fm 44-100 us army air and missile defense operations

FM 44-100
Key Terrain
A-4
A-15. Key terrain is any locality or area in which the seizure, retention, or
control of it will afford a marked advantage to either combatant. In the aerial
dimension, these consist of terrain features that canalize or constrain air
threat systems, and terrain with an elevation higher than the maximum
ceiling of air threat systems. Additionally, areas that can be used for
airfields, landing and drop zones, or forward arming and refueling points also
need to be considered as key terrain (since these areas could be used to
support friendly or enemy air operations). Terrain can be used as an aid to
navigation. Man-made features are also used as cues to navigate to targets.
Air Avenues of Approach
A-16. Air avenues of approach are evaluated using the same criteria as for
ground. A good air avenue of approach will permit maneuver while providing
terrain masking from surface-to-air weapon systems. Some common air
avenues of approach are valleys, direct lines from the threat point of origin,
and riverbeds. Factors that should be used to determine entry and exit air
avenues of approach are as follows:
• Type of air threat, attack profile, and ordnance.
• Air threat point of origin and ground control radar positions.
• Probable threat objective.
• Potential to support maneuver forces.
• Freedom to maneuver within the air avenue.
• Protection afforded to the air system and pilot.
• Air threat and pilot capabilities.
A-17. Type of Air Threat. UAVs are small and elusive. Although they
usually fly at low altitudes, their altitude can vary. Once in the target area,
they may fly an orbit attempting to stay out of engagement range of ADA.
Most surfaced-launched cruise missiles are terrain following and they use
terrain masking. Due to their range, they may take indirect approach routes.
Ballistic missiles are not terrain dependent. They fly a straight ground track
from launch point to objective. Their flight is not restricted by terrain. ASMs
usually fly direct routes from launch platform to the target. Rotary-wing
aircraft primarily conduct contour flights. They follow ridgelines and military
crests, using the terrain to mask their approach to the target area. Fixedwing
aircraft usually follow major terrain or man-made features. Depending
on range, they may fly a straight line to the target. Ordnance or payload may
affect range and altitude of the air system and thus influence the selection of
avenues of approach.
A-18. Point of Origin. Staff looks at the commander's entire area of interest
when determining air avenues. Analysis begins at the enemy airfield, UAV,
or missile launch site and works toward the probable enemy objective. This
allows a look at the big picture. The staff considers the range of the air
systems and location of navigation aids and ground control sites.
A-19. Probable Enemy Objective. Each avenue of approach must end at a
target, drop zone, or landing zone; or within reconnaissance, intelligence,