Crop-dusting unmanned helicopter gets cleared for commercial flight

An unmanned helicopter that has been used for cropdusting in Japan for over 20 years has gotten clearance for test use in the US from the Federal Aviation Administration. Yamaha’s RMAX is now free to be flown over farms across America under a “Section 333” exemption to FAA regulations governing commercial use of unmanned aircraft.

The RMAX is not a drone, at least in the sense that many think of them—it’s a giant remote control helicopter controlled by a pilot within line of sight, weighing 141 pounds and capable of carrying 61 pounds of liquid spray or granules for crop dusting. The radio-controlled craft is powered by a 21-horsepower two-stroke engine—essentially a riding lawnmower engine.

The RMAX recently gained approval for use in Australia by the Civil Aviation Safety Authority (CASA), and is also flown for agricultural purposes in South Korea. Overall, RMAX aircraft have logged over 2 million flight hours, and are responsible for spraying about 40 percent of Japan’s rice crop today—so this is hardly an experimental aircraft. The University of California, Davis has been conducting experiments with the RMAX to determine its usefulness in crop-dusting vineyards on terrain not normally suited to traditional crop-dusting operations since 2013.