Magnetism & CompassesAir Navigation — DGCA CPL practice questions
Question 1 of 94
Compass deviation is caused by:
All 94 questions — Magnetism & Compasses
Air Navigation · DGCA CPL. The correct option is marked on each.
Q1. Compass deviation is caused by:
- A.The difference between Magnetic and Geographic poles
- B.Magnetic fields produced by aircraft electrical and ferrous components✓
- C.Precession of the compass needle
- D.Atmospheric magnetic interference
Why: Deviation results from the aircraft's own magnetic fields (electrical systems, ferrous metals) deflecting the compass needle away from magnetic north.
Q2. Lines on a chart connecting places of equal magnetic variation are called:
- A.Isobars
- B.Isogonals✓
- C.Isogrives
- D.Isoclines
Why: Isogonals (isogonic lines) connect points of equal magnetic variation. The agonic line connects points of zero variation.
Q3. A direct-reading magnetic compass turning through NORTH in the Northern Hemisphere will:
- A.Read accurately
- B.Lag — turn slower than the aircraft
- C.Lead — appear to turn faster than the aircraft✓
- D.Oscillate randomly
Why: Northerly turning error: when turning through North in the NH, the compass leads (over-reads the turn). Through South it lags. Use the mnemonic UNOS (Undershoot North, Overshoot South).
Q4. Acceleration error in a direct-reading compass is most pronounced when the aircraft is on a heading of:
- A.000° or 180°
- B.090° or 270°✓
- C.045° or 225°
- D.135° or 315°
Why: Acceleration/deceleration errors are maximum on East/West headings (090°/270°) because inertia causes the compass card to swing fore and aft, creating a false indication.
Q5. Magnetic dip (inclination) is maximum at:
- A.The equator
- B.30° latitude
- C.60° latitude
- D.The magnetic poles✓
Why: Magnetic dip is the angle between the Earth's magnetic field lines and the horizontal. It is 0° at the magnetic equator and 90° (vertical) at the magnetic poles.
Q6. Magnetic heading 270°, deviation 3°E. Compass heading is:
- A.267°✓
- B.270°
- C.273°
- D.264°
Why: East deviation is subtracted when converting MH to CH: CH = MH − East dev = 270° − 3° = 267°. (CDMVT reversed for MH→CH).
Q7. The annual change of magnetic variation is typically:
- A.Several degrees per year globally uniform
- B.A few arcminutes to a fraction of a degree per year✓
- C.Exactly 1° per decade
- D.Not predictable
Why: Annual change in magnetic variation is small — typically a few arcminutes per year (printed on charts). Aeronautical charts are updated periodically to reflect current variation.
Q8. A 'compass swing' is carried out to determine:
- A.Variation
- B.Deviation✓
- C.Dip angle
- D.Magnetic intensity
Why: A compass swing is a calibration procedure that measures and records the deviation on each heading, producing a deviation card installed in the cockpit.
Q9. The formula CDMVT represents:
- A.Chart, Direction, Magnetic, Variation, True
- B.Compass, Deviation, Magnetic, Variation, True✓
- C.Course, Deviation, Magnetic, Vector, True
- D.Compass, Drift, Magnetic, Vector, True
Why: CDMVT = Compass + Deviation = Magnetic + Variation = True. Apply East errors by subtraction going left-to-right; West errors by addition.
Q10. The sensitivity of a direct reading magnetic compass is:
- A.Inversely proportional to the horizontal component of the Earth's magnetic field
- B.Proportional to the horizontal component of the Earth's magnetic field✓
- C.Inversely proportional to the vertical component of the Earth's magnetic field
- D.Inversely proportional to both the vertical and horizontal components
Why: Compass sensitivity depends on the horizontal component H of the Earth's field. A stronger H means a stronger directive force aligning the compass needle — greater sensitivity.
Q11. What is the definition of magnetic variation?
- A.The angle between the direction indicated by a compass and Magnetic North
- B.The angle between True North and Compass North
- C.The angle between Magnetic North and True North✓
- D.The angle between Magnetic Heading and Magnetic North
Why: Variation is the angle at a point between True North and the direction of the Earth's magnetic field (Magnetic North). It is named East or West depending on whether Magnetic North lies east or west of True North.
