaw string deflects to the left. What correction is needed to centre it? ^t20q120

DE · FR

A) More bank, less rudder in the direction of the turn.
B) More bank, more rudder in the direction of the turn.
C) Less bank, less rudder in the direction of the turn.
D) Less bank, more rudder in the direction of the turn.

Answer

Explanation

The correct answer is D because during a right turn, a yaw string deflecting to the left indicates the nose is sliding outward (skidding turn) — there is insufficient rudder coordination and possibly too much bank for the rate of turn. To correct this, apply more right rudder (in the direction of the turn) to bring the nose around, and reduce bank slightly to decrease the tendency to skid. A and C are wrong because they call for less rudder, which would worsen the skid.

B is wrong because adding more bank would increase the centripetal force demand and worsen the coordination problem.

Q121: What type of defect results in loss of airworthiness? ^t20q121

DE · FR

A) Dirty wing leading edge
B) Scratch on the outer painting
C) Damage to load-bearing parts
D) Crack in the cabin hood plastic

Answer

Explanation

Airworthiness of an aircraft is fundamentally determined by the structural integrity of load-bearing components (main spar, wing attachment, fuselage frames, control system attachment points). Damage to these parts compromises the aircraft's ability to sustain flight loads and constitutes a loss of airworthiness.

A dirty leading edge (A) reduces performance but is not an airworthiness defect.
A cracked canopy (B) and a scratch on paint (C) are cosmetic or minor defects that do not affect structural integrity.

Q122: The mass loaded on the aircraft is below the minimum load required by the load sheet. What action must be taken? ^t20q122

DE · FR

A) Change pilot seat position
B) Change incidence angle of elevator
C) Load ballast weight up to minimum load
D) Trim aircraft to "pitch down"

Answer

Explanation

The load sheet (weight and balance document) specifies a minimum pilot weight to ensure the centre of gravity remains within approved limits. If the actual pilot weight is below the minimum, ballast must be added (typically in the ballast area specified by the POH) to bring the total loaded mass up to the minimum required value.

Adjusting trim (A, C) does not address the underlying CG/mass problem, and changing seat position (B) is not a standard corrective action for under-weight loading.

Key Terms

CG = Centre of Gravity

Q123: Water ballast increases wing loading by 40%. By what percentage does the glider's minimum speed increase? ^t20q123

DE · FR

A) 18%
B) 200%
C) 40%
D) 100%

Answer

Explanation

Minimum speed (stall speed) is proportional to the square root of wing loading: Vs ∝ √(W/S). If wing loading increases by 40% (factor 1.4), stall speed increases by √1.4 ≈ 1.183, i.e., approximately 18.3%. Only the square-root relationship gives approximately 18%.

Option A 40% speed increase (B) would require a 96% increase in wing loading, 100% (A) would require a quadrupling of wing loading, and 200% (C) is far too large.

Key Terms

VS = Stall Speed

Q124: The maximum load according to the load sheet has been exceeded. What action must be taken? ^t20q124

DE · FR

A) Trim "pitch-up"
B) Trim "pitch-down"
C) Reduce load
D) Increase speed by 15%

Answer

Explanation

If the actual loaded mass exceeds the maximum allowed mass from the load sheet, the only correct action is to reduce the load (remove ballast, water ballast, baggage, or have a lighter pilot). Exceeding maximum mass means structural load limits may be reached at lower G-loads or airspeeds.

Increasing speed (A) or adjusting trim (C, D) does not address the structural overload problem.

Q125: What is a torsion-stiffened leading edge? ^t20q125

DE · FR

A) Both-side planked leading edge (from edge to cross-beam) to support torsion forces.
B) The point where the torsion moment on a wing begins to decrease.
C) Special shape of the leading edge.
D) The part of the main cross-beam to support torsion forces.

Answer

Explanation

A torsion-stiffened leading edge is a structural design feature in which the leading edge of the wing (from the leading edge to the main spar) is planked (covered) on both upper and lower surfaces, creating a closed-section D-box that resists torsional (twisting) loads.

This is not a spar component (A), not merely a shape descriptor (B), and not a reference to a torsion moment distribution point (C).

