Approach elevation performance requirements.

CFR · 2024-01-01 · US · Title 14

This section prescribes the performance requirements for the elevation equipment components of the MLS as follows: (a) (1) Laterally within a sector originating at the datum point which is at least equal to the proportional guidance sector provided by the approach azimuth ground equipment. (2) Longitudinally from 75 meters (250 feet) from the datum point to 20 nautical miles from threshold in the direction of the approach. (3) Vertically within the sector bounded by: (i) A surface which is the locus of points 2.5 meters (8 feet) above the runway surface; (ii) A conical surface originating at the datum point and inclined 0.9 degree above the horizontal and, (iii) A conical surface originating at the datum point and inclined at 15.0 degrees above the horizontal up to a height of 6000 meters (20,000 feet). (4) Within the elevation coverage sector defined in paragraphs (a) (1), (2) and (3) of this section, the power densities must not be less than those shown in Table 9, but the equipment design must also allow for: (i) Transmitter power degradation from normal by −1.5 dB. (ii) Rain loss of −2.2 dB at the coverage extremes. (b) (1) Be located as close to runway centerline as possible (without violating obstacle clearance criteria). (2) Be located near runway threshold such that the asymptote of the minimum glidepath crosses the threshold of the runway at the Approach Reference Datum height. Normally, the minimum glidepath should be 3 degrees and the Approach Reference Datum heigh

official document · source cfr-2024 · id 14:§ 171.317