text: Chapter 1
  area and limit the number of aircraft that can simultaneously operate in the LZ/PZs requiring greater power
  margins to maintain aircraft combat maneuver capabilities. Adjacent buildings and structures also provide
  cover and concealment for enemy forces and extend fields of view and fire from above the landing areas.
  Roof-top landing areas are typically cluttered with vertical obstructions (such as antennas and building
  mechanical systems) that may limit the size of touchdown areas, and based on the quality of the
  construction, may or may not be suitable to handle aircraft weights upon landing. The presence of sub-
  terrain structures (such as tunnels, subways, and sewers), as well as vast road networks bounded by vertical
  structures enables the enemy to rapidly reposition with cover and concealment from observation and fires.
  During night operations, high intensity lighting may reduce the effectiveness of using image-intensifying
  night vision devices, degrading the ability to acquire obstacles to flight and other aircraft, as well as
  limiting target acquisition capabilities for non-forward-looking infrared equipped aircraft. In heavily
  industrialized urban areas, power generation plants and other heavy industry can create localized areas of
  low to no visibility or layers of obscurants that impact both RW flight and UAS sensor employment.
  During attack and reconnaissance operations, high population densities in urban areas allow the hybrid
  threat to more easily blend in, increasing the difficulty of positive identification, and increasing the risk of
  collateral damage during engagements. Urban landscape surfaces can increase direct fire fragmentation
  effects due to less blast and fragmentation absorption of soft surfaces. This may increase target effect but
  also increases the danger of ricochets that risk fratricide or collateral damage. During engagements of
  structures, shaped-charge warheads on certain missile models are less effective in penetrating structures
  and achieving internal blast effects which may require greater expenditure of ordnance to achieve desired
  target effect. The prolific use of modern communications provides the enemy with early warning of
  operations, limiting the advantage of surprise. Measures to consider for mitigating risk in urban areas
  include—
  * Detailed technical reconnaissance of landing areas and obstacles.
  * Use of UAS conducting persistent reconnaissance.
  * Maximizing use of precision munitions.
  * Operating during the hours of darkness at higher altitudes.
  * Conducting detailed rehearsals of actions on the objective.
  * Use of special patrol or fast-rope insertion/extraction systems for small team infiltration and
  extraction, using common graphic control measures tailored for floor and room identification in
  buildings and increasing flight altitudes are all.
  Other Environments
  1-75. Pandemic zones. A pandemic zone is a geographical area infected with a pandemic disease. Within
  the pandemic environment, Army Aviation can conduct reconnaissance, convoy security, air movement of
  medical supplies and construction materials, air movement of medical, survey or security teams,
  aeromedical operations, and C2 support. Key considerations when operating in a pandemic zone are the
  difficulties associated with decontamination or sterilization of aircraft and ground support equipment and
  the limitations imposed on aircrews flying in personal protective equipment.
  1-76. Post-Disaster zones. A post-disaster zone is an area that has been struck with a natural,
  technological, or sociological disaster. As in a pandemic zone, Army Aviation can provide a wide range of
  capabilities to overcome the lack of available road networks and other infrastructure impacted in the
  disaster zone. Key considerations include challenges to radio communications with local authorities,
  limited availability of host-nation fuel support, damage to airfields and other supporting infrastructure,
  limited LZ/PZs due to debris, and deconfliction with other civil or non-governmental aviation operations in
  the disaster zone.
  1-77. CBRNE environments. Operations in CBRNE environments challenge aviation operations due to
  the lack of aircraft pressurization and the difficulty of conducting aircraft decontamination when exposed to
  radiological or persistent forms of chemicals or biological agents. Aircrew and support personnel
  performance is significantly degraded when operating in full protective posture. Key considerations before
  deliberately conducting aviation operations in a CBRNE environment include the following: