Flight Performance and Planning


Q1: Exceeding the maximum allowed aircraft mass is ^t30q1

DE · FR

Answer

A)

Explanation

The correct answer is A because the maximum takeoff mass (MTOM) is a hard certification limit set by the manufacturer based on structural strength, stall speed, and climb performance. Exceeding it increases wing loading, raises the stall speed, reduces climb performance, and may overstress the airframe beyond its certified load factors.

Q2: The center of gravity has to be located ^t30q2

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Answer

A)

Explanation

The correct answer is A because the aircraft's stability and controllability are only certified within the approved C.G. envelope, which lies between the forward and aft C.G. limits.

Key Terms

D — Drag ### Q3: An aircraft has to be loaded and operated in such a way that the center of gravity (CG) stays within the approved limits during all phases of flight. This is done to ensure ^t30q3

DE · FR

Answer

D)

Explanation

The correct answer is D because the C.G. position relative to the neutral point determines longitudinal static stability (the tendency to return to equilibrium after a disturbance), while the elevator's ability to command pitch changes provides controllability. Both properties must be maintained throughout flight, and the C.G. envelope ensures this.

Key Terms

CG = Centre of Gravity ### Q4: The empty weight and the corresponding center of gravity (CG) of an aircraft are initially determined ^t30q4

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Answer

C)

Explanation

The correct answer is C because each individual airframe must be physically weighed — typically on calibrated scales at three support points — to determine its actual empty mass and C.G. position. Manufacturing tolerances, repairs, modifications, and installed equipment vary between serial numbers.

Key Terms

CG = Centre of Gravity ### Q5: Baggage and cargo has to be properly stowed and fastened, otherwise a shift of the cargo may cause ^t30q5

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Answer

C)

Explanation

The correct answer is C because unsecured cargo can shift suddenly during turbulence or manoeuvres, moving the C.G. outside approved limits instantaneously — faster than a pilot can react. A sudden aft C.G. shift can cause an unrecoverable pitch-up, loose items can become projectiles injuring occupants or jamming controls, and asymmetric loading can overstress the structure.

Q6: The total weight of an aeroplane is acting vertically through the ^t30q6

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Answer

A)

Explanation

The correct answer is A because the center of gravity is, by definition, the single point through which the resultant gravitational force (the weight vector) acts on the entire aircraft.

Q7: The term "center of gravity" is described as ^t30q7

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Answer

B)

Explanation

The correct answer is B. The center of gravity is the mass-weighted average position of all individual mass elements — the point where the total weight force is considered to act. It is found by summing all moments about the datum and dividing by total mass.

Q8: The center of gravity (CG) defines ^t30q8

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Answer

D)

Explanation

The correct answer is D because the C.G. is the point through which the entire gravitational force (weight) acts as if all mass were concentrated there. This is the fundamental definition used in physics and aircraft mass-and-balance. A and B both describe the datum (reference point), not the C.G. itself. - C describes a moment (mass times arm), which is a calculation quantity, not the definition of the center of gravity.

Key Terms

CG = Centre of Gravity ### Q9: The term "moment" with regard to a mass and balance calculation is referred to as ^t30q9

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Answer

C)

Explanation

The correct answer is C because in mass and balance, moment equals mass multiplied by balance arm (M = m x d), expressed in units such as kg-m or lb-in. The total C.G. position is then found by dividing the sum of all moments by the total mass.

Q10: The term "balance arm" in the context of a mass and balance calculation defines the ^t30q10

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Answer

C)

Explanation

The correct answer is C because the balance arm (or moment arm) is the horizontal distance measured from the aircraft's datum to the center of gravity of a specific mass item. This distance determines the leverage that mass exerts about the datum.

Q11: The distance between the center of gravity and the datum is called ^t30q11

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Answer

B)

Explanation

The correct answer is B because in mass-and-balance terminology, the balance arm is the horizontal distance from the datum to any point of interest, including the overall C.G. once calculated.

Key Terms

D — Drag ### Q12: The balance arm is the horizontal distance between ^t30q12

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Answer

C)

Explanation

![](figures/BalancearmEN.png)

The correct answer is C because the balance arm of any mass item is measured as the horizontal distance from the aircraft's datum to that item's center of gravity.

The datum (reference datum) is an arbitrary imaginary vertical plane chosen by the aircraft manufacturer as the "zero" reference for all weight and balance measurements. It is typically located at or ahead of the aircraft nose, so that all balance arms are positive numbers. Its location is defined in the aircraft flight manual (AFM/POH) and never changes for a given aircraft type. (Ref: FAA-H-8083-1B Aircraft Weight and Balance Handbook; EASA CS-22)

Q13: The required data for a mass and balance calculation including masses and balance arms can be found in the ^t30q13

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Answer

D)

Explanation

The correct answer is D because the Pilot's Operating Handbook (POH) or Aircraft Flight Manual (AFM) contains a dedicated mass and balance section with the aircraft's empty mass, empty C.G. position, datum reference, C.G. limits, and loading configurations.

Q14: Which section of the flight manual describes the basic empty mass of an aircraft? ^t30q14

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Answer

C)

Explanation

The correct answer is C because the Weight and Balance section of the flight manual contains the basic empty mass, empty C.G. location, allowable C.G. range, and loading instructions.

Q15: Which factor shortens landing distance? ^t30q15

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Answer

B)

Explanation

The correct answer is B because a headwind reduces the groundspeed at touchdown for a given indicated airspeed, so the aircraft crosses the threshold with less kinetic energy relative to the ground, shortening the ground roll significantly.

Key Terms

IAS = Indicated Airspeed ### Q16: Unless the aircraft is equipped and certified accordingly ^t30q16

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Answer

B)

Explanation

The correct answer is B because for non-FIKI certified aircraft, flying into known or forecast icing is a regulatory prohibition. If icing is inadvertently encountered, the pilot must exit immediately by changing altitude or heading.

Key Terms

VMC = Visual Meteorological Conditions ### Q17: The angle of descent is described as ^t30q17

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Answer

B)

Explanation

The angle of descent is the angle α between the horizontal plane and the actual flight path, measured in degrees [°]. tan(α) = h / d, where h is the height lost and d is the horizontal distance.

![](figures/glideanglegeometry.png)

Important distinction — angle of descent vs. glide angle:

| | Glide angle | Angle of descent | |---|---|---| | Reference | Air mass | Ground | | Analogy | Airspeed (TAS) | Ground speed | | Wind effect | None | Headwind steepens, tailwind flattens |

In still air they are identical. In wind they differ because the ground speed changes while the sink rate stays the same:

Q18: Which is the purpose of "interception lines" in visual navigation? ^t30q18

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Answer

D)

Explanation

The correct answer is D because interception lines (also called catching lines) are prominent linear ground features — rivers, motorways, railways, coastlines — selected during pre-flight planning that the pilot can navigate toward if orientation is lost. Flying to the nearest interception line provides an unmistakable landmark for position recovery.

Key Terms

VFR = Visual Flight Rules ### Q19: The upper limit of LO R 16 equals ^t30q19

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![](figures/t30_q19.png)

Answer

D)

Explanation

The correct answer is D because low-level restricted areas (LO R) on VFR charts typically express their vertical limits in feet MSL (above mean sea level). The value 1,500 ft MSL is a fixed, absolute altitude reference.

Key Terms

DE · FR

![](figures/t30_q20.png)

Answer

A)

Explanation

The correct answer is A because LO R 4 has its upper limit published at 4,500 ft MSL — a fixed altitude above mean sea level.

Key Terms

DE · FR

![](figures/t30_q21.png)

Answer

C)

Explanation

The correct answer is C because NOTAM altitude references follow ICAO conventions where "altitude" refers to height above MSL. The NOTAM prohibits overflight up to 9,500 ft MSL.

Key Terms

DE · FR

Answer

C)

Explanation

The correct answer is C because under ICAO Annex 2 and national regulations, a flight plan is mandatory for any international flight crossing state borders, even for VFR glider flights. This ensures coordination for border control, search and rescue alerting, and customs/immigration procedures.

