2. Radar Seperation

Question 1

What functions can we perform in approach using position indications on a situation display?

what do we use radar for?

Answer 1

Provide vectoring of arriving traffic on to pilot
interpreted final approach aids

Provide flight path monitoring of parallel ILS
approaches and instruct aircraft to take appropriate action in the event of possible or actual
penetrations of the no transgression zone (NTZ);

Provide vectoring of arriving traffic to a point from which a visual approach can be completed;

Provide vectoring of arriving traffic to a point from which a precision radar approach or a surveillance radar approach can be made; (SRA)

Provide flight path monitoring of other pilot-
interpreted approaches;

Precision radar (PAR) approaches; and

• Provide separation between:
  Succeeding departing aircraft;
  Succeeding arriving aircraft; and
  A departing aircraft and a succeeding arriving
  aircraft.

Question 2

What is the separation minima?

Answer 2

The horizontal separation minimum based on radar and/or ADS-B and/or MLAT systems shall
be 5 NM.

Exceptions are with respect to independent and dependent parallel approaches and the
following:
The separation minimum may be reduced, but not below:
3 NM when radar and/or ADS-B and/or MLAT systems’ capabilities at a given location so
permit; and

2.5 NM between succeeding aircraft which are established on the same final approach track within 10 NM of the runway threshold, if……
The average runway occupancy time of landing aircraft does not to exceed 50 seconds;
Braking action is reported as good and runway is not adversely affected by runway contaminants
such as slush, snow or ice;

An ATS surveillance system with appropriate
azimuth and range resolution and an update
rate of 5 seconds or less is used in combination
with suitable displays;
The aerodrome controller is able to observe,
visually or by means of surface movement radar
(SMR), MLAT system or a surface movement
guidance and control system (SMGCS), the
runway-in-use and associated exit and entry
taxiways;

Question 3

What are the ground based safety nets? (4)

Answer 3

Short Term Conflict Alert (STCA)
Medium Term Conflict Detection (MTCD)

Runway Incursion Tools e.g.
- RIMCAS
- A-SMGCS

Can be Area, Approach or Tower based.

Question 4

What is STCA?

Answer 4

Short Term Conflict Alert

Generates a visual /and aural alert on the radar display, 2 minute warning before collision

Warns where the minimum separation distances between any pair of radar tracks is, or is predicted to be violated, within a short period ahead (usually 2 minutes).

Specific training needed

Question 5

What is MTCD?

Answer 5

Medium Term Conflict Detection

Generates a visual /and aural alert on a separate display, 20 minutes ahead of collision.

MTCD is a flight data processing system designed to warn the controller of potential conflict between flights in an area of responsibility up to 20 minutes ahead.

Part of the European FASTI programme iFACTS,
MONA and TCT are examples.

Question 6

What does MTCD consist of? (4)

Answer 6

• TP - Trajectory Prediction - Creates future trajectories for each aircraft/target.
• CD - Conflict Detection - identifying in the system potentially conflicting trajectories.
• TU - Trajectory Update - following an external input (i.e. human intervention) or due to a change in aircraft trajectory and/or automatic integration of detected aircraft position;
• TE - Trajectory Edition - responsible for allowing the human interaction with the predicted trajectory of one or more aircraft/targets.

Question 7

What is conflict resolution on MTCD?

Answer 7

A ‘what-if’ tool could be used for conflict resolution.

Ignoring the conflict (i.e. due to foreseen circumstances the conflict
will time expire or not occur) or;
Resolving it by modifying an entry or exit condition.
Deciding that the conflict is purely tactical and manageable by the
tactical controller and therefore transfers it to him/her.

Question 8

Comparison of the Tools

Answer 8

Short term conflict alert (STCA)
Look ahead time: usually 1-2 minutes.
Input: surveillance data
Used as: safety net

Medium term conflict detection (MTCD)
Look ahead time: up to 20 minutes
Input: flight plan data and controller input (clearances).
Used as: planning tool

Tactical controller tool (TCT)
Look ahead time: up to 5-8 minutes
Input: surveillance and/or FPL data
Used as: conflict resolution and clearance verification tool
(informs if the current clearance results in a breach).