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AIR NAVIGATION

Key Revision

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AIR NAVIGATION

Chapter 1 Distance, speed and time.

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Pilots must make regular checks of their Estimated Time of Arrival (ETA) at destination as well as estimated times for passing waypoints en-route.

Distance, Speed & Time

These are necessary for ATC reports, and vital for ensuring sufficient fuel remains to reach the destination.

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Regular checks of Estimated Time of Arrival (ETA) are important. These calculations help the crew to determine that:

a) The aircraft has sufficient fuel to reach the destination.

b) The wind velocity will not change.

c) They are flying the shortest route.

d) The drift is correct.

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Try again!

OK

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Regular checks of Estimated Time of Arrival (ETA) are important. These calculations help the crew to determine that:

a) The aircraft has sufficient fuel to reach the destination.

b) The wind velocity will not change.

c) They are flying the shortest route.

d) The drift is correct.

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Aircrew are always aware of their Estimated Time of Arrival (ETA). Why is this?

a) Fuel flow rate depends on ETA.

b) It is the easiest calculation to do.

c) It is important for fuel calculations and air traffic control purposes.

d) A revised ETA tells them the wind has changed.

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Try again!

OK

exit

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Aircrew are always aware of their Estimated Time of Arrival (ETA). Why is this?

a) Fuel flow rate depends on ETA.

b) It is the easiest calculation to do. .

c) It is important for fuel calculations and air traffic control purposes.

d) A revised ETA tells them the wind has changed.

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Distance on the earth’s surface is measured in Nautical Miles.

Distance on the Earth

One Nautical Mile (nm) is the equivalent to one minute of latitude, (one sixtieth of a degree).

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Degrees of latitude and longitude are marked with the symbol ° .

Distance on the Earth

Minutes of latitude and longitude are marked with the symbol ’.

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Distance on the earth's surface is measured in nautical miles (nm). Which of the following is true?

a) One nm is equal to one minute of latitude.

b) One nm equals 1/10,000th of the distance from the North Pole to the Equator.

c) One nm is equal to 5280 feet.

d) One nm is equal to one minute of longitude.

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Try again!

OK

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Distance on the earth's surface is measured in nautical miles (nm). Which of the following is true?

a) One nm is equal to one minute of latitude.

b) One nm equals 1/10,000th of the distance from the North Pole to the Equator.

c) One nm is equal to 5280 feet.

d) One nm is equal to one minute of longitude.

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One degree of latitude is equal to:

a) 360 nms

b) 60 nms

c) 60 kms

d) 1 nm

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OK

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One degree of latitude is equal to:

a) 360 nms

b) 60 nms

c) 60 kms

d) 1 nm

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One minute of latitude on the earth's surface is equal to:

a) 1 nautical mile.

b) 60 nautical miles.

c) 1 knot.

d) 1 km.

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Try again!

OK

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One minute of latitude on the earth's surface is equal to:

a) 1 nautical mile.

b) 60 nautical miles.

c) 1 knot.

d) 1 km.

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Nautical maps do not have scales on the borders. We use the scale shown along each meridian.

Measuring Distance

If dividers are used to measure distance, the degrees and minutes scale on the nearest meridian should be used to convert that distance into nautical miles.

The degrees and minutes on the parallels of latitude should not be used for measuring purposes because convergence towards the poles shrinks the scale.

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0 º

15 ºE

30 ºE

45 ºE

Longitude

Distances should not be measured using parallels as they converge towards the poles.

Only at the equator does one degree of longitude equal 60 nm.

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15 º N

30 º N

45 º N

60 º N

75 º N

0 º

Latitude

Distances measured using scales along the meridians will be accurate.

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The LATITUDE of a point is its distance measured in degrees and minutes:

a) From the Greenwich (Prime) Meridian.

b) From the true North Pole.

c) North or South of the Equator.

d) From the true South Pole.

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OK

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The LATITUDE of a point is its distance measured in degrees and minutes:

a) From the Greenwich (Prime) Meridian.

b) From the true North Pole.

c) North or South of the Equator.

d) From the true South Pole.

