Patent Publication Number: US-7900866-B2

Title: System and methods for airborne launch and recovery of aircraft

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to aircraft. 
     2. Description of Related Art 
     In modern warfare tactical aircraft are an indispensable asset to military commanders. However, tactical aircraft are limited by, for example, fuel capacity, weaponry capacity and configuration, and maintenance intervals. In-flight refueling can extend combat operations. However, aircraft must still return to a ground base to rearm and to have maintenance performed. Similarly aircraft used in civilian applications such as crop-dusting, aerial police/traffic surveillance, and countering man-portable air-defense systems are also limited by their need to return to ground for maintenance, reconfiguration, etc. 
     These limitations are exacerbated in unmanned air vehicles (UAVs) and unmanned combat air vehicles (UCAVs). For simplicity, the abbreviation UAV will be used herein to refer to both unmanned air vehicles and unmanned combat air vehicles. With the advent of unmanned tactical aircraft, mission endurances have increased steeply due to the elimination of pilot fatigue as a limiting factor. This steep increase in endurance is particularly acute for intelligence, surveillance, and reconnaissance (ISR) missions and hunter-killer missions. But tactical UAVs configured for high endurance typically achieve endurance at the expense of speed and range, thus limiting the spectrum of situations in which they can be deployed. The limited range of some UAVs can be overcome by launching them from airborne transport vehicles. 
     The ability to recover and re-launch aircraft using an airborne mother ship would enable the aircraft to operate virtually indefinitely. Upon recovery, the aircraft could be refueled, rearmed and serviced aboard the mother ship, after which it could be re-launched to return to the battle theatre. In the case of manned aircraft, pilot changes could also be performed while the aircraft is docked with the mother ship. Historically, however, attempts at airborne recovery of aircraft have met with little, if any, success. 
     Attempts at airborne recovery include the FICON (Fighter Conveyor) experiments, in which the daughter aircraft had a hook on its upper surface that caught a trapeze hanging from the mother ship, the Akron and Macon (U.S. airships that carried fighters and captured them with a trapeze system), the Tom-Tom experiments, the Tupolev Zveno and the Firebee II drone, which deployed a parachute that could be snagged by a trapeze device hanging from a passing helicopter. Thus far, trapeze-based solutions are the only ones that have worked to bring the aircraft inside the mother ship. However, even these moderate successes failed to solve the major problems associated with traditional trapeze- or arm-based airborne recovery, in which the recovered aircraft&#39;s weight must be transitioned from its own lift to the mother ship. The transition typically happens close to the mother ship, due to the length of the recovery device, requiring the difficult connection to be made as the deployed aircraft transitions from “clean” air, to a turbulent wake and boundary layer surrounding the mother ship and finally to dead air where it cannot create sufficient lift for flight. These transitions through different types of air make it very difficult to control the aircraft being recovered. 
     SUMMARY 
     The embodiments of the present system and methods for airborne launch and recovery of aircraft have several features, no single one of which is solely responsible for their desirable attributes. Without limiting the scope of the present embodiments as expressed by the claims that follow, their more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description”, one will understand how the features of the present embodiments provide advantages, which include the ability to recover and re-launch aircraft so that their missions can be extended indefinitely, and the ability to recover and launch aircraft smoothly without being significantly affected by turbulent airflow near the mother ship. 
     One aspect of the present embodiments includes the realization that it would be advantageous to be able to launch and recapture aircraft, such as UCAVs, from an airborne mother ship. The ability to recapture the aircraft would advantageously enable refueling, re-supplying, rearming and/or reconfiguration of the aircraft in flight, during the course of a mission. Such capabilities would enable the mission of each such aircraft to be extended indefinitely. 
     One embodiment of the present system for airborne launch and recovery of aircraft comprises a flexible tether configured to be towed behind an airborne mother ship, and a drag device secured to a distal end of the flexible tether. The drag device is configured to generate drag and maintain tension in the flexible tether. The system further comprises a reel associated with the mother ship. The reel is configured to anchor a proximal portion of the flexible tether and to selectively let out and take up the flexible tether. The system further comprises a capture mechanism associated with the aircraft. The capture mechanism is configured to engage the flexible tether to enable the aircraft to translate along the flexible tether. 
