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Airmanship Knowledge
Learning Outcome 1
Air Traffic Control
Revision 1.00
Airmanship Knowledge
Learning Outcome 1
Understand the types of airfield operations used
for the control of aircraft
Contents
• Control Towers
• Controllers
• Communication
Systems
• Visual
Communications
• RADAR
• Approach Aids
Air Traffic Control
Introduction
On RAF Airfields all movements of aircraft, both on the ground
and in the air are monitored by Air Traffic Control (ATC)
The Control Tower
• Is always in a prominent position in the aircraft
manoeuvring area
• Houses electronic & radio equipment and may also have
a Bird Control Unit
The Control Tower
The size & design of ATC Towers varies considerably.
Aerodrome Controller
Is in charge of movements:
•
On the Ground
•
In the Air
Sometimes Called:
•
Airfield Controller
•
Local Controller
On large airfields this is split in two as there is too much work for one person.
Aircraft movements on the ground up to the runway are controlled by
a controller called Ground.
Aircraft movements on the runway and in the local area are controlled
by a controller called Tower.
Approach Controller
On light usage airfields
On heavy usage airfields
The departures are separated
out under the Departures
Controller
They control aircraft:
• departing the airfield
• making instrument approaches
Both use RADAR displays, RT and
landline communications
Runway Controller
For more effective control a Runway Controller may be used:
• At small airfields with lots of
take-offs and landings
• They are in direct
contact with Aerodrome/Local
Controller
Runway Controller
The Runway controller can refuse aircraft permission to
move onto the runway, land or take-off in some
circumstances
Runway Controller
For example they might:
• Prevent an aircraft from landing with its undercarriage
retracted by firing a RED flare.
• Stop an aircraft from taking-off which had for example a
panel unlocked or a fuel leak, by showing a steady RED
on the signalling lamp.
Runway Controller
• Warn vehicles or aircraft on the ground to move clear of
the landing area, by showing RED flashes on the
signalling lamp.
• Give permission to take-off, with a steady GREEN on the
signalling lamp.
Communication Systems
Good Communications are essential to Air Traffic Control
Communication Systems
Swift and accurate contact is
achieved through the use of:
• Special Telephones
• Tele-Talk Systems
• Radio Telephony (RT) (Ground To Air)
– Uses VHF and UHF to talk to aircraft and vehicles.
– These frequencies provide clear lines of
communications.
– Each airfield and its section have their own
frequencies.
Visual Communications
Stationary Object Hazard
Bad Ground Markers
0.61 metres
square
Visual Communications
Helicopter Operating Areas:
• The ‘H’ is 4 metres high by 2 metres across
• It may also have a box around the ‘H’.
• Well clear of fixed wing aircraft
OR
Radar
Stands For:
RAdio
Detection
And
Ranging
Radar
• Consists of a Transmitter and a Receiver
• A short pulse energy is transmitted from an aerial and
the receiver “listens” for an echo.
Radar
• The receiver detects which reflections are from aircraft,
and it can determine their position, direction of travel and
speed.
• This information is then displayed through a cathode ray
tube onto a screen. In this way radar has become the
“eyes” of air traffic control
Radar Aids
The two main radar aids likely to be seen at Royal Air
Force airfields are:
• Surveillance Radar
• Precision Approach Radar (PAR)
Surveillance Radar
Is used both to monitor air traffic passing through an area
and as an airfield approach aid.
Surveillance Radar
Enables the controller to locate the aircraft and direct it to a
position and height near the airfield
Surveillance Radar
Can be used for an airfield approach:
Surveillance Radar Approach (SRA)
The pilot hears directions to put him on the runway centre
line and also heights that he should be passing every mile i.e.
“On runway centre line at 5 miles, should be passing
1850Ft”
Precision Approach Radar
The controller has two screens, one for the aircraft’s
elevation (height) and one for azimuth (left and right),
relating to the approach path
Precision Approach Radar
The controller passes instructions by RT to the pilot to
guide the aircraft down the correct glideslope and
centreline towards the touch-down point
The procedure is called a Ground Controlled Approach
(GCA) or PAR Approach.
The pilot hears directions to put him on the runway centre
line and the ideal glidepath i.e.
“Left of centre line, come right 2 degrees, slightly low
on glidepath, not correcting”
Precision Approach Radar
Precision Approach Radar
PAR 2000 Radar
Radio Aids
The two main Radio Aids likely to be seen at Royal Air
Force airfields are:
• Digital Resolution Direction Finding (DRDF)
• Instrument Landing System (ILS)
DRDF
• It is a common airfield approach aid at small airfields but
is seldom used at large busy airfields
• It receives a carrier wave only transmission (no speech)
from an aircraft and displays it on a CRT as a green line
called a “trace”.