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The distance between two points on a navigation chart can be measured with dividers. What scale will then be used to convert that distance to nautical miles?

a) The minute scale along a meridian close to the area of interest on the chart.

b) 1:50,000 scale.

c) The minute scale along a parallel of latitude.

d) Any meridian scale off any chart.

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Try again!

OK

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The distance between two points on a navigation chart can be measured with dividers. What scale will then be used to convert that distance to nautical miles?

a) The minute scale along a meridian close to the area of interest on the chart.

b) 1:50,000 scale.

c) The minute scale along a parallel of latitude.

d) Any meridian scale off any chart.

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Change of Latitude

If two places are on the same meridian, it is possible to determine how far apart they are by calculating the differences in Latitude.

In this example Keil is due north of Wartzburg.

54N

53N

52N

51N

50N

Keil 54 ° 20 ’ N

Wartzburg 49 ° 48 ’ N

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Change of Latitude

Remembering that one minute of latitude is one nautical mile, we can see that Wartzburg is just 12 nautical miles south of the 50 ° line of latitude .

49° 48’ plus 12’ = 50° 00’ .

54N

53N

52N

51N

50N

Keil 54 ° 20 ’ N

Wartzburg 49 ° 48 ’ N

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Change of Latitude

Each degree of latitude between 50 ° North and 54° North is a further 60 nautical miles .

4 times 60 = 240 nautical miles .

54N

53N

52N

51N

50N

Keil 54 ° 20 ’ N

Wartzburg 49 ° 48 ’ N

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Change of Latitude

Finally, we can see that Keil is another 20 ’ North of latitude 54° North .

So another 20 nautical miles must be added to our total.

54N

53N

52N

51N

50N

Keil 54 ° 20 ’ N

Wartzburg 49 ° 48 ’ N

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Change of Latitude

12’ + 240’ + 20’ = 272’

Keil is therefore 272 nautical miles due north of Wartzburg.

54N

53N

52N

51N

50N

Keil 54 ° 20 ’ N

Wartzburg 49 ° 48 ’ N

240’

12’

20’

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In Germany, Kiel is due north of Wartzburg. If Kiel's latitude is 54 20N and Wartzburg's is 49 48N how far are they apart?

a) 272 nm

b) 2720 nm

c) 27.2 nm

d) 227 nm

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Try again!

OK

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In Germany, Kiel is due north of Wartzburg. If Kiel's latitude is 54 20N and Wartzburg's is 49 48N how far are they apart?

a) 272 nm

b) 2720 nm

c) 27.2 nm

d) 227 nm

Each degree is 60 nm each minute is 1 nm. Wartzburg is 12 minutes South of 50N, Kiel 20 minutes North of 54N. 50N to 54N is 4 degrees. Each degree is 60 nm. 4 x 60 + 12 + 20 = 272 nm.

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Oslo airport (Norway) is due north of Braunschweig airfield near Hanover (Germany). If their latitudes are 59 53N and 52 20N respectively, how far are they apart?

a) 453 nm

b) 454 nm

c) 554 nm

d) 445 nm

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OK

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Oslo airport (Norway) is due north of Braunschweig airfield near Hanover (Germany). If their latitudes are 59 53N and 52 20N respectively, how far are they apart?

a) 453 nm

b) 454 nm

c) 554 nm

d) 445 nm

52 20N to 59 53N is 7 degrees and 33 minutes. Each degree is 60 nm, each minute is 1 nm. 7 degrees x 60 nm = 420nm, plus 33nm = 453nm.

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Your destination airfield is situated due south of your departure airfield. If the two latitudes are 63 25N and 57 58N, how far are they apart?

a) 327

b) 317

c) 323

d) 333

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OK

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Your destination airfield is situated due south of your departure airfield. If the two latitudes are 63 25N and 57 58N, how far are they apart?

a) 327

b) 317

c) 323

d) 333

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Dundee is due north of Abergavenny. If their latitudes are 56 27N and 51 50N, how far are they apart?

a) 277 kms.

b) 323 kms.

c) 323 nms.

d) 277 nms.

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Try again!