Key Terms

DE · FR

Answer

B)

Explanation

The correct answer is B because the Flight Information Service (FIS), reached on the published FIS frequency, can accept an airborne flight plan (AFIL) during flight. This is the standard procedure for filing when airborne.

Q24: While planning a cross country gliding flight, what ground structure ought to be avoided enroute? ^t30q24

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Answer

B)

Explanation

The correct answer is B because moist ground, water bodies, and marshes have high thermal inertia and specific heat capacity — they absorb solar radiation without heating quickly, suppressing thermal development above them. Flying over these areas means less lift and potentially a forced landing in unsuitable terrain.

Q25: During a cross-country flight, you approach a downwind turning point. The point ought to be taken ... ^t30q25

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Answer

A)

Explanation

The correct answer is A because at a downwind turning point, the glider must reverse direction and fly back into the wind. This immediately reduces groundspeed and shortens the achievable glide distance over the ground. Arriving high provides maximum altitude reserve for the subsequent upwind leg.

Q26: After getting around a turning point, what should a glider pilot be prepared for? ^t30q26

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Answer

D)

Explanation

The correct answer is D because when a glider turns 90 or 180 degrees at a waypoint, the pilot's entire visual perspective of the sky shifts dramatically. The sun appears to have moved relative to the heading, and cumulus clouds that were behind or beside the aircraft now appear in different positions. This perceptual shift can make the sky look completely different.

Q27: According ICAO, what symbol indicates a group of unlighted obstacles? ^t30q27

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ICAO Obstacle Symbols

Answer

D)

Explanation

The correct answer is D because ICAO Annex 4 chart symbology uses distinct symbols to differentiate between single obstacles versus groups, and lighted versus unlighted. The symbol for a group of unlighted obstacles is shown as D in the figure — two filled circles side by side with no light rays. Knowing these symbols is critical for cross-country planning and obstacle avoidance.

Key Terms

ICAO = International Civil Aviation Organization ### Q28: According ICAO, what symbol indicates a civil airport (not international airport) with paved runway? ^t30q28

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ICAO Airport Symbols

Answer

A)

Explanation

The correct answer is A because ICAO aeronautical chart symbology differentiates airports by civil versus military status and runway surface type. A civil airport with a paved runway is shown as symbol A in the figure — a circle with a solid filled runway bar through the centre. Glider pilots use these symbols when planning outlanding fields or alternate airports.

Key Terms

ICAO = International Civil Aviation Organization ### Q29: According ICAO, what symbol indicates a general spot elevation? ^t30q29

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ICAO Spot Elevation Symbols

Answer

A)

Explanation

The correct answer is A because ICAO charts use specific symbols to differentiate between general spot elevations, the highest elevation on a chart, mountain peaks, and trigonometric points. A general spot elevation is shown as symbol A — a small dot with a plain elevation number beside it. Familiarity with these symbols is essential for terrain clearance planning.

Key Terms

ICAO = International Civil Aviation Organization ### Q30: What distance can be covered during a glide in a glider plane with glide ratio 1/30 from a height of 1500 m? (Neglect wind and thermal effects) ^t30q30

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Answer

C)

Explanation

The correct answer is C because glide distance equals glide ratio multiplied by height: 30 x 1,500 m = 45,000 m = 45 km. The glide ratio of 1:30 means the glider covers 30 metres horizontally for every 1 metre of height lost.

![](figures/glideanglegeometry.png)

The diagram shows the relationship: distance d = h / tan(α), where α is the glide angle.

Key Terms

NM = Nautical Mile(s) ### Q31: Why can wing loading be increased when soaring conditions are good? ^t30q31

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Answer

B)

Explanation

The correct answer is B because in strong thermal conditions, the glider benefits from flying faster between thermals (MacCready theory). Adding water ballast increases wing loading, which shifts the speed polar to the right — improving the glide ratio at high cruising speeds while accepting a higher stall and minimum sink speed.

Q32: The tail wheel of a glider was not removed before departure. What will be the consequence? ^t30q32

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Answer

D)

Explanation

The correct answer is D because the tail wheel is mounted at the extreme rear of the fuselage, far aft of the nominal C.G. Even though its absolute mass is small, its large moment arm produces a significant moment that shifts the C.G. aftward — potentially beyond the aft limit, making the aircraft pitch-unstable and difficult to control.

Q33: The pilot exceeds the maximum cockpit payload by 10 kg. What has to be done? ^t30q33

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Answer

C)

Explanation

The correct answer is C because the maximum seat load is a certification limit that cannot be circumvented. Exceeding it may place the C.G. outside the forward limit and subjects the structure to loads beyond what was tested. The only remedy is to reduce the payload until the limits are respected. A and B are wrong because trimming changes the aerodynamic forces on the elevator but does not alter the aircraft's mass or C.G. position.

Q34: What propels a pure glider forward? ^t30q34

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Answer

C)

Explanation

The correct answer is C because in steady gliding flight, the weight vector can be resolved into two components: one perpendicular to the flight path (balanced by lift) and one along the flight path. This along-path component of gravity provides the forward-driving force that balances drag and maintains airspeed.

Q35: The current mass of an aircraft is 610 kg and the centre of gravity (C.G.) position is at 80.0. You remove a 10 kg item of baggage located at a moment arm of 150. Which is the new centre of gravity? ^t30q35

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Answer

D)

Explanation

The correct answer is D. The calculation proceeds as follows: Initial moment = 610 x 80.0 = 48,800. Removed moment = 10 x 150 = 1,500. New total moment = 48,800 - 1,500 = 47,300. New mass = 610 - 10 = 600 kg. New C.G. = 47,300 / 600 = 78.833. Since the baggage was located aft of the current C.G. (arm 150 > 80), removing it shifts the C.G. forward — consistent with the result (78.833 < 80.0).

Q36: The empty mass of the Discus B is 245 kg. You are planning to carry 184 kg of water ballast. What is the maximum load at the pilot's seat? ^t30q36

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Extract from the Discus B Flight Manual — Loading table with water ballast

![](figures/t30_q36.png)

Max. permitted all-up weight including water ballast : 525 kg Lever arm of water ballast : 203 mm aft of datum (BE)

Table of water ballast loads at various empty weights and seat loads:

| Empty mass (kg) | Seat load 70 kg | 80 kg | 90 kg | 100 kg | 110 kg | |---|---|---|---|---|---| | 220 | 184 | 184 | 184 | 184 | 184 | | 225 | 184 | 184 | 184 | 184 | 184 | | 230 | 184 | 184 | 184 | 184 | 184 | | 235 | 184 | 184 | 184 | 184 | 180 | | 240 | 184 | 184 | 184 | 184 | 175 | | 245 | 184 | 184 | 184 | 180 | 170 | | 250 | 184 | 184 | 184 | 175 | 165 |

Answer

C)

Explanation

*Water ballast in both wing tanks (kg). For empty mass 245 kg and ballast 184 kg: the maximum seat load is 90 kg (column 90 kg → value 184, but column 100 kg → 180 and column 110 kg → 170; with ballast=184 required, read the 245 kg row and find the seat load corresponding to ballast=184, i.e. max 90 kg permitted according to the table).*

The correct answer is C (90 kg). Reading the Discus B loading table at the row for empty mass 245 kg: with a seat load of 90 kg the permitted water ballast is 184 kg (matching our requirement), but at 100 kg seat load only 180 kg of ballast is permitted, and at 110 kg only 170 kg. Since we need the full 184 kg of ballast, the maximum seat load that still allows this is 90 kg.

Q37: What important principle must be observed when making an off-field landing on sloping terrain? ^t30q37

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Answer

B)

Explanation

The correct answer is B because landing uphill uses the slope to decelerate the glider — gravity assists braking, dramatically shortening the ground roll. A slightly higher approach speed provides a safety margin against wind shear and turbulence near unfamiliar terrain.

Q38: You must land in heavy rain. What must you pay particular attention to? ^t30q38

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Answer

D)

Explanation

The correct answer is D because heavy rain on the wing surface degrades the aerodynamic profile through increased roughness, potentially raising the stall speed. A higher approach speed provides an adequate safety margin.

Q39: You are taking off from a grass runway that has become waterlogged after several days of rain. What should you expect? ^t30q39

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Answer

A)

Explanation

The correct answer is A because a waterlogged grass runway creates greater rolling resistance due to soft ground deformation and water drag on the wheels, slowing acceleration and increasing the takeoff distance.

Q40: Which of these statements is correct at a speed of 170 km/h, taking into account the following speed polar? ^t30q40

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ASK 21 Speed Polar:

![](figures/t30_q40.png)

*Two curves: G=470 kp (light mass, min sink rate ~0.657 m/s at ~75 km/h) and G=570 kp (heavy mass, min sink rate ~0.724 m/s). The curves cross in the ~90–110 km/h range; above that, the G=570 kp curve sits above the G=470 kp curve (i.e. has the smaller sink rate).*

Answer

B)

Explanation

On a glider polar diagram the Y axis is sink rate increasing downward — higher points on the chart mean less sink (better), lower points mean more sink (worse).

On the attached ASK 21 speed polar, the two curves (G = 470 kp light and G = 570 kp heavy) cross somewhere around 90–110 km/h. At 170 km/h we are well above that crossover, and the **heavier curve sits visually above the lighter one on the chart** — meaning the 570 kp configuration has a smaller sink rate than the 470 kp one at that airspeed.

Why? The polar for a heavier mass is the lighter one scaled along both axes by √(mheavy / mlight). At low speeds the heavy configuration needs a larger sink rate to hold the extra weight up (more induced drag). At high speeds, where parasite drag dominates and sink rate is roughly proportional to V · D/W, the extra weight actually reduces sink per unit horizontal distance — the classic reason water ballast pays off above best-glide speed.

So at 170 km/h the heavier ASK 21 sinks more slowly than the lighter one: as the mass rises, the sink rate decreases → B.

See also t30q61, which asks the same physics at 150 km/h.

Q41: Which is the speed at the minimum sink rate in still air for a mass of 450 kg? ^t30q41

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Speed Polar (AIRSPEED):

![](figures/t30_q41.png)

Two curves: 450 kg and 580 kg. The minimum sink rate (top of the curve) for 450 kg is at approximately 75 km/h. The 580 kg curve is shifted to the right (higher speeds).

Answer

A)

Explanation

The correct answer is A because the minimum sink rate speed corresponds to the highest point on the speed polar curve — where the sink rate is smallest. For 450 kg, this peak occurs at approximately 75 km/h. This speed maximises flight endurance in still air and is optimal for centring thermals.

Q42: From what altitude on the route between Murten (approx. N46°56'/E007°07') and Neuchâtel aerodrome (approx. N46°57'/E006°52') are you required to request permission to cross the PAYERNE TMA? ^t30q42

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![](figures/t30_q42.png)

Payerne TMA Sectors (Class D, FL 100 upper limit):

| Sector | Lower limit | |--------|------------| | CTR | GND | | TMA 1 | 2300 ft AMSL (700 m) | | TMA 2 | 2800 ft AMSL (853 m) | | TMA 3 | 3100 ft AMSL (945 m) | | TMA 5 | 4000 ft AMSL (1219 m) | | TMA 6 | 4500 ft AMSL (1372 m) |

Answer

C)

Explanation

The Murten-Neuchatel route crosses TMA sector 1 of the Payerne TMA. TMA 1 has its lower limit at 2300 ft AMSL (700 m). Below this altitude you fly in uncontrolled airspace without clearance. Above it, you need ATC authorisation on 128.675 MHz.

The TMA sectors step up in altitude as you move away from the airfield: CTR at GND, TMA 1 at 2300 ft, TMA 3 at 3100 ft, TMA 5 at 4000 ft, etc. The sector numbers and their boundaries are shown on the ICAO chart (numbers 1, 3, 5 in the blue shading), but the altitude limits are published in the AIP (ENR 2.1), not on the chart itself.

Ref: Swiss AIP ENR 2.1; OpenAIP: search "Payerne" ### Q43: In which airspace class are you flying at 1400 m AMSL (QNH 1013 hPa) over Birrfeld aerodrome (47°25'36"N/007°14'02"E), and what are the visibility and cloud distance minima in that airspace? ^t30q43

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![](figures/t30_q43.png)

![](figures/luftraeume_overview.jpg)

Answer

A)

Explanation

Birrfeld (LSZF) sits at about 400 m elevation. It is not inside a CTR — it's in uncontrolled airspace. The vertical airspace profile over Birrfeld looks like this:

Ground (400 m) to ~600 m AGL (~1000 m AMSL): Class G - 1.5 km visibility, clear of cloud, ground contact required

~1000 m AMSL to 5500 ft / 1676 m AMSL: Class E - 5 km visibility, 1500 m horizontal cloud clearance, 300 m vertical

5500 ft AMSL to FL195: Class C (Zurich TMA) - ATC clearance required

At 1400 m AMSL (about 4593 ft), you are above Class G but below the Class C floor at 5500 ft. That puts you in Class E — answer A.

On the ICAO chart, the blue box near Birrfeld reading "C FL195 / 5500" marks where Class C starts. Below that, and above Class G, is uncontrolled Class E.

DE · FR

DABS — Daily Airspace Bulletin Switzerland (extract)

![](figures/t30_q44.png)

![](figures/t30_q44b.png)

| Firing-Nr D-/R-Area NOTAM-Nr | Validity UTC | Lower Limit AMSL or FL | Upper Limit AMSL or FL | Location | Center Point | Covering Radius | Activity / Remarks | |---|---|---|---|---|---|---|---| | B0685/14 | 0000–2359 | 900m / 3000ft | FL 130 | SION TMA SECT 1 | 461610N 0072940E | 4.7 KM / 2.5 NM | TMA SECT 1 ACT HX ONLY | | W0912/15 | 1145–1300 | GND | FL 120 | MORGARTEN | 470507N 0083758E | 10.0 KM / 5.4 NM | R-AREA ACT. ENTRY PROHIBITED. FOR INFO CTC ZURICH INFO 124.7 | | W0957/15 | 1400–1700 | 2150m / 7000ft | FL 120 | HINWIL | 471721N 0084859E | 7.0 KM / 3.8 NM | TEMPO R-AREA ACTIVE. ENTRY PROHIBITED. CTC 118.975 | | W0960/15 | 0800–1700 | GND | 1200m / 4050ft | 1.7 KM SE CERNIER | 470352N 0065442E | 1.5 KM / 0.8 NM | D-AREA ACT |

Answer

D)

Explanation

The correct answer is D. On 20 June 2015 (CEST = UTC+2), the planned time of 1515-1545 LT corresponds to 1315-1345 UTC. Zone W0912/15 (MORGARTEN) was active 1145-1300 UTC and has already expired. Zone W0957/15 (HINWIL) activates at 1400 UTC (1600 LT) — it is not yet active. The route can therefore be flown without coordination between 1500 and 1600 LT.

Key Terms

DE · FR

![](figures/t30_q45.png)

Answer

A)

Explanation

The correct answer is A. On the ICAO chart, Schwyz (47°01'N, 8°39'E) falls inside the AWY A9.1 corridor where Class C begins at FL 090. The blue box near Schwyz reads "C FL195 / FL090" — meaning Class C extends from FL 090 up to FL 195 in this sector.

The nearby "C FL195 / FL130" box (south, near Fluelen) belongs to a different sector (AWY A9.2). The boundary between these two sectors runs just south of Schwyz at approximately 47°00'N. Schwyz town at 47°01'N is north of this line, in the FL 090 sector.

Reading the chart: each blue "C" box shows the upper and lower limits of Class C for that sector. The label is placed inside the sector it belongs to. Look at the blue boundary lines to see which sector your position falls in.

