1. Senior/Master Air Cadet
PILOT NAVIGATION
Senior/Master Air Cadet

2. Learning Outcomes
Know the basic features of air navigation and navigational aids
Understand the techniques of flight planning
Understand the affects of weather on aviation

3. Flight Planning

4. We discussed the triangle of velocities and looked briefly
Introduction
We discussed the triangle of velocities and looked briefly
at how the triangle is solved
We shall revise the components of the triangle and learn how this helps us to plan a flight and then notify other people of our intentions.
That is how we calculate some of the unknown components of the triangle from those that we know

6. Triangle of Velocities
Comprises of 3 vectors
( a vector being a component of the triangle having both direction & speed ) drawn to scale
One side represents movement of the aircraft in still air
Another represents wind speed & direction
The third shows the actual movement of the plane over the surface of the earth As a result of the other 2 vectors

7. Triangle of Velocities
Thus there are 6 components
Wind Speed
Wind Direction
Aircraft Heading
True Airspeed
Groundspeed
Track

8. Solution of the Triangle
Micro computers
Mental arithmetic
As long as we have 4 of the components it can be solved by a number of methods:
Scale drawing on graph paper
Dalton dead reckoning computer

9. On this card the flight is divided into a number of legs
Flight Planning
Both in private aviation & military training flight planning is carried out using a
Pilot Nav Log Card
On this card the flight is divided into a number of legs

11. Triangle Of Velocities
Flight Planning
The card is divided into a number of legs
Before the flight the
Triangle Of Velocities
is solved for each leg

12. Flight Planning
However there is more to be done before the goal is reached
First, the pilot needs to know the tracks and distances of the various legs
So he draws them on a route chart
We will now look at a flight of a bulldog from Leeming to Marham via Cottesmore
Open ACP and display the map with the lines on
departing from Leeming at 1000 hrs

14. Flight Planning The wind forecast is southerly for the first leg
The Wind Forecast Is South Westerly For The Second Leg
Looking at the map the wind lines are drawn on & you can see there should be a headwind for leg 1 (GS < TAS )
Producing A Crosswind For Leg 2
(Hdg & Track Differ By Drift)

15. Flight Planning - Log Entries
TRACK
The Pilot Must Enter Various Details On The Log Card Before Applying The Triangle Of Velocities:
Measured With A Protractor
DISTANCE
Measured From The Chart

16. Flight Planning - Log Entries
Forecast Air Temperature
Forecast V/W
Indicated Air Speed
Height The Leg To Be Flown
Decided By Operational, Safety & Other Needs
Normally The Recommending Cruising Speed

17. Flight Planning - Log Entries
TRUE AIRSPEED
Calculated from the IAS/RAS & Air Temperature
Found from the Peripheral Information on the Chart
VARIATION

18. Flight Planning – Triangle of Velocities
Usually the Pilot Would use the
Rotatable Compass Rose or
Dalton Computer
We Must Use Graph Paper
The Theory is the same but the Dalton Computer is much quicker

19. Flight Planning – Triangle of Velocities
Once these are entered The Triangle of Velocities can be used to calculate, for each Leg:
The Heading to counter the wind
The Groundspeed

20. Flight Planning – Triangle of Velocities
We already have 4 of the 6 elements of the triangle (1st leg)
WIND DIRECTION
180º
WIND SPEED
30 KT
TRACK
161º
TAS
125 KT

21. Flight Planning – Triangle of Velocities
We First Draw The W/V From The Direction 180º & Give It A Length Of 3 Units ( To Represent 30 Kt)
NORTH (TRUE)
W/V

22. Flight Planning – Triangle of Velocities
Next, at the downwind end of the W/V draw the Trk/GS line in direction 161º It is an unknown length
This length, the Groundspeed, is one element we will discover

23. Flight Planning – Triangle of Velocities
All We Currently Know Is That The GS Will Be Less Than The TAS Of 125 Kt
(We Know This From The Log Card)
So The Max Length Of The Line Will Be 12.5 Graph Units

24. Flight Planning – Triangle of Velocities
Next at the other end of the W/V line draw the HDG/TAS line to A length of 12.5 graph units
(for the speed of 125 kt)
to where it crosses the GS line
& work out the angle with a pair of geometry compasses

25. Flight Planning – Triangle of Velocities
W/V
3 UNITS
Tk/GS
UNKNOWN
LENGHT
ANGLE TO BE
CALCULATED
HDG/TAS
12.5 Units

26. Flight Planning – Triangle of Velocities
We Can Now Calculate That The Length Of The TRK/GS Line Is 9.6 Units So The GS Will Be 96 Kt

27. Flight Planning – Triangle of Velocities
Using A Protractor We Find The HDG/TAS Is 166º.
We Can Now Apply The Magnetic Variation Of 7º To 166º(t) To Give A Heading Of 173º (M)

28. Flight Planning – Triangle of Velocities
Entering These On The Log Card We Can Work Out The Leg Time By Using The Gs Of 96kt & Distance Of 98nm To Give 61¼ Minutes From Leeming To Cottlesmore
We Can Do The Same For The Second Leg To Marham

29. Fuel Planning

30. Fuel Planning
One of the main purposes of calculating flight times is to ensure sufficient fuel is available
If this happens in a car it is inconvenient, in an aircraft it can be fatal

31. Fuel Planning The bulldog consumes fuel at: 12 gallons an hour
distance
So 12.3 gallons are needed for the first leg
12/60 X = 12.25

32. Other Information The most important is the Safety Altitude
This is the height a pilot must climb to, or not fly below, in
Instrument Meteorological Conditions (IMC)

