Freque Y News Today

Into each other in skies over syria. the u.s. is not revealing how vague the agreement is. >> our crews know what a safe distance is and the obligation is upon the russians to maintain that safe distance. >> reporter: but cnn has learned, it does not even specify how far away u.s. and russian aircraft have to stay from each other. >> these protocols include maintaining professional airmanship at all times, use of specific communication freque y frequencies and the establishment of a communicatio...