Flight routes: Are as short as pos

Flight routes: Are as short as possible, consistent with other considerations. Avoid turns in excess of 45 degrees, when formation flying is required, to facilitate control of the aircraft formation. Provide terrain masking to deny exposure to enemy observation, direct fire weapons, and radar acquisition, if possible. Provide cover when terrain permits, placing terrain mass and/or vegetation between the enemy and the aircraft. Provide for ease of navigation (day or night). Avoid masking friendly fires, particularly supporting artillery. Avoid known enemy units and air defense positions. Avoid over-flight of built up areas.