### Q1: Through which points does the Earth's rotational axis pass? ^t60q1
- A) The magnetic north pole and the magnetic south pole.
- B) The geographic North Pole and the geographic South Pole.
- C) The geographic North Pole and the magnetic south pole.
- D) The magnetic north pole and the geographic South Pole.

**Correct: B)**

> **Explanation:** The Earth's rotational axis is the imaginary line around which the planet spins, and it passes through the geographic (true) North and South Poles. These are fixed points defined by the axis of rotation itself. The magnetic poles (options A, C, D) are located at different positions, currently offset by several hundred kilometres from the geographic poles, and they drift over time due to changes in Earth's liquid iron core. Only the geographic poles are determined by the rotational axis.

### Q2: Which statement correctly describes the polar axis of the Earth? ^t60q2
- A) It passes through the magnetic south pole and the magnetic north pole and is perpendicular to the equatorial plane.
- B) It passes through the geographic South Pole and the geographic North Pole and is tilted 23.5° relative to the equatorial plane.
- C) It passes through the geographic South Pole and the geographic North Pole and is perpendicular to the equatorial plane.
- D) It passes through the magnetic south pole and the magnetic north pole and is tilted 66.5° relative to the equatorial plane.

**Correct: C)**

> **Explanation:** The polar axis passes through the geographic poles and is perpendicular (90°) to the equatorial plane by definition — the equator is the great circle that lies at right angles to the axis of rotation. Option B correctly identifies the geographic poles but incorrectly states the axis is tilted 23.5° to the equatorial plane; in fact, the 23.5° tilt is relative to the orbital plane (ecliptic), not the equatorial plane. Options A and D incorrectly reference the magnetic poles, which have no relationship to the rotational axis.

### Q3: For navigation systems, which approximate geometrical form best describes the shape of the Earth? ^t60q3
- A) A perfect sphere.
- B) A flat plate.
- C) An ellipsoid.
- D) A sphere of ecliptical shape.

**Correct: C)**

> **Explanation:** The Earth is slightly flattened at the poles and bulges at the equator due to its rotation, making it an oblate spheroid or ellipsoid. Modern navigation systems, including GPS, use the WGS-84 reference ellipsoid to model this shape accurately. A perfect sphere (A) ignores the equatorial bulge and would introduce positioning errors. A flat plate (B) is an antiquated model. "Sphere of ecliptical shape" (D) is not a recognised geometric term.

### Q4: Which of the following statements about a rhumb line is correct? ^t60q4
- A) The shortest track between two points along the Earth's surface follows a rhumb line.
- B) A rhumb line is a great circle that intersects the equator at a 45° angle.
- C) The centre of a complete cycle of a rhumb line is always the Earth's centre.
- D) A rhumb line crosses each meridian at an identical angle.

**Correct: D)**

> **Explanation:** A rhumb line (loxodrome) is defined as a line on the Earth's surface that crosses every meridian at the same constant angle. This property makes it useful for constant-heading navigation — a pilot or sailor can maintain a fixed compass bearing to follow a rhumb line. However, it is not the shortest path between two points (A) — that is the great circle route. A rhumb line is not a great circle (B) and it spirals toward the poles rather than having its centre at Earth's centre (C).

### Q5: The shortest distance between two points on the Earth's surface is a segment of… ^t60q5
- A) A small circle.
- B) A parallel of latitude.
- C) A great circle.
- D) A rhumb line.

**Correct: C)**

> **Explanation:** A great circle is any circle on Earth's surface whose centre coincides with Earth's centre, and its arc between two points represents the shortest possible surface distance (geodesic). Airlines plan long-haul routes along great circle tracks to minimise fuel burn and flight time. A rhumb line (D) is longer except when both points are on the equator or the same meridian. Parallels of latitude (B) are small circles (except the equator) and do not represent shortest paths. Small circles (A) by definition have a longer arc than the equivalent great circle segment.

### Q6: What is the approximate circumference of the Earth at the equator? See figure (NAV-002) ^t60q6
![Earth Globe](figures/NAV-002-earth-globe.svg)

- A) 40000 NM.
- B) 21600 NM.
- C) 10800 km.
- D) 12800 km.

