Varying weather and operational conditions influence the flight patterns of aircraft near airports. Wind has the greatest impact on flight paths as aircraft need to land and take off into the wind. As the wind changes, the flight paths change accordingly. Also, depending on aircraft volume, Air Traffic Control will put aircraft in holding patterns, increase aircraft spacing or set aside noise abatement procedures in the interest of safety. Aircraft are limited to where they can fly because of established flight paths, approach paths and departure paths. These paths are established and published to enhance safety during flight.