ppl_03_e2
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CHAPTER 8: MAP READING
The distance from Wycombe to Chichester is 45 nautical miles. So, if we assume a groundspeed of 90 knots it will take 30 minutes to complete the journey. You will, therefore, need to select a maximum of 3 or 4 checkpoints, ideally, evenly-spaced for timing and heading correction purposes. (See Figure 8.15.)
Figure 8.15 Checkpoints on the route from Wycombe Air Park to Chichester.
A suitable first checkpoint which would be easily identified, is White Watham airfield. White Waltham airfield. You will overfly White Waltham about 4½ minutes after setting off from Wycombe.
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CHAPTER 8: MAP READING
After White Waltham, Farnborough airfield is just over 8 minutes further on and is a possible checkpoint. However, you must take care not to confuse Farnborough with Blackbushe which should be on the right of your track, slightly further away, and only 3 minutes from the road junction.
After Farnborough, the next suitable feature would be the railway line between Haslemere and Liphook, about 8 minutes from Farnborough. The railway line runs just to the South of, and parallel to, a dual carriageway. Both railway and dual carriageway lie across your track, and, so, will give you a good timing check. From here to Chichester aerodrome is about 9 minutes flying time, so there will be no need for a further checkpoint. It is now time to think about your arrival procedures as you approach your destination.
To sum up, your recommended checkpoints would be White Waltham Aerodrome, Farnborough Aerodrome and the railway line between Haslemere and Liphook. You would, therefore, mark these features on your map with the estimated flight time required to reach each checkpoint from Wycombe. Take care to mark checkpoints in such a way that the checkpoint itself is not obscured. One method is illustrated in
Figure 8.15.
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CHAPTER 8: MAP READING QUESTIONS
Representative PPL - type questions to test your theoretical knowledge of Map Reading.
For questions 1 to 5, refer to the symbols on Page 121.
1.What is the symbol for an unlighted obstacle?
a.9
b.10
c.11
d.8
2.Which of the following is the symbol for an exceptionally high (over 1000 feet AGL) lighted obstruction?
a.6
b.9
c.11
d.7
3.What symbol is used to show an NDB on a map/chart?
a.5
b.7
c.6
d.10
4.Which is the symbol for a VOR?
a.4
b.6
c.11
d.3
5.What does symbol 3 represent?
a.Lit obstacle
b.Lighthouse
c.VRP
d.Aeronautical Light Beacon
For questions 6 to 7, refer to the chart beneath the questions.
6.The area you see on the chart, delineated by a rectangle of blue diamonds, is:
a.Yeovilton Aircraft Information Advisory Area
b.Yeovilton Area of Intense Aerial Activity
c.Yeovilton Air Interdiction Activity Area
d.Yeovilton Air Intelligence Advisory Area
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CHAPTER 8: MAP READING QUESTIONS
7.Where on the chart will you find a glider launching site co-located with a government heliport?
a.Yeovilton
b.Bournemouth
c.Bovington
d.Merryfield
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The answers to these questions can be found at the end of this book.
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Customer: Oleg Ostapenko E-mail: ostapenko2002@yahoo.com
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CHAPTER 8: MAP READING QUESTIONS
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5NM |
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5NM |
4NM |
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MATZ |
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LARS |
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126-5 |
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FIG |
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825 |
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VRP |
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SANDBACH |
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Customer: Oleg Ostapenko E-mail: ostapenko2002@yahoo.com
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CHAPTER 9
PRINCIPLES OF DEAD RECKONING
VISUAL AIR NAVIGATION
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CHAPTER 9: PRINCIPLES OF DEAD RECKONING VISUAL AIR NAVIGATION
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Customer: Oleg Ostapenko E-mail: ostapenko2002@yahoo.com
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CHAPTER 9: PRINCIPLES OF DEAD RECKONING VISUAL AIR NAVIGATION
INTRODUCTION.
In the previous chapter, you learnt about some of the skills of map reading that a pilot needs to acquire in order to fly a successful visual navigation trip.
However, the science of visual navigation does not involve simply map reading from ground feature to ground feature.
The most effective method of navigating visually cross-country is known as dead reckoning navigation.
