Patent Description:
This disclosure relates generally to unmanned aerial vehicles (UAV's), in particular to systems and methods for recovery of an airborne UAV or other target aircraft by an airborne host aircraft.

Unmanned aerial vehicles (UAV's) are aircraft that are piloted without a human pilot onboard. UAV's may be used for transport, surveillance, communications, weapons, and other uses. UAV's typically take off from the ground and return to the ground, which limits their versatility and usefulness. Recovery of UAV's or other aircraft in-flight may simplify missions and improve outcomes. Existing approaches to in-flight recovery are complex and unreliable. Improvements to these and other drawbacks are desirable. <CIT> discloses a system for recovery of a target aircraft by a host aircraft, where the movement of the target aircraft is realized by a shuttle which engages with the target aircraft or by an apparatus for controlling movement of the target aircraft along the towline. <CIT> discloses a hooking device on the target aircraft for capturing a blocking rope at the end of the towline of the host aircraft. <CIT> discloses a capture devise on the host aircraft for fitting into dock on the target aircraft. <CIT> discloses wing root regions configured to receive a towline which is attached to a parachute and deflect the towline into a latching hook.

The embodiments disclosed herein each have several aspects no single one of which is solely responsible for the disclosure's desirable attributes. Without limiting the scope of this disclosure, its more prominent features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the embodiments described herein provide advantages over existing systems, devices and methods for recovering unmanned aerial vehicles (UAV's) or other aircraft in flight.

The following disclosure describes non-limiting examples of some embodiments. Other embodiments of the disclosed systems and methods may or may not include the features described herein. Moreover, disclosed advantages and benefits may apply only to certain embodiments of the invention and should not be used to limit the disclosure, insofar as they fall within the scope of the appended claims.

A system for recovery of a target aircraft by a host aircraft during forward flight is provided in accordance with claim <NUM>.

Any embodiments of the devices, systems, and methods disclosed herein can include, in additional embodiments, one or more of the following features, components, and/or details, in any combination with any of the other features, components, and/or details of any other embodiments of the devices, systems, and methods disclosed herein: wherein, in the first position, the first and second movable portions can be positioned near the fuselage, in line with the fuselage, or against the fuselage of the target aircraft; wherein the first and second movable portions can be configured to move to a capture position, or return to respective first positions, to secure the target aircraft to the towline; wherein the opening can be smaller than a maximum cross-sectional size of the fitting; wherein the first movable portion and the second movable portion can be configured to rotate between the respective first and second positions; wherein the first movable portion of the capture mechanism can be configured to move independent of the position of the second movable portion; wherein the first movable portion can be integral with or rigidly attached to the second movable portion such that the first and second movable portions move together as one unit between the first and second positions; wherein the capture mechanism can be configured to receive the towline in the opening with the distal section of the towline oriented less than <NUM> degrees off a vertical direction; and/or wherein the host aircraft includes a system for securing a target aircraft to a host aircraft, the system including a winch configured to be supported by a wing of the host aircraft and to have a deployable towline carried by the winch, one or more fleet pulleys, the towline configured to extend from the winch through the one or more fleet pulleys, an upper sheave, the towline configured to extend from the fleet pulley to the upper sheave, and a towline connector, the towline configured to extend below the aircraft and be reeled in by the winch to secure the target aircraft with the host aircraft.

A method of recovering a target aircraft with a host aircraft during forward flight is provided in accordance with claim <NUM>.

Any embodiments of the devices, systems, and methods disclosed herein can include, in additional embodiments, one or more of the following features, components, and/or details, in any combination with any of the other features, components, and/or details of any other embodiments of the devices, systems, and methods disclosed herein: further including retracting the towline into the host aircraft to move the target aircraft toward the host aircraft; wherein deploying the one or more flaps includes deploying a first flap and a second flap; and/or wherein the first and second flaps can be deployed independently of each other.

The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter of the appended claims. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the drawing, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure, insofar as the fall within the scope of the appended claims.

The following detailed description is directed to certain specific embodiments of the development. In this description, reference is made to the drawings wherein like parts or steps may be designated with like numerals throughout for clarity. Reference in this specification to "one embodiment," "an embodiment," or "in some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrases "one embodiment," "an embodiment," or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. Similarly, various requirements are described which may be requirements for some embodiments but may not be requirements for other embodiments.

<FIG> depicts an embodiment of a system <NUM> for airborne or in-flight recovery of a target aircraft T having a capture mechanism <NUM>, using a towline from a host aircraft H. Some embodiments disclosed herein include an improved capture mechanism and system for unmanned aerial vehicles (UAV's) or other target aerial vehicles (collectively, target aerial vehicle or vehicles or target aircraft) for capturing a towline tethered to a host aircraft. For clarity, in <FIG> the host aircraft H, towline <NUM>, and the target aircraft T are not necessarily to scale. The host aircraft H may be any type of manned or unmanned aircraft. The host aircraft H may be a conventional aircraft such as a jet or prop-driven aircraft, UAV, or other aircraft type. The target aircraft T may be any type of UAV, although the target aircraft T may also be a manned or piloted aircraft in any embodiments disclosed herein. The host and/or target aircraft H, T in any embodiments disclosed herein may be forward flying aircraft. In some embodiments, one or both of the host and target aircraft H, T may be in vertical flight, such as a vertical takeoff and landing (VTOL) aircraft, helicopter, or other types of aircraft.

UAV's are aircraft without a human pilot onboard. UAV's may be piloted manually by a remote operator and/or through autonomous or semi-autonomous controls. The remote operator may pilot the UAV based on the UAV's flight cameras, gauges, and other control sensors. The target aircraft T may be a UAV with a fuselage F, one or more flight surfaces, such as wings W, extending outwardly from the fuselage, and a propulsion system, such as a combustion or electric engine. UAV's may be used in a number of roles, such as aerial reconnaissance and ground surveillance, monitoring terrestrial objects and people, scientific experiments, geological surveys, military or non-military contexts, weapon delivery, and others.

Larger aircraft may generally have greater operable ranges than smaller or lighter UAV's. Thus, carrying a UAV on the host aircraft H and launching therefrom may expand the useful range of the UAV. However, safely landing the UAV for terrestrial recovery may be difficult or impossible in certain circumstances. For example, the geography may lack sufficient landing space, or the landing spaces may be in undesirable locations (e.g., under enemy control). Moreover, existing methods of aerial recovery of UAV's are impractical and unreliable. Accordingly, a need exists for the reliable recovery of a UAV in-flight.

Some embodiments disclosed herein include a capture mechanism to enable airborne recovery of a wide range of small, unmanned air vehicles or other target aircraft T in flight using the towline <NUM> with a simple, passive end feature or fitting deployed from the host aircraft H. Some embodiments of the capture mechanism on the target aircraft may be scalable and/or tunable to conform to a wide range of airframe shapes and sizes. In some embodiments, the components and methods of capture employ existing airframe features (e.g. leading or trailing edge of wing, left or right hand side of fuselage) to funnel or bias the towline <NUM> to the capture mechanism. Using these relatively large airframe features as a towline funnel or guide increases reliability and leads to very high probability of recovery, even for a small UAV with poor or moderate flight control.

Once the target aircraft T captures the towline fitting, some embodiments of the target aircraft T may be transitioned to a passively stable towed body by retracting or rotating its wings and reducing or stopping thrust. In some embodiments, the host aircraft H may use a hoist system in a pod on or in the host aircraft H to reel-in the target aircraft T (e.g. as shown in <FIG>). The target aircraft T may be refueled or recharged by the host aircraft H and sent on a subsequent sortie, have maintenance performed on the target aircraft T, be transported to a mission point via captive carriage on the host aircraft H where the target aircraft T may be launched, or other actions taken. In some embodiments, the target aircraft T may conduct its mission and then be recovered by the host aircraft H. The host aircraft H may then transport the target aircraft T back to base for service (e.g. refuel, rearm, maintenance, etc.). Or, such maintenance, refueling, rearming, etc., may be provided to the target aircraft T while attached to the host aircraft H so that the target aircraft T may be launched or re-launched from the host aircraft H for another mission without having to return to base. Some embodiments of the capture mechanisms disclosed herein use a simple towline and hoist and may be used for capturing a very broad array of small UAV's (e.g. different airframe shapes, propulsion types, propulsion locations, etc.). Some embodiments of the capture mechanisms disclosed herein may be integrated into the fuselage during manufacturing of the UAV's and/or may be retrofit to existing fuselages of UAV's.

Existing solutions for in-flight recovery of aircraft are complex and unreliable. Today, some small UAV's may be very limited in their range and utility. Recovery of UAV's using conventional methods (e.g. skid landing or net arrest) risks significant damage. This precludes them from carrying expensive, advanced sensors and other equipment. The recovery systems according to the present disclosure provide reliable airborne approaches that may overcome these drawbacks. The host aircraft H may transport a small UAV or other target aircraft T long distances to a mission point. With little risk of damage to the target aircraft T upon recovery, small UAV's may carry expensive, advanced sensors with less risk of damage to such sensors. Therefore, providing reliable, robust systems for recovering UAV's has significant benefits. The capture mechanism <NUM> with deployable flaps and using the wing root as a guide for the near-vertical towline <NUM>, among other features of the present disclosure described herein, provide such enhanced reliability and robustness and in a simpler recovery process.

As further shown in <FIG>, the capture mechanism <NUM> may be coupled with or integrally formed with a portion of the target aircraft T, such as the fuselage F as shown. The target aircraft T may be traveling in a horizontal direction. The direction of travel is indicated by arrow AT. The capture mechanism <NUM> may be configured to capture the towline <NUM> tethered to the host aircraft H while traveling in a horizontal direction, indicated by arrow AH, which may be the same or similar direction as the direction AT of the target aircraft T. "Horizontal" as used herein has its usual and customary meaning and includes, without limitation, directions perpendicular to the direction of gravity, and directions that are approximately perpendicular to the direction of gravity, for example within +/-<NUM> degrees, +/-<NUM> degrees, +/-<NUM> degrees, or +/-<NUM> degrees of horizontal. The host and target aircraft H, T may be in horizontal or forward flight, and includes any aircraft or flying machine intended to fly horizontal. In some embodiments, the host aircraft H and/or target aircraft T may be flying only vertically, both horizontally and vertically, or they may be stationary in-flight without horizontal or vertical movement.

The target aircraft T in any of the embodiments disclosed herein may be any suitable or desired aerial vehicle. For example and without limitation, the target aircraft T shown in <FIG> and <FIG> may be a Sparrowhawk Small Unmanned Aircraft System (SUAS), by General Atomics Aeronautical Systems, Inc. In other embodiments disclosed herein, the target aircraft T may be any suitable or desired vertical lift aircraft, or any other suitable or desired manned or unmanned aircraft. The host aircraft H may be an MQ-<NUM> or other aircraft. The target aircraft T may have a deployed-wing wingspan of between <NUM> to <NUM> (<NUM> to <NUM> feet (ft)), between <NUM> and <NUM> (<NUM> and <NUM> ft), between <NUM> and <NUM> (<NUM> and <NUM> ft), or between <NUM> and <NUM> (<NUM> and <NUM> ft). The target aircraft T may have a length of between <NUM> and <NUM> (<NUM> and <NUM> ft), between <NUM> and <NUM> (<NUM> and <NUM> ft), between <NUM> and <NUM> (<NUM> and <NUM> ft), or between <NUM> and <NUM> (<NUM> and <NUM> ft).

In some embodiments, the host aircraft H may be include a hoist <NUM>. The hoist <NUM> may include a winch. The hoist <NUM> may have some or all of the same or similar features and/or functions as the hoist system <NUM> described with respect to <FIG>, and vice versa. The hoist <NUM> may be configured to pay out or release the towline <NUM> and may be configured to reel in the towline <NUM>, which may be done after the towline <NUM> has been captured by the target aircraft T. In this manner, the host aircraft H may tether the target aircraft T and move the target aircraft toward the host aircraft H. The hoist <NUM> may be attached to the fuselage and/or to the wing of the host aircraft H. In some embodiments, the hoist <NUM> may be an electric hoist. The host aircraft H may have some or all of the same or similar features and/or functions as the host aircraft <NUM> described with respect to <FIG>, and vice versa.

With reference to <FIG>, the capture mechanism <NUM> includes a first movable portion <NUM> and second movable portion <NUM>, such as arms or flaps. The first and second movable portions <NUM>, <NUM> may be configured to rotate or move between a first stowed position in which the movable portion is in a closed or stowed state, and a second deployed position in which the movable portion is in an open or extended position. In <FIG>, the movable portions <NUM>, <NUM> are shown in deployed positions.

The towline <NUM> is shown extended downward with a portion <NUM> of the towline <NUM> located between a space <NUM> defined by the movable portions <NUM>, <NUM>. The towline <NUM> further extends through a wing root WR in front of the wing W and adjacent the fuselage F, which may be a region adjacent the aircraft, as further described. A fitting <NUM> is located on a distal end of the towline <NUM>, which may be at the end of the towline <NUM> as shown. In some embodiments, there may be some length of the towline <NUM> extending beyond, e.g. through and beyond, the fitting <NUM>. The wing root WR and movable portions <NUM>, <NUM> may guide the towline into the space <NUM> to then stow the movable portions <NUM>, <NUM> and thereby capture the fitting <NUM>, as further described. The fitting <NUM> may be spherical as shown, or other shapes, as further described herein for example with respect to <FIG>.

The movable portions <NUM>, <NUM> may be elongated arms or flaps. The movable portions <NUM>, <NUM> may be made of metal, composite, other suitable materials, or combinations thereof. The movable portions <NUM>, <NUM> may each have a thickness that is less than a width or average width. The length of each movable portion <NUM>, <NUM> may be greater than the width and/or thickness. The movable portions <NUM>, <NUM> may have a variety of shapes, sizes, and configurations, such as prongs, poles, bars, members, or any other structure that may operate to secure the fitting <NUM> to the target aircraft T as described herein.

In some embodiments, the first and/or second movable portions <NUM>, <NUM> may have a contour that is rounded. The contour of the movable portions <NUM>, <NUM> may match a contour of the fuselage of the target aircraft T, for example to optimize the aerodynamics of the capture mechanism <NUM> and the target aircraft T when the first and second movable portions <NUM>, <NUM> are in the closed position. The movable portions <NUM>, <NUM> may be configured to reduce the aerodynamic drag of the capture mechanism <NUM> when the first and second movable portions <NUM>, <NUM> are in the first and second positions. For example, the movable portions <NUM>, <NUM> may be made from a thin sheet metal or other rigid material.

The movable portions <NUM>, <NUM> may move between various positions. For example, as shown in <FIG>, the first movable portion <NUM> is shown in a first position where it is closed or stowed in line with the fuselage, and the second movable portion <NUM> is shown in the second position where it is open or deployed. In some embodiments, the first and second movable portions <NUM>, <NUM> may be configured to move independently of one another - e.g., the first movable portion <NUM> may be moved independently of the second movable portion <NUM> and the second movable portion <NUM> may be moved independently of the first movable portion <NUM>. In some embodiments, first and second movable portions <NUM>, <NUM> may be connected and/or configured to move simultaneously and/or equal amounts. In some embodiments, there may be three, four, or more movable portions. Further, the movable portions <NUM>, <NUM> may move to any positions that are between the deployed and stowed positions, such as partially deployed positions, half-deployed positions, etc..

The capture mechanism <NUM> may have a first recess <NUM> (see <FIG>, <FIG> and <FIG>) configured to receive the first movable portion <NUM> therein when the first movable portion <NUM> is in the closed position. The capture mechanism <NUM> may have a second recess <NUM> (see <FIG>, <FIG> and <FIG>) configured to receive the second movable portion <NUM> therein when the second movable portion <NUM> is in the closed position. The recesses <NUM>, <NUM> may be different portions of one single, larger recess. The recesses <NUM>, <NUM> may be openings or spaces in the fuselage F.

The capture mechanism <NUM> may have or define a cavity <NUM>, as shown for example in <FIG>. The cavity <NUM> may be located underneath the stowed movable portions <NUM>, <NUM>. The cavity may be an open or empty space which receives the fitting <NUM> and part of the towline <NUM>. The movable portions <NUM>, <NUM> in the stowed positions close over the cavity <NUM> with the fitting <NUM> and part of the towline <NUM> therein to secure to the towline <NUM> to the target aircraft T. The recesses <NUM>, <NUM> may form an outer portion of the cavity <NUM>.

As shown in <FIG>, the first movable portion <NUM> may have a straight leading or forward edge 120a and an opposite aft or trailing edge 120b. The first movable portion <NUM> may have a lower or outer edge 120d at a distal end of the first movable portion <NUM>. The first movable portion <NUM> may have a rearward edge 120c, which may be angled as shown. The rearward edge 120c may be adjacent to the aft or trailing edge 120b. The rearward edge 120c may extend from the outer edge 120d to the aft edge 120b. The rearward edge 120c may be configured to guide or bias the towline <NUM> to a space <NUM> (also referred to as an opening or a gap) between the first and second movable portions <NUM>, <NUM>. The second movable portion <NUM> may have a leading edge 122a and an opposite, straight aft or trailing edge 122b. An angled forward edge 122c may extend from the leading edge 122a to a lower or outer edge 122d. The angled rearward edge 120c of the first movable portion and the angled forward edge 122c of the second movable portion <NUM> may face each other and partially define an outer receiving portion of the opening <NUM>. The opening <NUM> may thus decrease in width in the direction of the target aircraft T. The straight aft edge 120b of the first movable portion <NUM> and the straight leading edge 122a of the second movable portion <NUM> may face each other and partially define an inward securing portion of the opening <NUM>. The opening <NUM> may thus have a constant width between the straight aft edge 120b and the straight leading edge 122a. The towline <NUM> may be guided into the decreasing width portion of the opening <NUM> and then into the constant width portion of the opening <NUM>, as further described.

