A propulsion assembly for a rotorcraft includes a blade assembly, a drive shaft coupled to the blade assembly and an electric motor coupled to the drive shaft and operable to provide rotational energy to the drive shaft to rotate the blade assembly. The propulsion assembly includes a landing assistance turbine coupled to the drive shaft and operable to selectively provide rotational energy to the drive shaft during an underpowered descent to rotate the blade assembly and provide upward thrust, thereby reducing a descent rate of the rotorcraft prior to landing.

Systems and methods are provided that include features for determining a hover time remaining for an aircraft performing a hover maneuver. In some exemplary embodiments, the hover time remaining can be communicated to a pilot or aircrew member.

An inertia weight assembly positionable within a receiving portion of a rotor blade for use on a rotorcraft. The inertia weight assembly includes a weighted core and a casing having a closed outboard end and forming a cavity. The weighted core is disposed in the cavity such that the casing at least partially encloses the weighted core. The weighted core is formed from a first material and the casing is formed from a second material that is dissimilar to the first material. The casing provides an interface between the weighted core and the receiving portion of the rotor blade. The second material is more bondable to the receiving portion of the rotor blade than the first material.

A drone includes a surrounding cage which can be disassembled from a propeller-carrying internal base. In another aspect, a drone includes at least one fastening clip which attaches arcuate external ribs to a periphery of a central and internal frame, whereafter the fastening clip can be removed for disassembly of the ribs from the frame. Yet another aspect provides a flying drone employs a fastening clip including a snap fit and a generally U-shaped body. A further embodiment has a flying drone with at least one light externally mounted adjacent a periphery of a central propeller-carrying base, located between a pair of external ribs.

A method is provided for alerting a rotorcraft crew member of a potential collision of a rotor blade of the rotorcraft having a rotor shaft and a rotor azimuth. The method comprises estimating a total rotor flapping value associated with the rotor blade during an operating condition of the rotorcraft. The estimated total rotor flapping value is relative to the rotor shaft as a function of the rotor azimuth. The method also comprises comparing the estimated total rotor flapping value to a rotor flapping limit value during the operating condition of the rotorcraft. The method further comprises sending a warning signal to a warning device when the estimated total rotor flapping value lies outside of the rotor flapping limit value to alert the rotorcraft crew member of a potential collision of the rotor blade of the rotorcraft.

An assembly for monitoring torque applied to a control rod of an actuator, the control rod mounted within and rotational relative to a housing, the assembly comprising a torsional spring located between the control rod and the housing, and one or more sensors for monitoring angular displacement of the control rod relative to the housing as consequence of torque applied to the control rod transmitted through the torsional spring.

The invention relates to a helicopter including a structural framework, at least one main rotor for lift and propulsion integral with said structural framework and a drive train for driving said main rotor including a power transmission gearbox and at least one main engine, wherein it further includes a plurality of extra booster power units fixed to said structural framework and configured so as to be able to supply extra lift of the helicopter in case of failure of the helicopter's drive train.

An emergency collective actuator includes an actuator motor to produce an actuation force and an actuator linkage that directly engages a friction control lever that is pivotally supported on the collective stick of a helicopter to apply the actuation force directly to the friction control lever such that the actuation force initially disengages the friction control and then reduces the adjustable pitch toward a minimum collective pitch position. The actuator can include a clutch that slips to allow the pilot to overcome the actuation force and that slips responsive to an engagement of the friction control by the pilot, but otherwise the clutch co-rotates with the motor shaft to bias the adjustable pitch toward a minimum collective pitch position.

New methods and devices are described that are aimed at preventing the outbreak of fire in a hydraulic rotor brake. These methods and devices can be used in the rotor brake of a helicopter and comprise a first and second seal, with a drain groove positioned in between these two seals to drain leaked fluid away from the hot parts of the brake. In the brakes described, the second seal is positioned closer to the heat sink of the brake than the first seal. The drain groove is also connected via a channel or channels to a drain outlet or outlets.

An unmanned aerial vehicle is disclosed. The unmanned aerial vehicle includes a frame configured to fix a motor. The unmanned aerial vehicle also includes a housing configured to enclose the frame. The housing includes a top mesh corresponding to an upper surface of the housing and a bottom mesh that covers a portion of a bottom surface of the housing. The housing also includes middle part coupled to the top mesh and the bottom mesh. The housing also includes a plurality of duct areas that penetrate each of the top mesh, the bottom mesh, and the middle part. The motor and a propeller connected to the motor and for rotating are positioned within the duct area.