text: Chapter 2
  Figure 2-3. Wedge formation
  ECHELON FORMATION
  2-9. An echelon formation is a movement formation with elements arranged on an angle to the left or
  to the right of the direction of attack (echelon left, echelon right). This formation provides focused
  firepower forward and to the flank of the direction of the echelon. It facilitates control in open areas. It
  provides minimal security to the opposite flank in the direction of the echeloning. A unit with knowledge of
  potential enemy locations can use an echelon formation to deploy subordinate ground elements diagonally
  left or right or as a way to work within a higher echelon movement formation. Figure 2-4 depicts an echelon
  left formation and figure 2-5 depicts an echelon right formation. Units operating on the flank of a larger
  formation commonly use this formation. An echelon formation—
  * Facilitates control in open terrain.
  * Allows the concentration of the unit’s firepower forward and to the flank in the direction of the
  echelon.
  * Allows forces not in contact to maneuver against known enemy forces because all elements will
  not simultaneously make contact.
  2-10. The primary disadvantages of this formation are—
  * Difficult to maintain control over the unit in restricted terrain.
  * Lacks security or firepower on the opposite side of the echelon.