OK

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Dundee is due north of Abergavenny. If their latitudes are 56 27N and 51 50N, how far are they apart?

a) 277 kms.

b) 323 kms.

c) 323 nms.

d) 277 nms.

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On land we measure distance in miles and speed in miles per hour (mph).

Aircraft Speed

In aviation we use nautical miles (nm) to measure distances and speed is measured in nautical miles per hour , known as knots and abbreviated ‘kts’.

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An aircraft measures speed through the air using an instrument called an Air Speed Indicator (ASI).

Aircraft Speed

The ASI compares the pressure caused by the aircraft’s forward motion through the air (the ‘Pitot’ pressure) with the pressure of the air surrounding the aircraft (the ‘Static’ pressure).

The faster the aircraft flies, the greater is the difference between these two pressures.

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In aviation, speed is measured in:

a) kilometres per hour (km/hr).

b) miles per hour (mph).

c) knots (kts).

d) metres per hour (m/hr).

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OK

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In aviation, speed is measured in:

a) kilometres per hour (km/hr).

b) miles per hour (mph).

c) knots (kts).

d) metres per hour (m/hr).

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The Air Speed Indicator (ASI) calculates speed by:

a) Measuring the pressure difference between pitot and static pressures.

b) Measuring the pitot pressure.

c) Measuring the static pressure.

d) Multiplying pitot pressure by static pressure.

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Try again!

OK

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The Air Speed Indicator (ASI) calculates speed by:

a) Measuring the pressure difference between pitot and static pressures.

b) Measuring the pitot pressure.

c) Measuring the static pressure.

d) Multiplying pitot pressure by static pressure.

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The indicated airspeed (IAS) is corrected for Pressure Error and Instrument Error to give a more accurate airspeed – Calibrated Airspeed (CAS).

Calibrated Airspeed

IAS + Pressure Error + Instrument Error = CAS

Pressure Error is caused by the airflow around the aircraft. Carefully positioning the pitot and static tubes can minimise, but not eliminate completely, this error.

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Calibrated Air Speed (CAS) is:

a) Pitot pressure minus static pressure.

b) IAS after correction for pressure error and instrument error.

c) Always less than IAS.

d) Always greater than IAS.

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OK

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Calibrated Air Speed (CAS) is:

a) Pitot pressure minus static pressure.

b) IAS after correction for pressure error and instrument error.

c) Always less than IAS.

d) Always greater than IAS.

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Calibrated Air Speed (CAS) equals Indicated Air Speed (IAS) plus corrections for:

a) Altitude error.

b) Pressure error.

c) Instrument error.

d) Pressure and instrument error.

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Try again!

OK

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Calibrated Air Speed (CAS) equals Indicated Air Speed (IAS) plus corrections for:

a) Altitude error.

b) Pressure error.

c) Instrument error.

d) Pressure and instrument error.

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As an aircraft flies higher the air becomes less dense, so the aircraft flies faster through the thinner air to achieve the same force on the pitot tube.

True Airspeed

To find the True Airspeed (TAS) at altitude the Calibrated Airspeed must now be corrected for air density changes caused by temperature and altitude .

CAS + Density Error (temperature & altitude) = TAS

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To summarise:

True Airspeed

IAS + Pressure & Instrument Error = CAS

CAS + Density Error (temperature & altitude) = TAS

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To summarise:

True Airspeed

I AS + P ressure & I nstrument Error = C AS

CAS + D ensity Error (temperature & altitude) = T AS

I P I C D T

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When Calibrated Airspeed (CAS) is corrected for altitude and temperature, it becomes:

a) True Air Speed (TAS).

b) Indicated Airspeed (IAS).

c) Mach Number.

d) Indicated Groundspeed.

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Try again!

OK

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When Calibrated Airspeed (CAS) is corrected for altitude and temperature, it becomes:

a) True Air Speed (TAS).

b) Indicated Airspeed (IAS).

c) Mach Number.

d) Indicated Groundspeed.

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If a car travels 120 miles at 60 mph, it will take 2 hours to complete the journey.

