"On a conference call with analysts, Chairman and CEO Fred Smith was asked whether the company was doing any research into the use of drones and unmanned trucks.

"We have five separate ... work streams or projects in both aviation and automated vehicles," Smith said. He declined to provide details until they are ready to "make a meaningful difference in the company."

The company's Boeing 777 cargo jets are capable of taking off and landing on their own, Smith said, "but it's very difficult in the foreseeable future to substitute for the well-trained pilot, driver, person.""

MG2