text: Army Aviation Capabilities and Characteristics
  Figure 5–8. AN/MSQ-135 mobile tower system
  AN/TPN-31 AIR TRAFFIC NAVIGATION, INTEGRATION, AND
  COORDINATION SYSTEM
  5-15. The AN/TPN-31 (figure 5-9, page 5-12) normally deploys along with a tower system as part of initial
  or follow-on forces to establish an all-weather instrument landing capability at landing sites/airfields within
  the joint operations and theater areas of responsibility. The air traffic navigation, integration, and
  coordination system (ATNAVICS) can provide ground-controlled approach operations within 60 minutes
  of arrival in an AO. ATNAVICS directly interfaces by voice and digital data links with the tower systems
  and tactical airspace integration system (TAIS) of the CAB, TAB, AOB, division, and theater airspace
  elements for airspace data supporting current operations. When required, the ATNAVICS integrates into
  the national/host-nation airspace system and complies with Federal Aviation Administration, International
  Civil Aviation Organization, North Atlantic Treaty Organization, and the European Organization for the
  Safety of Air Navigation standards for stability and civil support operations. Although the ATNAVICS is a
  tactical system, it can support Army requirements in a non-temporary, non-tactical type setting. The
  inherent flexibility of the ATNAVICS design also allows for its use in fixed-base environments.