7754 Vol 2 Flyleaf - ICAO Public Maps

IV-F2
EUR FASID
a) Annex 11, Attachment A provides guidance on the
airspace requirements for VOR defined routes. Normally
the 95 per cent criteria can be used. In specified cases, to
ensure that a higher proportion of traffic will remain
within the boundaries prescribed, the width of the
protected airspace should be increased as indicated in
that guidance material. The use in specific cases of lower
values for the width of protected airspace along VOR
defined ATS routes should be agreed between States and
operators concerned. These can be based on an
assessment of the actual VOR performance instead of the
3 VOR radial signal error value assumed. Annex 10,
Volume I, Attachment C, 3.7.3.7 refers. Where traffic,
terrain and airspace considerations permit, it may also be
helpful to consider increasing the width of those portions
of ATS routes where the distance from navigation aids
and the overall system accuracy would otherwise be
incompatible.
b) for DME, co-located with an associated VOR in
accordance with the applicable provisions of ICAO
Annex 10, Volume I, the system use accuracy to be used
for planning purposes regarding the configuration of
ATS routes and related questions of separation should be
that given in Annex 10, Volume I, 3.5.3.1.3.
NUMBER 4: Track guidance
Deployment of VORs
VORs should be deployed along ATS routes forming
part of the agreed ATS route network and should be used
to define the centre lines of such routes so as to ensure a
smooth transition of navigational guidance at the
change-over point from one VOR to the next.
NUMBER 5: Spacing between VORs
Successive VORs providing track guidance along a given
ATS route should be spaced at the maximum distance
consistent with:
a) the required track-keeping accuracy; and
b) the lowest level at which navigational guidance along
the route in question is required. In those cases where
the VORs concerned serve ATS routes both in the
upper as well as in the lower airspace, the
requirements of the latter will dictate the spacing
between the aids concerned.
Account should be taken of the availability of 50 kHz
channel equipment in all cases where a reduction of
the full operational range would otherwise be
required because of frequency protection problems
arising from the need to conserve 100 kHz VOR
channels.
Note 1.— With respect to a), Criterion Number 9
is particularly relevant.
Note 2.— The requirement in b) results from the
quasi-optical propagation characteristics of VOR
signals.
Note 3.— With regard to b), VORs provided for use
in the lower airspace only should not be frequency
protected for utilization in the upper airspace.
Determination of designated
operational range and height
for VOR and DME
NUMBER 6: Designated operational
range requirements
The designated operational range for individual VOR
(including TVOR) along specific route segments should,
for planning purposes, extend up to half the segment
length in question plus 10 per cent of that distance or
10 NM, whichever is the greater. However, when
successive facilities along a given en-route segment are
spaced by a distance of 60 NM or less, each VOR should
have a designated operational range covering the entire
segment in question.
Note.— In specific cases where, due to the individual
requirements for minimum designated operational range
of adjacent VORs, significant savings of frequency
utilization may be achieved, derogation from the
mid-point principle may be made provided total
coverage of the route segment concerned is maintained.
NUMBER 7: Designated operational height requirement
In planning navigation coverage of VORs, the designated
operational height should be determined by the highest
level at which the aid concerned is planned to be used.
Note.— See also Note 3 to Criterion Number 5.
NUMBER 8: Specifications of designated operational range
for individual aids for frequency planning purposes