Remote control airplanes are unmanned airplanes that are controlled via a remote device of some sort. Remote control airplanes are generally assumed to refer to model airplanes, used for recreation, as opposed to military-grade unmanned drones, although these may also be remote control airplanes.
Model airplanes have been around as long as airplanes themselves, and in fact model airships predated airplanes themselves. In fact, the first remote control airplanes were not even airplanes, but were actually remote control ships filled with hydrogen during the late-19th century. These ships used a very simple radio signal to issue controls, and were flown around theatres as a form of entertainment.
There are many different sorts of remote control airplanes, for every level of skill and price range. At the most simple level are basic park flyers, which are simple electric remote control airplanes, which really can only move up and down and slightly side to side. These are usually fairly cheap remote control airplanes, and are what are most often purchased for children or beginners to the hobby. They are known as park flyers because their size and speed makes them suitable for flying around a small park, or even indoors in a large enough building. Because park flyers generally fly so slowly, they can’t really be flown in heavy winds, which can cause them to be pushed off course or to the ground.
Jets are another class of remote control airplanes, and tend to be substantially more expensive than park flyers. These remote control airplanes run on actual jet fuel, and they can go as fast as 200MPH (320KPH), making them fairly dangerous for anyone except expert flyers. In fact, these remote control airplanes are regulated by the FAA, and only certified hobby pilots can fly them in certain restricted areas. Jets generally cost upwards of $1,000 US Dollars (USD), with some reaching in excess of $15,000 USD.
Remote control airplanes can also be separated into two classes based on their level of control: simple flyers and 3D flyers. Simple flyers can generally only move up and down and slightly left and right, with limited variation in speed. 3D flyers, on the other hand, have a high thrust-to-weight ratio, and advanced controls, allowing them to manage any number of impressive feats. 3D remote control airplanes are able to do many of the tricks associated with real jets, such as barrel rolls, intentional stalling, and hovering.
Remote control airplanes can be purchased as finished kits, often called Ready to Fly (RTF), or as kits that need to be prepared. Most beginners buy simple RTF planes, which can cost less than $100 USD, to play with intermittently in a park or other large open space. More advanced hobbyists, however, generally choose to assemble their own plane, allowing them more control over everything from materials to fuel capacity to the tightness of controls.
In addition to hobbyist uses, remote control airplanes are used for a number of scientific and military purposes. Unmanned aerial vehicles, such as the Hewitt-Sperry Automatic Airplane of World War I, or the modern MQ-1 Predator, are used for military reconnaissance or for actually deploying payloads in hostile territory. Others, such as the Aerosonde, may be used for scientific research, such as traveling into the high-velocity winds of hurricanes to learn more about dangerous environments.