     One embodiment of the present methods for airborne launch of aircraft comprises the steps of deploying a flexible tether from an airborne mother ship, translating an aircraft, including wings, rearward along the flexible tether away from the mother ship, and transferring the weight of the aircraft from the flexible tether to the wings. 
     One embodiment of the present methods for airborne recovery of aircraft comprises the steps of deploying a flexible tether from an airborne mother ship, the aircraft engaging the flexible tether, transferring the weight of the aircraft from the wings to the flexible tether, and translating the aircraft forward along the flexible tether toward the mother ship. 
     Another embodiment of the present system for airborne launch and recovery of aircraft comprises a capture mechanism associated with the aircraft and configured to engage a flexible tether during airborne launch and recovery. The capture mechanism comprises a guide member extending from the aircraft, and a latch located at a base of the capture mechanism. The guide member is configured to guide the flexible tether toward the latch during recovery of the aircraft and the latch is configured to engage the flexible tether to enable the aircraft to translate along the flexible tether. 
     Another embodiment of the present methods for airborne recovery of aircraft comprises the step of guiding the flexible tether into a capture mechanism associated with the aircraft. The capture mechanism includes a latch located at a base thereof. The method further comprises the step of engaging the latch with the flexible tether. 
     Another embodiment of the present system for airborne launch and recovery of aircraft comprises a reel apparatus associated with a mother ship. The reel apparatus comprises a reel configured to take up and let out a flexible tether that the aircraft is configured to engage during launch and recovery. The reel apparatus further comprises a frame including a plurality of rigid members and configured to support the reel. 
     The features, functions, and advantages of the present embodiments can be achieved independently in various embodiments, or may be combined in yet other embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments of the present system and methods for airborne launch and recovery of aircraft will now be discussed in detail with an emphasis on highlighting the advantageous features. These embodiments depict the novel and non-obvious system and methods shown in the accompanying drawings, which are for illustrative purposes only. These drawings include the following figures, in which like numerals indicate like parts: 
         FIG. 1  is a rear perspective view of one embodiment of the present system and methods for airborne launch and recovery of aircraft; 
         FIG. 2  is a front elevation view of one embodiment of a capture mechanism of the present system and methods for airborne launch and recovery of aircraft; 
         FIG. 3  is a detail front elevation view of the capture mechanism of  FIG. 2 ; 
         FIG. 4  is a rear perspective view of one embodiment of a reel apparatus of the present system and methods for airborne launch and recovery of aircraft; 
         FIG. 5  is a flowchart illustrating one embodiment of the present methods for airborne launch of aircraft; and 
         FIG. 6  is a flowchart illustrating one embodiment of the present methods for airborne recovery of aircraft. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates one embodiment of the present system  10  for airborne launch and recovery of an aircraft  12 . In the present system  10  an airborne mother ship  14  tows a flexible tether  16 . A distal end  18  (spaced from the mother ship  14 ) of the flexible tether  16  includes a drag device  20 . The drag device  20  generates drag to maintain tension in the flexible tether  16 . The present system  10  further comprises a reel  22  associated with the mother ship  14 . The reel  22 , which is discussed in further detail below, anchors a proximal portion  24  (near the mother ship  14 ) of the flexible tether  16  and stows the flexible tether  16 . The reel  22  is also configured to selectively let out (deploy) the flexible tether  16  and take up the flexible tether  16 . The present system  10  further comprises a capture mechanism  26  ( FIGS. 2 and 3 ) associated with the aircraft  12 . The capture mechanism  26  is configured to engage the flexible tether  16  to enable the aircraft  12  to translate along the flexible tether  16 . 
