A remote controlled drone almost collided with a commercial jet at 4,000 feet Sunday as it approached Los Angeles International Airport.

An investigation has been launched after the case, which occurred as a Southwest Airlines plane prepared to land at the airport. Audio recordings of the pilot and control tower documented the moment the pilot told air control about the near-miss.

"Hey, there was just one of those radio-controlled helicopter things that went right over the top of us at 4,000," the pilot said. "One of those remotely piloted deals… (a) little bitty one, red in color."

It is just the latest in a number of incidents across the country in which drones were spotted flying far too close to airports. Federal Aviation Administration (FAA) administrator Michael Huerta warned flying drones near airports could lead to a tragedy.

"The thing that we have to avoid is any opportunity for aircraft to come into contact with one another because that is an extremely dangerous situation for everyone involved," Huerta said.

A day before the LAX sighting, a drone was spotted at 3,500 feet in Chicago. A few hours later, a private pilot reported a drone at 1,300 feet.

On Sunday in Atlanta, another drone was spotted at 8,000 feet, well above the FAA limit of 400 feet.

Drone pilots in Los Angeles say flying near places like runways is unacceptable behavior for responsible flyers

Taylor Chien, founder and CEO of Dronefly, is hoping software that uses drones' own GPS systems will be used to keep rogue pilots away from restricted areas.

"So say you fly near an airport like LAX and you are within a five-mile radius it will... stop, turn around and fly back to you," Chien said.

Congress has given the FAA until the end of the year to come up with rules on how drones will be flown in the United States.