Calculation of Flight Time

Distance (D) Speed (S)

= Time (T)

= 2 hours

120 miles 60 mph

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Similarly, if we know the distance and time taken, we can calculate the speed.

Calculation of Flight Time

Distance (D) Time (T)

= Speed (S)

= 60 mph

120 miles 2 hours

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If we know the speed of the vehicle and the time the journey has taken, then we can calculate the distance covered.

Calculation of Flight Time

Speed (S) x Time (T) = Distance (D)

60 mph x 2 hours = 120 miles

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Aircraft normally fly at faster speeds and cover greater distances, but the principle and the mathematics remain the same.

Calculation of Flight Time

Speed (S) x Time (T) = Distance (D)

600 kts x 2 hours = 1200 nm

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How fast must an aircraft fly to cover 1200 nm in 3 hours?

a) 400 kts

b) 800 kts

c) 400 mph

d) 3600 kts

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OK

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How fast must an aircraft fly to cover 1200 nm in 3 hours?

a) 400 kts

b) 800 kts

c) 400 mph

d) 3600 kts

1200 nm in 3 hours requires the aircraft to cover 400 nm each hour (1200 / 3 = 400). 400 nm per hour = 400 knots.

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A Hercules is flying at a groundspeed of 210 kts. How far will it travel in 3 hours?

a) 630 nms.

b) 70 nms

c) 630 km.

d) 210 nms.

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OK

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A Hercules is flying at a groundspeed of 210 kts. How far will it travel in 3 hours?

a) 630 nms.

b) 70 nms

c) 630 km.

d) 210 nms.

3 hours @ 210 kts (nautical miles per hour) = 630 nautical miles.

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A Tornado flies from its base to a target in 30 minutes. If the distance is 250 nms, what speed is it flying at?

a) 125 kts.

b) 500 kts.

c) 750 kts..

d) 800 kts.

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Try again!

OK

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A Tornado flies from its base to a target in 30 minutes. If the distance is 250 nms, what speed is it flying at?

a) 125 kts.

b) 500 kts.

c) 750 kts.

d) 800 kts.

250 nms in 30 minutes means the aircraft would cover 500 nms in one hour, giving a speed of 500 kts.

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A Nimrod flies on patrol for nine hours at a speed of 300 kts. How far does it travel in this time?

a) 2400 nms.

b) 2700 nms.

c) 3000 nms.

d) 3900 nms.

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Try again!

OK

exit

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A Nimrod flies on patrol for nine hours at a speed of 300 kts. How far does it travel in this time?

a) 2400 nms.

b) 2700 nms.

c) 3000 nms.

d) 3900 nms.

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A Hercules flies from A to B, a distance of 1000 nms at a groundspeed of 250 kts. How long does the flight take?

a) 3 hrs 20 mins.

b) 4 hrs.

c) 3 hrs 30 ins.

d) 5 hrs.

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OK

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a) 3 hrs 20 mins.

b) 4 hrs.

c) 3 hrs 30 mins.

d) 5 hrs.

A Hercules flies from A to B, a distance of 1000 nms at a groundspeed of 250 kts. How long does the flight take?

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All military and commercial aviators use the same time.

Units of Time

This is known as either Greenwich Mean Time (GMT) or Universal Time (UT).

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Universal Time (UT) time is used as standard in military and commercial aviation. By what other name is it known?

a) British Summer Time (BST).

b) European Daylight Saving Time (EDST).

c) Greenwich Mean Time (GMT).

d) Local Time (LT) i.e. the time of the country over which the aircraft is flying.

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Try again!

OK

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Universal Time (UT) time is used as standard in military and commercial aviation. By what other name is it known?

a) British Summer Time (BST).

b) European Daylight Saving Time (EDST).

c) Greenwich Mean Time (GMT).

d) Local Time (LT) i.e. the time of the country over which the aircraft is flying.

GMT is also known as Z or ZULU time, eg 0800Z is 8 a.m. GMT, or sometimes UTC, which stands for Universal Time Constant.

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AIR NAVIGATION

Chapter 2 The triangle.

