Commercial – in - Confidence
3
Site requirements for ILS
3.1
Localizer
The criteria given here are for the NORMARC localizer antenna arrays, NORMARC 3523, NORMARC 3524, NORMARC 3525 and NORMARC 3526.
3.1.1
General levelling and grading requirements
HBK 1193
Figure 3-1 Typical layout for a Localizer antenna site
Table 3-1 Explanation for Figure 3-1
Symbol RESA Runway strip Graded part of Runway strip
NORMARC 7000 ILS © 2005 Park Air Systems AS
Explanation R unway unway End Safety Area. As defined in ICAO ANNEX 14. As defined in ICAO ANNEX 14 As defined in ICAO ANNEX 14
Inst. and Comm. Handbook 21465/Rev.4.3/05-Apr-05 Page 11 of 48
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Table 3-2 Grading and levelling requirements
Area “A”
Area “B” Adjacent areas to Area “A” Transition between Area “A” and Area “B”
Area “A” should be graded to be compliant with ICAO Annex 14 requirements and recommendations for Runway end safety area as given in Annex 14 paragraph 3.4. In addition transverse slopes should be symmetrical about the extended runway centreline. Area “A” shall be free of localizer interference sources as trees, buildi ngs, fences, etc. Grading may be limited to removal of localizer interference sources as trees, buildings, fences, etc. Site specific. Should be approved by Park Air Systems for each specific site. Should be graded to natural surface in Area “B” at maximum 5% slope.
3.1.2
Positioning of localizer antenna and equipment shelter.
3.1.2.1
Localizer antenna
The localizer antenna distance from the stop end of the runway must be determined by terrain and siting conditions for each specific site. Normally the localizer antenna array should be positioned on the extended runway centreline beyond the end of RESA at a distance of 300m or more from the stop end of the runway. The position of the localizer must be compliant with ANNEX 14 obstacle limitation requirements. 3.1.2.2
Localizer equipment shelter
The Localizer equipment shelter should be positioned outside Area “A”, and must be compliant with ANNEX 14 obstacle limitation requirements. To avoid un-necessary loss in signal strength due to cable loss, the distance between the localizer antenna array and the localizer equipment shelter should be as small as possible.
3.1.3
Effect of scattering from buildings and other objects
To obtain a specified signal quality, the correct localizer antenna system, which matches the layout of buildings, fences etc. at the airport, must be selected. Park Air Systems should carry out a signal analysis for each specific site. Since the layout and sizes of buildings etc. is different for each airport, it is not practical to give general requirements.
3.2
Glide Path
The criteria given here are based on a Glide Path structure with maximum bends less than ±15 µA between ILS point A and B and less than ±10 µA between ILS point B and T.
Inst. and Comm. Handbook 21465/Rev.4.3/05-Apr-05 Page 12 of 48
NORMARC 7000 ILS © 2005 Park Air Systems AS
Commercial – in - Confidence
3.2.1
Longitudinal terrain profile requirements
HBK 119 4
Figure 3-2 Longitudinal terrain profile requirements for Glide Path
Table 3-3 Symbol explanation for Figure 3-2
Symbol
Explanation
θ
Glide Path angle. Normally 3.0°
P
Minimum distance from Glide Path antenna to terrain drop off
H
Distance from Glide Path antenna along extended reflection area to start of “horizon limitation line”
α
Horizon limitation angle.
Table 3-4 Longitudinal terrain profile (for guidance only, depends on each specific site)
M-array
Sideband Reference
Null-Reference
H
365 m for θ = 3.0°
Maximum allowable α
θ /3
P; α = θ
© 2005 Park Air Systems AS
365 m
P; α = 0°
320 m
H
400 m for θ = 3.0°
Maximum allowable α
θ /6
P; α = θ
/6
390 m
P; α = 0°
360 m
H
500 m for θ = 3.0°
Maximum allowable α
θ /8
P; α = θ P; α = 0°
NORMARC 7000 ILS
/3
/8
450 m 400 m
Inst. and Comm. Handbook 21465/Rev.4.3/05-Apr-05 Page 13 of 48
Commercial – in - Confidence
3.2.2
General levelling and grading requirements
HBK 1195
Area “C” 8°
X
E W W L
P Area “A” Area “B”
60m
Area “D”
8°
D
Figure 3-3 Levelling and grading requirements for Glide Path
Table 3-5 Symbol explanation for Figure 3-3
Symbol
Explanation
D
Glide Path antenna setback from threshold. Normally approx. 290m for a 3.0° Glide Path. The distance is dependent of selected RDH, terrain slopes in Area “A”+”B” and Glide Path angle.
L
Distance from Runway Centreline to Glide Path antenna. Normally 120 m. The distance must be selected to comply with ICAO Annex 14 requirements.
P
As described for Figure 3-2.
E
Lateral distance from Glide Path antenna to furthermost edge of Beam Forming Area. Typical value is 30m to 60m, dependent of Glide Path antenna system and condition of Area “C” and “D”.
W
± Width of Area “A” at the base of the Glide Path antenna mast. Minimum length of W is 20m.
X
Site dependent distance from Glide Path antenna to edge of Area “C”. Typical value is 120m.
Inst. and Comm. Handbook 21465/Rev.4.3/05-Apr-05 Page 14 of 48
NORMARC 7000 ILS © 2005 Park Air Systems AS
Commercial – in - Confidence
Table 3-6 Grading and levelling requirements
Area
Description
Area “A” and Area “B” (BFA)
Area “A” and Area “B” are often referred to as the “Beam Forming Area” (BFA), and shall be treated as one continuous surface except for grading specifications within each area. The area shall be uniformly graded with a constant average longitudinal slope and a constant average lateral slope. The lateral slope shall normally not be greater than 1.5%. Acceptable roughness (undulations with “wavelength” 1 - 3 meter) within Area “A” is ± 4 cm, and within Area “B” ± 15 cm. Dimensions of Area “A” and “B” are defined in Figure 3-2 and Figure 3-3, and Table 3-3, Table 3-4 and Table 3-5.
Area “C”
Grading may be limited to removal of objects, which would reflect the Glide Path signal into the usable area.
Area “D”
Grading may be limited to removal of objects, which penetrate the “extended” Beam Forming Area up to distance H, or penetrating the “horizon limitation line”. (Se Figure 3-2 and Table 3-3 and Table 3-4).
Transition between BFA and Area “C”
Should be graded to natural surface in Area “C” at maximum 5% slope for the part that is inside the runway strip. (Ref. ICAO ANNEX 14)
Transition between BFA and Area “D”
No specific requirement, but transition should be as smooth as possible.
Transition between BFA and the Runway side of the Runway strip.
The transition shall be as smooth as possible and must comply with ICAO ANNEX 14 requirements and recommendations for slopes on and grading of the graded portion of the runway strip.
3.2.2.1
Specific sites - optimised M-Array Glide Path.
For a specific Glide Path site, it may be necessary or possible to deviate from these general specifications. If the site does not fully comply with these requirements, Park Air Systems should be consulted. Park Air Systems has a long experience in analysing Glide Path sites, and if appropriate, optimising the antenna feeds for M-Array type Glide Paths. Optimising the feeds for a specific site may relax the siting requirements considerably or improve the signal quality and possibly reduce the cost of levelling.
NORMARC 7000 ILS © 2005 Park Air Systems AS
Inst. and Comm. Handbook 21465/Rev.4.3/05-Apr-05 Page 15 of 48
Commercial – in - Confidence
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NORMARC 7000 ILS © 2005 Park Air Systems AS