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AD INFO 1 — LA CÔTE / LSGP

![](figures/t30_q46.png)

| Data | Value | |--------|--------| | ICAO | LSGP | | Elevation | 1352 ft (412 m) | | ARP | 46°24'23"N / 006°15'28"E | | Runway | 04 / 22 — true/mag: 041°/040° and 221°/220° | | Dimensions | 560 x 30 m — GRASS | | LDG distance available | 490 m | | TKOF distance available | 490 m | | SFC strength | 0.25 MPa | | Status | Private — Airfield, PPR | | Location | 25 km NE Geneva | | Hours MON–FRI | 0700–1200 LT / 1400–ECT –30 min | | Hours SAT/SUN | 0800–1200 LT / 1400–ECT –30 min | | ECT reference | → VFG RAC 1-1 |

ECT = End of Civil Twilight. The aerodrome closes 30 minutes before end of civil twilight.

Answer

C)

Explanation

The correct answer is C because the AD INFO sheet for LSGP shows afternoon hours as "1400-ECT -30 min," meaning the aerodrome closes 30 minutes before the end of civil twilight.

Key Terms

DE · FR

Visual Approach Chart — GRUYÈRES / LSGT

![](figures/t30_q47.png)

AD 124.675 — PPR — ELEV 2257 ft (688 m)

Key chart data (altitudes in ft, magnetic headings):

| Data | Value | |--------|--------| | ICAO | LSGT | | AD Frequency | 124.675 MHz | | Elevation | 2257 ft (688 m) | | Status | PPR | | Minimum AD overfly altitude (MNM ALT) | 4000 ft | | Glider ARR/DEP sector W (GLD ARR/DEP W) | MAX 3100 ft | | Glider ARR/DEP sector E (GLD ARR/DEP E) | MAX 3600 ft | | HEL ARR/DEP | 3000 ft | | Preferred ARR sectors | WEST and EAST | | CTN (cross-country traffic) | 3000 ft | | MNM AD overfly | 4000 ft | | Class C airspace above | FL 100 / 119.175 GENEVA DELTA | | Winch launches | Intensive SAT/SUN (CTN: Intense winch launching SAT/SUN) | | Nearby VOR/DME | SPR R076, 113.9 MHz |

Noise-sensitive areas (yellow) around Bulle/Broc. Avoid overflying the field during PJE (parachute dropping). Contact RTF 5 min before ETA.

Answer

B)

Explanation

The correct answer is B (124.675 MHz) because this is the aerodrome frequency shown on the Visual Approach Chart for LSGT Gruyeres. Local traffic information, including intensive winch launching activity on weekends, is broadcast on this frequency.

Key Terms

DE · FR

Answer

B)

Explanation

The correct answer is B because distance = speed x time. Ground speed = 90 km/h, time = 90 minutes = 1.5 hours. Distance = 90 x 1.5 = 135 km. Remember to convert minutes to hours before multiplying: 90 minutes = 1.5 hours, not 0.9 hours.

Q49: At an altitude of 6000 m, the airspeed indicator shows 160 km/h (IAS). The true airspeed (TAS) ^t30q49

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Answer

D)

Explanation

The correct answer is D because the airspeed indicator measures dynamic pressure, which depends on air density. At 6000 m, air density is significantly lower than at sea level. For the pitot tube to register the same dynamic pressure (same IAS), the aircraft must be moving faster through the thinner air. TAS increases by approximately 2% per 300 m of altitude gain, so at 6000 m, TAS is roughly 40% higher than IAS.

Key Terms

DE · FR

Answer

B)

Explanation

The correct answer is B because at high altitude the true airspeed corresponding to a given IAS is much higher, and it is the TAS that determines aerodynamic loads on the structure. Glider flight manuals provide a speed-altitude table (or VNE reduction curve) displayed in the cockpit, giving the corrected maximum IAS at each altitude. At 6000 m, the allowable IAS is lower than the sea-level VNE mark.

Key Terms

DE · FR

Answer

C)

Explanation

The correct answer is C because to convert pounds to kilograms, divide by 2.2: 1235 / 2.2 = 561.4 kg, which rounds to approximately 560 kg. The key formula is: mass in kg = weight in lbs / 2.2.

Q52: What has to be particularly observed when landing on an upsloping field with a tailwind? ^t30q52

DE · FR

Answer

C)

Explanation

The correct answer is C because on an upsloping field with a tailwind, the competing effects partially cancel each other: the upslope shortens the ground roll while the tailwind lengthens it. The normal approach speed (yellow triangle on the ASI) provides the correct balance of energy management.

Flare (also: round-out) = the pitch-up manoeuvre just before touchdown. The pilot pulls back on the stick to raise the nose, reducing the descent rate and converting speed into lift for a smooth touchdown.

Q53: In which airspace class are you above Langenthal aerodrome (47 deg 10'58''N / 007 deg 44'29''E) at an altitude of 2000 m AMSL (QNH 1013 hPa), and what are the minimum visibility and cloud distance requirements? ^t30q53

DE · FR

![](figures/t30_q53.png)

Answer

A)

Explanation

The correct answer is A because at 2000 m AMSL above Langenthal, you are in Class E airspace. VFR flight in Class E requires 5 km horizontal visibility, 1500 m horizontal cloud clearance, and 300 m vertical cloud clearance.

Key Terms

DE · FR

Answer

C)

Explanation

The correct answer is C because when the C.G. is too far aft, the glider loses longitudinal static stability — the nose tends to pitch up without returning to equilibrium, potentially leading to uncontrollable divergent oscillations or a stall/spin.

Q55: How does the indicated VNE (never-exceed speed) change as altitude increases? ^t30q55

DE · FR

Answer

C)

Explanation

The correct answer is C because the airspeed indicator measures dynamic pressure, which inherently accounts for air density. The V_NE marking on the ASI (red line) represents a fixed IAS value that corresponds to the structural limit. However, note that the allowable maximum IAS must actually be reduced at high altitude per the flight manual's speed-altitude table — the ASI marking itself does not change, but the pilot must observe a lower limit. The subtlety is that while the ASI reading mechanism inherently accounts for density, glider pilots must consult the altitude-correction table for the actual limit at high altitude.

Key Terms

DE · FR

Answer

C)

Explanation

The correct answer is C because ground speed = distance / time = 150 km / 1.25 hours = 120 km/h. The key step is converting 1 hour 15 minutes to decimal hours: 15 minutes = 0.25 hours, so total time = 1.25 hours.

Q57: The following NOTAM was published on 18 August (summer time). Which of the following statements is correct? ^t30q57

DE · FR

![](figures/t30_q57.png)

Answer

C)

Explanation

The correct answer is C because the NOTAM establishes that from 2 to 6 September 2013, between 0600 and 1500 UTC, the extended CTR/TMA Payerne is activated as a holding area, while LS-R4 serves as both a demonstration and holding area for an airshow. These areas must be strictly avoided during the active period.

Key Terms

DE · FR

![](figures/t30_q58.png)

Answer

B)

Explanation

The correct answer is B (75 km/h) because the best glide speed is found by drawing a tangent from the origin to the speed polar curve for 470 kg. The point where this tangent touches the curve gives the speed for maximum lift-to-drag ratio (best glide).

Key Terms

D — Drag ### Q59: A VFR flight will follow the route shown on the map below (the red line on the map) from APPENZELL towards MUOTATHAL. The route is planned for 19 March 2013 (winter time) between 1205 and 1255 LT. Answer using the DABS below. Which of these answers is correct? ^t30q59

DE · FR

![](figures/t30_q59.png)

![](figures/t30_q59b.png)

Answer

C)

Explanation

The correct answer is C because checking the DABS for 19 March 2013 (winter time, CET = UTC+1), the planned time of 1205-1255 LT converts to 1105-1155 UTC. During this period, the relevant danger and restricted zones along the route are not active, allowing the route to be flown without coordination.

Key Terms

DE · FR

Answer

A)

Explanation

The correct answer is A because stall speed (and therefore minimum speed) is proportional to the square root of wing loading. If wing loading increases by 40% (factor 1.4), the new minimum speed is the original multiplied by the square root of 1.4, which equals approximately 1.183 — an increase of about 18.3%.

