Abstract: A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.

Abstract: An implementation of an external airbag system may include a plurality of inflatable air bags, a duct coupled to the plurality of inflatable air bags, and an exhaust vent coupled to each of the plurality of inflatable air bags via the duct.

Abstract: A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.

Abstract: A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.

Abstract: In some implementations, in an emergency in the vehicle, an emergency evacuation path is illuminated using the light emitted from the emergency evacuation rope where at least a portion of the emergency evacuation path extends to a location outside the vehicle. Egress of occupants along the emergency evacuation path is enabled using an emergency evacuation rope.

Abstract: In some examples, an oscillatory pumping system comprises: one or more active piston, a fluid, and two motors. The one or more active piston is disposed in a channel fluidically coupling two fluid chambers. The passive piston has a frequency response operable to counteract a vibratory displacement. The fluid is disposed in the channel and the two fluid chambers. The two motors couple to the one or more active piston. The two motors are operable to selectively change the frequency response of the passive piston based on oscillating the one or more active piston.

Abstract: An implementation of an external airbag system may include a plurality of inflatable air bags, a duct coupled to the plurality of inflatable air bags, and an exhaust vent coupled to each of the plurality of inflatable air bags via the duct.

Abstract: In an embodiment, a ducted fan assembly includes a housing that further includes a rotor. The ducted fan assembly also includes a rim that extends around at least a portion of a perimeter of the ducted fan assembly, where the rim defines an opening surrounding at least a portion of the housing. The ducted fan assembly also includes a skin that is attached to the rim and extends around the at least a portion of a perimeter of the ducted fan assembly to form a leading edge of the ducted fan assembly. The ducted fan assembly also includes a blade positioned on the rim underneath the skin.

Abstract: In an embodiment, a ducted fan assembly includes a housing that further includes a rotor. The ducted fan assembly also includes a rim that extends around at least a portion of a perimeter of the ducted fan assembly, where the rim defines an opening surrounding at least a portion of the housing. The ducted fan assembly also includes a skin that is attached to the rim and extends around the at least a portion of a perimeter of the ducted fan assembly to form a leading edge of the ducted fan assembly. The ducted fan assembly also includes a blade positioned on the rim underneath the skin.

Abstract: An advancing blade concept rotorcraft includes an airframe and a pylon assembly subject to vibration. The pylon assembly includes a dual rotor system having coaxially disposed top and bottom rotor assemblies that counter rotate relative to one another. The advancing blade concept rotorcraft includes a vibration isolation system including at least one pylon link coupled to the airframe and the pylon assembly. The pylon link includes a Liquid Inertia Vibration Eliminator unit operable to reduce transmission of the pylon assembly vibration to the airframe. The advancing blade concept rotorcraft includes active force generators adjacent to the pylon assembly. The active force generators include a first active force generator producing a force in a first direction and a second active force generator producing a force in a second direction to counteract multidirectional oscillations of the pylon assembly, thereby reducing vibration of the advancing blade concept rotorcraft.

Abstract: A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.

Abstract: A mount system for tiltably supporting a pylon assembly of a rotorcraft. First, second, third and fourth pylon links are each coupled between the pylon assembly and the airframe of the rotorcraft. The first pylon link has a first axis, the second pylon link has a second axis, the third pylon link has a third axis and the fourth pylon link has a fourth axis. Each of the axes intersects at a focal point located proximate a coaxial rotor system having counter-rotating upper and lower rotor assemblies such that the focal point provides a virtual pivot point about which the pylon assembly tilts to generate a control moment about a center of gravity of the rotorcraft that counteracts lateral and fore/aft moments generated by the upper and lower rotor assemblies during rotorcraft maneuvers.

Abstract: An in-flight impact protection system for aircraft. An aircraft having a panel, with a sensor disposed on the aircraft and adapted to transmit a signal and receive a reflection of the signal. A controller coupled to the sensor and adapted to receive the reflection from the sensor to determine whether an object is near the aircraft's panel. An inflation device, which includes a tube member, is coupled to the controller and positioned inside the aircraft, proximate the panel. After determining that the object is near the panel, the controller can activate the inflation device so that the tube member inflates, thereby buttressing at least a portion of the panel. The panel can be a windshield, fuselage member, or other suitable component.

