US Patent 7273195 Vertical lift craft

A vertical lift craft includes a vertical lift craft, a powered rotor system including two counter-rotating lift rotors rotatably mounted to the body and a cage fixed to the body and extending about the powered rotor system, the cage including flexible rods extending in an open mesh pattern and mutually attached at a plurality of intersections between the flexible rods and netting extending between the flexible rods to cover the cage. The mesh pattern includes latitudinally and longitudinally extending flexible rods and the cage further includes elastomeric bumpers at the plurality of intersections between flexible rods. A base has axles fixed relative to the body and wheels on the axles.