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Whenever we talk about aircraft or wind movement, we must always give both direction and speed of that movement.

Vectors and Velocity

Direction and speed together are called a velocity .

A velocity can be represented on paper by a line called a vector .

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

The length of the line represents speed.

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

The length of the line represents speed.

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

The length of the line represents speed.

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

The length of the line represents speed.

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

The length of the line represents speed.

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The bearing of the line represents the direction of the movement.

Vectors and Velocity

The length of the line represents speed.

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Vectors and Velocity

A

Imagine trying to sail a boat across a fast flowing river.

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Vectors and Velocity

A

This line with one arrow represents the velocity of the boat (its speed and the direction it was pointed).

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Vectors and Velocity

A

B

If a boat is pointed directly across a river, the flow of the river will push the boat downstream.

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Vectors and Velocity

A

B

The line with three arrows represents the speed and direction of the current.

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Vectors and Velocity

A

B

Although the boat started off pointing at ‘A’ it finished up at ‘B’ because of this current.

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Vectors and Velocity

A

B

Joining the ends of these two lines with a third line completes the ‘ vector triangle ’.

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Vectors and Velocity

A

B

This line, with two arrows, is the resultant and represents the actual course of the boat.

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A similar triangle can represent an aircraft’s movement through air which is itself moving (wind).

The Air Triangle

heading and true airspeed (HDG/TAS)

wind speed and direction

track and groundspeed

Note that the wind vector describes the direction the wind is blowing from – northerly in this example.

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The angle between the heading and the track, caused by the wind, is called drift .

The Air Triangle

heading and true airspeed (HDG/TAS)

wind speed and direction

track and groundspeed

drift

heading and true airspeed (HDG/TAS)

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Velocity consists of:

a) Speed only.

b) Direction only.

c) Speed and direction together.

d) Several speed vectors together.

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OK

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Velocity consists of:

a) Speed only.

b) Direction only.

c) Speed and direction together.

d) Several speed vectors together.

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A vector is a representation on paper of:

a) Speed.

b) Time.

c) Direction.

d) Direction and speed.

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Try again!

OK

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A vector is a representation on paper of:

a) Speed.

b) Time.

c) Direction.

d) Direction and speed.

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A vector is a line, drawn to represent a velocity. This is achieved by:

a) The bearing represents knots at all times.

b) The bearing represents speed and the length represents direction.

c) The length represents mph at all times.

d) The bearing represents direction and the length represents speed.

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Try again!

OK

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A vector is a line, drawn to represent a velocity. This is achieved by:

a) The bearing represents knots at all times.

b) The bearing represents speed and the length represents direction.

c) The length represents mph at all times.

d) The bearing represents direction and the length represents speed.

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In the diagram, vector 2 is added to vector 1. What is vector 3 (A-C) known as?

a) The ready vector.

b) Current.

c) The resultant vector.

d) Drift.

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Try again!

OK

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In the diagram, vector 2 is added to vector 1. What is vector 3 (A-C) known as?

a) The ready vector.

b) Current.

c) The resultant vector.

d) Drift

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In the triangle of velocities, DRIFT is:

a) The bearing of the wind vector.

b) The angle between the wind and track vectors.

c) The angle between heading and track vectors.

d) The angle between heading and wind vectors.

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Try again!

OK

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In the triangle of velocities, DRIFT is:

a) The bearing of the wind vector.

b) The angle between the wind and track vectors.

c) The angle between heading and track vectors.

d) The angle between heading and wind vectors.

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In the air triangle, the heading vector includes 2 components. They are:

a) Heading and wind velocity.

b) Heading and groundspeed.

c) Heading and drift.

d) Heading and true air speed.

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Try again!

OK

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In the air triangle, the heading vector includes 2 components. They are:

a) Heading and wind velocity.

b) Heading and groundspeed.

c) Heading and drift.

d) Heading and true air speed.

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In the air triangle, the track vector includes 2 components. They are:

a) Track and drift.

b) Track and heading.

c) Track and groundspeed.

d) Track and true air speed.

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Try again!

