text: FM 7-100.1________________________________________________________________________________
  9-76. Another method is to emplace remote sensors to overwatch the sites,
  and have the sites registered as preplanned artillery targets. Once the sen-
  sors pick up the incoming helicopters, the information is relayed to artillery
  units that take the sites under fire using variable-time-fuzed munitions. This
  tactic can either destroy or damage the aircraft or cause the area to be unusable.
  In lieu of remote sensors, small teams of SPF or affiliated forces can be posi-
  tioned to overwatch the most likely sites and relay information back to the guns.
  9-77. Another crude but potentially effective method is to have engineers
  string cables across the helicopters’ avenues of ingress. Engineers can also
  assist in the construction of deception positions to divert enemy air attack
  from actual forces or to lure the enemy into air defense ambushes.
  ASSETS
  9-78. In the OPFOR’s approach to all-arms air defense, various services of
  the Armed Forces and various branches within the services participate in the
  mission of air defense. However, there are some forces that specialize in air
  defense.
  9-79. Both the Air Force and the Army maintain air defense forces. In
  peacetime, all these air defense assets belong to the OPFOR’s administrative
  force structure. Even in wartime, some of themsuch as the national-level
  Air Defense Forcesmay remain centrally controlled at the national or
  theater level. Other assets from the administrative force structure are
  initially allocated to OSCs. An OSC, in turn, may allocate some of its air
  defense assets to augment those of its tactical subordinates. Thus, it is
  hard to predict where national-, operational-, and tactical-level assets may
  actually appear in the wartime, fighting force structure.
  9-80. Within the limits of its economic capabilities, the OPFOR has incorpo-
  rated recent technological developments into its air defense weapons. It may
  invest in a few high-technology systems that provide it a technological niche
  that it can exploit against even the most modern enemy air forces. Deploy-
  ment of advanced air defense systems, even in limited numbers, would affect
  all enemy air operations.
  NATIONAL-LEVEL ASSETS
  9-81. National-level air defense forces focus their efforts on destroying enemy
  aircraft, while protecting critical defensive positions and key political and
  economic sites. National-level assets include fighter-interceptor aircraft of
  the Air Force. Against a regional opponent, the OPFOR can use these aircraft
  to prevent enemy aircraft from entering or operating in OPFOR airspace. It
  can destroy enemy aircraft before they even take off by using air attacks and
  the long-range rockets and missiles of the Strategic Forces or direct action
  teams from its SPF Command.
  9-82. The Air Force also includes Air Defense Forces with which the
  OPFOR can successfully defend its airspace against regional opponents.
  These national-level assets, along with operational-level air defenses, also
  provide the capability to challenge or deny air access into the region by out-
  side forces, at least initially.