1. Uncontrolled copy not subject to amendment
Airmanship Knowledge for Air Cadets Learning Outcome 1 Know types of airfield operations used for the control of aircraft
Revision 2.00

2. Contents Control Towers Controllers Communication Systems
Visual Communications
RADAR
Radio Aids

3. Introduction
On RAF Airfields all movements of aircraft, both on the ground and in the air are monitored by Air Traffic Control (ATC)

4. 1. Control Towers

5. The Control Tower
Is always in a prominent position in the aircraft manoeuvring area
Houses electronic and radio equipment
May have a Bird Control Unit (BCU)

6. The size and design of Air Traffic Control Towers vary considerably.

7. 2. Controllers

8. Aerodrome Controller Is in charge of movements: On the ground
In the air
Is sometimes called:
Airfield Controller
Local Controller
Movements include:
Aircraft
Vehicles
Pedestrians
Is also in charge of aircraft in the circuit.
Aerodrome Controllers always work in the control room, with big glass windows, so they have uninterrupted views of the airfield.

9. Approach Controller The Approach Controller controls aircraft:
departing the airfield
making instrument approaches
Uses Radar displays, RT and landline communications
1. Controls aircraft departing the airfield circuit and those making instrument approaches.
2. May sometimes provide radar service to aircraft in transit through the area of responsibility of the airfield.
3. As most of the aircraft are out of sight of the field the approach controller does not need a window.
4. Instead he obtains information from RT, landline communications and Radar displays

10. Runway Controller
For more effective control a Runway Controller may be used at airfields with a lot of take-offs and landings The Runway Controller is in direct contact with Air Traffic Controller
Caravan is painted in red and white squares, positioned to the left of the touch-down end of the runway in use.

11. The Runway controller can refuse aircraft permission to move onto the runway, land or take-off in some circumstances

12. For example the Runway Controller 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.

13. The Runway Controller will also:
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

14. 3. Commnication Systems

15. Communication Systems
Good Communications are essential
to Air Traffic Control

16. 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
VHF and UHF provide clear lines of communication
Each airfield and its section have their own frequencies

17. 4. Visual Communications

18. Visual Communications
1. Stationary Object Hazard
2. Bad Ground Markers
0.61 metres squared

19. 3. Helicopter Operating Areas:
The ‘H’ is 4 metres high by 2 metres across
It may also have a box around the ‘H’
Sited well clear of fixed wing aircraft

20. 5. RADAR

21. RADAR
Stands For:
RAdio
Detection
And
Ranging

22. 1. A RADAR system consists of a transmitter and a receiver
2. A short pulse energy is transmitted from an aerial and the receiver “listens” for an echo

23. 3. The receiver detects which reflections are from aircraft and it determines their position, direction of travel and speed
4. This information is displayed through a cathode ray tube onto a screen. In this way radar has become the “eyes” of air traffic control

24. Radar Aids
The two main radar aids likely to be seen at Royal Air Force airfields are:
Surveillance Radar
Precision Approach Radar (PAR)

25. Surveillance Radar
Is used both to monitor air traffic passing through an area and as an airfield approach aid
It enables the controller to locate an aircraft and direct it to a position and height near the airfield

26. Precision Approach Radar
The Controller has two screens:
for the aircraft’s elevation (height)
for azimuth (left and right), relating to the approach path

27. Using the Precision Approach Radar, the Controller is able to pass instructions by RT to the pilot to guide the aircraft down the correct glide slope towards the touch-down point
This procedure is called a Ground Controlled Approach (GCA)

28. Ground Controlled Approach

29. Precision Approach Radar
PAR 2000 Radar

30. 6. Radio Aids

31. 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)

32. Digital Resolution Direction Finding (DRDF)
DRDF is a common airfield approach aid
It receives a transmission from an aircraft and displays it on a CRT screen as a green line called a “trace”
It enables the approach controller to tell the pilot what course to fly to reach the airfield
Controllers can direct the aircraft to a point above the airfield and from there control its descent through cloud (CDTC) to a height and position on the approach from which the pilot can either land visually or employ a runway approach aid.

33. Instrument Landing System (ILS)
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 leads to the touch-down point on the runway

34. The Instrument Landing System (ILS) transmits 2 frequencies:
1. 90Hz (the aircraft is too high)

35. 2. 150Hz (the aircraft is too low)

36. 3. No noise = the aircraft is on a good glide path

37. Any questions?