Q12. At the magnetic equator:
- A.Dip is zero✓
- B.Variation is zero
- C.Deviation is zero
- D.The isogonal is an agonic line
Why: The magnetic equator (also called the aclinic line) is defined as the line joining all points of zero magnetic dip. Variation and deviation may still have non-zero values at the magnetic equator.
Q13. Which of these is a correct statement about the Earth's magnetic field?
- A.It acts as though there is a large blue magnetic pole in Northern Canada✓
- B.The angle of dip is the angle between the vertical and the total magnetic force
- C.It may be temporary, transient, or permanent
- D.It has no effect on aircraft deviation
Why: The Earth's field behaves as if a large bar magnet were embedded in the Earth, with the blue (south-seeking) end of this imaginary magnet located near the geographic North Pole region (Northern Canada). Blue poles attract the red (north-seeking) end of compass needles.
Q14. Where is a compass most effective?
- A.About midway between the Earth's magnetic poles✓
- B.In the region of the magnetic South Pole
- C.In the region of the magnetic North Pole
- D.On the geographic equator
Why: The compass is most effective where the horizontal component H of the Earth's field is largest — this is approximately midway between the magnetic poles, near the magnetic equator where the field is most horizontal.
Q15. The value of magnetic variation on a chart changes with time. This is due to:
- A.Movement of the magnetic poles, causing an increase
- B.Increase in the magnetic field, causing an increase
- C.Reduction in the magnetic field, causing a decrease
- D.Movement of the magnetic poles, which can cause either an increase or a decrease✓
Why: The magnetic poles move over time (secular variation). Depending on the direction of that movement relative to a given location, the local variation value can either increase or decrease.
Q16. The agonic line:
- A.Is midway between the magnetic North and South poles
- B.Follows the geographic equator
- C.Is the shorter distance between the respective True and Magnetic North and South poles
- D.Follows separate paths out of the North polar regions, one currently running through Western Europe and the other through the USA✓
Why: The agonic line is the isogonal (line of equal variation) where variation = 0. It does not follow a simple geometric path but snakes across the Earth, currently running in two main branches — one through the Americas and one through Europe.
Q17. What is the maximum possible value of dip angle?
- A.66°
- B.180°
- C.90°✓
- D.45°
Why: Magnetic dip is the angle between the horizontal and the Earth's total magnetic field. At the magnetic poles, the field is completely vertical, giving a dip of 90°. This is the maximum possible value.
Q18. What is the dip angle at the South Magnetic Pole?
- A.0°
- B.90°✓
- C.180°
- D.64°
Why: At a magnetic pole, the Earth's total magnetic field is directed vertically — straight into or out of the Earth. The dip angle is therefore 90° at either magnetic pole.
Q19. What is a line of equal magnetic variation?
- A.An isocline
- B.An isogonal✓
- C.An isogriv
- D.An isovar
Why: An isogonal is a line drawn on a chart joining all places of equal magnetic variation. The special case where variation = 0 is called the agonic line.
Q20. Isogonal lines converge at:
- A.The North Magnetic Pole only
- B.The North and South Magnetic and both Geographical Poles✓
- C.The North and South Magnetic Poles
- D.The Magnetic equator
Why: At both magnetic poles and both geographic poles. Variation is the angle between true north and magnetic north. At a magnetic pole the direction of magnetic north is undefined; at a geographic pole the direction of true north is undefined. In both cases every value of variation is found around the point, so the isogonals all meet there.
Q21. If variation is West, then:
- A.True North is West of Magnetic North
- B.Compass North is West of Magnetic North
- C.True North is East of Magnetic North✓
- D.Magnetic North is West of Compass North
Why: True North is East of Magnetic North. Variation is named East or West according to whether Magnetic North lies to the East or West of True North. With West variation, Magnetic North lies to the west of True North, so True North lies to the east of Magnetic North. Magnetic direction is then greater than true: variation west, magnetic best.
