An Air Force cargo plane collided with a drone in Afghanistan, a potentially serious mishap that could give ammunition to critics wary of allowing pilotless aircraft to operate in civilian airspace.

Air Force Capt. Justin Brockhoff, a spokesman for the military in Afghanistan, confirmed that a C-130 cargo plane made an emergency landing Monday at a base in eastern Afghanistan after colliding with an RQ-7 Shadow, an unmanned aerial vehicle that is usually operated by the Army...