Draft:Yamaha R-50

The Yamaha R-50 is an unmanned helicopter developed by the Japanese Yamaha Motor Company.

In 1980, Japan's Agriculture, Forestry and Fishery Aviation Association was in the process of developing a system known as Remote Control Aerial Spraying System "RCASS", which was later handed off to Yamaha to develop. The coaxial-rotor RCASS led Yamaha in 1985 to begin development on a prototype single-rotor vehicle, completed in June 1986. Ongoing problems with the RCASS led Yamaha to prioritize work on this design, designated the R-50 Aero Robot.

The first model of the R-50, dubbed the "L09" was completed in 1987, and was able to crop-dust with a payload of around 15 kilograms at a demonstration flight later that year. The R-50 was the world's first unmanned crop-dusting helicopter. Beginning in 1988, agricultural schools in Japan began to use the R-50, and in 1991, after the Ministry of Agriculture passed the guidelines for training in relation to the craft, the R-50 began to be used for training purposes.

The same year, Yamaha began marketing the R-50 Type II in Japan. Customers provided feedback on the model. The model initially featured little assistance for the operator, and following this Yamaha's Research and Development implemented an altitude control system (ACS) into the R-50, which would allow for better ability to spray the targeted field or rice paddies. An ultrasonic sensor was also tested on the model, but the rice paddies that the R-50 were tested on largely absorbed the waves.

A laser sensor was also tested, and was later adapted into a technical system that was meant to control the altitude of the R-50, and was named the Yamaha Operator Support System (YOSS). The YOSS system was installed on the R-50 for a short period of time, but was unable to effectively function above uneven terrain and was later removed from production. In 1995, fiber-optic gyros initially developed for use in vehicle navigational systems were repurposed to develop the Yamaha Attitude Control System (YACS). The YACS had an operator-controlled tracing device that allowed the craft to more effectively respond to commands from the control. It was added to the R-50 and was first marketed the same year. The introduction of the YACS gained the craft much popularity due to its efficiency and easiness to use.

About 1,000 R-50s were produced, and initial models were monitored heavily. The R-50 was developed with the intentions of being able to spray pesticides on orchards, farms and other areas abundant in crops. It was also used in forest and on golf courses, where the R-50 was useful for spraying pine trees from damaging insects. The R-50 was successful in its' initial purpose, and was used heavily to spray pesticides on crops like rice and barley. The R-50 also replaced labour which had been done by hand, and cut down labour costs. It was also used for aerial photography purposes, and heavily cut down costs to take aerial photographs.

The R-50 also allowed higher-value crops to be grown on largely hilly landscapes, and the craft was able to spray pesticides and other nutrients on these crops.

The R-50 also proved useful to researchers developing more advanced systems for UAV control, including:
 * name of organization or solo researcher (and optionally, if you can summarize in one sentence, what they were researching)
 * next researcher
 * next researcher
 * etc

The R-50 has a streamlined design, with two skids being attached to the craft by four legs. The fuselage is of conventional pod-and-boom design. On the tail are two horizontal stabilizers that face slightly downward, and a tail rotor which is positioned to the left of the craft. Under the tail rotor is a ventral fin. Above the main body is a single rotor with a relatively large mast, two blades, and a stabilizer bar. The R-50 is powered by a liquid-cooled, 2-stroke, 98cc, 12 hp engine, which is located in the main pod. It has a 20 kg (44 pound) maximum payload and in 2021, it cost between $150,000-$200,000. In 1995, the Yamaha Attitude Control System (YACS) was introduced onto the R-50.