Q61: Based on the polar below, which statement applies at a speed of 150 km/h? See attached sheet ^t30q61

DE · FR

![](figures/t30_q61.png)

Answer

B)

Explanation

On a glider polar diagram the Y axis is sink rate increasing downward — higher points on the chart mean less sink (better), lower points mean more sink (worse).

On the attached polar, the two curves (G = 570 kp heavy and G = 470 kp light) cross well below 150 km/h — roughly in the 90–110 km/h range. Past that crossover, at 150 km/h, the **heavier curve sits visually above the lighter one on the chart** — i.e. the 570 kp ASK 21 has a smaller sink rate than the 470 kp one at the same airspeed.

Why? The polar for a heavier mass is the lighter one scaled along both axes by √(mheavy / mlight). At low speeds this means the heavy configuration needs a larger sink rate to balance the extra weight (more induced drag). At high speeds, where parasite drag dominates and the sink rate is roughly proportional to V · D/W, the extra weight reduces sink per unit distance — which is exactly why water ballast pays off above best-glide speed.

So at 150 km/h:

Q62: At Amlikon aerodrome, what is the maximum available landing distance heading East? ^t30q62

DE · FR

![](figures/t30_q62.png)

Answer

D)

Explanation

Heading East means landing on RWY 09 (bearing 093°). Reading the declared-distances table in the Amlikon (LSZT) AIP chart:

| RWY | BRG | AVBL LEN LDG | AVBL LEN TKOF | |-----|-----|---|---| | 09 (East) | 093/091 | 700 m | 780 m | | 27 (West) | 273/271 | 780 m | 780 m |

So the landing distance available (LDA) on RWY 09 is 700 m → answer D.

Note the asymmetry: RWY 09's LDA is shorter than its TKOF distance because of an obstacle on the approach or a displaced threshold; on the reciprocal RWY 27 the LDA equals the TKOF distance.

Key Terms

AIP = Aeronautical Information Publication ### Q63: From what altitude must you request a transit clearance for the EMMEN TMA between Cham (approx. N47 deg 11' / E008 deg 28') and Hitzkirch (approx. N47 deg 14' / E008 deg 16')? ^t30q63

DE · FR

![](figures/t30_q63.png)

Emmen TMA Sectors (Class D):

| Sector | Lower limit | Upper limit | |--------|------------|-------------| | CTR 1 | GND | FL 130 | | CTR 2 | GND | 4500 ft MSL | | TMA 1 | 2400 ft MSL | FL 80 | | TMA 2 | 3800 ft MSL | FL 130 | | TMA 3 | 3500 ft MSL | FL 80 | | TMA 4 | 6700 ft MSL | FL 130 | | TMA 5 | 4500 ft MSL | FL 80 |

Answer

A)

Explanation

The Cham–Hitzkirch route crosses TMA sector 1 of the Emmen TMA. TMA 1 has its lower limit at 2400 ft AMSL. Below this altitude you fly in uncontrolled airspace without clearance. Above it, you need ATC authorisation.

The TMA sectors step up in altitude as you move away from the airfield: CTR at GND, TMA 1 at 2400 ft, TMA 3 at 3500 ft, TMA 5 at 4500 ft, etc. The sector numbers and their boundaries are shown on the ICAO chart, but the altitude limits are published in the AIP (ENR 2.1).

Ref: Swiss AIP ENR 2.1; OpenAIP: search "Emmen" ### Q64: The maximum permitted payload is exceeded. What action must be taken? ^t30q64

DE · FR

Answer

D)

Explanation

The correct answer is D because when the maximum permitted payload is exceeded, the only correct action is to reduce the payload until it complies with the limit. The maximum payload is a certification limit based on structural strength and C.G. envelope. A and C are wrong because trimming adjusts aerodynamic forces on the tail but does not change the aircraft's mass or C.G. — it cannot make an overloaded aircraft safe.

Q65: Which is the effect of wind on the glide angle over the ground if the aircraft's true airspeed remains constant? ^t30q65

DE · FR

Answer

D)

Explanation

The correct answer is D because a headwind reduces groundspeed while the sink rate in the airmass remains unchanged. Since the glider covers less horizontal ground distance per unit of altitude lost, the descent angle relative to the ground steepens (increases).

![](figures/glideanglegeometry.png)

See the diagram for the geometry. Wind changes d (horizontal distance) without changing h (height loss), shifting α.

Q66: How does indicated airspeed (IAS) compare to true airspeed (TAS) as altitude increases? ^t30q66

DE · FR

Answer

B)

Explanation

The correct answer is B because as altitude increases, air density decreases. For the same true airspeed, the pitot tube measures less dynamic pressure, so the IAS reading is lower than TAS. Conversely, to maintain the same IAS at altitude, the aircraft must fly at a higher TAS. The relationship is approximately TAS = IAS x square root of (sea-level density / actual density).

Key Terms

DE · FR

Answer

A)

Explanation

The correct answer is A because heavy rain on the wing surface increases roughness and can degrade the boundary layer, potentially raising the stall speed and reducing maximum lift coefficient. A higher approach speed provides a safety margin against these effects.

Q68: What must a glider pilot take into account at Bex aerodrome? ^t30q68

DE · FR

![](figures/t30_q68.png)

Answer

D)

Explanation

The correct answer is D because at Bex aerodrome, terrain constraints (the Rhone valley and surrounding mountains) mean the traffic pattern direction for runway 33 depends on the prevailing wind conditions. The chart shows that either a left or right circuit may be used.

Q69: What is the maximum flying altitude above Biel Kappelen aerodrome (SE of Biel) if you wish to avoid requesting a transit clearance for TMA BERN 1? ^t30q69

DE · FR

![](figures/t30_q69.png)

Answer

D)

Explanation

The correct answer is D because the lower limit of TMA BERN 1 over Biel Kappelen is 3500 ft AMSL. By staying below this altitude, you remain in uncontrolled airspace and do not need a transit clearance.

Key Terms

DE · FR

  • Aircraft mass: 800 lb
  • Current C.G.: 77
  • C.G. limits: forward 75.2, aft 80.5
  • Move: 10 lb baggage item from arm 30arm 150

Answer

A)

Explanation

The correct answer is A.

Calculation: moving 10 lb from arm 30 to arm 150 shifts the moment by 10 × (150 − 30) = +1200 lb·in. The aircraft mass is unchanged (the baggage is relocated, not removed), so the new C.G. is:

new C.G. = 77 + 1200 / 800 = 77 + 1.5 = 78.5

Since 75.2 ≤ 78.5 ≤ 80.5, the new C.G. lies within the approved envelope.

Key Terms

DE · FR

Answer

B)

Explanation

The correct answer is B because a waterlogged grass surface reduces wheel braking effectiveness (similar to aquaplaning) during the ground roll, causing the glider to take longer to stop. While the soft ground adds some drag, the loss of braking friction dominates, resulting in a longer landing distance. This is consistent with the general rule that wet grass increases both takeoff and landing distances.

Q72: At Schänis aerodrome, what is the maximum available landing distance heading NNW? ^t30q72

DE · FR

![](figures/t30_q72.png)

Answer

B)

Explanation

The correct answer is B (470 m) because the AIP chart for Schanis aerodrome shows a maximum landing distance available of 470 metres in the NNW direction. Always read the correct runway direction and corresponding distance from the aerodrome chart.

Key Terms

AIP = Aeronautical Information Publication ### Q73: The current mass of an aircraft is 6400 lbs. Current CG: 80. CG limits: forward CG: 75.2, aft CG: 80.5. What mass can be moved from its current position to arm 150 without exceeding the aft CG limit? ^t30q73

DE · FR

Answer

D)

Explanation

The correct answer is D (45.71 lbs). The calculation uses the shift formula: when mass x is moved from the current C.G. position (80) to arm 150, the C.G. shifts aft. The new C.G. must not exceed 80.5. Using the formula: delta CG = (x × delta arm) / total mass, we get: 0.5 = (x × 70) / 6400, therefore x = (0.5 × 6400) / 70 = 45.71 lbs.