With reference to <FIG>, sequential views of an embodiment of the recovery system <NUM> are shown illustrating a method of capturing the target aircraft T having the capture mechanism <NUM> with the host aircraft H. As further described, in some embodiments, a method for in-flight recovery of the target aircraft T by the host aircraft H during forward flight may include, for example, deploying the towline <NUM> downward and away from the host aircraft H, receiving a vertically-oriented portion of the towline <NUM> into the wing root WR of the target aircraft T, deploying first and second movable portions <NUM>, <NUM> of the target aircraft T to deployed positions to define the opening <NUM>, maneuvering the target aircraft T to move the capture mechanism <NUM> toward the towline <NUM>, guiding the towline <NUM> into the opening <NUM>, guiding the fitting <NUM> toward undersides of the deployed movable portions <NUM>, <NUM>, stowing the movable portions <NUM>, <NUM> to capture the fitting <NUM>, retracting the towline <NUM> toward the host aircraft H to direct the target aircraft T toward the host aircraft H, and/or securing the target aircraft T with the host aircraft H.

As shown in <FIG>, the target aircraft T may be maneuvered into an optimal position relative to the host aircraft H, and/or vice versa. The target aircraft T may be below and behind the host aircraft H. The target aircraft T may be laterally in line with the host aircraft H (with respect to directions into and out of the plane of the figure as oriented), or the target aircraft T may be laterally offset from the host aircraft H. The towline <NUM> may be deployed from the host aircraft H either prior to or after relative positioning of the aircraft H, T.

The towline <NUM> or portion or thereof, such as a distal end containing the fitting <NUM>, may be oriented vertically or near vertical. "Vertical" as used herein has its usual and customary meaning and includes without limitation a direction aligned with the direction of gravity. In some embodiments, "vertical" may refer to a direction perpendicular to a horizontal component of travel of the host and/or target aircraft H, T. The towline <NUM> may form an angle B with the vertical direction V, as shown in <FIG>. In some embodiments, the portion of the towline <NUM> adjacent to or otherwise near the fitting <NUM>, such as any portions that would interact with the capture mechanism <NUM>, may form the angle B. The angle B may be less than <NUM> degrees, less than <NUM> degrees, less than <NUM> degrees, less than <NUM> degrees, less than <NUM> degrees, less than <NUM> degrees, less than <NUM> degrees, less than <NUM> degrees, or less than <NUM> degrees off the vertical direction V. In some embodiments, the towline <NUM> in free space (e.g. prior to contact with the target aircraft T) may be angled more than <NUM> degrees, or more than <NUM> degrees, and then form the angle B in response to contacting the wing and/or fuselage of the target aircraft. The towline <NUM> may thus form the angle B immediately prior to the towline <NUM> entering the space defined between the moveable portions.

As shown in <FIG>, the towline <NUM> extends through the wing root WR of the target aircraft T. As the target aircraft T is maneuvered, the towline <NUM> may be directed along the fuselage F and/or the wing W of the target aircraft T toward the wing root WR. As used herein, the "wing root WR" may include a region of the target aircraft T where the leading or trailing edge of the wing W intersects the fuselage F. This region is not limited to the surfaces of the wing W and fuselage F, and includes space adjacent to these surfaces extending forward from the wing W and laterally outward away from the fuselage F. The wing root WR may include a triangular region, defined between the nose of the aircraft, the outer tip of the wing, and the intersection of the fuselage and leading edge of the wing. The target aircraft T may be maneuvered relative to the towline <NUM> so that the towline <NUM> makes contact directly at the wing root WR of the target aircraft T without contacting the wing W or the fuselage F of the target aircraft T.

As shown in <FIG>, the target aircraft T may be maneuvered toward the towline <NUM> to cause the towline <NUM> to contact the target aircraft T along the wing W of the target aircraft T and/or the fuselage F of the target aircraft T. The towline T may make some contact with the wing W and/or fuselage F of the target aircraft T before the towline <NUM> is captured by the capture mechanism <NUM> of the target aircraft. In some embodiments, the target aircraft T may be maneuvered toward the towline <NUM> to bring the towline <NUM> in proximity with the wing W or the fuselage F of the target aircraft T, without necessarily having the towline <NUM> make contact with the fuselage F or the wing W of the target aircraft T. For instance, the recovery system <NUM> may use a natural funneling effect to cause the towline <NUM> to move toward the wing root WR of the target aircraft T, which may be due to contact with the wing W and/or fuselage F, and/or due to aerodynamic forces acting on the towline <NUM> and/or fitting <NUM>. The leading edge of wing W and side of fuselage F may create and/or enhance an airflow funnel and/or reduced pressure zone that may guide or bias the towline <NUM> toward the wing root WR and/or toward the fuselage F.

With reference to <FIG>, in some embodiments, the target aircraft T may be maneuvered such that, once the towline <NUM> reaches the wing root WR and/or with the towline <NUM> located within the opening <NUM> as further described, the flight path of the target aircraft T may be altered. For example and without limitation, the target aircraft T may be maneuvered to roll toward the towline <NUM>, yaw toward the towline <NUM>, and/or decrease altitude so that the fitting <NUM> is brought into proximity with the capture mechanism <NUM>. In some embodiments, at a certain proximity from the towline <NUM>, the target aircraft T may roll, maneuver laterally toward the towline <NUM>, and/or maneuver vertically up or down to bring the towline <NUM> and/or fitting <NUM> into proximity with the capture mechanism <NUM>. The first and second movable portions <NUM>, <NUM> may be in a stowed position during these maneuvers. In some embodiments, the target aircraft T may maneuver laterally toward the towline <NUM> a distance of <NUM> meter (five feet) or less, <NUM> meter (ten feet) or less, <NUM> meter (fifteen feet) or less, <NUM> meter (twenty feet) or less, <NUM> meter (twenty-five feet) or less, or <NUM> meter (thirty feet) or less. The target aircraft T may lower relative to the towline <NUM>, e.g. decrease the target aircraft T's altitude if the towline <NUM> is vertically stationary, by <NUM>,<NUM> meter (one foot) or less, <NUM>,<NUM> meter (two feet) or less, <NUM>,<NUM> meter (three feet) or less, <NUM>,<NUM> meter (four feet) or less, <NUM>,<NUM> meter (five feet) or less, <NUM>,<NUM> meter (six feet) or less, <NUM>,<NUM> meter (seven feet) or less, <NUM>,<NUM> meter (eight feet) or less, <NUM>,<NUM> meter (nine feet) or less, <NUM>,<NUM> meter (ten feet) or less, <NUM>,<NUM> meter (fifteen feet) or less, or <NUM>,<NUM> meter (twenty feet) or less. The target aircraft T may roll, i.e. rotate along its longitudinal axis, toward the towline <NUM> an angular amount, which may be five degrees or less, ten degrees or less, fifteen degrees or less, or twenty degrees or less. This rotation may be relative to a current roll orientation of the target aircraft T, or relative to the horizon.

In any embodiments of the recovery systems disclosed herein, the target aircraft T may approach aft of and to the lateral side of the towline <NUM>, such as from the right of the towline <NUM> as shown. For capture mechanisms that open to the right side of the target aircraft T, the target aircraft T may approach from the aft and left side of the towline <NUM>. Looking down at the target aircraft T, for instance as shown in <FIG>, the target aircraft T may be moved at an angle toward the towline <NUM>, such as at a forty-five degree angle or an approximately a forty-five degree angle relative to the towline <NUM>. In some embodiments, the target aircraft T may be maneuvered toward the towline <NUM> at a vertical distance of approximately <NUM>,<NUM> meter to <NUM>,<NUM> meter (ten to one hundred feet), <NUM>,<NUM> meter to <NUM>,<NUM> meter (twenty to eighty feet), <NUM>,<NUM> meter to <NUM>,<NUM> meter (thirty to fifty feet), or <NUM>,<NUM> meter (forty feet) below the host aircraft H. <FIG> shows the target aircraft T nearing contact with the towline <NUM>. In some embodiments, visual navigation by the remote controller or autonomous flight system of the target aircraft T may be used to assist in the navigation and/or maneuvering of the target aircraft T relative to the towline <NUM> once the target aircraft T is in close proximity with the towline <NUM>, for example and without limitation, when the target aircraft T is within <NUM> meter (ten feet) or approximately <NUM> meter (ten feet) of the towline <NUM>, or within <NUM> meter (five feet) or approximately <NUM> meter (five feet) of the towline, or within <NUM> to <NUM> meter (five to twenty feet) of the towline <NUM>.

As shown in <FIG>, in some embodiments, with the towline <NUM> either moving along the leading edge of the wing W toward the wing root WR, and/or along the fuselage F toward the wing root WR, and/or in contact with or in proximity of the wing root WR, the second movable portion <NUM> may be moved to or toward the open or deployed position. The second movable portion <NUM> may be deployed prior to the towline <NUM> being deployed and/or being near the target aircraft T. The second movable portion <NUM> may be located aft of the first movable portion <NUM>. The second movable portion <NUM> may be positioned on the target aircraft T and configured so that a leading or forward edge 122a of the second movable portion <NUM> will be aft of the towline <NUM> during the capture operation, e.g., when the towline <NUM> is in contact with or proximal to the wing root WR, or as the towline <NUM> is moving along the leading edge of the wing W of the target aircraft T. In this configuration, the towline <NUM> may be captured forward of the second movable portion <NUM> so that the capture mechanism <NUM> may capture the towline <NUM> between the first and second movable portions <NUM>, <NUM>.

