 The stingers did make an impact at first but within a few months flares, beacons, and exhaust baffles were installed to disorient the missiles, along with night operation and terrain-hugging tactics to prevent the rebels from getting a clear shot.By 1988 the mujahideen had all but stopped firing them.Stingers also forced Soviet helicopters and ground attack planes to bomb from higher altitudes with less accuracy, but did not bring down many more aircraft than Chinese heavy machine guns and other less sophisticated antiaircraft weaponry.