An active countermeasure for military rotorcraft against a heat-seeking missile threat involves one or more telescoping booms or poles that are articulated at their proximal end to the fuselage of the rotorcraft and have an IR-radiating decoy mounted on their distal tip. When a missile launch is detected the missile flight path is computed and one or more of the booms are extended and swung out to place the decoy on the shot line of the missile. The decoy is then switched on and lures the missile away from the vulnerable components of the craft, such as the engine, rotors, and fuselage so as to cause a miss or failing that a detonation away from the rotorcraft. The countermeasures are stored compactly against or within the tail when not deployed.

An active countermeasure for military rotorcraft against a heat-seeking missile threat involves one or more telescoping booms or poles that are articulated at their proximal end to the fuselage of the rotorcraft and have an IR-radiating decoy mounted on their distal tip. When a missile launch is detected the missile flight path is computed and one or more of the booms are extended and swung out to place the decoy on the shot line of the missile. The decoy is then switched on and lures the missile away from the vulnerable components of the craft, such as the engine, rotors, and fuselage so as to cause a miss or failing that a detonation away from the rotorcraft. The countermeasures are stored compactly against or within the tail when not deployed.

A rotary wing aircraft with a fuselage and a non-retractable skid-type landing gear that is mounted to the fuselage, the non-retractable skid-type landing gear comprising at least one landing box, the at least one landing box being provided with a skid-type landing base member and an associated box shell that delimits an internal volume of the at least one landing box.

An actuator for aviation applications, in particular for adjusting rotor blades in a helicopter, may include an electromechanical drive assembly connected to an output drive via a downstream transmission, where the drive assembly is divided into sub-drives that can be operated independently, and where at least two sub-drives are spatially separated from one another in that the transmission is placed between these sub-drives. The transmission may include at least two harmonic gearings coupled to one another by at least one first coupling element, where a first harmonic gearing is located inside a non-rotating first housing, where a second harmonic gearing is located inside a rotating second housing, and where the second housing is connected to the output drive.

A method and a device for detecting that a rotorcraft is approaching a vortex domain. After previously determining a limit advance speed threshold and a limit vertical speed threshold defining a limit for said rotorcraft entering into a vortex domain, a predictive advance speed and a predictive vertical speed for said rotorcraft are calculated, said predictive vertical speed being calculated differently depending on the value of said instantaneous advance speed. Thereafter, said predictive advance speed and said predictive vertical speed are compared with said thresholds, which may be thresholds with hysteresis, in order to determine whether said rotorcraft is approaching a vortex domain, and if so to signal this situation to a pilot of said rotorcraft.

A method and a device for detecting that a rotorcraft is approaching a vortex domain. After previously determining a limit advance speed threshold and a limit vertical speed threshold defining a limit for said rotorcraft entering into a vortex domain, a predictive advance speed and a predictive vertical speed for said rotorcraft are calculated, said predictive vertical speed being calculated differently depending on the value of said instantaneous advance speed. Thereafter, said predictive advance speed and said predictive vertical speed are compared with said thresholds, which may be thresholds with hysteresis, in order to determine whether said rotorcraft is approaching a vortex domain, and if so to signal this situation to a pilot of said rotorcraft.

A rotor-hub flap-measurement system includes a rotor hub operable to flap relative to a rotational axis of a rotor mast. The rotor hub includes a fork driver fixedly coupled to the rotor mast and operable to rotate about the rotational axis, a drive plate operable to rotate about the rotational axis and to rotate out of a plane perpendicular to the rotational axis, out-of-plane rotation indicating flapping of the rotor hub, and a universal joint coupled to the drive plate and comprising a cross, the cross comprising four trunnions equally spaced azimuthally about the rotational axis. The rotor-hub flap-measurement system also includes a magneto-resistive sensor system coupled to the cross and operable to detect rotation of a first trunnion of the four trunnions.

A fuel-cell system at 540 VDC for powering an electrical load of a rotorcraft with a first fuel cell and a second fuel cell. Each fuel cell is configured identically and features a positive electrical node and a negative electrical node. Each fuel cell is configured to provide one half of the electrical load of the rotorcraft and one half of the voltage of the electrical load.

A fuel-cell system at 540 VDC for powering an electrical load of a rotorcraft with a first fuel cell and a second fuel cell. Each fuel cell is configured identically and features a positive electrical node and a negative electrical node. Each fuel cell is configured to provide one half of the electrical load of the rotorcraft and one half of the voltage of the electrical load.

The present invention includes an a plurality of first variable speed motors arranged in a first matrix pattern and mounted on a tail boom of the helicopter; one or more fixed pitch blades attached to each of the plurality of first variable speed motors; and wherein a speed of one or more of the plurality of first variable speed motors is varied to provide an anti-torque thrust.