A Predator B drone has successfully completed tests with so-called sense-and-avoid radar, bringing it a step closer to legal operation in US and international airspace. You may be thinking, "haven't they already operated extensively in places like Iraq?" Yes, but in the US and other nations where skies are packed with traffic, drones are forbidden to operate. The flight test, conducted by Predator manufacturer General Atomics (using a NASA-owned Predator B) consisted of "scripted encounters" with multiple aircraft at Edwards Air Force base. The idea was to test the drone's ability to detect other planes with air-to-air radar and see how it fares under civilian air traffic control (TCAS II) systems.