The towline <NUM> may be guided into the opening <NUM>, such as a gap or space, defined by and located between the first and second movable portions <NUM>, <NUM>, as the first movable portion <NUM> is moved to or toward the open position, as shown in <FIG>. In some embodiments, the first movable portion <NUM> may already be deployed prior to movement of the towline toward the opening <NUM>. The opening <NUM> may have a decreasing width from an outer edge of the movable portions <NUM>, <NUM> in the inward direction toward the aircraft T between the angled portion 120c of the first movable portion <NUM> and the outward part of the leading edge 122a of the second movable portion <NUM>. This may create a funnel-shape between the movable portions <NUM>, <NUM>. The opening <NUM> may then have a constant width section between the trailing edge 120b of the first movable portion <NUM> and the inward part of the leading edge 122a of the second movable portion. The towline <NUM> may be received into the decreasing width portion of the opening <NUM> and then into the constant width portion of the opening <NUM>.

The opening <NUM> may have an inner-most endpoint <NUM>, which may be a region of the opening <NUM>, that limits further lateral travel of the towline <NUM>. The endpoint <NUM> may be aligned with a longitudinal axis of the aircraft T, for example located directly over such axis, such that this endpoint <NUM> is near the middle of the fuselage F as viewed from the top. In some embodiments, this endpoint <NUM> may be aligned with the center of gravity of the target aircraft T. In some embodiments, the opening <NUM> may be forward or aft of the center of gravity of the target aircraft T. In some embodiments, the opening <NUM> may be slightly forward of the center of gravity of the target aircraft T to create a passively stable towed body once the wings are folded or moved to a collapsed state (if the wings are folded or moved to a collapsed state) and/or the engine of the target aircraft is shut down. In some embodiments, the opening <NUM> may be forward or aft of the center of gravity of the target aircraft T by a particular percentage of the overall longitudinal length of the aircraft, for example by from <NUM>% or less, less than <NUM>%, less than <NUM>%, less than <NUM>% or less than <NUM>% of the length of the aircraft. The opening <NUM> may have other configurations, such as a uniform width, a changing width, a decreasing width, an increasing width, or combinations thereof.

As shown in <FIG>, once the target aircraft T and/or towline <NUM> have been maneuvered so that the towline <NUM> is positioned forward of and adjacent to the forward edge 122a of the second movable portion <NUM>, the first movable portion <NUM> may be deployed to or toward the open position so that the towline <NUM> is positioned between the aft edge 120b of the first movable portion <NUM> and the forward edge 122a of the second movable portion <NUM>. With the towline <NUM> positioned between the aft edge 120b of the first movable portion <NUM> and the forward edge 122a of the second movable portion <NUM>, the towline <NUM> and/or target aircraft T may move such that the towline <NUM> moves vertically upward relative to the target aircraft T, which movement may be toward the host aircraft H, and is drawn upward through the opening <NUM> of the capture mechanism <NUM>. The fitting <NUM> or other limiting object fixed to the towline <NUM> at a particular position on the towline <NUM> may thus be moved into contact with the capture mechanism <NUM>, for example and without limitation, moved into contact with a lower surface of the first and second movable portions <NUM>, <NUM>.

In some embodiments, the capture mechanism <NUM> and the fitting <NUM> may be configured such that the fitting <NUM> has a width that is larger than a width of an inner section of the opening <NUM>. This inner section may be a portion of the opening <NUM> that has a constant width, or that otherwise has a width smaller than the width of the fitting <NUM>. The width of the fitting <NUM> may be larger than a perpendicular distance between the aft edge of the first movable portion <NUM> and the forward edge of the second movable portion <NUM>. This inner section of the opening <NUM> may be at or near a base of the first and second movable portions <NUM>, <NUM>. The inner section may be configured such that the fitting <NUM> cannot vertically pass through the opening <NUM> between the first and second movable portions <NUM>, <NUM> as the towline <NUM> is moved upwardly through the inner section of the opening <NUM> between the first and second movable portions <NUM>, <NUM> when the first and second movable portions <NUM>, <NUM> are in the stowed or deployed positions. In this manner, the capture mechanism <NUM> may be used to capture or secure the towline <NUM> to the target aircraft T.

In some embodiments, the target aircraft T may maneuver to locate the towline <NUM> within the opening <NUM>, into the inner section of the opening <NUM>, and/or into the endpoint <NUM> of the opening <NUM>. The target aircraft T may roll, yaw, pitch, etc. as previously described.

As shown in <FIG>, with the fitting <NUM> located in the inner section and/or at the endpoint <NUM> of the opening <NUM>, the first and second movable portions <NUM>, <NUM> may be moved, e.g. simultaneously, toward their respective stowed positions to prevent the towline <NUM> and/or the fitting <NUM> from escaping the fuselage F of the target aircraft T or otherwise moving out of engagement with the capture mechanism <NUM>. The towline <NUM> may extend from the endpoint <NUM> of the opening <NUM>, or from the inner section of the opening <NUM>.

As shown in <FIG>, some embodiments of the target aircraft T may be configured to take a passive towed body configuration. For example, the wings W may move or rotate to a stowed position. In this example, the wings W move in line with the fuselage F of the target aircraft T. Further details of towed body configurations of the target aircraft are shown in and described with respect to <FIG>.

As shown in <FIG>, the towline <NUM> may be reeled in by a hoist system having a winch to pull the target aircraft T toward the host aircraft H. Once the towline <NUM> is retracted, the target aircraft T may be securely attached to or secured by the host aircraft H. For example, the target aircraft T may attach to a pylon of the host aircraft H. Further details of various embodiments of hoist systems and securement features are shown in and described with respect to <FIG>. Optionally, the target aircraft T may also be deployable from the host aircraft H before and/or after recovery. The recovery or deployment may occur during any phase of flight. The recovery may occur during forward flight, ascending or descending flight, takeoff, landing, or other phases.

<FIG> depicts another embodiment of a system <NUM> for recovery of a target aircraft T having a capture mechanism <NUM>. The recovery system <NUM> may have the same features and/or functions as the recovery system <NUM>, and vice versa. For example, the capture mechanism <NUM> may be coupled with a fuselage F of a target aircraft T and may be configured to capture a towline <NUM> tethered to a host vehicle (not shown). The capture mechanism <NUM> may include a first movable portion <NUM> and second movable portion <NUM>. The first movable portion <NUM> may have a leading edge 220a and a trailing edge 220b, and the second movable portion <NUM> may have a leading edge 222a and a trailing edge 222b. The first and second movable portions <NUM>, <NUM> may be configured to rotate or move between a first, closed or stowed position and a second, open or extended position. For example and without limitation, <FIG> shows the first and second movable portions <NUM>, <NUM> in a second, open position. The capture mechanism <NUM> may have a first recess <NUM> configured to receive the first movable portion <NUM> therein when the first movable portion <NUM> is in the closed position, and a second recess <NUM> configured to receive the second movable portion <NUM> therein when the second movable portion <NUM> is in the closed position, to optimize the aerodynamics of the capture mechanism.

Further, the capture mechanism <NUM> may include a catch <NUM> configured to receive the fitting <NUM>. The catch <NUM> may be located within the recess <NUM> and/or recess <NUM>. The catch may be a device the secures, for example grabs, the fitting <NUM>. In some embodiments, the catch <NUM> may be a round opening in the cavity or recesses configured to receive the fitting <NUM> therein as the movable portions <NUM>, <NUM> close and move the fitting <NUM> through and/or into the catch <NUM>.

<FIG> depict sequential views of another embodiment of a recovery system <NUM> for recovery of a target aircraft T having a capture mechanism <NUM>. The recovery system <NUM> may have any of the same features and/or functions as the recovery system <NUM> or <NUM>, and vice versa. For example, the capture mechanism <NUM> may be coupled with a fuselage F of a target aircraft T and may be configured to capture a towline <NUM> tethered to a host vehicle (not shown). The capture mechanism <NUM> may include a first movable portion <NUM> and second movable portion <NUM>. The first movable portion <NUM> may have a leading edge 320a and a trailing edge 320b, and the second movable portion <NUM> may have a leading edge 322a and a trailing edge 322b. The first and second movable portions <NUM>, <NUM> may be configured to rotate or move between a first, closed or stowed position and a second, open or extended position. For example and without limitation, <FIG> shows the first and second movable portions <NUM>, <NUM> in a second, open position. The capture mechanism <NUM> may have a first recess <NUM> configured to receive the first movable portion <NUM> therein when the first movable portion <NUM> is in the closed position, and a second recess <NUM> configured to receive the second movable portion <NUM> therein when the second movable portion <NUM> is in the closed position.