• Enables the approach controller to tell the pilot what
course to fly to the vicinity of the airfield for a visual
approach
Instrument Landing System
ILS is a runway approach aid:
• Fixed transmitters on the ground send out a special
pattern of radio signals
• These define a radio beam that is like a pathway in the
sky
• The pathway then leads to the touch-down point on the
runway
Instrument Landing System
Glidepath
ILS transmits 2 frequencies
90Hz signal is strongest, so aircraft is above the Glidepath
Localizer Glidepath
Transmitter Transmitter
90Hz
150Hz
Runway
Instrument Landing System
Glidepath
ILS transmits 2 frequencies
150Hz signal is strongest, so aircraft is below the Glidepath
Localizer Glidepath
Transmitter Transmitter
90Hz
150Hz
Runway
Instrument Landing System
Glidepath
ILS transmits 2 frequencies
Both signals are equal, so aircraft is on the Glidepath
Localizer Glidepath
Transmitter Transmitter
90Hz
150Hz
Runway
Instrument Landing System
Localizer
ILS transmits 2 frequencies
90Hz signal is strongest, so aircraft is right of the Localizer
Localizer
Transmitter
90Hz
Runway
Runway Centre Line
150Hz
Glideslope
Transmitter
Instrument Landing System
Localizer
ILS transmits 2 frequencies
150Hz signal is strongest, so aircraft is left of the Localizer
Localizer
Transmitter
90Hz
Runway
Runway Centre Line
150Hz
Glideslope
Transmitter
Instrument Landing System
Localizer
ILS transmits 2 frequencies
Both signals are equal, so aircraft is on the Localizer
Localizer
Transmitter
90Hz
Runway
Runway Centre Line
150Hz
Glideslope
Transmitter
90Hz
Localizer Glidepath
Transmitter Transmitter
150Hz
Runway
Localizer
Transmitter
90Hz
Runway
Runway Centre Line
150Hz
Glideslope
Transmitter
GPS Approach
Some airfields have been approved for GPS Approaches
as long as the aircraft equipment has been approved.
The GPS Approach is flown on the same instruments as
an ILS Approach and gives the same indications.
Questions?
QUESTION
WHICH BUILDING ON AN AIRFIELD HOUSES THE PEOPLE
THAT MONITOR AIRCRAFT ON THE GROUND AND IN THE AIR?
A.
AIR TRAFFIC CO-ORDINATION ROOM
B.
AIRBORNE TRAFFIC CONTROL ROOM
C.
AIR TRAFFIC CONTROL TOWER
D.
AIR TRAFFIC CO-ORDINATION TOWER
QUESTION
WHICH OF THE FOLLOWING WOULD NORMALLY WORK IN
A GLASS WALLED ROOM IN A CONTROL TOWER
A.
PAR CONTROLLER
B.
AIR CONTROLLER
C.
APPROACH CONTROLLER
D.
AIRFIELD CONTROLLER
QUESTION
HOW DOES AN APPROACH CONTROLLER RECEIVE
INFORMATION ABOUT AN AIRCRAFT
A.
RT, LANDLINE COMMUNICATIONS AND RADAR
B.
RADAR ONLY
C.
RT ONLY
D.
RT AND LANDLINE COMMUNICATIONS
QUESTION
WHAT COLOURED SIGNAL WOULD BE USED BY A RUNWAY
CONTROLLER TO CLEAR AN AIRCRAFT FOR TAKE-OFF ?
A.
A STEADY RED
B.
A FLASHING GREEN
C.
A FLASHING RED
D.
A STEADY GREEN
QUESTION
HOW DOES THE CONTROLLER PASS PAR INSTRUCTIONS
TO THE PILOT ?
A.
RT
B.
RADAR
C.
MORSE CODE
D.
RF BEAM
QUESTION
WHERE DOES THE PAR ALLOW THE PILOT TO GUIDE
THE AIRCRAFT TO ?
A.
TO THE DESIGNATED DISPERSAL AREA
B.
TO THE CORRECT GLIDESLOPE AND CENTRELINE
C.
TO AN AIRWAY IN CONTROLLED AIRSPACE
D.
TO THE TAKE-OFF POINT
QUESTION
DRDF IS USED TO ?
A.
DIRECT AN AIRCRAFT WHILE TAXYING
B.
DIRECT AN AIRCRAFT AFTER TAKE-OFF
C.
DIRECT AN AIRCRAFT TO THE VICINITY OF THE
AIRFIELD FOR A VISUAL APPROACH
D.
DIRECT AN AIRCRAFT TO THE RUNWAY
TOUCHDOWN POINT
QUESTION
AN ILS APPROACH IS USED TO ?
A.
TALK AN AIRCRAFT ONTO THE CORRECT
GLIDEPATH AND CENTRELINE
B.
FOLLOW ELECTRONIC SIGNALS ONTO THE
CORRECT GLIDEPATH AND CENTRELINE
C.
APPROACH THE AIRFIELD FOR A VISUAL APPROACH
D.
DEPART THE AIRFIELD
QUESTION
A GPS APPROACH IS DISPLAYED ON THE SAME
INSTRUMENTS AS ?
A.
A PAR
B.
A DRDF
C.
AN ILS
D.
AN SAR