OK

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In the air triangle, the track vector includes 2 components. They are:

a) Track and drift.

b) Track and heading.

c) Track and groundspeed.

d) Track and true air speed.

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In the air triangle, the wind vector includes 2 components. They are:

a) Wind speed and drift.

b) Wind speed and heading.

c) Wind speed and the direction the wind is blowing from.

d) Wind speed and track.

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Try again!

OK

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In the air triangle, the wind vector includes 2 components. They are:

a) Wind speed and drift.

b) Wind speed and heading.

c) Wind speed and the direction the wind is blowing from.

d) Wind speed and track.

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In the Air Triangle shown below, name the components of the 3rd side, represented by a dotted line:

a) Wind velocity.

b) Heading and true airspeed.

c) Drift and groundspeed.

d) Track and groundspeed.

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Try again!

OK

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In the Air Triangle shown below, name the components of the 3rd side, represented by a dotted line:

a) Wind velocity.

b) Heading and true airspeed.

c) Drift and groundspeed.

d) Track and groundspeed.

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In the Air Triangle shown below, name the components of the 3rd side, represented by a dotted line:

a) Wind direction and speed.

b) Heading and true airspeed.

c) Drift and groundspeed.

d) Drift .

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Try again!

OK

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In the Air Triangle shown below, name the components of the 3rd side, represented by a dotted line:

a) Wind direction and speed.

b) Heading and true airspeed.

c) Drift and groundspeed.

d) Drift .

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As we have demonstrated, the vector triangle consists of 6 elements:

- heading and true airspeed
- windspeed and direction
- track and groundspeed

Solving the Vector Triangle

Providing we know four of the elements of the vector triangle ( any four) it is possible to calculate the other two .

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The Air Triangle of velocities can be used to calculate flight data. There are 6 elements in total. How many elements are needed to calculate those missing?

a) 2

b) 4

c) 5

d) 6

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Try again!

OK

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The Air Triangle of velocities can be used to calculate flight data. There are 6 elements in total. How many elements are needed to calculate those missing?

a) 2

b) 4

c) 5

d) 6

Any of the four elements will enable the remaining two to be found.

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Despite modern equipment, pilots must still make quick, accurate calculations in their heads.

Mental Calculations

Every pilot should know the distance his aircraft will cover in one minute for any given groundspeed.

For instance, a Tornado flying at 420 kts groundspeed will cover 7 nm per minute. If the next turning point is 35 nm away, dividing 35 by 7 tells him he will be there in 5 minutes.

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The table on the next page shows how many nautical miles per minute are covered at various groundspeeds.

Mental Calculations

Ensure you know the examples in italics.

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Mental Calculations

Groundspeed (kts) nm/minute 60 1 120 2 180 3 240 4 300 5 360 6 420 7 480 8 540 9

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You are flying at 120 kts groundspeed. How long will it take to fly 20 nms?

a) 60 minutes.

b) 10 minutes.

c) 6 minutes.

d) 2 minutes.

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OK

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You are flying at 120 kts groundspeed. How long will it take to fly 20 nms?

a) 60 minutes.

b) 10 minutes.

c) 6 minutes.

d) 2 minutes.

120 kts is 120 nms per hour or 2 nms per minute. To fly 20 nms at 2 nms per minute would take 10 minutes.

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You are flying a Tornado at 420 kts groundspeed. How many miles do you travel each minute?

a) 42 nm

b) 8 nm

c) 7 nm

d) 6 nm

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Try again!

OK

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You are flying a Tornado at 420 kts groundspeed. How many miles do you travel each minute?

a) 42 nm

b) 8 nm

c) 7 nm

d) 6 nm

There are 60 minutes in each hour. 420 divided by 60 is 7 nm per minute.

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You fly between 2 features on the ground and you notice it takes 3 minutes. If the features are 18 nm apart, what is your groundspeed?

a) 54 kts

b) 180 kts

c) 280 kts

d) 360 kts

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Try again!

OK

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You fly between 2 features on the ground and you notice it takes 3 minutes. If the features are 18 nm apart, what is your groundspeed?

a) 54 kts

b) 180 kts

c) 280 kts

d) 360 kts

3 minutes to cover 18 nm is 6 nm per minute. Each hour is 60 minutes, you will cover 6 x 60 = 360 nm per hour.

