Abstract: A defense barrier for protecting a target from critical damage from the impact of a predetermined group of aircraft comprises: a plurality of towers spaced from the target, each tower being spaced from a neighboring tower by a distance less than the wingspan of an aircraft in the predetermined group of aircraft having the smallest wingspan in the group; each tower being spaced from the target at least a distance d given by the formula: d=h/tan(theta) where h is the height of the tower and theta is the smallest vertical approach angle of any aircraft from the predetermined group of aircraft sufficient to inflict critical damage to the target.

Abstract: A defense barrier for protecting a target from critical damage from the impact of a predetermined group of aircraft comprises: a plurality of towers spaced from the target, each tower being spaced from a neighbouring tower by a distance less than the wingspan of an aircraft in the predetermined group of aircraft having the smallest wingspan in the group; each tower being spaced from the target at least a distance d given by the formula: d=h/tan(theta) where h is the height of the tower and theta is the smallest vertical approach angle of any aircraft from the predetermined group of aircraft sufficient to inflict critical damage to the target.