PPL(A) 060 NavigationRevision notes and practice questions

PPL 060 NavigationFree sample, 10 questions

1. 1Which statement about great circles and rhumb lines is correct?

   1. Every parallel of latitude is a great circle, because it goes all the way round the earth.
   2. A rhumb line is always the shortest distance between two points on the earth's surface.
   3. The equator and each meridian with its anti-meridian are great circles, and the shortest route follows a great circle.
   4. A great circle crosses every meridian at the same angle, so its true track never changes.
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   Answer C. A great circle is the intersection of the earth's surface with a plane through the centre of the earth: the equator and every meridian joined to its anti-meridian are great circles, and the shorter arc of a great circle is the shortest distance between two points. Parallels other than the equator are small circles. The line that cuts every meridian at the same angle is the rhumb line, which is longer than the great circle except along a meridian or the equator.

2. 2The true heading is 087°, the variation is 2°E and the deviation card gives a deviation of 3°W on this heading. Which compass heading should the pilot fly?

   1. 082°
   2. 088°
   3. 092°
   4. 086°
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   Answer B. Work from true to compass, with east positive and west negative. Magnetic heading = true heading minus variation: 087 − 2 = 085°. Compass heading = magnetic heading minus deviation: 085 − (−3) = 088° (deviation west, compass best). 082° applies the deviation with the wrong sign and 092° applies the variation with the wrong sign.

3. 3Which statement about the Lambert conformal conic projection, used for most ICAO 1:500 000 charts in Europe, is correct?

   1. Angles are preserved, a straight line is close to a great circle and the scale is almost constant over the sheet.
   2. Rhumb lines are straight lines, meridians are parallel and the scale increases with latitude.
   3. Areas are preserved but angles are distorted, so measured tracks must be corrected before use.
   4. A straight line is a rhumb line, so its true track is the same at every meridian it crosses.
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   Answer A. The Lambert conformal conic projection is conformal, so angles measured on it are correct. Its meridians are straight lines converging towards the pole, a straight line drawn on it is very close to a great circle, and between its two standard parallels the scale is practically constant. Straight rhumb lines, parallel meridians and a scale increasing with latitude describe the Mercator projection.

4. 4You plan a leg on a true track of 090°. TAS is 105 kt and the forecast wind is 040°/24 kt. What true heading must you fly and what will the groundspeed be?

   1. Heading 100°, groundspeed 88 kt
   2. Heading 080°, groundspeed 88 kt
   3. Heading 080°, groundspeed 119 kt
   4. Heading 080°, groundspeed 105 kt
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   Answer B. The wind blows from 50° left of the track, so the aeroplane must point into wind, to the left. Wind correction angle = arcsin(24 × sin 50° ÷ 105) = 10.1°, so the heading is 090 − 10 = 080°. Groundspeed = 105 × cos 10.1° − 24 × cos 50° = 88.0, that is 88 kt, because the wind has a headwind component. Turning to 100° applies the correction on the wrong side, and 119 kt treats the headwind component as a tailwind.

5. 5On a 75 NM leg, after 45 NM you fix your position 3 NM right of the planned track. Using the 1 in 60 rule, what is the track error?

   1. 4°
   2. 3°
   3. 6°
   4. 7°
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   Answer A. Track error = distance off track × 60 ÷ distance flown = 3 × 60 ÷ 45 = 4°. The track error is computed on the distance already flown, not on the 30 NM still to go, which would give 6°. The distance off track in NM only equals the angle in degrees after 60 NM.

6. 6Which of the following statements about the frequency bands used in light aircraft are correct?
   1. VOR stations transmit between 108 and 118 MHz, in the VHF band.
   2. NDBs transmit between 190 and 1,750 kHz, in the LF and MF bands.
   3. DME operates in the VHF band, on the same frequency as the paired VOR.
   4. VHF voice communications use the band from 118 to 137 MHz.

   1. 1 and 2 only.
   2. 2, 3 and 4.
   3. 1, 2 and 4.
   4. 1, 3 and 4.
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   Answer C. VOR uses 108.00 to 117.975 MHz and VHF communications 118.000 to 136.975 MHz, both in the VHF band (ICAO Annex 10). NDBs use 190 to 1,750 kHz, in the LF and MF bands. Statement 3 is false: DME works in the UHF band, between 962 and 1,213 MHz. Only its channel is paired with the VOR frequency, so selecting the VOR tunes the DME automatically.

7. 7You call a VHF direction finding (VDF) station and receive "QDM 075". Which statement is correct?

   1. You are on the 075 radial and must fly a heading of 255° M to reach the station.
   2. The magnetic bearing to the station is 075°: in nil wind, a heading of 075° M takes you there, and your QDR is 255°.
   3. The true bearing of the aircraft from the station is 075°, so you are to the east of the station.
   4. The true bearing to the station is 075°, so you must correct for variation before steering it.
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   Answer B. QDM is the magnetic bearing to the station, the magnetic heading to steer in nil wind to reach it; with wind, it is the magnetic track to follow. The reciprocal, 255°, is the QDR, the magnetic bearing from the station. QTE is the true bearing from the station and QUJ the true bearing to the station. Confusing QDM and QDR sends you directly away from the station.

8. 8Which of the following statements about ground radar are correct?
   1. A primary radar can detect an aircraft that has no transponder.
   2. Mode A transmits the pressure altitude of the aircraft.
   3. Code 7600 indicates a radio communication failure.
   4. The secondary radar interrogates the transponder on 1,090 MHz.

   1. 1 and 2.
   2. 1 and 3.
   3. 2 and 4.
   4. 3 and 4.
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   Answer B. A primary radar receives the energy reflected by the aircraft itself, so it needs no equipment on board. Code 7600 is the radio failure code, 7500 unlawful interference and 7700 emergency. Mode A only sends the 4-digit identity code; the altitude is added by mode C. The ground station interrogates on 1,030 MHz and the transponder replies on 1,090 MHz, so statement 4 reverses the two frequencies.

9. 9What is the minimum number of satellites a GPS receiver needs for a three-dimensional position, and why?

   1. 3, one for each dimension of the position.
   2. 4, three for the position and one to solve the receiver clock error.
   3. 5, the fifth being used to check the integrity of the other four.
   4. 4, the fourth being used to correct the ionospheric delay.
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   Answer B. Each satellite gives a distance, measured from the time the signal takes to arrive. The receiver clock is not as accurate as the atomic clocks on board, so the measured distances are pseudo-ranges with a common clock error. Solving latitude, longitude, altitude and that clock error needs 4 satellites. A fifth is needed only for RAIM fault detection, not for the position itself.

10. 10Aerodrome A is at N43°20' E001°30' and aerodrome B is at N45°05' E001°30'. What is the distance between A and B?

    1. 105 NM
    2. 145 NM
    3. 175 NM
    4. 194 NM
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    Answer A. Both aerodromes are on the same meridian, so the distance is the difference of latitude. From 43°20' to 45°05' is 1°45', that is 60' + 45' = 105', and one minute of latitude is 1 NM, so 105 NM. Reading 1°45' as 145' or as 1.75 × 100 gives the wrong values, and 194 is 105 × 1.852, the distance in km.