The situation is becoming so tense that federal workers now travel mostly in pairs and are in constant radio contact with district offices. (washingtonpost.com)
You're in frequent radio contact with various ground controllers (and sometimes other aircraft) to maintain separation and proper position. (automobilemag.com)
All three men knew there was precious little room for error, and for Frank Borman the most amazing moment of the flight came when Apollo 8 lost radio contact with Earth as it flew behind the moon — at the precise time mission control had predicted; it meant they were right on target. (scientificamerican.com)