Q126: Where can information about maximum permissible airspeeds be found? ^t20q126

DE · FR

A) POH, approach chart, vertical speed indicator
B) POH, cockpit panel, airspeed indicator
C) POH and posting in briefing room
D) Airspeed indicator, cockpit panel and AIP part ENR

Answer

Explanation

Maximum permissible airspeeds (VNE, VNO, etc.) are published in the Pilot's Operating Handbook (POH/AFM), displayed on the cockpit instrument panel (placard), and indicated on the airspeed indicator by the red line (VNE) and arc markings.

The AIP ENR (A) does not contain aircraft-specific speed limitations.
Approach charts and VSI (B) do not show speed limits.
The briefing room posting (C) is informal and not authoritative.

Key Terms

AIP = Aeronautical Information Publication; VNE = Never Exceed Speed; VNO = Maximum Structural Cruising Speed

Q127: The airspeed indicator is unserviceable. The aircraft may only be operated ^t20q127

DE · FR

A) When the airspeed indicator is fully functional again.
B) If no maintenance organisation is available.
C) When a GPS with speed indication is used during flight.
D) If only aerodrome patterns are flown.

Answer

Explanation

The airspeed indicator is a required instrument for safe flight; without it a pilot cannot determine safe operating speeds, stall speed, or structural speed limits. An inoperative airspeed indicator means the aircraft must remain on the ground until the instrument is serviceable.

No exception exists for local aerodrome patterns (B) or GPS substitute (D — GPS ground speed is not equivalent to IAS for aerodynamic purposes).
Absence of maintenance (A) is irrelevant to the operational requirement.

Key Terms

IAS = Indicated Airspeed

Q128: During a left turn, the yaw string deflects to the left. What rudder input can centre the string? ^t20q128

DE · FR

A) More bank, less rudder in turn direction
B) Less bank, less rudder in turn direction
C) Less bank, more rudder in turn direction
D) More bank, more rudder in turn direction

Answer

Explanation

During a left turn, a yaw string deflecting to the left indicates the aircraft is slipping into the turn (too much bank relative to rudder input). To centre the string in a slip, the pilot needs to increase bank to steepen the turn and reduce rudder (less rudder in the turn direction). This is opposite to correcting a skid.

Options B, C, and D use incorrect combinations for correcting a slip in a left turn.

Q129: What is the purpose of winglets? ^t20q129

DE · FR

A) Increase gliding performance at high speed.
B) Increase of lift and turning manoeuvering capabilities.
C) Reduction of induced drag.
D) Increase efficiency of aspect ratio.

Answer

Explanation

Winglets are upward (or downward) curving extensions at the wingtip that reduce induced drag by weakening the wingtip vortex — the main source of induced drag on a finite wing.

They do not primarily increase aspect ratio efficiency (A — though functionally similar, they are a different mechanism), are not specifically for high-speed performance (C), and do not increase lift or turning agility (D).

Q130: What does dynamic pressure depend directly on? ^t20q130

DE · FR

A) Air pressure and air temperature
B) Air density and lift coefficient
C) Air density and airflow speed squared
D) Lift and drag coefficient

Answer

Explanation

Dynamic pressure (q) is defined by Bernoulli's equation as q = ½ρv², where ρ is air density and v is airflow speed. Dynamic pressure depends directly on air density and the square of velocity.

Lift and drag coefficients (A) are aerodynamic effects that depend on dynamic pressure, not the other way around.
Air pressure and temperature (D) influence density indirectly but are not the direct parameters in the formula.

Q131: The airspeed indicator, altimeter and vertical speed indicator all display incorrect readings simultaneously. What could be the cause? ^t20q131

DE · FR

A) Failure of the electrical system.
B) Leakage in compensation vessel.
C) Blocking of static pressure lines.
D) Blocking of pitot tube.

Answer

Explanation

The airspeed indicator, altimeter, and vertical speed indicator are all connected to the static pressure port. If the static pressure system is blocked (e.g., by ice, water, or a cover left on), all three instruments will give erroneous readings simultaneously.

