PILOT NAVIGATION Senior/Master Air Cadet. Learning Outcomes Understand the affects of weather on aviation Know the basic features of air navigation and.

PILOT NAVIGATION

Senior/Master Air Cadet

Learning Outcomes

Understand the affects of weather on aviation

Know the basic features of air navigation and navigational aids

Understand the techniques of flight planning

Flight Planning

Introduction

That is how we calculate some of the unknown components of the triangle

from those that we know

We discussed the triangle of velocities and looked brieflyat how the triangle is solvedWe 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.

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

Track Groundspeed

Solution of the Triangle

As long as we have 4 of the components it can be solved by a number of methods:

Scale drawing on graph paperDalton dead reckoning computerMental arithmeticMicro computers

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

LEG 1 2 3 4 5To

Heading

HeightFL

IASMach

Time

ETA

FU

Remaining

EL

Required

Safety Altitude

TAS

Track

Distance

W/V

Temp

G/S

Varn

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

departing from Leeming at 1000 hrs

Flight Planning

The wind forecast is southerly for the first leg

Looking at the map the wind lines are drawn on & you can see there should be a headwind for leg 1 (GS < TAS )

The Wind Forecast Is South Westerly For The Second Leg

Producing A Crosswind For Leg 2 (Hdg & Track Differ By Drift)

Flight Planning - Log Entries

The Pilot Must Enter Various Details On The Log Card Before Applying The Triangle Of

Velocities:

TRACK

Measured With A Protractor

DISTANCE

Measured From The Chart


Forecast V/W

Height The Leg To Be Flown

Decided By Operational, Safety & Other Needs

Forecast Air Temperature

Indicated Air Speed

Normally The Recommending Cruising Speed


TRUE AIRSPEED

Calculated from the IAS/RAS & Air Temperature

VARIATION

Found from the Peripheral Information

on the Chart

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


Once these are entered The Triangle of Velocities can be used

to calculate, for each Leg:

The Heading to counter the wind

The Groundspeed


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


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


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


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


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


W/V3 UNITS

Tk/GSUNKNOWNLENGHT

ANGLE TO BECALCULATED

HDG/TAS12.5 Units


We Can Now Calculate That The Length Of The TRK/GS Line Is 9.6

Units So The GS Will Be 96 Kt


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)


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

So 12.3 gallons are needed for the first leg

12/60 X 61.25 = 12.25

distance

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

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

Speed & altitude

Route ETA

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

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

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

Bearing - 280ºSlant - 55 nm

LYE Ch 35 (109.8)

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 NavigationUsing 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

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 NavigationWith the rapid development of electronics in the 1950’s & 60’s area navigation systems

where introduced :

GEE DECCA LORAN & OMEGA

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


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


This includes GPS information combined with Internal Navigation Systems.

These are known as Passive Systems

PILOT NAVIGATION Senior/Master Air Cadet. Learning Outcomes Understand the affects of weather on aviation Know the basic features of air navigation and.

Documents

leg slide

chart slide

drift slide

quicker slide

air speed

wind forecast

wind speed direction

direction speed