Key Terms

CG = Centre of Gravity ### Q74: Correct loading of an aircraft depends on: ^t30q74

DE · FR

Answer

C)

Explanation

The correct answer is C because correct loading requires satisfying two independent conditions simultaneously: the total mass must not exceed the maximum allowable mass (MTOM), and the payload must be distributed so that the C.G. remains within the approved envelope.

Q75: What information can be read from this speed polar? (See attached sheet.) ^t30q75

DE · FR

![](figures/t30_q75.png)

Answer

D)

Explanation

The correct answer is D because when comparing polar curves for different masses, the tangent from the origin touches each curve at the same angle, meaning the maximum lift-to-drag ratio (best glide ratio) is essentially unchanged by mass, apart from minor Reynolds number effects. However, the speed at which this best glide ratio occurs increases with mass.

Q76: At what indicated speed do you approach an aerodrome located at an altitude of 1800 m AMSL? ^t30q76

DE · FR

Answer

A)

Explanation

The correct answer is A because the airspeed indicator measures dynamic pressure, which directly relates to aerodynamic forces regardless of altitude. At 1800 m AMSL, air density is lower, so the TAS will be higher for the same IAS — but the aerodynamic forces (lift, stall characteristics) depend on IAS, not TAS. Therefore, the same indicated approach speed provides the same safety margins as at sea level.

Key Terms

DE · FR

![](figures/t30_q77.png)

Answer

B)

Explanation

The correct answer is B (90 km/h) because the best glide ratio speed is found where the tangent from the origin touches the speed polar curve for 470 kg. For this glider type at 470 kg, this occurs at approximately 90 km/h.

Q78: The maximum aft CG limit is exceeded. What action must be taken? ^t30q78

DE · FR

Answer

C)

Explanation

The correct answer is C because when the aft C.G. limit is exceeded, the useful load must be redistributed to move mass forward — for example, adding nose ballast, repositioning equipment, or adjusting the pilot's seating position. This physically moves the C.G. within approved limits.

Key Terms

CG = Centre of Gravity ### Q79: Which factors increase the aerotow takeoff run distance? ^t30q79

DE · FR

Answer

D)

Explanation

The correct answer is D because high temperature reduces air density, decreasing the lift generated at any given groundspeed, requiring a longer acceleration to reach flying speed. A tailwind reduces the headwind component, meaning the aircraft needs a higher groundspeed to achieve the same airspeed, further lengthening the takeoff run.

Q80: The following NOTAM was published for 18 November. Which of these statements is correct? ^t30q80

DE · FR

![](figures/t30_q80.png)

Answer

D)

Explanation

The correct answer is D because the NOTAM specifies a military night flying exercise on 18 November from 1800 to 2100 UTC in the ZUGERSEE, SUSTEN, and TICINO areas, with vertical limits from GND to 15,000 ft AMSL.

Key Terms

DE · FR

![](figures/t30_q81.png)

Answer

D)

Explanation

The correct answer is D because the CTR (Control Zone) of Bern-Belp airport has an upper limit of 3000 ft AMSL. Above this altitude, you exit the CTR and enter different airspace. VFR flight within the CTR requires a clearance from Bern Tower and must remain below the published upper limit.

Key Terms

DE · FR

![](figures/t30_q82.png)

Answer

D)

Explanation

The correct answer is D because at 1700 m AMSL above Bex aerodrome, you are in Class E airspace. VFR minima in Class E require 5 km horizontal visibility, 1500 m horizontal cloud clearance, and 300 m vertical cloud clearance.

Key Terms

DE · FR

![](figures/t30_q83.png)

Answer

C)

Explanation

The correct answer is C (2.0 m/s) because reading the speed polar curve for a flying mass of 570 kg at 160 km/h, the sink rate is approximately 2.0 m/s. When reading a speed polar, always identify the correct curve for the given mass before reading the value at the specified speed.

Q84: 550 kg (rounded) correspond to (1 kg = approx. 2.2 lbs): ^t30q84

DE · FR

Answer

B)

Explanation

The correct answer is B because to convert kilograms to pounds, multiply by 2.2: 550 x 2.2 = 1,210 lbs. The key formula is: weight in lbs = mass in kg x 2.2.

Q85: At what speed must a glider fly in calm air to cover the maximum possible distance? ^t30q85

DE · FR

Answer

D)

Explanation

The correct answer is D because the best glide ratio speed (also called best L/D speed) maximises the horizontal distance covered per unit of altitude lost in still air. This speed is found on the polar curve where the tangent from the origin touches the curve.

Q86: The mass of a glider is increased. Which parameter will NOT be affected by this increase? ^t30q86

DE · FR

Answer

A)

Explanation

The correct answer is A because the maximum glide ratio (best L/D) is essentially independent of mass — both the lift coefficient and drag coefficient at the optimal angle of attack remain the same, so their ratio is unchanged. Only a minor Reynolds number effect exists.

Key Terms

IAS = Indicated Airspeed ### Q87: How long does it take to cover a distance of 150 km at an average ground speed of 100 km/h? ^t30q87

DE · FR

Answer

D)

Explanation

The correct answer is D because time = distance / speed = 150 km / 100 km/h = 1.5 hours = 1 hour 30 minutes. The calculation is straightforward: 150 / 100 = 1.5 hours. Convert the decimal 0.5 hours to 30 minutes.

Q88: When preparing an alpine VFR flight along the route shown on the map below (dotted line) between MUNSTER and AMSTEG, you consult the DABS. You intend to fly this route on a summer weekday between 1445-1515 LT. According to the DABS, zones R-8 and R-8A are active during this period. Answer using the DABS map below and the ICAO aeronautical chart 1:500,000 Switzerland. Which of these answers is correct? ^t30q88

DE · FR

![](figures/t30_q88.png)

Answer

C)

Explanation

The correct answer is C because when restricted zones LS-R8 and LS-R8A are active, they cover the planned alpine route between Munster and Amsteg, making it impossible to fly through them. Restricted zones with "entry prohibited" status cannot be transited, regardless of altitude or radio contact.

Key Terms

DE · FR

Answer

A)

Explanation

The correct answer is A because to transit the Zurich TMA, the pilot must make first radio contact on frequency 124.7 MHz (Zurich Information) at least 10 minutes before entering the controlled airspace. This provides ATC sufficient time to assess traffic, issue a clearance or alternative instructions, and ensure separation.

Key Terms

DE · FR

Answer

A)

Explanation

The correct answer is A because in a turn, the stall speed increases by the square root of the load factor: Vsturn = Vsstraight x sqrt(n). With n = 2.0: Vs_turn = 60 x sqrt(2) = 60 x 1.414 = 84.85 kts. The increase is (84.85 - 60) / 60 x 100 = 41.4%, which rounds to approximately 40%.

Key Terms

n — Load Factor (ratio of lift to weight: n = L/W) ### Q91: The upper limit of LO R 16 equals ^t30q91

DE · FR

![](figures/t30_q91.png)

Answer

C)

Explanation

The correct answer is C. On the chart extract, LO R 16 shows "1500 ft" — this is the upper limit of the restricted area, measured in feet above mean sea level (MSL).

Reading restricted area labels on ICAO charts: the number in the pink/red zone is the upper limit. "1500" with no prefix means feet. "MSL" or "AMSL" means above mean sea level (a fixed altitude). "GND" would mean above ground level (varies with terrain).

Key Terms

FL = Flight Level; MSL = Mean Sea Level; GND = Ground (above ground level)

Q92: The upper limit of LO R 4 equals ^t30q92

DE · FR

![](figures/t30_q92.png)

Answer

B)

Explanation

The correct answer is B because LO R 4 has its upper limit at 4,500 ft MSL, a fixed altitude above mean sea level.

Key Terms

AGL = Above Ground Level; MSL = Mean Sea Level

Q93: Up to which altitude is an overflight prohibited according to the NOTAM? ^t30q93

DE · FR

![](figures/t30_q93.png)

Answer

B)

Explanation

The correct answer is B because the NOTAM prohibits overflight up to an altitude of 9,500 ft MSL, following ICAO convention where "altitude" refers to height above mean sea level.