Further, the first and/or a second movable portions <NUM>, <NUM> may have a segmented "ski" shape. The movable portions <NUM>, <NUM> may be elongated members with multiple segments to match the contour of the fuselage F and provide a wider outer opening <NUM> for the towline <NUM>. The inner segments of each movable portion <NUM>, <NUM> may be spaced to define a constant width opening therebetween. A second outward segment adjacent the inner segment of each movable portion <NUM>, <NUM> may angle away from each other and have an increasing width therebetween in a direction away from the base of the movable portions <NUM>, <NUM>. A third outer segment adjacent the second segment of each movable portion <NUM>, <NUM> may angle outward even more than the second segments, and have an increasing width therebetween that increases at a faster rate in an outer direction as compared to the distance between the second segments. This configuration may create a larger outermost width of an opening <NUM> located between outer endpoints of the movable portions <NUM>, <NUM> to increase reliability of receiving the towline <NUM> between the movable portions <NUM>, <NUM> and into the inner section of the opening <NUM>.

<FIG> depict sequential views of another embodiment of a recovery system <NUM> for recovery of a target aircraft T having a capture mechanism <NUM>. The recovery system <NUM> may have any of the features and/or functions as the recovery systems <NUM>, <NUM>, or <NUM>, and vice versa. For example, the capture mechanism <NUM> may be coupled with a fuselage F of the target aircraft T and may be configured to capture a towline <NUM> tethered to a host vehicle (not shown). The capture mechanism <NUM> may include a first movable portion <NUM> and second movable portion <NUM>. The first movable portion <NUM> may have a leading edge 420a and a trailing edge 420b, and the second movable portion <NUM> may have a leading edge 422a and a trailing edge 422b. The first and second movable portions <NUM>, <NUM> may be configured to rotate or move between a stowed position and a deployed position. The capture mechanism <NUM> may have a first recess <NUM> configured to receive the first movable portion <NUM> therein when the first movable portion <NUM> is in the closed position, and a second recess <NUM> configured to receive the second movable portion <NUM> therein when the second movable portion <NUM> is in the closed position.

Further, the first and second movable portions <NUM>, <NUM> may be integral and move together. The movable portions <NUM>, <NUM> may have a single shared base <NUM> that rotates outward, and include two prongs <NUM>, <NUM> respectively extending outwardly from the base <NUM>. The base <NUM> may rotate about an axis that is located on an opposite side, for example right side, of the fuselage F as the side from which the towline <NUM> is incoming, for example the left side. The base <NUM> and/or movable portions <NUM>, <NUM> may have a rounded, e.g. circular or elliptical, contour to match the fuselage cross-sectional shape. An opening <NUM> may be defined between the two prongs <NUM>, <NUM> having a width that decreases in an inward direction toward the aircraft T to a smaller width inner section, which may have a constant width. A fitting <NUM> may have an elongated shape, such as cylindrical and, in some embodiments, have rounded edges near the longitudinal ends of the fitting <NUM>, as shown. In any embodiments disclosed herein, the fitting <NUM> can be cylindrical in shape, as shown in <FIG>, but may be shorter or longer in length than shown. For example and without limitation, the fitting <NUM> of any embodiments can have more of an elongated pill shape. The fitting <NUM> may be long enough to not fit through the inner section of the opening <NUM>. The fitting <NUM> may be rounded to match a rounded contour of the underside of the movable portions <NUM>, <NUM>, for example to self-center itself underneath the movable portions <NUM>, <NUM> in the stowed position.

<FIG> depict sequential views of another embodiment of a system <NUM> for recovery of a target aircraft T having a capture mechanism <NUM>. The recovery system <NUM> may have any of the features and/or functions as the recovery systems <NUM>, <NUM>, <NUM> or <NUM>, and vice versa. For example, the capture mechanism <NUM> may be coupled with a fuselage F of the target aircraft T and may be configured to capture a towline <NUM> tethered to a host vehicle (not shown). The capture mechanism <NUM> may include a first movable portion <NUM> and second movable portion <NUM>. The first movable portion <NUM> may have a leading edge 520a and a trailing edge 520b, and the second movable portion <NUM> may have a leading edge 522a and a trailing edge 522b. The first and second movable portions <NUM>, <NUM> may be configured to rotate or move between a stowed position and a deployed position.

Further, the wing root WR may be a region located aft of the wing, as shown. This region may include space aft of the wing and laterally to the left side of the fuselage. The region may be bounded by the intersection of the trailing edge of the wing and the fuselage, the tail, and the outer tip of the left wing. Thus, the towline <NUM> may be located aft of the wing and/or to the left of the fuselage. The target aircraft T may slow its speed while maneuvering to have the towline <NUM> located within this aft wing root WR. Additionally, the first and second movable portions <NUM>, <NUM> may be separate and configured to move independently of one another or to move simultaneously and equally depending on the desire of the operator or of the autonomous system. For example, the towline <NUM> may be at an angle or position where only one, or both, movable portions <NUM>, <NUM> should be deployed, and the mechanism can be operated accordingly. The movable portions <NUM>, <NUM> may also have a length that, when deployed, extends an outermost tip of the movable portions <NUM>, <NUM> farther outward to allow for capture of the towline <NUM> located farther from the fuselage F. For example, the movable portions <NUM>, <NUM> may deploy to locate the outermost tips beyond an outer, lateral side of the fuselage F, and/or beyond the intersection of the wing W and fuselage F, and/or beyond <NUM>%, beyond <NUM>%, beyond <NUM>%, or beyond <NUM>% or more of the wingspan as measured between opposite tips of the wings W.

The following details apply to any recovery system and any capture mechanism embodiments disclosed herein. In some embodiments, servos, electric motors (high torque geared motors), linear or rotational actuators (for example and without limitation, screw driven linear actuators), hydraulic, pneumatic, and/or other actuation mechanisms may be used to move the first and second movable portions between the first and second positions. For example and without limitation, a first servo, motor, and/or actuator may be configured to rotate a shaft or axle that the first movable portion is coupled with to rotate the first movable portion between the first and second positions. A second servo, motor, and/or actuator may be configured to rotate a shaft or axle that the second movable portion is coupled with to rotate the second movable portion between the first and second positions. The first and second servo, motor, and/or actuators may be independently controlled. In some embodiments, a single servo, motor, actuator, and/or combination thereof may be used to move both the first and second movable portions.

In some embodiments, the first and second movable portions may be integrally formed - e.g., may be formed as a single structure, and/or may be separately formed and rigidly connected. In this arrangement, the capture mechanism may be configured such that the first and second movable portions move as a single unit, such that they both moved between the first, close position and a second, open position simultaneously.

In some embodiments, the first and second movable portions may be configured to rotate around one or two shafts or axes. For example and without limitation, embodiments wherein the first and second movable portions are connected, made from a single piece, or otherwise configured to move together and simultaneously, the first and second movable portions may rotate about a single shaft or axis.

In some embodiments, the shaft or axis of rotation that the first and second movable portions may be configured to move or rotate about may be located on the same side of the fuselage as the target wing root toward which the towline will be directed. In some embodiments, the shaft or axis of rotation that the first and second movable portions may be configured to move or rotate about may be located on the opposite side of the fuselage as the target wing root toward which the towline will be directed, as in the embodiment of the capture mechanism <NUM> shown in <FIG>, or on an upper portion of the fuselage, as in the embodiment of the capture mechanism <NUM> shown in <FIG>.

In any embodiments disclosed herein, the capture mechanism and/or fuselage of the target aircraft T may be configured to have a recess or chamber sized and positioned to receive the fitting therein so that the fitting does not prevent or inhibit the moving of the capture mechanism to the second, closed state. For example and without limitation, any embodiments of the capture mechanism or the fuselage of the target aircraft T may have a recess, chamber, or space formed therein that is sized and configured to receive the fitting therein as the towline is being advanced into the space or recess between the first and second movable portions of the capture mechanism. In some embodiments, the recess or space configured to receive the fitting may be generally aligned with the space or recess between the first and second movable portions of the capture mechanism since, in some embodiments, the capture mechanism may be configured to bias the towline and the fitting toward the space between the first and second movable portions of the capture mechanism. In some embodiments, the recess or space configured to receive the fitting may have sloping side portions and/or be configured to bias the fitting toward a middle of the recess or space, or otherwise facilitate the movement of the fitting into the recess or space.

Additionally, in some embodiments, though not required, the capture mechanism may have latch mechanisms or other securing mechanisms to selectively latch or secure the first and second movable portions in the closed position to prevent the first and second movable portions from moving toward the open position as the target aircraft T is being lifted toward the host aircraft H (e.g., as an upward force is exerted on the first and second movable portions from the towline and fitting). The latch mechanisms in some embodiments may be electronically controlled so that the latch mechanisms may be released or opened before the first and second movable portions are desired to be moved to the open position. In some embodiments, the latch mechanism may include sliding pins and complementary receiving features.

In any embodiments disclosed herein, though not required, the capture mechanism can be configured to couple with the fitting or couple with the towline so that the towline extends from the target aircraft T at an approximately lateral center of the target aircraft so that the force exerted on the target aircraft by the towline as the towline is being withdrawn is approximately at a lateral center of the target aircraft. In some embodiments, the capture mechanism may be configured to bias the fitting or fitting, or the towline so that the towline extends from the target aircraft T at an approximately lateral center of the target aircraft so that the force exerted on the target aircraft by the towline as the towline is being withdrawn is approximately at a lateral center of the target aircraft. In other embodiments, the capture mechanism may be configured to bias the fitting or fitting or the towline so that the towline extends from the target aircraft T offset from the lateral center of the target aircraft. In these embodiments, the target aircraft may be configured to counteract any off-center force applied to the target aircraft T by the towline as the towline is being withdrawn toward the host aircraft.