**Correct: B)**

> **Explanation:** The equator is a great circle spanning 360° of longitude, and by definition 1° of arc on a great circle equals 60 NM (since 1 NM = 1 arcminute). Therefore: 360° x 60 NM = 21,600 NM. In kilometres, the equatorial circumference is approximately 40,075 km — option A has the right number but the wrong unit (NM vs km). Option C (10,800 km) is about half the actual circumference. Option D (12,800 km) approximates the Earth's diameter, not its circumference.

### Q7: What is the latitude difference between point A (12°53'30''N) and point B (07°34'30''S)? ^t60q7
- A) .20°28'00''
- B) .05°19'00''
- C) .05,19°
- D) .20,28°

**Correct: A)**

> **Explanation:** When two points lie on opposite sides of the equator, the latitude difference is the sum of their absolute latitudes. Adding: 12°53'30'' + 07°34'30'' = 19°87'60''. Converting: 60'' = 1', so 87' + 1' = 88' = 1°28'. Therefore: 19° + 1°28' = 20°28'00''. Options B and C give 5°19', which would be a subtraction (wrong when points are in opposite hemispheres). Option D gives the correct numerical value but in decimal format.

### Q8: At which latitudes are the two polar circles located? ^t60q8
- A) 23.5° north and south of the equator
- B) 20.5° south of the poles
- C) At a latitude of 20.5°S and 20.5°N
- D) 23.5° north and south of the poles

**Correct: D)**

> **Explanation:** The Arctic Circle (66.5°N) and Antarctic Circle (66.5°S) are each located 23.5° from their respective geographic poles (90° - 23.5° = 66.5°). This 23.5° offset corresponds to the axial tilt of the Earth, which determines the extent of the polar day and polar night. Option A (23.5° from the equator) describes the Tropics of Cancer and Capricorn, not the polar circles. Options B and C (20.5°) use an incorrect value that does not correspond to any standard geographic reference.

### Q9: Along a meridian line, what is the distance between the parallels of latitude 48°N and 49°N? ^t60q9
- A) 10 NM
- B) 1 NM
- C) 60 NM
- D) 111 NM

**Correct: C)**

> **Explanation:** Along any meridian, 1 degree of latitude always equals 60 NM, because meridians are great circles and 1 NM is defined as 1 arcminute of arc along a great circle. The difference between 48°N and 49°N is exactly 1° = 60 NM. Option D (111 NM) confuses nautical miles with kilometres — 1° of latitude equals approximately 111 km, not 111 NM. Option A (10 NM) and B (1 NM) are far too short.

### Q10: Along any degree of longitude, what distance corresponds to one degree of latitude? ^t60q10
- A) 1 NM
- B) 60 NM
- C) 30 NM
- D) 60 km

**Correct: B)**

> **Explanation:** One degree of latitude equals 60 NM along any meridian (line of longitude), because all meridians are great circles and the nautical mile is defined as 1 arcminute of arc on a great circle. This relationship is constant regardless of which meridian you measure along. Option A (1 NM) is off by a factor of 60. Option C (30 NM) is half the correct value. Option D (60 km) confuses the units — 60 NM equals approximately 111 km, not 60 km.

### Q11: Point A lies exactly on the parallel of latitude 47°50'27''N. Which point is located exactly 240 NM north of A? ^t60q11
- A) 51°50'27'N'
- B) 43°50'27''N
- C) 49°50'27''N
- D) 53°50'27''N

**Correct: A)**

> **Explanation:** Converting 240 NM to degrees of latitude: 240 NM / 60 NM per degree = 4°. Moving north (increasing latitude) by 4° from 47°50'27''N gives 51°50'27''N. Option B (43°50'27''N) would be 4° south, not north. Option C (49°50'27''N) represents only a 2° displacement (120 NM). Option D (53°50'27''N) represents a 6° displacement (360 NM).

### Q12: Along the equator, what is the distance between the two meridians 150°E and 151°E? ^t60q12
- A) 1 NM
- B) 60 NM
- C) 60 km
- D) 111 NM

**Correct: B)**

> **Explanation:** On the equator, 1° of longitude equals 60 NM because the equator is itself a great circle with the same properties as a meridian. The distance between adjacent meridians at 150°E and 151°E is therefore 60 NM. At higher latitudes this distance decreases proportionally to the cosine of the latitude, but on the equator it equals the full 60 NM per degree. Option C (60 km) confuses units. Option D (111 NM) confuses NM and km.

