A projectile deployed cable weapons system for defeating helicopter rotor systems is disclosed. The deployed cable is intended to settle on the target helicopter from above, and damage is inflicted on the main rotor blade or tail rotor blade of the helicopter by sudden stoppage or catastrophic failure of the contacted rotor system.A particularly advantageous assemblage for deploying an amount of cable to defeat helicopter rotor systems is also disclosed. The weapons assemblage includes a first cavity for receiving a projectile, a second cavity containing an amount of cable, and an inelastically deformable snaring means attached to the cable and situated with respect to the first cavity so as to intercept the projectile when projected. Most advantageously the assemblage consists of a field container containing both the projectile and cable as a single operating unit to be attached to the muzzle of a mortar cannon of conventional design.