In any embodiments of the systems for recovering a target aircraft disclosed herein, including without limitation the embodiments of the systems <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, the towline may be a simple, uniform towline and may include a fitting (such as, without limitation, fitting <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) positioned along a length thereof. The towline of any embodiment herein may have a width between <NUM>,<NUM> meter to <NUM>,<NUM> meter (<NUM> to <NUM> inch), or <NUM>,<NUM> meter to <NUM>,<NUM> meter (between <NUM> to <NUM> inch), or <NUM>,<NUM> meter to <NUM>,<NUM> meter (between <NUM> to <NUM> inch), or <NUM>,<NUM> meter to <NUM>,<NUM> meter (between <NUM> to <NUM> inch). The towline maybe steel, stainless steel, improved plow steel, aluminum, synthetic such as nylon, aramid, dyneema or any other material suitable for extended outdoor use in moderately harsh environments. The towline may have a core that is strand, fiber, or independent wire rope core (IWRC). The towline finish may have a corrosion resistant coating (e.g. zinc, nickel, galvanized), or be unfinished. The towline may be uncoated, or coated for abrasion, chemical and/or weather resistance. The towline may have a breaking strength of between <NUM><NUM>,<NUM> N to <NUM><NUM>,<NUM> N (<NUM>,<NUM> and <NUM>,<NUM> pound-force), or between <NUM><NUM>,<NUM> N to <NUM><NUM>,<NUM> N (<NUM>,<NUM> and <NUM>,<NUM> pound-force), or between <NUM><NUM>,<NUM> N to <NUM><NUM>,<NUM> N (<NUM>,<NUM> and <NUM>,<NUM> pound-force).

As described above, the fitting of any embodiments of the system for recovering a target aircraft disclosed herein may be configured to provide a stop on the towline, when the fitting engaged with the capture mechanism, to prevent further movement of the towline in at least an upward direction relative to the capture mechanism. Further, at least when the capture mechanism is in a closed position, the fitting may be captured by the capture mechanism and be prevented from moving out of contact with or away from the capture mechanism. In some embodiments, all or a portion of the fitting may be sufficiently rigid so as to remain substantially undeformed or uncollapsed during any recovery operation. For example and without limitation, all or a portion of the fitting may be rigid enough to remain substantially undeformed and uncollapsed when the fitting has been captured by the capture mechanism, when the capture mechanism moves to the second, closed state, and/or when the target aircraft is being withdrawn toward the host aircraft during a recovery operation by withdrawing the towline that the fitting is coupled with.

In any embodiments, the fitting may have any desirable weight and size, and may have any desired shape. For example with without limitation, in any embodiments, the fitting may have a spherical shape, a conical shape, an oblong shape, or any other desired shape, as further described.

<FIG> illustrate different embodiments of fittings that may be used with or as part of any embodiments of the recovery systems disclosed herein. Any of the fittings shown in <FIG> may be used with any of the various recovery systems described herein. Further, any features of one of the fittings may be applied to any of the other fittings.

<FIG> shows an embodiment of a fitting <NUM> coupled with or attached to a towline <NUM>. The fitting <NUM> may have a distal portion <NUM> (also referred to herein as a body portion) that may be spherical and a proximal portion <NUM> (also referred to herein as a leading portion) that may be generally cylindrical. The distal portion <NUM> may be solid, hollow, thin walled, or combinations thereof. The proximal portion <NUM> may be coupled with the distal portion <NUM> or may be integrally formed. A proximal end of the proximal portion <NUM> may be pointed or tapered. The proximal portion <NUM> may extend through the opening formed by the flaps of the capture mechanism. The distal portion <NUM> may be too large to fit through the opening, such that the flaps contact and engage the distal portion to move the fitting <NUM> into the recess of the fuselage when the flaps move from the deployed position to the closed position.

A diameter or size of the proximal portion <NUM> may be less than a maximum diameter or size of the distal portion <NUM>, such as, without limitation, at a distal end of the distal portion <NUM>. In some embodiments, the diameter or size of the proximal portion <NUM> may be <NUM>%, less than <NUM>%, or approximately <NUM>% of a size or diameter of the distal portion, or from <NUM>% to <NUM>% or approximately <NUM>% of a maximum size or diameter of the distal portion <NUM>. In some embodiments, the spherical portion of the fitting <NUM> may have a width, e.g. diameter, From <NUM>,<NUM> meter to <NUM>,<NUM> meter (<NUM> to <NUM> inches), from <NUM>,<NUM> meter to <NUM>,<NUM> meter (<NUM> to <NUM> inches), from <NUM>,<NUM> meter to <NUM>, <NUM> meter (<NUM> to <NUM> inches), from <NUM>,<NUM> meter to <NUM>,<NUM> meter (<NUM> to <NUM> inches), or about <NUM>,<NUM> meter (about <NUM> inches). The fitting <NUM> may weigh from <NUM>,<NUM> to <NUM>,<NUM> (<NUM> to <NUM> pounds), from <NUM>,<NUM> to <NUM>,<NUM> (<NUM> to <NUM> pounds), from <NUM>,<NUM> to <NUM>,<NUM> (<NUM> to <NUM> pounds), or from <NUM>,<NUM> to <NUM>,<NUM> (<NUM> to <NUM> pounds) These width and weight features may apply to any of the embodiments of the fittings described herein.

In some embodiments, a maximum diameter or size of the distal portion <NUM> of the fitting <NUM> may be many times greater than a diameter of the towline <NUM>, for example and without limitation, at least fifty times greater than a diameter of the towline, or from twenty times greater to eighty times greater than a diameter of the towline, or from thirty times greater to sixty times greater than a diameter of the towline.

<FIG> is a side view of another embodiment of a fitting <NUM> having a tear-drop shape. The fitting <NUM> may increase in width from a top to a bottom portion and then decrease in width. The contour may be smooth, with a conical upper portion and spherical lower portion. The conical upper portion may extend through the opening of the flaps and the width of the bottom portion may prevent the fitting from traversing the opening completely.

<FIG> is a side of another embodiment of a fitting <NUM> having an arrow shape. The fitting <NUM> may have a forward angular portion <NUM> attached via an elongated member <NUM> to an aft feathered portion <NUM>. The angular portion <NUM> may form a vertex pointing forward and increase in width in the aft direction. The angular portion <NUM> may be planar or three-dimensional, e.g. a conical shape. The feathered portion <NUM> may have various protrusion extending outward and aft, and may be planar or three-dimensional. In use, the towline may attach along the member <NUM>, with the towline extending through the opening of the flaps, and the fitting <NUM> engaging with the underside of the flaps.

<FIG> is a side view of another embodiment of a fitting <NUM> having a flying saucer shape. The fitting <NUM> may have upper and lower portions <NUM>, <NUM> that have spherical contours bulging upward and downward from a ring-like middle portion <NUM>. The middle portion <NUM> may extend radially farther than the upper and lower portions <NUM>, <NUM>. The upper and lower portions <NUM>, <NUM> may be symmetric about the middle portion <NUM>.

<FIG> are front and side views respectively of a fitting <NUM> having a blended-wing body shape with dihedral wings <NUM> attached on both sides of a center portion <NUM>. The wings <NUM> may extend upward from the center portion <NUM>. The center portion <NUM> may have an airfoil profile, for example a rounded, blunt forward end that tapers to a point or reduced height at an aft end, as shown in <FIG>. In use, the towline may extend through the opening of the flaps, with the wings <NUM> preventing the fitting <NUM> from completely traversing the opening.

<FIG> are front and side views respectively of a fitting <NUM> having a blended-wing body shape with anhedral wings <NUM> attached on both sides of the center portion <NUM>. The wings <NUM> may extend downward from the center portion <NUM>. In use, the towline may extend through the opening of the flaps, with the wings <NUM> preventing the fitting <NUM> from completely traversing the opening.

<FIG> are front, perspective, and top views respectively of a host aircraft <NUM> in flight having multiple target aircrafts <NUM> secured via hoist systems <NUM>. The aircraft <NUM> includes a right wing <NUM>, a left wing <NUM>, a central fuselage <NUM>, and an inverted-V tail <NUM>. The host aircraft <NUM> may be unmanned, and it may be autonomously flown or remote controlled by a human operator. Other types and configurations of the aircraft <NUM> may be used, and this is merely one example embodiment.

The hoist systems <NUM> are attached to an underside of a respective wing <NUM>, <NUM>. The hoist system <NUM> may have some or all of the same or similar features and/or functions as the hoist <NUM> described with respect to <FIG>, and vice versa. There may be fewer than or greater than one hoist system <NUM> per wing. There may be zero, one, two, three, four, five, six or more hoist systems <NUM> per wing. The hoist system <NUM> in flight may deploy one or more towlines to capture a respective target aircraft <NUM>, reel in the respective target aircraft <NUM> toward the host aircraft <NUM> by reeling in the respective towline, and secure the respective target aircraft <NUM> to a respective hoist system <NUM>, as further described herein.

