The Federal Aviation Administration (FAA) is investigating how pilots flying into Denver International Airport temporarily lost contact with air traffic controllers on Monday.  The FAA told FOX Business that part of the Denver Air Route Traffic Control Center (ARTCC) experienced a loss of communications for approximately 90 seconds around 1:50 p.m. local time on Monday after both transmitters that cover a segment of airspace went down. Sources told Denver7 that as many as...