Methods and apparatus to recover unmanned aerial vehicles (UAVs) with kites are disclosed. A disclosed example apparatus to recover a UAV during flight includes a tether line, a tensioner operatively coupled to the tether line, and a kite operatively coupled to the tether line to support the tether line for recovery of the UAV.

Features for in-flight recovery of an unmanned aerial vehicle (UAV). A towline may be deployed by a host aircraft in-flight to recover an in-flight target UAV. The towline or portion thereof may be oriented nearly vertical. The towline may have a fitting thereon. A capture mechanism on the target UAV may have one or more deployable flaps that engage with the near vertical towline and fitting. The flaps may stow to secure the target aircraft to the towline and fitting. The host aircraft may then retract the towline to pull in the target UAV to the host aircraft using a hoist system having a winch. A latching system located in a pylon of the host aircraft, which may be under a wing, may have a towline connector that engages with and secures the target UAV. The host aircraft may have multiple hoist systems for deployment and/or recovery of multiple target UAV's.

Features for in-flight recovery of an unmanned aerial vehicle (UAV). A towline may be deployed by a host aircraft in-flight to recover an in-flight target UAV. The towline or portion thereof may be oriented nearly vertical. The towline may have a fitting thereon. A capture mechanism on the target UAV may have one or more deployable flaps that engage with the near vertical towline and fitting. The flaps may stow to secure the target aircraft to the towline and fitting. The host aircraft may then retract the towline to pull in the target UAV to the host aircraft using a hoist system having a winch. A latching system located in a pylon of the host aircraft, which may be under a wing, may have a towline connector that engages with and secures the target UAV. The host aircraft may have multiple hoist systems for deployment and/or recovery of multiple target UAV's.

Various embodiments of the present disclosure provide a rotorcraft-assisted system and method for launching and retrieving a fixed-wing aircraft into and from free flight. The launch and retrieval system includes a modular multicopter, a storage and launch system, an anchor system, a flexible capture member, and an aircraft-landing structure. The multicopter is attachable to the fixed-wing aircraft to facilitate launching the fixed-wing aircraft into free, wing-borne flight. The storage and launch system is usable to store the multicopter (when disassembled) and to act as a launch mount for the fixed-wing aircraft by retaining the fixed-wing aircraft in a desired launch orientation. The anchor system is usable with the multicopter, the flexible capture member, and the aircraft-landing structure to retrieve the fixed-wing aircraft from free, wing-borne flight.

A system uses existing pipelines, e.g., natural gas, oil, etc., to transport hydrogen to one or more distribution points. The disclosed hydrogen distribution system enables use of water, sewer, storm drain and other existing pipelines for local distribution. Hydrogen is produced from an energy source at a producing location. A safety pipe is located inside an existing pipeline configured to carry a first product and a hydrogen delivery line, configured to carry hydrogen, is placed inside the safety pipe such that a channel is formed between an exterior of the hydrogen delivery line and an interior of the safety pipe. Hydrogen is injected into the hydrogen delivery line and a sweeper gas is injected into the channel to purge any hydrogen that might be leaking from the hydrogen delivery line.

A system uses existing pipelines, e.g., natural gas, oil, etc., to transport hydrogen to one or more distribution points. The disclosed hydrogen distribution system enables use of water, sewer, storm drain and other existing pipelines for local distribution. Hydrogen is produced from an energy source at a producing location. A safety pipe is located inside an existing pipeline configured to carry a first product and a hydrogen delivery line, configured to carry hydrogen, is placed inside the safety pipe such that a channel is formed between an exterior of the hydrogen delivery line and an interior of the safety pipe. Hydrogen is injected into the hydrogen delivery line and a sweeper gas is injected into the channel to purge any hydrogen that might be leaking from the hydrogen delivery line.

Launch and land system for a tethered aircraft (in connection with FIG. 1) The invention provides for a launch and land system (1) for a tethered aircraft (90) comprising a runway (12) for the aircraft and a winch (62) for the tether (92), wherein the runway comprises a funnel-shaped target area (14) with a wide end oriented towards one end of the runway and a narrow end opposite of the wide end, wherein said target area is laterally bordered by restriction devices (80) extending from one end of the target area to the other for preventing the aircraft to roll out of the target area.

A control system is described that is connected to an advanced arresting gear system. The control system has: (a) an outer control loop; (b) a first inner control loop associated with a port-side motor current controller for outputting a voltage command for controlling a port side motor that controls a port side of an arrestment cable; (c) a second inner control loop associated with a starboard-side motor current controller outputting a second voltage command for controlling a starboard side motor that controls the starboard side of the arrestment cable. Each of the port-side motor current controller and the starboard-side motor controller comprises: a positive sequence controller, at least one negative sequence controller, one or more delay state feedback to counter control loop delays, wherein the delay state feedback provides high bandwidth, low current overshoot, small current rise time and good current stability margins.

A device for catching and launching a guided UAV, the device comprises a supporting post, a horizontal shaft mounted on the post, and a lever is mounted on the horizontal shaft and can make a full revolution around a horizontal axis within a vertical plane, the lever is equipped with an engagement/disengagement device a means for interaction with the UAV catching device and an optical member, preferably arranged on the lever, for determining a location of the lever interaction means by an optical guidance system of the UAV. The lever comprises two coaxial portions, one is the engagement/disengagement device, and the second is a bar, wherein one end of the bar is coupled to the horizontal shaft, while another end thereof is connected to the engagement/disengagement device. The bar and the engagement/disengagement device are connected by a hinge that enables their fixation in a coaxial state and allows offset the axis of the engagement/disengagement device relative to the axis of the bar within a rotation plane of the lever. The horizontal shaft is equipped with a means for accumulating and/or dissipating the kinetic energy of the UAV, the lever is fixed on the shaft and can provide an elastic offset of the interaction means of the engagement/disengagement device within a plane perpendicular to the rotation plane of the lever, the interaction means configured to provide mutual locking/unlocking with the UAV catching device.

Various embodiments of the present disclosure provide a helicopter-mediated system and method for launching and retrieving an aircraft capable of long-distance efficient cruising flight from a small space without the use of a long runway.