Key Terms

AGL = Above Ground Level; FL = Flight Level; ICAO = International Civil Aviation Organization; MSL = Mean Sea Level; NOTAM = Notice to Air Missions; VFR = Visual Flight Rules

Q94: According ICAO, what symbol indicates a group of unlighted obstacles? ^t30q94

DE · FR

![](figures/t30_q94.png)

Answer

B)

Explanation

The correct answer is B (symbol C in the annex) because ICAO aeronautical chart symbology (defined in ICAO Annex 4) uses specific symbols to distinguish between single and grouped obstacles, and between lighted and unlighted ones. Symbol C represents a group of unlighted obstacles. Correct identification of these symbols is essential for cross-country flight planning and obstacle avoidance.

Key Terms

ICAO = International Civil Aviation Organization ### Q95: According ICAO, what symbol indicates a civil airport (not international airport) with paved runway? ^t30q95

DE · FR

![](figures/t30_q95.png)

Answer

B)

Explanation

The correct answer is B (symbol A in the annex) because ICAO chart symbology uses distinct depictions for different aerodrome types — civil versus military, international versus domestic, and paved versus unpaved. Symbol A represents a civil (non-international) airport with a paved runway. Glider pilots must recognise these symbols when identifying potential emergency landing options.

Key Terms

ICAO = International Civil Aviation Organization ### Q96: According ICAO, what symbol indicates a general spot elevation? ^t30q96

DE · FR

![](figures/t30_q96.png)

Answer

D)

Explanation

The correct answer is D (symbol C in the figure) because on ICAO aeronautical charts, a general spot elevation is indicated by a specific symbol showing a terrain point of known height, used for situational awareness and terrain clearance planning.

Key Terms

ICAO = International Civil Aviation Organization ### Q97: The term center of gravity is defined as ^t30q97

DE · FR

Answer

A)

Explanation

The correct answer is A. The center of gravity is the single point through which the resultant of all gravitational forces acts on the aircraft — it is the mass-weighted average position of all components.

Q98: The term moment with regard to a mass and balance calculation is referred to as ^t30q98

DE · FR

Answer

B)

Explanation

The correct answer is B because in mass-and-balance calculations, moment is defined as the product of mass and balance arm: Moment = Mass x Arm (e.g., in kg-m or lb-in). This follows the physical definition of a torque. The total C.G. is found by summing all moments and dividing by total mass.

Key Terms

D — Drag ### Q99: The term balance arm in the context of a mass and balance calculation defines the ^t30q99

DE · FR

Answer

C)

Explanation

The correct answer is C because the balance arm (moment arm) is the horizontal distance measured from the aircraft's datum reference point to the center of gravity of a specific mass item.

Q100: Which is the purpose of interception lines in visual navigation? ^t30q100

DE · FR

Answer

D)

Explanation

The correct answer is D because interception lines (also called catching lines or line features) are prominent linear ground features — motorways, rivers, coastlines, railways — that a pilot selects during pre-flight planning to navigate toward if orientation is lost. By flying toward a known interception line, the pilot can re-establish position and resume navigation.

Key Terms

VFR = Visual Flight Rules

Q101: You want to fly a glider over the Dittigen area. Who can activate this zone? ^t30q101

DE · FR

![](figures/t30q101.png)

Answer

C)

Explanation

The correct answer is C because local glider zones are managed by the responsible flight service officer of the relevant aerodrome. It is that person who activates and deactivates the zone in coordination with local authorities according to operational requirements. The pilot, Zurich ATC, or FOCA do not hold the role of local activation.

Q102: You are planning a cross-country triangle flight Schänis-Kloster-Klausenpass-Schänis. What is the total distance of this flight? ^t30q102

DE · FR

![](figures/t30q102.png)

Answer

D)

Explanation

The correct answer is D because, on a 1:300 000 scale map: - Schänis - Kloster: 24 cm × 300 000 = 72 km - Kloster - Klausenpass: 26 cm × 300 000 = 78 km - Klausenpass - Schänis: 12 cm × 300 000 = 36 km - Total: 72 + 78 + 36 = 186 km

The result in nautical miles would be different; 62 km only covers approximately one leg, and 310 km would indicate a scale calculation error.

Q103: You are flying from Gruyère to Sion via the Sanetsch Pass. At what altitude is this pass located? ^t30q103

DE · FR

![](figures/t30q103.png)

Answer

C)

Explanation

The ICAO chart shows 7388 ft next to the Sanetsch Pass. Since ICAO charts express altitudes in feet, you must convert: 7388 × 0.3048 ≈ 2252 m AMSL (option C).

Q104: What category of aerodrome is Les Eplatures? ^t30q104

DE · FR

![](figures/t30q104.png)

Answer

A)

Explanation

The correct answer is A because Les Eplatures (LSGC), located near La Chaux-de-Fonds, is a regional airport open to public traffic. Its status is indicated on the ICAO chart by the civil aerodrome symbol with a paved runway. It has a flight information service and is accessible to commercial and private flights according to applicable procedures.

Q105: Up to what altitude is safety-relevant aeronautical information shown on the gliding map? ^t30q105

DE · FR

Answer

C)

Explanation

The correct answer is C because the folded front page of the Swiss gliding map specifies that aeronautical safety information (airspaces, restrictions, obstacles) is depicted up to 5950 m AMSL. Above this limit, the glider is beyond the practical Swiss gliding airspace, and other publications (AIP, special charts) would be required.

Q106: What information must always be noted on the navigation chart for a cross-country flight? ^t30q106

DE · FR

Answer

A)

Explanation

The correct answer is A because for a cross-country flight, the true track (TT) is first drawn directly on the chart, measured relative to true north. This TT is the basis for all navigation planning: it is then corrected for magnetic variation to obtain the magnetic heading, then for deviation to obtain the compass heading. Without the TT noted on the chart, subsequent corrections cannot be made.

Q107: What is the flight distance between Schänis and the Arlberg Pass? ^t30q107

DE · FR

![](figures/t30q107.png)

Answer

C)

Explanation

The correct answer is C because on a 1:300 000 scale map, the measured distance between Schänis and the Arlberg Pass is 29.5 cm. The conversion gives: 29.5 cm × 300 000 = 8 850 000 cm = 88.5 km. Option D is wrong because 88.5 nm would represent approximately 164 km, which is far too large.

Q108: You are flying at the height of the Uri-Rotstock toward Amlikon. The sink rate is 0.6 m/s at 125 km/h. At what altitude do you reach Amlikon? ^t30q108

DE · FR

![](figures/t30q108.png)

Answer

A)

Explanation

The correct answer is A because: - Altitude Uri-Rotstock: 2928 m AMSL - Distance Uri-Rotstock - Amlikon: 29.5 cm × 3 km/cm = 88 km (1:300 000 map) - Flight time: t = 88 km / 125 km/h = 0.70 h = 2530 s - Altitude loss: 0.6 m/s × 2530 s = 1520 m - Arrival altitude: 2928 m - 1520 m = 1408 m ≈ 1400 m AMSL

Q109: What is the meaning of the green dotted line passing above Montreux and north of Thun? ^t30q109

DE · FR

![](figures/t30q109.png)

Answer

B)

Explanation

The correct answer is B because the green dotted line on the Swiss gliding map marks the conventional boundary between the thermal and topographic regions of the Plateau/Jura on one side and the Alps on the other. This distinction is important for planning: soaring conditions, airspaces, and instrument cloud-flying rules differ significantly on either side of this line.

Q110: What should a glider pilot do regarding speed when severe turbulence occurs in flight? ^t30q110

DE · FR

Answer

A)

Explanation

The correct answer is A because in severe turbulence, the pilot must maintain speed within the green arc (normal operating range). The green arc corresponds to the normal operating speed range for which the structure is certified even during turbulence. Flying in the yellow arc (caution range) is prohibited in turbulent air; extending spoilers would change the polar and could be hazardous.