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Pilots are constantly calculating and updating their ETA’s, both for turning points and final destination.

Estimated Time of Arrival (ETA)

ETA’s are important for both fuel and Air Traffic Control purposes.

If an aircraft fails to arrive at its destination on time, then ATC will initiate ‘overdue action’.

*

An aircraft departs from base, but does not arrive at the destination on its Estimated Time of Arrival (ETA). What action will Air Traffic Control take?

a) No immediate action is required.

b) Close down and go home.

c) Contact the departure base.

d) Initiate overdue action.

*

Try again!

OK

exit

*

An aircraft departs from base, but does not arrive at the destination on its Estimated Time of Arrival (ETA). What action will Air Traffic Control take?

a) No immediate action is required.

b) Close down and go home.

c) Contact the departure base.

d) Initiate overdue action.

*

AIR NAVIGATION

Chapter 3 The 1 in 60 rule.

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*

The 1 in 60 rule

A

B

A line drawn on the map between departure and destination (or from one turning point to another) is known as the Track Required .

Track Required

*

The 1 in 60 rule

A

B

If the aircraft drifts off track, then the line from our departure airfield to our present position is known as Track Made Good (TMG).

pinpoint

Track Made Good

Track Required

*

An aircraft is flying from point A to point B. Halfway a pinpoint fix shows it to be off track. A line between point A and the fix would be known as:

a) Drift.

b) Revised track.

c) Track made good.

d) Track required.

*

Try again!

OK

exit

*

An aircraft is flying from point A to point B. Halfway a pinpoint fix shows it to be off track. A line between point A and the fix would be known as:

a) Drift.

b) Revised track.

c) Track made good.

d) Track required.

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The 1 in 60 rule

A

B

The angle between the Track Required and the Track Made Good (the actual track of the aircraft) is called the Track Error (TE).

pinpoint

Track Made Good

Track Required

Track Error

*

The 1 in 60 rule

A

B

The 1 in 60 rule states ‘if an aircraft flies a Track Made Good (TMG) one degree off the Track Required, after 60 miles of flying the aircraft will be one mile off track’.

pinpoint

Track Made Good

Track Required

Track Error

*

The 1 in 60 rule

A

B

Similarly, if an aircraft flies a Track Made Good (TMG) ten degrees off the Track Required, after 60 miles of flying the aircraft will be ten miles off track.

pinpoint

Track Made Good

Track Required

T E = 10 degrees

10 miles

60 miles

*

The 1 in 60 rule

A

B

The pilot now has the information he requires to get the aircraft back on track.

pinpoint

Track Made Good

Track Required

T E = 10 degrees

10 miles

60 miles

*

The 1 in 60 rule

A

B

The rule works for track errors up to 23 degrees.

pinpoint

Track Made Good

Track Required

T E = 10 degrees

10 miles

60 miles

*

The 1 in 60 rule

A

B

Where the aircraft has flown less than 60 miles the triangle has to be extended to determine how far the aircraft would be off track after 60 miles.

pinpoint

Track Made Good

Track Required

T E

4 miles

30 miles

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The 1 in 60 rule

A

B

In this example the aircraft is 4 miles off track after just 30 miles . After 60 miles it would be 8 miles off track giving a Track Error (TE) of 8 degrees .

pinpoint

Track Made Good

Track Required

T E

4 miles

30 miles

*

The 1 in 60 rule

A

B

Here the aircraft is 6 miles off track after 40 miles . After 60 miles therefore, it would be 9 miles off track giving a Track Error (TE) of 9 degrees .

pinpoint

Track Made Good

Track Required

T E

6 miles

40 miles

*

Using the 1 in 60 rule, calculate how many miles off track an aircraft will be if it flies 60 nm with a track error of 2 degrees.

a) 60 nms

b) 6 nms

c) 4 nms

d) 2 nms

*

Try again!