Q22. European regulations (CS OPS-1) state that the maximum permissible residual deviation after compensation for the Direct Reading Compass is:
- A.10 degrees✓
- B.3 degrees
- C.1 degree
- D.2 degrees
Why: Under CS OPS-1 (European aviation regulations), the direct reading magnetic compass must be within ±10° after compensation on any heading. This is the accuracy limit for the standby compass.
Q23. The aim of a compass swing is:
- A.Only to find deviation on the cardinal headings and calculate coefficients
- B.Only to record residual deviation and prepare a compass correction card
- C.To find deviation, eliminate or reduce coefficients, and record residual deviation✓
- D.None of the above
Why: A compass swing has three aims: (1) observe deviation and calculate coefficients A, B, C; (2) correct/reduce those coefficients; and (3) record residual deviation on a deviation card for use by the pilot.
Q24. Aircraft magnetism caused by vertical soft iron (VSI):
- A.Varies with magnetic heading but not with magnetic latitude
- B.Varies with magnetic latitude but not with heading✓
- C.Is not affected by magnetic latitude or heading
- D.Varies as the cosine of the compass heading
Why: VSI magnetism is induced by the vertical component Z of the Earth's field. Z varies with magnetic latitude (zero at the equator, maximum at the poles) but is constant for a given latitude regardless of heading.
Q25. Deviation due to coefficient A is mainly caused by:
- A.Hard iron force acting along the longitudinal axis
- B.Hard and soft iron forces acting along the lateral axis
- C.Vertical soft iron forces
- D.A misaligned lubber line✓
Why: Coefficient A represents a constant deviation on all headings, and is mainly caused by a mechanical misalignment of the lubber line relative to the fore-aft axis of the aircraft. It is corrected by rotating the compass body.
Q26. What is a line of equal grivation called?
- A.An isocline
- B.An isogonal
- C.An isogriv✓
- D.An isovar
Why: An isogriv is a line on a chart joining all positions of equal grivation (the algebraic sum of variation and grid convergence). Isogrivs are plotted on gridded navigation charts.
Q27. What is the value of magnetic dip at the South Magnetic Pole?
- A.360°
- B.180°
- C.090°✓
- D.0°
Q28. Isogonic lines connect positions that have:
- A.the same variation✓
- B.0° variation
- C.the same elevation
- D.the same angle of magnetic dip
Q29. At a specific location, the value of magnetic variation:
- A.depends on the true heading
- B.depends on the type of compass installed
- C.depends on the magnetic heading
- D.varies slowly over time✓
Q30. The horizontal component of the earth's magnetic field:
- A.is approximately the same at all magnetic latitudes less than 60°
- B.weakens with increasing distance from the magnetic poles
- C.weakens with increasing distance from the nearer magnetic pole
- D.is approximately the same at magnetic latitudes 50°N and 50°S✓
Q31. Isogonals converge at the:
- A.Magnetic equator
- B.North and South geographic and magnetic poles✓
- C.North magnetic pole only
- D.North and South magnetic poles only
Q32. Complete the following statement regarding magnetic variation. The charted values of magnetic variation on earth normally change annually due to:
- A.a reducing field strength causing numerical values at all locations to decrease
- B.magnetic pole movement causing numerical values at all locations to increase
- C.magnetic pole movement causing numerical values at all locations to increase or decrease✓
- D.an increasing field strength causing numerical values at all locations to increase
Q33. When turning right from 330° (C) to 040° (C) in the northern hemisphere, the reading of a direct reading magnetic compass will:
- A.over-indicate the turn and liquid swirl will decrease the effect
- B.under-indicate the turn and liquid swirl will increase the effect✓
- C.under-indicate the turn and liquid swirl will decrease the effect
- D.over-indicate the turn and liquid swirl will increase the effect
Q34. A negative (westerly) magnetic variation signifies that:
- A.True North is East of Magnetic North✓
- B.True North is West of Magnetic North
- C.Compass North is East of Magnetic North
- D.Compass North is West of Magnetic North
Q35. An aircraft is over position HO (55o30N 060o15W), where YYR VOR (53o30N 060o15W) can be received. The magnetic variation is 31°W at HO and 28°W at YYR. What is the radial from YYR?