Q111: What does the glide ratio of a glider signify? ^t30q111

DE · FR

Answer

D)

Explanation

The correct answer is D because the glide ratio (L/D ratio) is defined as the ratio between lift (L) and drag (D): L/D. It also directly indicates the horizontal distance covered per unit of altitude lost in unpowered gliding flight without wind. A glide ratio of 48 means the glider travels 48 m horizontally for every 1 m of descent.

![](figures/glideanglegeometry.png)

Glide ratio = d/h from the diagram — the horizontal distance per unit of height lost.

Q112: What does a glide ratio of 48 mean for a glider? ^t30q112

DE · FR

Answer

D)

Explanation

The correct answer is D because the glide ratio directly expresses the horizontal distance covered for each unit of altitude lost. A glide ratio of 48 means: for 1 km (1000 m) of available altitude, the glider can glide 48 km in calm air without thermals. This is the operational definition of glide ratio, used directly to calculate a glider's range during flight planning.

![](figures/glideanglegeometry.png)

A ratio of 48 means d = 48 × h, i.e. 48 m forward for every 1 m of height lost.

Q113: What can cause a shift of the center of gravity? ^t30q113

DE · FR

Answer

B)

Explanation

The correct answer is B because the center of gravity is the resultant of all masses and their positions (moment arms). If a load (baggage, water ballast, pilot) shifts forward or rearward, the sum of moments changes, which displaces the CG. The angle of incidence (A and C) has no effect on the CG. The center of pressure (D) may shift with angle of attack but does not displace the CG.

Q114: When loading a glider with an aft center of gravity at the AFM-approved limit, a takeoff cannot be made because... ^t30q114

DE · FR

Answer

D)

Explanation

The correct answer is D because with a CG at the extreme aft limit, longitudinal static stability is at its minimum. Any speed change or disturbance is no longer automatically compensated, the glider becomes difficult to control in pitch, and in the worst case can enter divergent oscillations or an uncontrollable stall/spin. The law prohibits exceeding the limit, but the actual physical reason is pitch instability.

Q115: In severe turbulence, at what speed should you fly? ^t30q115

DE · FR

Answer

C)

Explanation

The correct answer is C because the maneuvering speed V(A) is the maximum speed below which gusts and full control deflections will not overstress the structure: if an excessive load factor is generated, the wing will stall before being damaged. Above V(A), severe gusts can generate load factors exceeding structural limits. Flying below V(A) in turbulence is therefore the only safe procedure.

Q116: Above what speed can abrupt or full control inputs damage the glider's structure? ^t30q116

DE · FR

Answer

A)

Explanation

The correct answer is A because V(A), the maneuvering speed, is defined precisely as the maximum speed at which full control deflections cannot damage the structure: below V(A), a stall occurs before the structural load limits are exceeded. Above V(A), an abrupt or full control input can generate load factors that exceed the certified structural limits and cause damage.

Q117: What must be observed when loading water ballast? ^t30q117

DE · FR

Answer

B)

Explanation

The correct answer is B because water ballast is an additional mass placed at a specific moment arm (typically in the wings). Its addition shifts the CG. It is therefore necessary to verify, with the total mass and pilot position, that the resulting CG remains within the forward and aft limits stated in the flight manual (AFM). Exceeding the aft limit would make the glider unstable; exceeding the forward limit would overload elevator authority on landing.

Q118: What is meant by the takeoff mass of a glider? ^t30q118

DE · FR

Answer

A)

Explanation

The correct answer is A because the takeoff mass (maximum takeoff mass, MTOM) is the sum of all masses at the moment of takeoff: empty airframe + pilot + water ballast + any onboard equipment. This is the value that must not exceed the certified limit stated in the AFM. Option C is wrong: water ballast is included in the takeoff mass.

Q119: Your glider has a glide ratio of 1:45. What distance can you cover while maintaining a height reserve of 500 m if you are at 3200 m? ^t30q119

DE · FR

Answer

D)

Explanation

The correct answer is D because: - Usable altitude: 3200 m - 500 m (reserve) = 2700 m - Distance = glide ratio × altitude = 45 × 2700 m = 121 500 m = 121.5 km

Option A (270 km) would correspond to a glide ratio of 100, far too high. Option B (60 km) ignores the glide ratio. Option C (12.1 km) is a factor of 10 too small.

Q120: You are flying from the Säntis toward Amlikon at best glide speed of 110 km/h. At what time do you reach Amlikon if you fly over the Säntis at 17:45? ^t30q120

DE · FR

![](figures/t30q120.png)

Answer

C)

Explanation

The correct answer is C because: - Distance Säntis - Amlikon: 14 cm × 300 000 = 42 km (1:300 000 map) - Flight time: t = 42 km / 110 km/h = 0.382 h × 60 min/h ≈ 23 min - Arrival time: 17:45 + 23 min = 18:08

Q121: At 17:21 you fly from the Rigi toward Birrfeld. You reach Birrfeld at 17:42. The distance measured on the chart is 15.5 cm. What was your ground speed? ^t30q121

DE · FR

![](figures/t30q121.png)

Answer

A)

Explanation

The correct answer is A because: - Distance Rigi - Birrfeld: d = 15.5 cm × 300 000 = 4 650 000 cm = 46.5 km (measured on 1:300 000 map) - Flight time: t = 17:42 − 17:21 = 21 min = 0.35 h - Ground speed: v = d / t = 46.5 km / 0.35 h ≈ 133 km/h ≈ 130 km/h

Q122: On a return flight from Samedan toward Schänis in very calm air, with a constant sink rate of 0.9 m/s and a glide speed of 125 km/h, at what altitude do you reach Schänis? (Altitude at Samedan: 4150 m) ^t30q122

DE · FR

![](figures/t30q122.png)

Answer

B)

Explanation

The correct answer is B because: - Distance Samedan - Schänis: 32 cm × 3 km/cm = 96 km (1:300 000 map) - Flight time: t = 96 km / 125 km/h = 0.768 h × 3600 s/h = 2765 s - Altitude loss: 0.9 m/s × 2765 s = 2488 m - Arrival altitude: 4150 m - 2488 m ≈ 1662 m ≈ 1666 m

Q123: In which publication can you find information about military firing activities? ^t30q123

DE · FR

Answer

B)

Explanation

The correct answer is B because KOSIF (Koordinationsstelle fur flugbeschränkende Massnahmen der Armee) is the official Swiss publication listing military activities (artillery firing, exercises) that may temporarily restrict or prohibit airspace. GAFOR is a visual flight forecast for Alpine passes, SIGMET concerns dangerous meteorological phenomena, and GAMET is a low-altitude meteorological forecast.

Q124: Where do you find detailed information about Swiss aerodromes? ^t30q124

DE · FR

Answer

C)

Explanation

The correct answer is C because the Swiss VFR manual (AIP VFR Switzerland), in its MAP chapter (aerodrome charts), contains detailed information about each aerodrome: frequencies, procedures, runway lengths, available services, opening hours, etc. The ICAO chart provides an overview but not operational details. The air traffic manual and aviation law cover other aspects.

Q125: What important information should be noted on a chart for the safe completion of a flight in the Alps? ^t30q125

DE · FR

Answer

C)

Explanation

The correct answer is C because for an alpine glider flight, the two key pieces of information to plot on the chart are: 1. The distance circle (range circle): shows how far the glider can reach from its current position with the available height, taking the glide ratio into account. 2. Field landing sites: identifies emergency landing fields available along the route, essential in the mountains where diversion options are scarce.

The glide angle (A) is calculated but not plotted on the chart; GPS coordinates (B) are useful but not essential for basic safety; thermal zones (D) are relevant but secondary compared to emergency information.

Q126: Where do you find information on the boundary between day and night? ^t30q126

DE · FR

Answer

C)

Explanation

The correct answer is C because the Swiss VFR guide (AIP VFR Switzerland) contains tables of sunrise and sunset times, as well as legal definitions of the boundaries between aeronautical day and night (civil twilight). This information is essential for complying with VFR night-flying restrictions. The ICAO chart does not contain these time-related data; aviation law defines the rules but not the specific times.