OK

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*

Using the 1 in 60 rule, calculate how many miles off track an aircraft will be if it flies 60 nm with a track error of 2 degrees.

a) 60 nms

b) 6 nms

c) 4 nms

d) 2 nms

*

An aircraft flies a track made good, 3 degrees in error from the required track. Using the 1 in 60 rule, how many miles off track will the aircraft be after 60 miles of flying?

a) 2 nms

b) 6 nms

c) 1 nm

d) 3 nms

*

Try again!

OK

exit

*

An aircraft flies a track made good, 3 degrees in error from the required track. Using the 1 in 60 rule, how many miles off track will the aircraft be after 60 miles of flying?

a) 2 nms

b) 6 nms

c) 1 nm

d) 3 nms

*

An aircraft is flying from A to B, after 20 nms it is found to be 3 nms off track. What is the track error?

a) 6 degrees.

b) 2 degrees.

c) 9 degrees.

d) 4 degrees.

*

Try again!

OK

exit

*

An aircraft is flying from A to B, after 20 nms it is found to be 3 nms off track. What is the track error?

a) 6 degrees.

b) 2 degrees.

c) 9 degrees.

d) 4 degrees.

If the aircraft was 3 nms off track after 20 nms, projecting ahead it would be 9 nms off track after 60 nms, therefore 9 degrees.

*

The 1 in 60 rule

A

B

Where the aircraft has flown more than 60 miles before obtaining a pinpoint, you must determine how far the aircraft was off track back at the 60 mile point.

pinpoint

Track Made Good

Track Required

T E

6 miles

120 miles

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The 1 in 60 rule

A

B

In this example the aircraft is 6 miles off track after 120 miles , so would have been 3 miles off track after 60 miles , a 3 degree Track Error.

pinpoint

Track Made Good

Track Required

T E

6 miles

120 miles

*

The 1 in 60 rule

A

B

Here the aircraft is 6 miles off track after 90 miles , so would have been 4 miles off track after 60 miles , that’s a 4 degree Track Error.

pinpoint

Track Made Good

Track Required

T E

6 miles

90 miles

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The 1 in 60 rule

A

B

Once a pilot has determined his position and therefore his Track Error, then he can adjust his heading.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

*

The 1 in 60 rule

A

B

The aircraft is to the left of the Track Required, so must turn to the right. If the Track Error is 8 degrees, by how many degrees should he change heading?

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

If he turns by only eight degrees (the Track Error) the pilot will only parallel the Track Required.

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

A further eight degrees (16 degrees in all) will put him back on track after another 60 miles.

*

The 1 in 60 rule

A

B

This new track is known as the Revised Track .

pinpoint

Track Made Good

Track Required

60 miles

60 miles

TE

The angle between the Revised Track and the original Track Required is the Closing Angle (CA).

Closing Angle

Revised Track

*

An aircraft is flying from point A to point B. A pinpoint fix shows it to be off track. A line from the pinpoint fix to point B would be known as:

a) Track made good.

b) Track required.

c) Revised track.

d) Heading required.

*

Try again!

OK

exit

*

An aircraft is flying from point A to point B. A pinpoint fix shows it to be off track. A line from the pinpoint fix to point B would be known as:

a) Track made good.

b) Track required.

c) Revised track.

d) Heading required.

*

An aircraft is flying from A to B, a distance of 120 nm. Halfway, a fix shows the aircraft to be 4 nm right of track. What heading change does the pilot require to reach point B?

a) 8 degrees right

b) 8 degrees left

c) 4 degrees right

d) 4 degrees left

*

Try again!

OK

exit

*

An aircraft is flying from A to B, a distance of 120 nm. Halfway, a fix shows the aircraft to be 4 nm right of track. What heading change does the pilot require to reach point B?

a) 8 degrees right

b) 8 degrees left

c) 4 degrees rght

d) 4 degrees left

*

20 nm after takeoff for a pre-planned destination, a pilot finds that he is 3 nm off track. By how much does the pilot need to turn to regain the intended track after flying a further 20 nm?

a) 18 degrees

b) 9 degrees

c) 6 degrees

d) 3 degrees

*

Try again!