Abstract: A vibration attenuating fluid mount with a partitioned compensator includes an inner member, an outer member, a flexible member having a castellated transition between a fluid passageway and at least one operating chamber. A membrane may be disposed in a volume compensator in fluid communication with one or more operating chambers. The inner member and outer member may be connected via a castellated connection, a swaged lock ring, or a split-lock ring.

Abstract: In some examples, an aircraft comprises an airframe, a rotor system coupled to the airframe, and a vibration attenuation system. The rotor system is operable to exert a vibratory force on the airframe. The vibration attenuation system comprises two or more batteries and elastic devices. The two or more batteries are operable to supply power to the rotor system. The elastic devices coupled to the two or more batteries and the airframe. The elastic devices are configured to attenuate the vibratory force based on facilitating oscillation of the two or more batteries. In other examples, a method comprises coupling elastic devices to two or more batteries and an airframe of an aircraft. The elastic devices receiving a vibratory force via the airframe and attenuate the vibratory force based on facilitating oscillation of the two or more batteries.

Abstract: An anti-tail buffet device leverages existing rotorcraft components to attenuate a tailboom's lateral “ringing” from air buffeting. Anti-buffet masses are tuned to the tailboom's lateral-bending or torsional natural frequency such that when lateral motion occurs, the response at this frequency is cancelled by the anti-buffet system, preventing this vibration from entering into the tailboom structure. Motion stops prevent over-travel. The mass of the tail rotor actuator is soft-mounted, such that its natural frequency is equal to the tailboom's lateral-bending or torsional natural frequency. When lateral loading occurs on the tail rotor disk, the lateral response at this frequency is attenuated by the soft-mounted tail rotor actuator, thereby preventing the vibration in the tailboom structure.

Abstract: A mount system for tiltably supporting a pylon assembly of a rotorcraft. First, second, third and fourth pylon links are each coupled between the pylon assembly and the airframe of the rotorcraft. The first pylon link has a first axis, the second pylon link has a second axis, the third pylon link has a third axis and the fourth pylon link has a fourth axis. Each of the axes intersects at a focal point located proximate a coaxial rotor system having counter-rotating upper and lower rotor assemblies such that the focal point provides a virtual pivot point about which the pylon assembly tilts to generate a control moment about a center of gravity of the rotorcraft that counteracts lateral and fore/aft moments generated by the upper and lower rotor assemblies during rotorcraft maneuvers.

Abstract: A high-performance descent system for a multi-rotor aircraft includes a flight control computer comprising a processor, a propulsion system communicatively coupled to the flight control computer and configured to allow a direction of thrust relative to a vertical z-axis to be selected by the flight control computer. The processor is operable to implement a method including preparing the multi-rotor aircraft for a high-performance descent, instructing, via a flight control system, a proprotor to reduce an amount of vertical thrust produced by the proprotor by tilting the proprotor away from a vertical axis, and reducing an altitude of the multi-rotor aircraft.

Abstract: In some examples, an oscillatory pumping system comprises: one or more active piston, a fluid, and two motors. The one or more active piston is disposed in a channel fluidically coupling two fluid chambers. The passive piston has a frequency response operable to counteract a vibratory displacement. The fluid is disposed in the channel and the two fluid chambers. The two motors couple to the one or more active piston. The two motors are operable to selectively change the frequency response of the passive piston based on oscillating the one or more active piston.

Abstract: In some examples, an aircraft comprises an airframe, a rotor system coupled to the airframe, and a vibration attenuation system. The rotor system is operable to exert a vibratory force on the airframe. The vibration attenuation system comprises two or more batteries and elastic devices. The two or more batteries are operable to supply power to the rotor system. The elastic devices coupled to the two or more batteries and the airframe. The elastic devices are configured to attenuate the vibratory force based on facilitating oscillation of the two or more batteries. In other examples, a method comprises coupling elastic devices to two or more batteries and an airframe of an aircraft. The elastic devices receiving a vibratory force via the airframe and attenuate the vibratory force based on facilitating oscillation of the two or more batteries.