### Q13: On the equator, what is the great circle distance between two points A and B when their associated meridians differ by exactly one degree of longitude? ^t60q13
- A) 120 NM
- B) 60 NM
- C) 216 NM
- D) 400 NM

**Correct: B)**

> **Explanation:** The equator is a great circle, so two points on the equator separated by 1° of longitude are separated by exactly 60 NM of great circle distance (1° x 60 NM/degree). This is the same relationship as 1° of latitude along a meridian. Options A (120 NM), C (216 NM), and D (400 NM) all significantly overstate the distance and do not correspond to any standard navigation calculation for a 1° separation.

### Q14: Consider two points A and B on the same parallel of latitude, but not on the equator. Point A lies at 010°E and point B at 020°E. The rhumb line distance between A and B is always… ^t60q14
- A) More than 600 NM.
- B) Less than 300 NM.
- C) More than 300 NM.
- D) Less than 600 NM.

**Correct: D)**

> **Explanation:** On the same parallel of latitude, the rhumb line distance equals the longitude difference multiplied by 60 NM multiplied by the cosine of the latitude: 10° x 60 NM x cos(lat). On the equator (lat = 0°), cos(0°) = 1, giving exactly 600 NM. Since the points are explicitly not on the equator, cos(lat) is always less than 1, so the distance is always strictly less than 600 NM. It cannot be definitively said to be less than 300 NM (B) or more than 300 NM (C) without knowing the exact latitude.

### Q15: How much time does the sun need to traverse 20° of longitude? ^t60q15
- A) 0:20 h
- B) 0:40 h
- C) 1:20 h
- D) 1:00 h

**Correct: C)**

> **Explanation:** The Earth rotates 360° in 24 hours, which equals 15° per hour or 1° every 4 minutes. For 20° of longitude: 20° x 4 minutes = 80 minutes = 1 hour and 20 minutes (1:20 h). Option A (20 minutes) assumes 1° per minute, which is incorrect. Option B (40 minutes) would correspond to 10° of longitude. Option D (1 hour) would correspond to 15° of longitude.

### Q16: When the sun traverses 10° of longitude, what is the resulting time difference? ^t60q16
- A) 0:30 h
- B) 0:04 h
- C) 1:00 h
- D) 0:40 h

**Correct: D)**

> **Explanation:** Using the standard relationship of 15° per hour (or 4 minutes per degree): 10° x 4 minutes/degree = 40 minutes = 0:40 h. Option B (4 minutes) is the time for just 1° of longitude. Option A (30 minutes) would correspond to 7.5°. Option C (1 hour) would correspond to 15°.

### Q17: The sun covers 10° of longitude. What is the corresponding time difference? ^t60q17
- A) 0.33 h
- B) 1 h
- C) 0.66 h
- D) 0.4 h

**Correct: C)**

> **Explanation:** This is the same calculation as Q16 but expressed in decimal hours: 10° / 15° per hour = 0.6667 h, which rounds to 0.66 h (equivalent to 40 minutes). Option A (0.33 h = 20 min) would correspond to 5°. Option B (1 h) corresponds to 15°. Option D (0.4 h = 24 min) corresponds to 6° of longitude, not 10°.

### Q18: If Central European Summer Time (CEST) is UTC+2, what is 1600 CEST expressed in UTC? ^t60q18
- A) 1500 UTC.
- B) 1400 UTC.
- C) 1700 UTC.
- D) 1600 UTC.

**Correct: B)**

> **Explanation:** CEST is 2 hours ahead of UTC, so to convert from CEST to UTC, subtract 2 hours: 1600 - 0200 = 1400 UTC. In aviation, all times in flight plans, ATC communications, METARs, and NOTAMs are expressed in UTC to avoid time zone confusion. Option A subtracts only 1 hour (CET conversion). Option C adds instead of subtracts. Option D assumes no time difference.

### Q19: UTC is described as… ^t60q19
- A) A local time used in Central Europe.
- B) A zonal time.
- C) An obligatory time reference used in aviation.
- D) Local mean time at a specific point on Earth.

**Correct: C)**

> **Explanation:** Coordinated Universal Time (UTC) is the mandatory time standard for all international aviation — flight plans, radio communications, weather reports, and NOTAMs worldwide use UTC to ensure a single unambiguous time reference. It is not a local time (A) — it applies globally. It is not a zonal time (B) — zonal times are local time zones. It is not the local mean time of any specific location (D), though it closely approximates Greenwich Mean Time (GMT).

