LIQUID/LIQUID, LIQUID/GAS OR GAS/GAS SEPARATION Method General operations by centrifugal force, using centrifuges or free-vortex apparatus using magnetic or electrostatic effect Apparatus General operations by centrifugal force, using centrifuges or free-vortex apparatus , using magnetic or electrostatic effect SOLID/LIQUID OR SOLID/GAS SEPARATION Method General operations by centrifugal force using centrifuges or free-vortex apparatus using magnetic or electrostatic effect Apparatus General operations by centrifugal force using centrifuges or free-vortex apparatus , using magnetic or electrostatic effect SOLID/SOLID SEPARATION Method Dry methods material in bulk Individual sorting Screening, sifting, pneumatic sorting using pneumatic tables or jigs by magnetic or electrostatic effect by centrifugal force using centrifuges or free-vortex apparatus Wet methods General operations flotation, differential sedimentation screening Combinations Dry methods - wet methods Apparatus Dry methods material in bulk Individual sorting Screening, sifting, pneumatic sorting using pneumatic tables or jigs by magnetic or electrostatic effect by centrifugal force using centrifuges or free-vortex apparatus , Wet methods General operations flotation, differential sedimentation screening Combinations Dry methods - wet methods As far as possible, classification is made according to constructional features; classification according to particular kinds of aircraft is normally regarded as being of secondary importance, except in cases where this is considered to be the characteristic feature. STRUCTURES, FAIRINGS Features common to different elements Fuselages; wings; stabilising surfaces ; ; Other structural elements PROPELLERS, FLIGHT CONTROL Propellers Adjustable control surfaces or members; control systems ; Control by jet reaction Stabilisation and controls not otherwise provided for , MODIFYING LIFT BY ACTION ON AIR-FLOW , , ALIGHTING GEAR AIRCRAFT KINDS AND THEIR COMPONENTS NOT OTHERWISE PROVIDED FOR Supersonic Seaplanes Aircraft intended to be sustained without power plant; powered hand-glider-type aircraft; microlight aircraft Convertible aircraft Vertical-take-off or landing aircraft Rotorcraft; ornithopters ; Others FLIGHT ARRANGEMENTS ON AIRCRAFT Of power plant and auxiliaries , , , Of power-plant controls and transmissions , For fuel supply , Of flying instruments USE OF AIRCRAFT For military purposes , For persons or freight SAFETY OR EMERGENCY ARRANGEMENTS OR EQUIPMENTS For the aircraft against icing; against lightning ; for landing , For jettisoning or other means concerning fuel , For persons or material by holding or ejecting means by parachutes; parachuting ; Other safety, emergency, or protection means , , EQUIPMENT FOR OPERATIONS PERFORMED DURING FLIGHT Releasing or receiving articles, fluent materials, or another aircraft , Towing, fuel replenishing , OTHER ARRANGEMENTS OR EQUIPMENT In this subclass, the following terms or expressions are used with the meanings indicated: "installations" embraces equipment, including mobile equipment, peculiar to use in connection with aircraft and not fitted thereto; "ground installations" embraces waterborne installations. This subclass covers only vehicles, equipment or the like, which are specially adapted for cosmonautics. This subclass does not cover vehicles and equipment applicable to both cosmonautics and aeronautics, which are covered by the appropriate aeronautical subclasses of class . In this subclass, the following term is used with the meaning indicated: "cosmonautics" includes all transport outside the earth's atmosphere, and thus includes artificial earth satellites, and interplanetary and interstellar travel.