<FIG> are top views of the target aircraft <NUM> shown with the wings <NUM>, <NUM> deployed and stowed, respectively. <FIG> are front views of the target aircraft <NUM> showing the wings <NUM>, <NUM> deployed and stowed, respectively. The <NUM>, <NUM> are rotatably attached to a center fuselage <NUM> and may move from a deployed configuration having a larger width for horizontal flight to a stowed configuration having a smaller width for recovery by the host aircraft and hoist system. The target aircraft <NUM> has a propeller <NUM> shown schematically. The target aircraft <NUM> may be propeller driven, or it may have a turbofan, turbojet, or other type engine.

<FIG> is a perspective view of the host aircraft <NUM> recovering the target aircraft <NUM> in flight via the towline <NUM> extending from the hoist system <NUM>. The hoist system <NUM> includes a pylon <NUM> attached to an underside of the left wing <NUM>. The other hoist systems <NUM> are removed for clarity, but other hoist systems on either wing may be included. The pylon <NUM> is a supporting structure made of metal, composite, or combinations thereof, that supports and protects the various components of the hoist system <NUM>, as further described.

<FIG> are perspective, side, and front views respectively of the hoist system <NUM> securing the target aircraft <NUM> to the wing <NUM>. The wing <NUM> is removed in <FIG> for clarity. The hoist system <NUM> may be located to avoid interference with the wing flap <NUM> and wing flap hinge <NUM>. A clearance <NUM> may exist between the pylon <NUM> and the lowered flap <NUM>, as shown most clearly in <FIG>. The side of the pylon <NUM> may avoid interference with the wing flap hinge <NUM>, as shown in <FIG>.

The hoist system <NUM> includes forward and aft sway bars <NUM>, <NUM> that extend outward and downward from a bottom end of the pylon <NUM>. The sway bars <NUM> surround an upper portion of the fuselage target aircraft <NUM> for lateral stability of the target aircraft <NUM> and for ensuring alignment of the target aircraft <NUM> during the last phase of reeling in the target aircraft <NUM>. In some embodiments, the sway bars <NUM>, <NUM> may guide the target aircraft <NUM> with stowed wings into position so that a securement mechanism, as further described, may engage with the target aircraft <NUM>. The pylon <NUM> and sway bars <NUM>, <NUM> are further shown in, and described with respect to, <FIG>.

In <FIG>, the pylon <NUM> is shown transparently for clarity purposes, to show components of the hoist system <NUM> therein. The hoist system <NUM> may include a motorized winch <NUM>. The winch <NUM> may be located in an aft section of the pylon <NUM> relative to other components of the hoist system <NUM>. The hoist system <NUM> may include a latching system <NUM> located forward of the winch <NUM>. The towline <NUM> may extend from the winch <NUM> to the latching system <NUM> and to the target aircraft <NUM>. The latching system <NUM> may guide the towline <NUM> along a path. There may be a fleet pulley assembly <NUM> through the towline <NUM> extends, a top sheave <NUM> along which the towline <NUM> wraps around down through a latch housing <NUM> located beneath the top sheave <NUM>. Further details of the winch <NUM> and latching system <NUM> are described herein with respect to <FIG>. The target aircraft <NUM> may be secured with the hoist system <NUM> with the center of gravity CG of the target aircraft <NUM> located toward a forward portion of the pylon <NUM>, as shown. The latch housing <NUM> or other engaging features of the hoist system <NUM>, as described herein, may be located generally above and in line with the center of gravity CG of the target aircraft <NUM>.

<FIG> are front, side, cross-section, and bottom views of the pylon <NUM>. <FIG> is a cross-section, taken from <FIG> along the line 12C-12C, and includes a cross-sectional part of the target aircraft <NUM> for illustration. The shape, size, configuration, etc. of the pylon <NUM> is merely one example embodiment, and other variations of the pylon may be incorporated.

The pylon <NUM> extends from a forward end <NUM> to an aft end <NUM>, each end having tapering profiles for aerodynamic efficiency. Opposing lateral sidewalls <NUM>, <NUM> may increase in width from the forward end <NUM> in the aft direction to a central portion <NUM>, and then decrease in width from the central portion <NUM> to the aft end <NUM>. The sidewalls <NUM> may have a maximum width at the central portion <NUM>, which width may be sized based on size of the hoist system <NUM> components therein, based on the width of the stowed target aircraft <NUM>, and/or based on the configuration of the host aircraft wing <NUM> and associated features of the host aircraft <NUM>. The pylon <NUM> may have a length of Between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), or between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches). The pylon <NUM> may have a width of between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), or between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches). The pylon <NUM> may have a height of between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), or between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches).

The pylon <NUM> may include an upper attachment portion <NUM> for attaching the pylon <NUM> to the wing. The upper attachment portion <NUM> may have a smaller width than that between the sidewalls <NUM>, <NUM>. There may be an upper side <NUM> having a contour that matches that of the underside of the wing. The upper side <NUM> may be an upper surface of A gap may exist between the upper side <NUM> and the lower side of the wing, or there may not be a gap. The pylon <NUM> may include a lower side <NUM> having a contour that matches an upper portion of the fuselage of the target aircraft <NUM>. A gap may or may not exist between the fuselage and the lower side <NUM>.

The sway bars <NUM>, <NUM> may be located on the lower side <NUM> at forward portions of the pylon <NUM> as shown, or in other locations. The forward sway bar <NUM> may be located at or near a lower portion of the forward edge <NUM>. The aft sway bar <NUM> may be located at or near the central portion <NUM> of the pylon <NUM>. An opening <NUM> in the lower side <NUM> of the pylon <NUM> may be located in between the sway bars <NUM>, <NUM>. The towline may extend from the latching system <NUM> through the opening <NUM> and out to the target aircraft <NUM>.

As shown in <FIG>, the sway bar <NUM> may match the contour of the target aircraft <NUM> fuselage. The sway bar <NUM> may extend along the upper and side surfaces of the upper portion of the target aircraft <NUM> fuselage after securing the target aircraft <NUM> to the hoist system <NUM>. Similar relationships may exist for the aft sway bar <NUM> and a rearward portion of the fuselage of the target aircraft <NUM>.

<FIG> is a perspective view of a schematic of part of the hoist system <NUM>, showing the winch <NUM>, fleet pulley assembly <NUM>, and top sheave <NUM> in isolation from other components. <FIG> is a cross-section view taken from <FIG> along the line 13B-13B.

The winch <NUM> includes a rotating drum <NUM> around which the towline <NUM> is wrapped. The drum <NUM> may be cylindrical. A motor <NUM> rotates the drum <NUM> to control the length of the towline <NUM> that is paid out from the host aircraft. The motor <NUM> may be controlled based on desired length of towline <NUM>, based on speed of paying our or reeling in of the towline <NUM>, based on vertical position of the target aircraft <NUM>, etc. The winch <NUM> may have a width, height and depth no greater than <NUM> in, <NUM> in, and <NUM> in, respectively.

The towline <NUM> may extend through a movable cartridge <NUM> at a forward portion of the winch <NUM>. The cartridge <NUM> may move axially along one or more axles <NUM>. The cartridge <NUM> may move in response to the relative lateral position of the towline <NUM> on the drum <NUM>. As the towline <NUM> unwraps from the drum <NUM> to pay out, the towline <NUM> may extend from various lateral locations of the drum <NUM>. "Lateral" refers to a direction that is parallel to the axis of rotation <NUM> of the drum <NUM>, which axis may be perpendicular to a longitudinal axis of the host aircraft fuselage <NUM>.

The cartridge <NUM> may move such that the towline <NUM> portion located between the fleet pulley assembly <NUM> and the drum <NUM> may sweep out an angle <NUM> of at least ten degrees, at least twenty degrees, at least thirty degrees, at least forty degrees, at least fifty degrees, at least sixty degrees, at least seventy degrees, at least eighty degrees, or at least ninety degrees. In some embodiments, the angle <NUM> is sixty degrees or about sixty degrees. In some embodiments, the angle <NUM> is not symmetric about the towline <NUM>. As shown in <FIG>, the fleet pulley assembly <NUM> may be located along a geometric reference line <NUM> that is optimized for the pylon <NUM> geometry. The line <NUM> may be selected for example to allow the towline <NUM> to be at angle of about thirty degrees on one side but less than thirty degrees on the other side of the line <NUM>. These are just examples and other configurations and angles may be used.

