(GCA) radars. In some parts of the world, blowing sand creates conditions which
modulation (FM) communications. During cold weather, windchill will reduce
aircraft sortie generation rates and aircraft refueling or rearming times by
requirement for heated aircraft shelters as major aircraft repairs and maintenance
cannot be performed in exposed areas.
Wind speed and direction will affect the accuracy of air defense weapons to varying
degrees. Wind is also of concern to air defense personnel because of its impact on
NBC operations. High winds reduce visibility and together with rain, snow,
drizzle, or dust create conditions which reduce the effectiveness of visual air
defense target acquisition and tracking. During cold weather, the effects of
windchill on air defense personnel and operations are of prime concern.
High winds and associated turbulence will have an adverse effect on the accuracy of
airborne and air resupply operations. A ground wind speed of 13 knots is normally
considered the maximum allowable to safely drop personnel. High or variable winds
aloft will often result in airborne drops being dispersed over too large an area.
Turbulence and associated aircraft buffeting will decrease the efficiency of
airlifted personnel due to airsickness.
Precipitation often affects aircraft performance, in addition to reducing
visibility and the effectiveness of radars. Both rain and snow are often
accompanied by icing conditions at aircraft operating altitudes. Icing forces
aircraft to operate at lower altitudes, or limits operations to aircraft that have
an in-flight deicing capability. Parked or grounded aircraft must have snow
removed and be thoroughly deiced prior to operations. Rain, snow, and ice on
runways will increase the incidence of damage to aircraft on takeoff or landing and
will decrease the effectiveness of aircraft braking during landings.
Rain and snow on airfields hinder aircraft refueling, rearming, and maintenance.
Sortie generation rates are reduced during periods of heavy rain and snow due to
the requirement for greater caution by the refueling and rearming crews, personnel
discomfort, and the requirement to move aircraft under cover for even routine
Rain and snow will affect cross-country movement by air defense units, and will
often make low-lying deployment sites unusable. Extremes of precipitation may
restrict off-road access entirely, or swell rivers and streams beyond their banks.
This affects both unit mobility and the ability to effectively position air defense
assets to support river-crossing operations. Rain and snow will reduce the