Compound aircraft having fairings to reduce drag on rotor hub during fixed-wing mode

摘要

A stopped-rotor aircraft 10 comprises a fuselage 14, a rotor hub 12 comprising a plurality of blades attached thereto, said hub 12 being rotatable by an engine 22, there being at least one retractable fairing 60, 64, covering a portion of said hub, said fairing being deployable / retractable by an actuator operated by a controller. The rotor may be locked into placed to provide lift surfaces when it transforms from rotary-wing (helicopter) to fixed-wing (aeroplane) flight. The retractable fairings 60, 64, when deployed form a flush aerodynamic surface with a rotating fairing 62, thereby reducing parasitic drag otherwise caused by the exposed rotor hub on the convertible aircraft. Ideally two retractable fairings 60, 64, are employed. The compound rotorcraft may comprise more than one hub and/or engine. Figure 5 shows the fairings in the retracted position, with the deployed positions shown by dashed-line 76.