What is the purpose of radar?
To assist ATCOs in there main task of ensuring safe separation between ACFT.
Radar sites at many airports around the country and other strategic sites ensures that…
Controllers at various UK units receive the best possible picture and information.
What is Primary radar? (2)
- ) Shows very basic information about ACFT position in relation to radar.
- ) All ACFT within its coverage are displayed as well as other objects such as high terrain, certain weather and possibly large flocks of birds.
What is Secondary radar?
Secondary radar is more selective than primary radar, only displaying information from ACFT equipped with a transponder.
How does secondary radar work? (3)
- ) Before departure or entry into the airways system, the ACFT is allocated an individual squawk code which the pilot will input to the transponder.
- ) When ACFT is airborne or before it enters the airways system, ground based radar interrogates the transponder. When it recognises the allocated squawk code, ACFT callsign and height info is displayed to the controller in a label next to the ACFT position.
- ) The controller is also able to display maps of airways and Upper Air Routes as well as coastlines and danger areas.
What is the purpose of navigational aids? (Which NATS provides and maintains)
To enable ACFT to fly the airways system with the necessary accuracy.
What does VOR stand for?
VHF (Very High Frequency) Omnidirectional Range.
How does a VOR work?
By emitting radial signals which the ACFT can fly along. There are 360 radials which can ACFT can use to fly to or from the VOR, each representing 1 degree.
What is a DME?
Distance Measuring Equipment - often associated with a VOR and shows pilots how far away they are from the DME/VOR (Slant range).
Due to their accuracy, VORs can be used to establish _____. Heathrow has __________ overhead VORs. The range of a VOR is in the order of _____ nautical miles.
- ) Stacks.
- ) 4 Stacks.
- ) 125.
What is an NDB and what is their range?
- ) Non-Directional Beacon - Emits a signal which the pilot navigates towards.
- ) Much shorter range than a VOR at around 25 nautical miles.
Why are an increasing number of approach and en-route navigational aids being phased out?
GPS is becoming more accurate, capable, reliable and widespread.
ACFT gather data from various sources e.g. _____, _____, _____ and the information is fed into the _______________ (FMS).
- ) Navaids.
- ) Inertial Navigation System (INS).
- ) GPS.
- ) Flight Management System.
The FMS can vary in complexity from basic _____ and _____ to the systems which can control the ACFT from _____ to _____.
- ) Heading.
- ) Altitude.
- ) Departure.
- ) Arrival.
Approach controllers issue instructions to enable the ACFT to intercept the ILS. What is the ILS? (3)
- ) Instrument Landing System.
- ) Ground based radio guidance which transmits 2 directional beams - the glide path and the localiser (Usual descent path is 3 degrees).
- ) Pilot receives indications in the cockpit as to weather the ACFT needs to fly up, down, left or right to keep on the correct approach path.