- A.031°
- B.208°
- C.028°✓
- D.332°
Q36. A line drawn on a chart which joins all points where the value of magnetic variation is zero is called an:
- A.isogonal
- B.aclinic line
- C.agonic line✓
- D.isotach
Q37. The angle between True North and Magnetic North is called:
- A.compass error
- B.deviation
- C.variation✓
- D.drift
Q38. Given: True track is 348° Drift 17° left Variation 32°W Deviation 4°E What is the compass heading?
- A.007°
- B.033°✓
- C.359°
- D.337°
Q39. Which of the following statements concerning earth magnetism is completely correct?
- A.An isogonal is a line which connects places with the same magnetic variation; the agonic line is the line of zero magnetic dip
- B.An isogonal is a line which connects places with the same magnetic variation; the aclinic is the line of zero magnetic dip✓
- C.An isogonal is a line which connects places of equal dip; the aclinic is the line of zero magnetic dip
- D.An isogonal is a line which connects places with the same magnetic variation; the aclinic connects places with the same magnetic field strength
Q40. An Agonic line is a line that connects:
- A.positions that have the same variation
- B.positions that have 0° variation✓
- C.points of equal magnetic dip
- D.points of equal magnetic horizontal field strength
Q41. The Earth can be considered as being a magnet with the:
- A.blue pole near the north pole of the earth and the direction of the magnetic force pointing straight up from the earth's surface
- B.red pole near the north pole of the earth and the direction of the magnetic force pointing straight down to the earth's surface
- C.blue pole near the north pole of the earth and the direction of the magnetic force pointing straight down to the earth's surface✓
- D.red pole near the north pole of the earth and the direction of the magnetic force pointing straight up from the earth's surface
Q42. When is the magnetic compass most effective?
- A.In the region of the magnetic South Pole
- B.About midway between the magnetic poles✓
- C.In the region of the magnetic North Pole
- D.On the geographic equator
Q43. The value of magnetic variation:
- A.varies between maximum values of 45°E and 45°W
- B.is a maximum of 180°✓
- C.is always 0° at the magnetic equator
- D.is never greater than 90°
Q44. A magnetic compass will be most effective at:
- A.a position roughly half way between the magnetic poles✓
- B.the South Magnetic Pole
- C.the North Magnetic Pole
- D.the Equator
Q45. When accelerating on a westerly heading in the northern hemisphere, the compass card of a direct reading magnetic compass will turn:
- A.clockwise giving an apparent turn towards the north
- B.clockwise giving an apparent turn towards the south
- C.anti-clockwise giving an apparent turn towards the north✓
- D.anti-clockwise giving an apparent turn towards the south
Q46. When a magnetized compass needle is freely suspended in the Earth's magnetic field, when free from extraneous magnetic influence, it will align itself with:
- A.true North
- B.magnetic North✓
- C.absolute North
- D.relative North
Q47. When is Magnetic North Pole is East of the True North Pole variation is:
- A.+ and easterly✓
- B.- and easterly
- C.- and westerly
- D.+ and westerly
Q48. When the Magnetic Pole is West of the True North pole variation is:
- A.+ and easterly
- B.- and easterly
- C.- and westerly✓
- D.+ and westerly
Q49. An isogonal is:
- A.a line of equal wind speed
- B.a line of equal magnetic deviation
- C.a line of zero magnetic variation
- D.a line of equal magnetic variation✓
Q50. The agonic line is:
- A.a line of zero magnetic deviation
- B.a line of equal magnetic deviation
- C.a line of zero magnetic variation✓
- D.a line of equal magnetic variation
Q51. What is deviation?