### Q20: With Central European Time (CET) defined as UTC+1, what UTC time corresponds to 1700 CET? ^t60q20
- A) 1800 UTC.
- B) 1500 UTC.
- C) 1700 UTC.
- D) 1600 UTC.

**Correct: D)**

> **Explanation:** CET is UTC+1, meaning CET is 1 hour ahead of UTC. To convert from CET to UTC, subtract 1 hour: 1700 - 0100 = 1600 UTC. Switzerland uses CET in winter and CEST (UTC+2) in summer. Option A (1800) adds instead of subtracting. Option B (1500) subtracts 2 hours (the CEST offset). Option C (1700) applies no conversion.

### Q21: Vienna (LOWW) is at 016°34'E and Salzburg (LOWS) at 013°00'E. Assuming both lie at the same latitude, what is the difference in UTC sunrise and sunset times between Vienna and Salzburg? (2,00 P.) ^t60q21
- A) In Vienna the sunrise is 4 minutes later and sunset is 4 minutes earlier than in Salzburg
- B) In Vienna the sunrise is 14 minutes earlier and sunset is 14 minutes later than in Salzburg
- C) In Vienna the sunrise and sunset are about 4 minutes later than in Salzburg
- D) In Vienna the sunrise and sunset are about 14 minutes earlier than in Salzburg

**Correct: D)**

> **Explanation:** The longitude difference is 016°34' - 013°00' = 3°34' = 3.567°. At 4 minutes per degree: 3.567 x 4 = 14.3 minutes, approximately 14 minutes. Vienna is east of Salzburg, so the sun reaches Vienna first — both sunrise and sunset occur about 14 minutes earlier in UTC at Vienna. Both events shift equally because they are on the same latitude. Options A and C give 4 minutes, which corresponds to only 1° of longitude, not the 3.5° actual difference.

### Q22: How is the term 'civil twilight' defined? ^t60q22
- A) The interval before sunrise or after sunset when the sun's centre is 12 degrees or less below the apparent horizon.
- B) The interval before sunrise or after sunset when the sun's centre is 12 degrees or less below the true horizon.
- C) The interval before sunrise or after sunset when the sun's centre is 6 degrees or less below the true horizon.
- D) The interval before sunrise or after sunset when the sun's centre is 6 degrees or less below the apparent horizon.

**Correct: C)**

> **Explanation:** Civil twilight is formally defined as the period when the sun's geometric centre is between 0° and 6° below the true (geometric) horizon — during this time there is sufficient natural light for outdoor activities without artificial illumination. The true horizon is used in the definition, not the apparent horizon (which is affected by atmospheric refraction). Options A and B use 12°, which defines nautical twilight. Option D uses the apparent rather than the true horizon. In aviation, civil twilight often defines the boundary between day and night VFR operations.

### Q23: Given: WCA: -012°; TH: 125°; MC: 139°; DEV: 002°E. Determine TC, MH and CH. (2,00 P.) ^t60q23
- A) TC: 137°. MH: 127°. CH: 125°.
- B) TC: 113°. MH: 127°. CH: 129°.
- C) TC: 137°. MH: 139°. CH: 125°.
- D) TC: 113°. MH: 139°. CH: 129°.

**Correct: A)**

> **Explanation:** Working through the heading chain: TC = TH - WCA = 125° - (-12°) = 137°. Next, from MC and TC: VAR = TC - MC = 137° - 139° = -2° (2°W). MH = TH - VAR (applying variation to heading): since VAR is 2°W, MH = TH + VAR(W) = 125° + 2° = 127°. Finally, CH = MH - DEV(E) = 127° - 2° = 125°. Options B and D give TC = 113°, which would result from adding WCA instead of subtracting it.

### Q24: Given: TC: 179°; WCA: -12°; VAR: 004° E; DEV: +002°. Determine MH and MC. ^t60q24
- A) MH: 163°. MC: 161°.
- B) MH: 167°. MC: 175°.
- C) MH: 163°. MC: 175°.
- D) MH: 167°. MC: 161°

**Correct: C)**

> **Explanation:** First, TH = TC + WCA = 179° + (-12°) = 167°. Then MH = TH - VAR(E) = 167° - 4° = 163° (East variation is subtracted: "East is least"). For MC: MC = TC - VAR(E) = 179° - 4° = 175°. Option A has MH correct but MC wrong. Option B has the wrong MH (not applying WCA). Option D has correct TH calculation but applies variation incorrectly for MC.

