12. Technologies relevant to air traffic

Question 1

what is MTCD?

Answer 1

Medium Term Conflict Detection (MTCD).

Developed to improve both safety and capacity.

It is the intention that implementing such systems will help NATS meet the future demands of over 3 million annual movements.

Question 2

How does MTCD try to reduce the controllers work load?

Answer 2

MTCD aims to reduce the controllers’ workload by equipping them with a tool that aids them with decision making.

The tool uses a variety of data inputs to predict where an aircraft will be up to 20 minutes in the future, based on the aircraft’s level, speed and heading/ route.

If the controller inputs any tactical instructions the system is updated.

Controllers can also enter a “what- if” instruction, this allows a controller to check what may happen without yet committing to the decision. This “what-if” trajectory is displayed on the radar screen so that the controller can visualise the new information.

Question 3

What is time based separation? (3)

Answer 3

1. ) ACFT spacing is determined by time instead of distance (As has historically been the case).
2. ) Takes prevailing winds and associated wake turbulence being produced by the ACFT into account.
3. ) The stronger the wind, the quicker the produced vortex is dispersed, therefore as wind speed increases, ACFT can be positioned closer in trail on the final approach, therefore increasing the available landing rate.

Question 4

In 2015, NATS was the first ANSP to introduce what? on the Final Approach (Initially at Heathrow).

Answer 4

Time based separation.

Question 5

Much development in aviation is to ensure _____ is increased or _____ increased without _____ being compromised.

Answer 5

1. ) Safety.
2. ) Capacity.
3. ) Safety.

Question 6

What is the purpose of new developments in aviation?

Answer 6

To either increase safety, or

to increase capacity without compromising safety

Question 7

What is the purpose of radar?

Answer 7

To assist ATCOs in there main task of ensuring safe separation between ACFT.

Question 8

Radar sites at many airports around the country and other strategic sites ensures that…

Answer 8

Controllers at various UK units receive the best possible picture and information.

Question 9

What is Primary radar? (2)

Answer 9

1. ) Shows very basic information about ACFT position in relation to radar.
2. ) All ACFT within its coverage are displayed as well as other objects such as high terrain, certain weather and possibly large flocks of birds.

Question 10

What is Secondary radar?

Answer 10

Secondary radar is more selective than primary radar, only displaying information from ACFT equipped with a transponder.

Question 11

How does secondary radar work? (3)

Answer 11

1. ) Before departure or entry into the airways system, the ACFT is allocated an individual 4-digit code which the pilot will input to the transponder (this is called mode A).
2. ) When ACFT is airborne or before it enters the airways system, ground based radar interrogates the transponder. When it recognises the allocated code, ACFT height info (this is called Mode C) and callsign is displayed to the controller in a label next to the ACFT position.
3. ) The controller is also able to display maps of airways and Upper Air Routes as well as coastlines and danger areas.

Question 12

What is Mode S?

Answer 12

A development to supersede present mode A and C technology and their limitations.

Question 13

How does existing Mode A and C technology work?

Answer 13

1. ) Radars interrogate the transponders of ACFT and receive information about the ACFT and its height.
2. ) In high traffic density areas e.g. Heathrow stacks, the integrity of Mode A and C can be adversely affected by the garbling of all the returns.

Question 14

How does Mode S alleviate the shortcomings of Mode A and C?

Answer 14

It targets individual ACFT rather than trying to resolve all the replies.

Question 15

What information set by pilots in the cockpit does Mode S allow the controller to access?

Answer 15

1. ) Selected flight level, indicated speed, heading, etc.

2. ) It aids in conformance monitoring and reduces communications between the controllers and the pilot.

Question 16

What is conformance monitoring?

Answer 16

use of electronic data to record ATC instructions given by the controller, combined with the radar information, allows ATC systems to monitor an aircraft’s conformance with instructions.

Question 17

What happens if aircraft do not conform to ATC instructions?

Answer 17

if there is a discrepancy between ATC instructions and the aircraft, the system provides the controller with an alert that can be checked and if necessary acted upon.