- A.The angle between magnetic North and compass North✓
- B.The angle between magnetic North and True North
- C.The angle between True North and compass North
- D.The angle between True North and magnetic North
Q52. Deviation is:
- A.an error to be added to magnetic headings
- B.a correction to be added to magnetic heading to obtain compass heading
- C.a correction to be added to compass heading to obtain magnetic heading✓
- D.an error to be added to compass heading to obtain magnetic heading
Q53. The force acting on the needle of a direct reading compass varies:
- A.directly with the horizontal component of the earth's magnetic field✓
- B.directly with the vertical component of the earth's magnetic field
- C.inversely with both vertical and horizontal components of the earth's magnetic field
- D.inversely with the horizontal component of the earth's magnetic field
Q54. The lines on a chart joining places of equal magnetic dip are called:
- A.Aclinic lines
- B.Isogonals
- C.Isoclinals✓
- D.Agonic lines
Q55. An aircraft is accelerating on a westerly heading in the Northern Hemisphere; the effect on a Direct Reading Compass will result in:
- A.An apparent turn to the West
- B.An indication of a turn to the North✓
- C.A decrease in the indicated reading
- D.An indication of a turn to the South
Q56. When should a DRC be "swung"?
- A.Every 6 months
- B.Following a change of magnetic latitude✓
- C.For night use
- D.After flying in an area where lightning is visible
Q57. An aircraft, in the Northern Hemisphere, turns right from 330(C) in a Rate 1 Turn for 30 secs. As the aircraft rolls out, does the compass overread or underread and will liquid swirl increase or decrease the error:
- A.Underread Decrease
- B.Underread Increase✓
- C.Overread Decrease
- D.Overread Increase
Q58. An aircraft is accelerating on a westerly heading in the Northern Hemisphere. The effect on a Direct Reading Magnetic Compass is:
- A.Underreads North
- B.Underreads South
- C.Overreads North✓
- D.Overreads South
Q59. Given: True Track = 352 deg Variation = 11W Deviation = .5 Drift = 10R What is Heading (C)?
- A.078 C
- B.346 C
- C.358 C✓
- D.025 C
Q60. When decelerating on a westerly heading in the Northern Hemisphere, the compass card of a direct reading magnetic compass will turn:
- A.clockwise giving an apparent turn toward the south✓
- B.anti-clockwise giving an apparent turn towards the south
- C.clockwise giving an apparent turn towards the north
- D.anti-clockwise giving an apparent turn towards the north
Q61. When an aircraft on a westerly heading on the northern hemisphere accelerates, the effect of the acceleration error causes the magnetic compass to:
- A.lag behind the turning rate of the aircraft
- B.indicate a turn towards the north✓
- C.indicate a turn towards the south
- D.to turn faster than the actual turning rate of the aircraft
Q62. In Northern Hemisphere, during an acceleration in an easterly direction, the magnetic compass will indicate:
- A.a decrease in heading✓
- B.an increase in heading
- C.an apparent turn to the South
- D.a heading of East
Q63. Concerning direct reading magnetic compasses, in the northern hemisphere, it can be said that:
- A.on an Easterly heading, a longitudinal acceleration causes an apparent turn to the South
- B.on an Easterly heading, a longitudinal acceleration causes an apparent turn to the North✓
- C.on a Westerly heading, a longitudinal acceleration causes an apparent turn to the South
- D.on a Westerly heading, a longitudinal deceleration causes an apparent turn to the North
Q64. The angle between Magnetic North and Compass North is called:
- A.magnetic variation
- B.compass error
- C.compass deviation✓
- D.alignment error
Q65. You are in the Northern hemisphere, heading 135C on a Direct Reading Magnetic Compass. You turn right in a Rate 1 turn for 30 seconds. Do you roll out on an indicated heading of:
- A.greater than 225✓
- B.less than 225
- C.equal to 225
- D.not possible to determine
Q66. When turning right from 330o(C) to 040o(C) in the northern hemisphere the reading of a direct reading magnetic compass will:
- A.over-indicate the turn and liquid swirl will decrease the effect
- B.under-indicate the turn and liquid swirl will increase the effect✓
- C.under-indicate the turn and liquid swirl will decrease the effect
- D.over-indicate the turn and liquid swirl will increase the effect
Q67. Compass deviation is defined as the angle between:
- A.True North and Magnetic North
- B.Magnetic North and Compass North✓
- C.True North and Compass North
- D.The horizontal and the total intensity of the earth's magnetic field
Q68. Deviation applied to magnetic heading gives:
- A.magnetic course
- B.true heading
- C.compass heading✓
- D.magnetic track
Q69. At the magnetic equator, when accelerating after take off on heading West, a direct reading compass:
- A.underreads the heading
- B.overreads the heading
- C.indicates the correct heading✓
- D.indicates a turn to the south
Q70. An aircraft in the northern hemisphere makes an accurate rate one turn to the right/starboard. If the initial heading was 330° after 30 seconds of the turn the direct reading magnetic compass should read:
- A.060°
- B.less than 060°✓
- C.more than 060°
- D.more or less than 060° depending on the pendulous suspension used
Q71. When accelerating on an easterly heading in the Northern hemisphere, the compass card of a direct reading magnetic compass will turn:
- A.anti-clockwise giving an apparent turn toward the south
- B.clockwise giving an apparent turn toward the south
- C.anti-clockwise giving an apparent turn toward the north
- D.clockwise giving an apparent turn toward the north✓
Q72. You are turning from 330° to 040° in the Northern hemisphere using timing. You stop the turn at the correct time. Before the direct indicating magnetic compass settles down, does it over-read or under-read, and does the effect of liquid swirl increase or decrease?
