Visits from men in black often go hand in hand with sightings of black helicopters in America. After a bit of research we have found this seems to be the case with the Berwyn incident as well.
During the autumn of 1973 up on the Berwyn, a helicopter was spotted by beaters flying very low in bad weather. The witnesses said it appeared to be looking for something or attempting to land, as the beaters got near to the helicopter it flew off into the clouds.