CAP 413, Manual

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CAP 413 Radiotelephony Manual
Chapter 6 Page 28
1.17.6 Reduced Traffic Information
1.17.6.1 When providing a surveillance derived ATS, there may be circumstances that prevent
controllers from passing timely traffic information and/or deconfliction advice, e.g.
high workload, areas of high traffic density, against aircraft conducting high energy
manoeuvres, or when traffic is not displayed to the controller. Controllers shall inform
the pilot of reductions in traffic information along with the reason and the probable
duration; however, it may not always be possible to provide these warnings in a
timely fashion.
1.17.6.2 In high workload situations, which may not always be apparent from RTF loading, it
may not be possible for controllers to always provide timely traffic information and/or
deconfliction advice. High workload situations may not necessarily be linked to high
traffic density.
1.17.6.3 High traffic density can cause difficulty interpreting ATS surveillance system data and
may affect radiotelephony loading or controller workload to the extent that he is
unable to pass timely traffic information and/or deconfliction advice on all traffic.
1.17.6.4 Where aircraft are operating close to the lateral and/or vertical limits of solid ATS
surveillance system cover, or close to a radar overhead, there is potential for
conflicting traffic to be detected late.
1.17.6.5 Where aircraft are operating in known areas of poor surveillance performance,
permanent echoes, weather clutter or when the controller suspects the performance
of the ATS surveillance system is degraded, there is potential for aircraft to be
undetected or detected late.
G-CD, helicopter conducting power
line inspection 5 miles north of
Borton below altitude 500 feet
G-CD, reduced traffic information
due to controller workload
G-CD, approaching an area of high
traffic density, possible late warning
of traffic for the next 8 miles
G-CD, reduced traffic information
from the left for the next 10 miles
due to the limits of surveillance
coverage
G-CD reduced traffic information
due to limited surveillance
performance
17 November 2011