A drone featuring LATAS (Low Altitude Tracking and Avoidance System) is prepared for a demonstration in Durham, North Carolina, U.S., on Tuesday, July 7, 2015. Google Inc. is joining some of the biggest companies in technology, communications and aviation -- including Amazon.com Inc., Verizon Communications Inc. and Harris Corp. -- in trying to create an air-traffic control system to prevent mid-air collisions. PrecisionHawk, a Raleigh, North Carolina, drone company with about 100 employees, began developing its own drone traffic control system because the large agriculture and oil companies it flies for wanted something to keep tabs on unmanned flights. Photographer: Jason Arthurs/Bloomberg via Getty Images