Amazon's dream of door-to-door delivery by drone might not be dead after all. The Federal Aviation Administration has granted the company an "experimental airworthiness certificate" to test drones outdoors, but it comes with some pretty tough restrictions: The tests must take place below 400 feet during daylight hours and the drone must remain in sight of the operator, who will be required to have a private pilot's certificate, according to an FAA press release. Still, the FAA certificate is "huge news for Amazon," which had threatened to move its development program overseas after the agency announced drone restrictions last month, a BI Intelligence research analyst tells CNN. "It seems like the FAA is giving Amazon a runway to at least test in the US." (More drones stories.)