### Q25: What is the name of the angle between the true course and the true heading? ^t60q25
- A) Variation.
- B) WCA.
- C) Deviation.
- D) Inclination.

**Correct: B)**

> **Explanation:** The Wind Correction Angle (WCA) is the angular difference between the true course (the desired ground track) and the true heading (the direction the aircraft's nose actually points). A crosswind requires the pilot to "crab" into the wind, creating this difference. Variation (A) is the angle between true north and magnetic north. Deviation (C) is the error between magnetic north and compass north caused by aircraft magnetic interference. Inclination (D) refers to the angle of the Earth's magnetic field lines with the horizontal.

### Q26: The angle between the magnetic course and the true course is known as… ^t60q26
- A) Deviation.
- B) WCA.
- C) Inclination.
- D) Variation.

**Correct: D)**

> **Explanation:** Magnetic variation (also called declination) is the angular difference between true north and magnetic north at any given location, which creates a corresponding angular difference between the true course and the magnetic course. Variation changes with geographic position and over time as the magnetic poles drift. Deviation (A) is the aircraft-specific compass error. WCA (B) is the wind correction angle between course and heading. Inclination (C) is the vertical dip angle of Earth's magnetic field lines.

### Q27: How is the term 'magnetic course' (MC) defined? ^t60q27
- A) The angle between true north and the course line.
- B) The angle between magnetic north and the course line.
- C) The direction from an arbitrary point on Earth to the geographic North Pole.
- D) The direction from an arbitrary point on Earth to the magnetic north pole.

**Correct: B)**

> **Explanation:** The magnetic course is the direction of the intended flight path (course line) measured clockwise from magnetic north. Since aircraft compasses indicate magnetic north, magnetic references are directly usable for navigation. Option A defines the true course (measured from true north). Option C defines the direction to the geographic pole (which is true north itself). Option D defines the direction to the magnetic pole (which is magnetic north itself, not the course).

### Q28: How is the term 'True Course' (TC) defined? ^t60q28
- A) The direction from an arbitrary point on Earth to the geographic North Pole.
- B) The angle between true north and the course line.
- C) The direction from an arbitrary point on Earth to the magnetic north pole.
- D) The angle between magnetic north and the course line.

**Correct: B)**

> **Explanation:** The True Course (TC) is the angle measured clockwise from true (geographic) north to the intended flight path (course line), as measured on an aeronautical chart oriented to true north. It is the starting point for all heading calculations. Option A describes true north itself, not the course angle. Option C describes the direction to the magnetic pole. Option D defines the magnetic course, not the true course.

### Q29: Given: TC: 183°; WCA: +011°; MH: 198°; CH: 200°. Determine TH and VAR. (2,00 P.) ^t60q29
- A) TH: 172°. VAR: 004° W
- B) TH: 194°. VAR: 004° E
- C) TH: 172°. VAR: 004° E
- D) TH: 194°. VAR: 004° W

**Correct: D)**

> **Explanation:** TH = TC + WCA = 183° + 11° = 194°. For variation: MH = TH + VAR (when going from true to magnetic with west variation, you add). MH 198° = TH 194° + VAR, so VAR = +4°, which is 4° West (West is Best — add to True to get Magnetic). Option B correctly calculates TH but assigns East variation, which would mean subtracting, giving MH = 190° (wrong). Options A and C incorrectly calculate TH as 172° (subtracting WCA instead of adding).

### Q30: Given: TC: 183°; WCA: +011°; MH: 198°; CH: 200°. Determine TH and DEV. (2,00 P.) ^t60q30
- A) TH: 172°. DEV: +002°.
- B) TH: 194°. DEV: +002°.
- C) TH: 194°. DEV: -002°.
- D) TH: 172°. DEV: -002°.

**Correct: C)**

> **Explanation:** TH = TC + WCA = 183° + 11° = 194°. For deviation: CH = 200° and MH = 198°, so the compass reads 2° more than the magnetic heading. Deviation is the correction from compass to magnetic: MH = CH + DEV, giving 198° = 200° + DEV, so DEV = -2°. A negative deviation means the compass reading is higher than the actual magnetic heading. Options A and D incorrectly calculate TH as 172°. Option B has DEV = +2°, which would give MH = 202°.