Since their introduction in 1997, Yamaha RMAX helicopters have flown more than 2 million hours. Used in Japan for years to primarily seed and spray rice, RMAX was recently given clearance by the Federal Aviation Administration to spray crops in the U.S.

With over 2,600 helicopters operating worldwide, each 207-pound unmanned helicopter can deliver and dispense tanks of fertilizer and pesticides across large tracts of land.

A statement released by the FAA noted: "The enhanced safety achieved using an unmanned aircraft with the specifications described by Yamaha and carrying no passengers or crew, rather than a manned aircraft of significantly greater proportions, carrying crew in addition to flammable fuel, gives the FAA good cause to find that the UAS operation enabled by this exemption is in the public interest."

The approval, however, came with 28 conditions, one of which was that the only machine approved was the RMAX. All others would need individual approval.

The RMAX will also be limited to operating at speeds of no more than 45 mph and a maximum altitude of 400 feet above ground level. The pilot and an observer will have to maintain a direct line of sight with the RMAX whenever it is in operation.

"I certainly understand their cautious approach," notes Steve Markofski of Yamaha. "It's a daunting task given that our airspace is complicated."