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DYACON Quick-start Guide
Ideally, the weather station wind sensor would be mounted on a 30 ft tower, positioned within a
clear circle of 1000 ft in diameter the center of which is offset from the center of the field by 500
ft to 1000 ft. (See the diagram below.)
Rural and private airports may not have sufficient area to meet this ideal, especially if a 30 ft
rigid tower is used. For small aircraft (<12,500 lbs), a setback from the centerline of the runway
of 125 ft plus 7 times the height of the wind sensor structure should be considered a minimum.
If the Dyacon 7-segment tripod is used, the weather station would be placed at mid-field at least
244 feet from the runway centerline. (7 x 17 ft + 125 ft = 244)
Airport owners should use their best judgment of prevailing wind directions, nearby
obstructions, and surface characteristics to position the station for best indication of surface
conditions while observing setback guidelines.
The Dyacon tripod would be considered “frangible” in that it would be knocked over if struck
by an aircraft.
Visual or Non-precision Runway Diagram
Ideal weather station placement. (FAA Order 6560.20B, Siting Criteria For Automated Weather
Observing Systems(AWOS), 7/20/98. Also, see ICAO Doc 9837 AN/454, Fig. 3-1)
Manual on Automatic Meteorological Observing Systems at Aerodromes (ICAO Doc 9837 AN/
454) states:
3.6.1 Measurements cannot of course be taken on the runway, and it is important to follow
the obstacle clearance rules in Annex 14 — Aerodromes, Volume I, Chapter 8, and the
Airport Services Manual (Doc 9137), Part 6. The minimum distance of a 10-m frangible
mast in relation to the runway centre line is 90 m. The mast must be placed in this zone only
if absolutely necessary; in most circumstances, a 10-m mast should be at least 220 m from
the runway centre line. These criteria are shown in more detail in Figure 3-1.
The Dyacon tripod is less than than the 10-m mast referenced above and may be placed closer to
the runway.
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2
3
5
5
0
0
f
t
to
1
0
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0
f
t
1000 ft to 3000 ft
Weather station inside of
circular clearing of 1000
ft diameter.