- A.Under-read; increase✓
- B.Over-read; decrease
- C.Under-read; decrease
- D.Over-read; increase
Q73. Which of the following statements is correct concerning the effect of turning errors on a direct reading compass?
- A.Turning errors are greatest on north/south headings, and are least at high latitudes
- B.Turning errors are greatest on east/west headings, and are least at high latitudes
- C.Turning errors are greatest on north/south headings, and are greatest at high latitudes✓
- D.Turning errors are greatest on east/west headings, and are greatest at high latitudes
Q74. Permanent magnetism in aircraft arises chiefly from:
- A.exposure to the earth's magnetic field during normal operation
- B.hammering, and the effect of the earth's magnetic field, whilst under construction✓
- C.the combined effect of aircraft electrical equipment and the earth's magnetic field
- D.the effect of internal wiring and exposure to electrical storms
Q75. One purpose of a compass calibration is to reduce the difference, if any, between:
- A.compass north and magnetic north✓
- B.compass north and true north
- C.true north and magnetic north
- D.compass north and the lubber line
Q76. In a remote indicating compass system the amount of deviation caused by aircraft magnetism and electrical circuits may be minimised by:
- A.positioning the master unit in the centre of the aircraft
- B.the use of repeater cards
- C.mounting the detector unit in the wingtip✓
- D.using a vertically mounted gyroscope
Q77. The main advantage of a remote indicating compass over a direct reading compass is that it:
- A.is able to magnify the earth's magnetic field in order to attain greater accuracy
- B.has less moving parts
- C.requires less maintenance
- D.senses, rather than seeks, the magnetic meridian✓
Q78. The purpose of compass check swing is to:
- A.cancel out the horizontal component of the earth's magnetic field
- B.cancel out the vertical component of the earth's magnetic field
- C.measure the angle between Magnetic North and Compass North✓
- D.cancel out the effects of the magnetic fields found on board the aeroplane
Q79. Which of the following is an occasion for carrying out a compass swing on a Direct Reading Compass?
- A.After an aircraft has passed through a severe electrical storm, or has been struck by lightning✓
- B.Before an aircraft goes on any flight that involves a large change of magnetic latitude
- C.After any of the aircraft radio equipment has been changed due to unserviceability
- D.Whenever an aircraft carries a large freight load regardless of its content
Q80. Why are the detector units of slaved gyro compasses usually located in the aircraft wingtips?