In dead reckoning navigation, the pilot starts from a known location and uses a reliable wind forecast to calculate a heading to steer and an expected groundspeed (based on a chosen true airspeed) in order to predict an arrival time over a visual checkpoint, turning point or destination, along a desired track. The pilot then concentrates on flying an accurate speed and heading which, after a calculated time interval, he hopes will result in his aircraft arriving over the checkpoint, turning point or destination at the expected time.
Figure 9.1 depicts an aircraft which, by flying a particular heading, at a given airspeed, will achieve a given track over the ground, at a particular ground speed, depending on wind strength and direction.
Headings to fly, true airspeeds and expected groundspeeds are calculated, and tracks, checkpoints and timings chosen, during pre-flight planning. The more thorough the pre-flight planning, the less demanding will be the navigation task in the air.
Mental dead reckoning, then, permits a pilot to estimate future position by calculating an expected direction, and distance travelled in that direction, over the surface of the Earth, in a predetermined time; (usually every 5 to
10 minutes during a typical light aircraft cross country flight.). When that time has elapsed, the pilot consults his chart to confirm his ground position.
If examination of the checkpoints confirms the expected ground position, the pilot will know that his aircraft has covered the planned distance, over the planned track, in the planned time. The pilot will then know exactly where he is, and will be confident that the forecast wind and his own flying are accurate. Furthermore, if he is on track, on time and “on position”, the pilot will also know that his estimated time of arrival (ETA) at destination, or at the next checkpoint or turning point, will be as predicted.
On the other hand, if he finds that he arrives early or late at a particular ground fix along his route, or if he sees from his ground fix that he is off track, the application of mental dead reckoning techniques will enable him to estimate a new heading to fly
The more 
thorough 
the pre-flight 
planning, the less demanding will be the navigation task in the air.
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CHAPTER 9: PRINCIPLES OF DEAD RECKONING VISUAL AIR NAVIGATION
in order to rejoin track further along the route, or to fly directly to the destination from his observed position. The pilot will also be able to recalculate groundspeed, update ETAs, and revise his fuel management, so that the flight can be continued in safety, and future events remain under the pilot’s control.
Visual air navigation then, is much more than map reading.
In this chapter, you will learn the basic principles of mental dead reckoning in air navigation.
As an aside, you should know that the CD-ROM which comes with this book will teach you how to carry out all the calculations associated with mental dead reckoning, on the navigation computer. There are many models of navigation computer, but for the current PPL theoretical knowledge examination in Navigation, the Dalton type navigation computer, sometimes referred to as the whiz-wheel, is required. (See Chapter 11.) The CD-ROM which accompanies this book will teach you all you need to know about this computer.
MENTAL DEAD RECKONING AND THE TRIANGLE OF VELOCITIES.
In dead reckoning navigation, the pilot starts from a known location and uses a reliable wind forecast to calculate a heading to steer, in order to follow a planned track over the ground towards a desired destination. Based on a planned true airspeed, the pilot also uses the wind to calculate a groundspeed along his planned track and is thus able to calculate the time required to reach his destination. The pilot then concentrates on flying an accurate speed and heading which, after a calculated time interval, he hopes will result in his aircraft arriving at destination at the expected time.
If the wind forecast is correct and the pilot has calculated the required headings and his groundspeed correctly, he will follow his planned track to his destination, and he will arrive at his destination at the calculated time. Pilots, however, come to realise very early in their flying career that wind forecasts tend not to be 100% exact (though they may be) and that the accuracy of their navigation calculations and flying may often be less than perfect. Corrections to planned headings and ETAs often have to be made, therefore. Obviously, visual checkpoints along the chosen route are identified from the chart during flight planning, in order that the pilot can confirm that he is on his desired track, or determine any track or timing error. But let us, for the moment, concentrate on the initial navigation calculations of how to get from starting point to destination.
The key to understanding how to calculate the heading required to arrive at your destination after following your planned track, and to determine the time of arrival at destination, is the triangle of velocities.
The Triangle of Velocities.
An aircraft flies through the air. This is rather an obvious statement, but consider for a moment the fact that the mass or block of air through which the aircraft flies will, itself, be moving over the surface of the Earth. A person standing on the surface of the Earth will sense this movement of the air as wind. If the mass of air is moving quickly, the person will say that the wind is strong, if it is moving slowly, the person will sense a light wind. But the important thing for the pilot to register is that his aircraft in flight is moving relative to the air mass in which it is flying, and that the air mass has
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