33. Other Information
This ensures the aircraft does not hit the ground or obstacles such as TV masts

34. In mountainous regions a greater safety height is added
Other Information
Safety Altitude is calculated by adding 1000’ to the highest elevation on or near the track & rounding it up to the next 100’
In mountainous regions a greater safety height is added

35. Other Information
An aircraft can not descend below the safety height unless the crew has good visual contact with the ground or the services of ATC

36. ATC Flight Plan
Aircraft crews must notify ATC of their intentions so the overdue action can be initiated if the aircraft is overdue

37. ATC Flight Plan
Additionally aircraft entering busy airspace have to submit a flight plan so their flight can be coordinated with other aircraft

38. ATC Flight Plan ATC has a standard format for this, including:
Aircraft call sign
Aircraft type
Time & place of departure
Route
ETA
Speed & altitude
Safety info

39. Conclusion
The principles of flight planning are the same for across country flight in a bulldog or a Intercontinental flight on a Boeing

40. Conclusion We must measure tracks & distances from a chart/databases,
Calculate the effects of the weather (especially the wind) ,
Have sufficient fuel,
& inform ATC along the route
This ensures that if anything goes wrong help will be available immediately

41. Position Fixing ?

42. Introduction
In the pioneering days of aviation aircraft could not fly unless the crew could see the ground, as map reading was the only means of navigating

43. Introduction
Later aircraft where fitted with sextants & radio direction finding equipment, but the big strides occurred during & after the second world war

44. Introduction
It was not until the 1970’s that world wide coverage with a navigation aid known as Omega was achieved

45. Introduction
More recently Satellite Navigation (SatNav) & the Global Position Satellite have come into use

46. Any process of finding an aircraft’s position is known as
Introduction
Any process of finding an aircraft’s position is known as
Fixing

47. Visual Fixing There are many factors affecting map reading
At this moment we need to know that when you look out of an aircraft & identify some unique feature this gives a visual fix know as a pinpoint

48. It is still a reliable method & is used in the early training of crews
Visual Fixing
The accuracy depends on the uniqueness of the feature, accuracy of the map, & skill of the observer
It is still a reliable method & is used in the early training of crews

49. Radio Aids
If you move a radio through 360º in the horizontal plane you should find 2 points where reception is good & 2 points where it is bad

50. Radio Aids
The radio direction finder (RDF) works on this principle. It shows , on a dial in the aircraft, its bearing from a transmitting beacon.
As long as the position of the Tx beacon is known a “position line” can be drawn, with the aircraft being somewhere along this line

51. Radio Aids
If 2 further position lines can be plotted, with 2 other known beacons, preferably at 60º to one another, then a “3 position line fix” can be obtained

52. Radio Aids

53. Radio Aids
This was a main method in the 1920s & 1930s. However it does depend on the range of the beacon

54. VOR/DME & TACAN
A more modern method of gathering position lines is from VOR/DME & TACAN beacons

55. VOR/DME & TACAN
TACAN is a military system, & gives the magnetic bearing, or radial, from the beacon to the aircraft and the slant range

56. VOR/DME & TACAN
LYE Ch 35
(109.8)
Bearing - 280º
Slant - 55 nm
The above airfield has a TACAN on channel 35 & transmits its ID code in Morse - l y e

57. VOR/DME & TACAN VOR/DME is a civilian system
It gives the magnetic bearing, or radial, from the beacon to the aircraft and the slant range although the information is less accurate
Civil aircraft fly from beacon to beacon

58. VOR/DME & TACAN There is a beacon at Stappleford airfield
operating on 115.6mhz
On CHANNEL 103
CALLSIGN:
Lima Alpha Mike
L A M
FOR LAMBOURNE

59. Astro Navigation
Radio beacons are ideal for overland flights, but for overseas flight early aircrew used the stars
The principle behind this is that if you think you know your position (dead or deduced reckoning) you can calculate the relative position of the star

60. Astro Navigation
Using a sextant to measure the angle accurately you can compare the actual position of the star to its calculated position
The difference between the 2 represents the error in the DR position. As with RDF 2 or 3 fixes are needed

61. This can be extremely accurate, but is being replaced with GPS
Astro Navigation
This can be extremely accurate, but is being replaced with GPS
However it cannot be jammed by an enemy!

62. Radar Navigation

63. Radar Navigation Radar was invented in the 1930’s & rapidly developed
Early systems where crude & unreliable
Modern systems , such as used in tornado are highly effective

64. Radar Navigation
This enables the radar picture to be matched to a very accurate map by the press of a button
This enables the navigator to concentrate on other tasks, such as weapon system management

65. Radar Navigation
The main problems is that the radar transmits electronic emissions which are detectable, & radar failure

66. Radar Navigation
With the rapid development of electronics in the 1950’s & 60’s area navigation systems where introduced :
GEE
DECCA
LORAN
& OMEGA

67. Each pair gives a position line
Radar Navigation
These work by measuring the time it takes for 2 synchronized signals to arrive from 2 different stations.
Each pair gives a position line

68. Radar Navigation
With the advent of global position satellites fix’s will be available at the touch of a button with accuracies of a few metres

70. Active/Passive Systems
We have already seen that the main disadvantage of radar navigation is their liability to disclosed there presence & location to the enemy
This had lead to the development of Radar Homing Missiles

76. Active/Passive Systems
Scientists have developed electronic warfare to enable the use of radar. This includes frequency hoping “smart” radars. It is a ever evolving area
EW measures are used to protect “active” navigation systems, but another approach is to use equipment that do not transmit, but merely receive

77. Active/Passive Systems
This includes GPS information combined with Internal Navigation Systems.
These are known as Passive Systems