text: Chapter 3
  once a 9-line MEDEVAC mission request is received, and all critical data is provided in order to complete
  the necessary information required to complete planning and respond.
  AEROMEDICAL EVACUATION REQUESTS
  3-161. Specific procedures, frequencies, and security requirements for transmittal of MEDEVAC requests
  are delineated through the orders process and are made a part of the unit/command SOP. Based on the
  mission variables, each AO may have a different primary method of MEDEVAC (via ground or air).
  Sectors with a high ground-to-air or air-to-air threat may rely on ground evacuation assets to move the
  majority of patients. In other sectors where the ground threat is high and comprised of small arms or IEDs,
  AE operations may be more efficient. It may take a combination of both air and ground evacuation assets
  and air and ground force protection assets working in concert to mitigate the risk to perform the evacuation.
  3-162. Soldiers are evacuated from the point of injury to an AXP or MTF by the most expeditious means
  of MEDEVAC based on their medical condition, assigned evacuation precedence, availability of
  MEDEVAC platforms, and the threat. It is critical that all commanders with C2 of AE assets understand the
  categories of casualty precedence. The evacuation precedence for the Army operations at Role 1 through 3
  MTFs are—
  * Priority I, Urgent is assigned to emergency cases that should be evacuated as soon as possible
  and within a maximum of 1 hour to save life, limb, or eyesight; prevent complications of serious
  illness; and avoid permanent disability.
  * Priority IA, Urgent-Surgical is assigned to patients that should be evacuated as soon as possible
  and within a maximum of 1 hour who must receive far forward surgical intervention to save life,
  limb, or eyesight and stabilize for further evacuation.
  * Priority II, Priority is assigned to sick and wounded personnel requiring prompt medical care.
  This precedence is used when the individual should be evacuated within 4 hours, if medical
  condition could deteriorate to such a degree that patient becomes an URGENT precedence,
  whose requirements for special treatment are not available locally, or who may suffer
  unnecessary pain or disability.
  * Priority III, Routine is assigned to sick and wounded personnel requiring evacuation but whose
  condition is not expected to deteriorate significantly. The sick and wounded in this category
  should be evacuated within 24 hours.
  * Priority IV, Convenience is assigned to patients for whom evacuation by medical vehicle is a
  matter of medical convenience rather than necessity.
  Note. The North Atlantic Treaty Organization no longer recognizes Priority IV, Convenience;
  however, this category is still included in the United States Army evacuation priorities.
  3-163. Evacuation precedence assists the supporting headquarters to determine priorities for committing
  AE assets. Proper classification of each evacuation mission is especially important, since over-
  classification can lead to reduced evacuation assets available for follow-on missions.
  3-164. Figure 3-28, page 3-43, depicts the sequence of two different AE missions in a LSCO
  environment:
  * The right-hand portion of the figure shows a casualty in an AO with a high enemy air defense
  threat. The casualty is ground-evacuated from the point of injury, through a casualty collection
  point and battalion aid station, to a brigade support medical company in the brigade support area.
  Due to the enhanced anti-aircraft threat in this particular example, the DS forward support
  MEDEVAC platoon only operates between the brigade support area and the division support
  area. Once the casualty arrives at a field hospital in the division support area, he or she is then
  evacuated to higher levels of care by the area support MEDEVAC platoon until being evacuated
  from theater by inter-theater AE assets.
  * The left-hand portion of the figure shows an AE request and mission execution in a lower-threat
  AO. The initial MEDEVAC request flows from forward elements to a BCT headquarters while
  the casualty is evacuated to an AXP by ground. Due to the lower air defense threat in this AO,