PHOENIX, AZ (3TV/CBS 5) -- Last year, pilots and other witnesses reported 81 close encounters between drones and other manned aircraft in Arizona.
It is such a concern to aviation officials that the Federal Aviation Administration is developing a system to track drones and their pilots in real time.
"We are concerned with the number of pilot-drone sighting reports we're getting and the number or reports we're getting around airports," said Ian Gregor, who works for the FAA.
Across the country last year, pilots and other witnesses reported 1237 "drone encounters" where drones were spotted in the close vicinity of aircraft or airports.
"The numbers have gone up every year over the past three years," said Gregor.
In Arizona, an Airbus 319 passenger jet reported a drone passing 100 feet overhead while the jet was descending to Sky Harbor.
A helicopter was forced to circle back and land after takeoff at Mesa Gateway, after a drone got in its way.
A police helicopter in Tucson chased a drone. Its pilot was arrested.
And a firefighting helicopter in the Yuma area was forced to cease firefighting activity after a drone was spotted near the fire.
"If you fly, we can't," said Andrew Mandell, who works for the US Forest Service.
Mandell said there were 21 incidents across the country last year, when people flying drones interrupted wildfire-fighting efforts.
"Generally speaking, all aircraft operations get halted until we can be sure that the airspace is safe," said Mandell.
Aviation safety officials say education is a big part of reducing the number and frequency of these close-encounters. They say the number of hobby drones keeps increasing, and that their operators often are not aware of safety rules. Soon, more operators will be required to pass a safety test in order to legally operate their drones.
But the FAA is also helping to develop guidelines and infrastructure for systems to track drones and their operators in real-time, in case the drones at issue pose a serious safety risk.
"Technology is going to be a very important solution going forward," said Gregor.