The fleet pully assembly <NUM> may include a first pulley <NUM> and a second pulley <NUM> oriented generally horizontally and approximately vertically level with the outlet of the towline <NUM> at the cartridge <NUM>. The pulleys <NUM>, <NUM> may be wheels rotatable on a central axis and supported by a support structure within the pylon <NUM>. The fleet pully assembly <NUM> stabilizes the horizontal or lateral direction of the towline away from the cartridge <NUM>. The pulleys <NUM>, <NUM> may be positioned forward of the winch <NUM> to prevent vertical separation of the towline <NUM> from the groove formed by the opposing pulleys <NUM>, <NUM>. In some embodiments, other guides besides pulleys may be used, such as sheaves, stationary and lubricated rounded surfaces, etc. An aft-most portion of the fleet pully assembly <NUM> may be located greater than <NUM>,<NUM> meter (<NUM> inches), greater than <NUM>,<NUM> meter (<NUM> inches), greater than <NUM>,<NUM> meter (<NUM> inches), greater than <NUM>,<NUM> meter (<NUM> inches), greater than <NUM>,<NUM> meter (<NUM> inches), or greater than <NUM>,<NUM> meter (<NUM> inches)in forward of a forward-most portion of the winch. The sweep angle of the towline <NUM> may be with respect to this distance between the winch <NUM> and fleet pulley assembly <NUM>. The centers of rotation of the pulleys <NUM>, <NUM> may be located about <NUM>,<NUM> meter to <NUM>,<NUM> meter (<NUM> to <NUM> in) from a forward-most portion of the winch <NUM>. Each of the pulleys <NUM>, <NUM>, and/or the top sheave as further described, may have a diameter between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), between <NUM>,<NUM> meter and <NUM>,<NUM> meter (<NUM> to <NUM> inches), or <NUM>,<NUM> meter (<NUM> inches).

The top sheave <NUM> may be located forward of the fleet pulley assembly <NUM>. The top sheave <NUM> may guide the towline <NUM> in a downward direction as shown. The top sheave <NUM> may be a rotating wheel. In some embodiments, the top sheave <NUM> may be a stationary guide surface, or other type guide.

<FIG> is a perspective view of an embodiment of the latching system <NUM>. The latching system <NUM> may include fewer or more components than shown. The towline <NUM> wraps around the top sheave <NUM> and extends down to a towline connector <NUM>. The towline connector <NUM> may define a channel through which the towline <NUM> extends. An upper opening of the towline connector <NUM> may be located adjacent and below the top sheave <NUM> to minimize the amount of towline <NUM> extending freely between the top sheave <NUM> and the upper opening. The towline <NUM> may exit a lower opening in the towline connector <NUM> to extend to the end fitting <NUM>. In some embodiments, the towline <NUM> may not extend through the towline connector <NUM>. For example, the towline <NUM> may connect with the towline connector <NUM>, which may connect with or be integral to the end fitting <NUM>, as further described.

In some embodiments, the towline connector <NUM> may be used to couple the towline <NUM> with the end fitting <NUM>. In some embodiments, the towline connector <NUM> may be integrally formed with the end fitting <NUM> or may be separately formed and attached to or otherwise coupled with the end fitting <NUM>.

With reference to <FIG>, some embodiments of the towline connector <NUM> may have a first proximal portion <NUM> and a second distal portion <NUM> that is coupled with or integrally formed with the first portion <NUM>. The first portion <NUM> may be tapered at a leading or proximal portion 1531a of the first portion <NUM>. Additionally, a distal section 1531b of the first portion <NUM> of the towline connector <NUM> may have a round cross-section, as shown, or can have a square cross-section, polygonal cross-section, or have any other suitably shaped cross-section. The second portion <NUM> of the towline connector <NUM> can have a round cross-section, as shown, or can have a square cross-section, polygonal cross-section, or have any other suitably shaped cross-section. The second portion <NUM> can have a cross-sectional size or diameter that is smaller than a cross-sectional size or diameter of the first portion <NUM> such that the towline connector <NUM> has a shoulder or ledge <NUM> that can engage with a latch assembly <NUM>, as will be described in greater detail below. The first and second portions <NUM>, <NUM> of the towline connector <NUM> maybe coaxially aligned along a longitudinal axis of the first and second portions <NUM>, <NUM>. The towline connector <NUM> may move up and down (or proximally and distally) along with the towline <NUM> in order to secure with the target aircraft <NUM>.

In some embodiments, the towline connector <NUM> may include a tube with an opening or pin at the lower end thereof configured to secure with a corresponding structure of the target aircraft <NUM>, e.g. to secure with the capture mechanism <NUM>. In some embodiments, the towline connector may be guided by a bottom sheave (not shown) located below the top sheave <NUM> and adjacent to the towline connector <NUM>. The towline connector <NUM> may be guided by the bottom sheave, for example a rotating wheel thereof. In some embodiments, the towline connector <NUM> may be guided by a stationary guide or other component.

The latching system <NUM> may include a latch housing <NUM>. The towline connector <NUM> may be located partially inside the latch housing <NUM>. The latch housing <NUM> may vertically secure the towline connector <NUM>, for example by inserting one or more pins or bars through and/or around the adapter. For example, the latch assembly <NUM> may be actuated (e.g., advanced and withdrawn in a horizontally axially direction as oriented) to engage and disengage with the towline connector <NUM> to vertically secure the towline connector <NUM> in place. For example and without limitation, the latch housing <NUM> may include the latch assembly <NUM> that may move between a first, latched position (as shown in <FIG>) wherein the latch assembly <NUM> is engaged with the towline connector <NUM> so as to prevent any outfeed (e.g. movement vertically downward away from the latching system <NUM>) of the towline <NUM> and a second, unlatched position (not shown) wherein the latch assembly <NUM> is axially withdrawn (e.g. leftward as oriented in the figure) and is disengaged from the towline connector <NUM> so that the towline <NUM> can be fed out (e.g. move vertically downward away from the latching system <NUM>). The latch assembly <NUM> may move within a channel or passageway within the latch housing <NUM>. In some embodiments, the latch assembly <NUM> or a pin thereof may be spring-loaded. A spring may bias the latch assembly <NUM> into the locked position as shown. The latch assembly <NUM>, whether spring-loaded or otherwise, may be actuated in response to receiving the tow connector, which may be automatic, performed by a control system of the latching system, or actuated by a remote operator.

In some embodiments, the latch assembly <NUM> may have a main body portion <NUM> and a distal portion <NUM>. The distal portion <NUM> may have a recess or opening <NUM> formed therein that maybe sized and configured to receive the second portion <NUM> of the towline connector <NUM> (e.g., may fit around an outside surface of the second portion <NUM> of the towline connector <NUM>). The recess or opening <NUM> formed in the distal portion <NUM> maybe sized and configured to prevent the first portion <NUM> of the towline connector <NUM> from sliding therethrough such that, when the latch assembly <NUM> is in the first, latched position (as shown in <FIG>), the shoulder <NUM> of the towline connector <NUM> maybe abutted against the distal portion <NUM> of the latch assembly <NUM>. In some embodiments, the distal portion <NUM> of the latch assembly <NUM> can have an angled or beveled lower surface configured to cause the latch assembly <NUM> to axially move or withdraw toward the unlatched position when the towline connector <NUM> is reeled in (i.e., withdrawn) and forced into contact with the beveled lower surface of the latch assembly <NUM>. In this arrangement, the latch assembly <NUM> can be caused to automatically move to the unlatched position when the towline connector <NUM> is reeled in and forced into contact with the beveled lower surface of the latch assembly <NUM>. In some embodiments, the latch assembly <NUM> may include a pin extending outwardly away from the body <NUM> which extends through the towline connector <NUM>. Therefore, a variety of different latching connections may be implemented.

In some embodiments, the latching system <NUM> may include a cutter assembly <NUM>. The cutter assembly <NUM> may be configured to cut the towline <NUM>. The cutter assembly <NUM> may include a blade, edge, knife, rotating saw, or other sharp edge to sever the towline <NUM>. The towline <NUM> may be cut in case of emergency where the target aircraft <NUM> must be cut loose from the host aircraft <NUM>, for instance if the winch <NUM> or other mechanism has failed during recovery operations.

Claim 1:
A system (<NUM>) for recovery of a target aircraft (T) by a host aircraft (H) during forward flight, the system comprising:
a towline (<NUM>) comprising a proximal section configured to be coupled with the host aircraft (H) and a distal section configured to be paid out from the host aircraft (H);
a fitting (<NUM>) coupled with the distal section of the towline (<NUM>); and
a capture mechanism (<NUM>) comprising a first movable portion (<NUM>) and a second movable portion (<NUM>) configured to be coupled with a fuselage (F) of the target aircraft;
wherein:
the first movable portion (<NUM>) of the capture mechanism (<NUM>) is configured to move from a first position to a second position in which the first movable portion (<NUM>) extends away from the fuselage (F) of the target aircraft (T),
the second movable portion (<NUM>) of the capture mechanism (<NUM>) is configured to move from a first position to a second position in which the second movable portion (<NUM>) extends at an angle away from the fuselage (F) of the target aircraft (T),
the capture mechanism (<NUM>) is configured to receive the towline (<NUM>) in an opening (<NUM>) defined by the first (<NUM>) and second movable portions (<NUM>) in the second positions and to permit vertical movement of the towline (<NUM>) through the opening (<NUM>), and
characterised in that the capture mechanism (<NUM>) is configured to prevent the fitting (<NUM>) attached to the towline (<NUM>) from moving vertically through the opening (<NUM>).