- A.With one detector unit in each wingtip, compass deviations are cancelled out
- B.To isolate the detector unit from the aircraft deviation sources✓
- C.To isolate the detector unit from the Earth's magnetic field
- D.To reduce turning and acceleration errors
Q81. A direct reading compass should be swung when:
- A.there is a large, and permanent, change in magnetic latitude✓
- B.there is a large change in magnetic longitude
- C.the aircraft is stored for a long period and is frequently moved
- D.the aircraft has made more than a stated number of landings
Q82. The direct reading magnetic compass is made aperiodic (dead beat) by:
- A.using the lowest acceptable viscosity compass liquid
- B.keeping the magnetic assembly mass close to the compass point and by using damping wires✓
- C.using long magnets
- D.pendulous suspension of the magnetic assembly
Q83. The main reason for usually mounting the detector unit of a remote indicating compass in the wingtip of an aeroplane is to:
- A.facilitate easy maintenance of the unit and increase its exposure to the Earth's magnetic field
- B.reduce the amount of deviation caused by aircraft magnetism and electrical circuits✓
- C.place it is a position where there is no electrical wiring to cause deviation errors
- D.place it where it will not be subjected to electrical or magnetic interference from the aircraft
Q84. The annunciator of a remote indicating compass system is used when:
- A.synchronising the magnetic and gyro compass elements✓
- B.compensating for deviation
- C.setting local magnetic variation
- D.setting the heading pointer
Q85. Which one of the following is an advantage of a remote reading compass as compared with a standby compass?
- A.It senses the magnetic meridian instead of seeking it, increasing compass sensitivity✓
- B.It is lighter than a direct reading compass because it employs, apart from the detector unit, existing aircraft equipment
- C.it eliminates the effect of turning and acceleration errors by pendulously suspending the detector unit
- D.It is more reliable because it is operated electrically and power is always available from sources within the aircraft
Q86. What is the advantage of the remote indicating compass (slaved gyro compass) over the direct reading magnetic compass?
- A.It is lighter
- B.It is connected to a source of electrical power and so is more accurate
- C.It senses the earth's magnetic field rather than seeks it, so is more sensitive✓
- D.It is not affected by aircraft deviation
Q87. The main reason for mounting the detector unit of a remote reading compass in the wingtip of an aeroplane is:
- A.to ensure that the unit is in the most accessible position on the aircraft for ease of maintenance
- B.by having detector units on both wingtips, to cancel out the deviation effects caused by the aircraft structure
- C.to minimise the amount of deviation caused by aircraft magnetism and electrical circuits✓
- D.to maximise the units exposure to the earth's magnetic field
Q88. The sensitivity of a direct reading compass varies:
- A.inversely with the vertical component of the earth's magnetic
- B.directly with the horizontal component of the earth's magnetic field✓
- C.directly with the vertical component of the earth's magnetic field
- D.inversely with both vertical and horizontal components of the earth's magnetic field
Q89. If compass HDG is 340° and deviation +3, what is magnetic heading?
- A.Deviation is plus therefore East, so compass is least, so magnetic is 343°✓
- B.Deviation is plus therefore West, so compass is least, so magnetic is 343°
- C.Deviation is plus therefore East, so compass is best, so magnetic is 337°
- D.Deviation is plus therefore East, so compass is best, so magnetic is 343°
Q90. If true HDG is 165° and variation -3 what is magnetic heading?
- A.Variation is minus therefore West, so magnetic is best, so magnetic is 168°✓
- B.Variation is minus therefore West, so magnetic is least, so magnetic is 162°
- C.Variation is plus therefore East, so magnetic is best, so magnetic is 162°
- D.Variation is plus therefore East, so magnetic is best, so magnetic is 168°
Q91. In still air, you wish to fly a true of 315°. Variation is 4°W. Deviation is 2°E. What Compass heading should you fly?
- A.321
- B.313
- C.317✓
- D.309
Q92. Magnetic compass calibration is carried out to reduce:
- A.deviation✓
- B.variation
- C.parallax error
- D.acceleration errors
Q93. You are in the northern hemisphere, heading West, and the aircraft is accelerating. Will a direct reading magnetic compass over-read or under-read and is the compass indicating a turn to the north or to the south:
- A.over-reads north✓
- B.over- reads south
- C.under-reads north
- D.under-reads south
Q94. Concerning a Direct Reading Compass in the Northern Hemisphere, it can be said:
- A.On an easterly heading, a lateral acceleration produces an apparent turn to the South
- B.On an easterly heading, a longitudinal acceleration produces an apparent turn to the North✓
- C.On a westerly heading, a lateral acceleration produces an apparent turn to the North
- D.On a westerly heading, a longitudinal acceleration produces an apparent turn to the South