text: Army Aviation’s Role in Unified Land Operations
  over-the-horizon communication capabilities and ability to rapidly reposition ground maneuver leaders
  enhance the combined arms team’s ability to perform C2 over extended distances and beyond line of sight
  (LOS).
  1-66. Limitations. Operations in high, hot mountainous environments can limit aviation maneuver due to
  reduced load carrying capacity and maneuver power margins of aircraft. Depending upon the severity of
  the altitudes and temperatures, trade-offs may be necessary between aircraft loads (weapons, cargo, and
  personnel) and fuel carried, as well as adjustments to TTP which can impact station time, maneuver in the
  objective area, LZ and PZ selection, and aircraft ranges. Additionally, trade-offs may require additional
  FARP locations and/or more aircraft to complete a mission. Canalizing terrain reduces LOS
  communications, may limit the size or freedom of maneuver of aviation formations, and can drive
  predictable flight patterns that can be targeted by the enemy. Detailed planning, varying mission timelines,
  choosing longer or multiple routes, and employing non-line of sight or communications relay packages on
  UAS can mitigate canalizing terrain limitations. Several unique weather factors also influence operations in
  mountainous terrain. Unpredictable wind speeds, varying wind directions and frequent up and downdrafts,
  combined with high density altitude, low ceilings that obscure terrain, increased frequency of turbulence
  and reduced night time illumination due to shadows and terrain masking of the moon or man-made light
  sources requires more detailed planning, more experienced crews and adjustments to TTP. Severe cold
  weather is also prevalent during the winter in mountainous terrain. Severe cold temperatures, snow, and ice
  increase time requirements for aircraft preparation and launch due to deicing and snow removal, increased
  maintenance due to cold soaked seals and electronics, and increased flight hazards due to white-out, icing
  of blades and wings and loss of visibility due to falling or blowing snow. Aviation operations above 10,000
  feet mean sea level for more than an hour, above 12,000 feet for more than 30 minutes, above 14,000 feet
  for any period of time, require the use of supplemental oxygen for all Army RW aircraft. Additionally,
  depending upon the height of terrain, UAS service ceilings may reduce the height above ground for UAS
  operations which can increase their likelihood of visual or audio detection which could compromise the
  ground scheme of maneuver while increasing UAS vulnerability to engagement. Finally, all aircraft have
  weather restrictions as outlined in Army Regulation 95-1; UAS takeoff and landing operations may be
  especially limited due to weather patterns in mountainous areas.
  Desert Operations
  1-67. Capabilities. Army Aviation provides the combined arms team with enhanced capabilities to operate
  in desert environments. The extended sensor, communications, and weapons ranges of attack and
  reconnaissance RW and UAS enable long-range engagement of targets and collection of combat
  information to confirm or deny the commander’s PIR at the extended visual ranges typically associated
  with desert environments. Use of air assaults through the depth of the AO to seize typically limited key
  terrain or road networks can enable the combined arms team to counter the advantage of increased enemy
  ground maneuver speeds due to open and trafficable terrain afforded in a desert environment. Use of air
  movements to reposition supplies, ammunition and fuel over typically extended LOCs enables greater
  tempo and agility, while reducing operational risk to ground logistics and maneuver units. Use of aviation
  reconnaissance and security operations forward or to the flanks of ground maneuver forces to identify
  obstacles, enemy forces and the most suitable routes or axis of advance enables the combined arms team to
  maintain the tempo of operations while protecting friendly units through economy of force. These examples
  above highlight how Army Aviation’s speed, range, lethality and versatility enable the combined arms team
  to gain, maintain and exploit a position of relative advantage in the desert environment.
  1-68. Limitations. Blowing dust, sand, high temperatures, reduced visibility, low contrast and extended
  observation ranges all present unique challenges to aviation operations in the desert environment. Much
  like mountainous environments, extremely high temperatures can reduce the load carrying capacity of
  aircraft, requiring trade-offs between fuel, cargo, personnel, and munitions. High temperatures, along with
  dust and sand, increase maintenance requirements. The expansion and contraction of seals during extreme
  temperature swings increases the frequency of leaks and electronic component failures. Abrasion on rotor
  blades and other dynamic surfaces requires more frequent cleaning, and can reduce component life,
  especially blades, bearing assemblies and engines. Reduced visibility due to blowing sand, coupled with
  low contrast, increases the risk of brown-out during takeoffs and landings, especially in larger formations