A blocked pitot tube (C) would affect only the airspeed indicator.
A leaking compensating vessel (B) affects only the VSI.
An electrical failure (D) does not affect these purely pneumatic instruments.

Q132: When is it necessary to adjust the pressure on the altimeter's reference scale? ^t20q132

DE · FR

A) Every day before the first flight
B) Before every flight and during cross country flights
C) Once a month before flight operation
D) After maintenance has been finished

Answer

Explanation

The altimeter's reference pressure (subscale) must be set before every flight to the correct local QNH/QFE so that the altimeter reads the correct altitude or height. During cross-country flights, QNH changes as the pilot moves between pressure regions, so updates are required when crossing into new altimeter setting regions.

Monthly (C) or only after maintenance (A) settings would result in significant altitude errors.

Key Terms

QFE = Atmospheric pressure at aerodrome elevation; QNH = Pressure adjusted to mean sea level

Q133: The term "inclination" is defined as ^t20q133

DE · FR

A) Angle between magnetic and true north
B) Angle between the airplane's longitudinal axis and true north.
C) Deviation induced by electrical fields.
D) Angle between Earth's magnetic field lines and horizontal plane.

Answer

Explanation

Magnetic inclination (dip) is the angle between the Earth's magnetic field vector and the horizontal plane at any given location. It is 0° at the magnetic equator and 90° at the magnetic poles. - Deviation (A) is the error caused by magnetic fields within the aircraft. - Magnetic variation/declination (B) is the angle between magnetic and true north.

Option D describes aircraft heading, which is unrelated.

Q134: As air density decreases, the airflow speed at stall increases (TAS) and vice versa. How should a final approach be flown on a hot summer day? ^t20q134

DE · FR

A) With decreased speed indication (IAS)
B) With additional speed according to the POH
C) With increased speed indication (IAS)
D) With unchanged speed indication (IAS)

Answer

Explanation

The airspeed indicator measures IAS (Indicated Airspeed), which is derived from dynamic pressure. At lower air density (hot day, high altitude), TAS is higher than IAS for the same dynamic pressure. The aerodynamic behaviour of the wing (lift, stall) depends on dynamic pressure (and thus IAS), not on TAS. Therefore stall occurs at the same IAS regardless of density.

The approach should be flown at the same IAS as always (B).
Adding speed (D) or reducing IAS (C) based on temperature alone is not correct for stall margin management with IAS.

Key Terms

IAS = Indicated Airspeed; TAS = True Airspeed

Q135: The load factor n describes the relationship between ^t20q135

DE · FR

A) Thrust and drag.
B) Drag and lift
C) Weight and thrust.
D) Lift and weight

Answer

Explanation

The load factor (n) is the ratio of the aerodynamic lift acting on the aircraft to the aircraft's weight: n = L/W. In level unaccelerated flight, n = 1. In turns or pull-ups, n increases.

It does not describe weight/thrust (A), drag/lift (B), or thrust/drag (D) relationships.

Q136: The term static pressure is defined as the pressure ^t20q136

DE · FR

A) Sensed by the pitot tube.
B) Inside the airplane cabin.
C) Resulting from orderly flow of air particles.
D) Of undisturbed airflow.

Answer

Explanation

Static pressure is the pressure of the undisturbed ambient airmass — the atmospheric pressure acting equally in all directions at a given altitude. It is sensed through flush static ports on the fuselage skin.

It is not the cabin pressure (A), not related to orderly flow direction (C — that is dynamic pressure), and is not sensed by the pitot tube alone (D — the pitot senses total pressure).

Q137: The term inclination is defined as ^t20q137

DE · FR

A) Angle between the airplane's longitudinal axis and true north.
B) Deviation induced by electrical fields.
C) Angle between Earth's magnetic field lines and horizontal plane.
D) Angle between magnetic and true north.

Answer

Explanation

Magnetic inclination (dip) is the angle between the Earth's total magnetic field vector and the local horizontal plane. - At the magnetic equator, field lines are horizontal (0° dip); at the poles, they are vertical (90° dip). Deviation (A) is caused by onboard magnetic interference. - Variation/declination (B) is the angle between magnetic and geographic north.

Option D describes aircraft heading relative to true north.