Patents by Inventor Douglas Challis

Douglas Challis has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8424798
    Abstract: An aircraft features a source of forward thrust on a fuselage having a helicopter rotor assembly and an asymmetric primary wing configuration providing more wing-generated lift on one side of the fuselage than the other. The primary wing configuration counteracts the rotor's dissymmetry of lift during forward cruising, and reliance on the separate thrust source for such cruising reduces demand on the main rotor, keeping the angle of attack on the rotor blades low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. In some embodiments, an oppositely asymmetric tail wing or horizontal stabilizer acts alone, or together with an offset vertical stabilizer laterally outward from the tail, to counteract yaw-inducing drag of the primary wing.
    Type: Grant
    Filed: November 5, 2010
    Date of Patent: April 23, 2013
    Inventor: Douglas Challis
  • Patent number: 8336808
    Abstract: An aircraft features a nose mounted propeller on a fuselage having a typical helicopter rotor assembly. By reducing the amount of forward thrust needed from the main rotor, the propeller allows greater forward speeds as the angle of attack on the rotor's blades can be kept low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. By reducing the maximum angle of attack experienced by the main rotor during its rotation during forward cruising from that of a conventional helicopter but still using the main rotor to generate lift, the addition of wings extending from both sides of the fuselage can be avoided. The aircraft may be flown in a forward direction in a generally horizontal orientation, as the nose does not have to be pitched downward to create thrust from the main rotor.
    Type: Grant
    Filed: October 27, 2006
    Date of Patent: December 25, 2012
    Inventor: Douglas Challis
  • Publication number: 20110272519
    Abstract: An aircraft features a source of forward thrust on a fuselage having a helicopter rotor assembly and an asymmetric primary wing configuration providing more wing-generated lift on one side of the fuselage than the other. The primary wing configuration counteracts the rotor's dissymmetry of lift during forward cruising, and reliance on the separate thrust source for such cruising reduces demand on the main rotor, keeping the angle of attack on the rotor blades low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. In some embodiments, an oppositely asymmetric tail wing or horizontal stabilizer acts alone, or together with an offset vertical stabilizer laterally outward from the tail, to counteract yaw-inducing drag of the primary wing.
    Type: Application
    Filed: November 5, 2010
    Publication date: November 10, 2011
    Inventor: Douglas Challis
  • Publication number: 20100258671
    Abstract: An aircraft features a nose mounted propeller on a fuselage having a typical helicopter rotor assembly. By reducing the amount of forward thrust needed from the main rotor, the propeller allows greater forward speeds as the angle of attack on the rotor's blades can be kept low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. By greatly reducing the amount of thrust produced by the main rotor but still using it to generate lift, the addition of wings can be avoided. The aircraft can be flown in a forward direction in a generally horizontal orientation, as the nose does not have to be pitched downward to create thrust from the main rotor.
    Type: Application
    Filed: July 24, 2006
    Publication date: October 14, 2010
    Inventor: Douglas Challis
  • Publication number: 20080237393
    Abstract: An aircraft features a nose mounted propeller on a fuselage having a typical helicopter rotor assembly. By reducing the amount of forward thrust needed from the main rotor, the propeller allows greater forward speeds as the angle of attack on the rotor's blades can be kept low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. By reducing the maximum angle of attack experienced by the main rotor during its rotation during forward cruising from that of a conventional helicopter but still using the main rotor to generate lift, the addition of wings extending from both sides of the fuselage can be avoided. The aircraft may be flown in a forward direction in a generally horizontal orientation, as the nose does not have to be pitched downward to create thrust from the main rotor.
    Type: Application
    Filed: October 27, 2006
    Publication date: October 2, 2008
    Inventor: Douglas Challis
  • Publication number: 20070095973
    Abstract: An aircraft features a nose mounted propeller on a fuselage having a typical helicopter rotor assembly. The propeller axis of rotation is tilted upward from the longitudinal axis of the fuselage so that its rear face points downward. By reducing the amount of lift and forward thrust needed from the main rotor, the propeller allows greater forward speeds as the angle of attack on the rotor's blades can be kept low to avoid the stalling and violent vibration experienced by conventional helicopters at relatively high speeds. By greatly reducing the amount of thrust produced by the main rotor but still using it to generate lift, the addition of wings can be avoided. The aircraft can be flown in a forward direction in a generally horizontal orientation, as the nose does not have to be pitched downward to create thrust from the main rotor.
    Type: Application
    Filed: October 27, 2005
    Publication date: May 3, 2007
    Inventor: Douglas Challis