Senior/Master Air Cadet PILOT NAVIGATION Senior/Master Air Cadet

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

Flight Planning

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

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

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

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

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

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

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

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)

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

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

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

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

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

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

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

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

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

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

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

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

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)

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

Fuel Planning

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

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 61.25 = 12.25

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)

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

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

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

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

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

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

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

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

Position Fixing ?

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

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

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

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

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

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

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

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

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

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

Radio Aids

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

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

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

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

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

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

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

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

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!

Radar Navigation

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

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

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

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

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

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

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

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

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