     With reference to  FIGS. 2 and 3 , the capture mechanism  26  comprises first and second guide members  27  extending generally upward from a dorsal surface  29  of the aircraft  12 . In one embodiment, the guide members  27  may comprise rotatable portions of the aircraft&#39;s fuselage  31 . With reference to  FIG. 3 , the guide members  27  are rotatable between a first position, shown in dashed lines, in which they lie against or are integrated into the aircraft&#39;s fuselage  31 , and a second position, shown in solid lines, in which they extend upward. The guide members  27  are curved to match the contours of the fuselage  31  when in the first position and to present an inward tapering capture space  33  with which to capture the flexible tether  16 . The aircraft  12  may include a single capture mechanism  26 , which may be located over the aircraft&#39;s center of gravity, or the aircraft  12  may include fore and aft capture mechanisms  26 . In certain embodiments the capture mechanism  26  may include only a single guide member  27 . 
     With continued reference to  FIG. 3 , at a base  35  of the capture mechanism  76  between the guide members  27  a rotatable latch  37  secures the flexible tether  16 . The latch  37  is generally L-shaped, including a first depending portion  39  and a second depending portion  41 . The latch is  37  pivotable about a base portion  43  between a receiving position, shown in solid lines, and a latched position, shown in dashed lines. When in the receiving position, the latch  37  is configured to receive the flexible tether  16 . As the flexible tether  16  enters the base  35  of the capture mechanism  26  it contacts the first depending portion  39 . As the flexible tether  16  moves farther into the base  35  it applies force to the first depending portion  39 , causing the latch  37  to rotate into the latched position, trapping the flexible tether  16 , and securing the aircraft  12  to the flexible tether  16 . The latch  37  may include a locking mechanism (not shown) to prevent undesired disengagement of the aircraft  12  from the flexible tether  16 . Rather than force applied by the flexible tether  16  causing the latch  37  to rotate, the capture mechanism  26  may include a sensor (not shown) that detects the presence of the flexible tether  16  and automatically moves the latch  37  from the receiving position to the latched position. 
     With reference to  FIG. 4 , in the illustrated embodiment the reel  22  is secured to a frame  45  in the cargo hold  34  of the mother ship  14 . In certain embodiments the frame  45  may be located on a cargo ramp  36  ( FIG. 1 ) of the mother ship  14 . The frame  45  comprises a plurality of rigid members  47  secured to one another to form several rigid truss structures, including first and second side trusses  49  supporting a top truss  51 . The rigid members  47  may be constructed of a variety of materials such as metals or composites. The side trusses  49  may lock into existing pallet rails  63  aboard the mother ship  14 . 
     First and second reel-supporting trusses  53  extend forward from the side trusses  49 . The reel  22  is advantageously mounted forward of and at about the same height as or slightly below the top truss  51 . The flexible tether  16  thus extends from the reel  22  and beneath the top truss  51  so that as the aircraft  12  is brought into the mother ship  14  it can safely enter the space surrounded by the frame  45  without hitting the frame  45 . Rollers  61  may be provided to guide the flexible tether  16  as it is unwound from and wound onto the reel  22 . The rollers  61  may also assist in leveling the flexible tether  16  and the aircraft  12  during the launch and recovery processes. 
     As illustrated in  FIG. 4 , a cradle  55  may be provided to support the aircraft  12  both before it is secured to the flexible tether  16  before launch and after it has been detached from the flexible tether  16  subsequent to recovery. The cradle  55  may comprise first and second substantially U-shaped members  57  configured to support the rounded belly of the aircraft  12 . The cradle  55  may be configured to move forward and backward along rails  59  within the cargo hold  34  to move the aircraft  12  back and forth between a storage location within the mother ship  14  and a launch/recovery position. The rails  59  may comprise existing Air Delivery System (ADS) rails such as those that are currently present on many cargo lifters. 
     The mother ship  14  and/or the aircraft  12  may include one or more sensors and/or guidance apparatus (not shown) to assist the aircraft  12  in locating the mother ship  14  during the recovery process. For example, the sensors and/or guidance apparatus may include global positioning receivers (GPS), radio frequency (RF) apparatus, satellite guidance apparatus, visual guidance, etc. Further details of the present recovery methods are described below. 
     The mother ship  14  contains components used in the refueling, rearming and servicing of the aircraft  12 . For example, the mother ship  14  may contain fuel, armaments, spare parts, extra pilots, etc. For extended missions, the mother ship  14  may include sleeping quarters for pilots and other personnel. For example, some of the personnel aboard the mother ship  14  may perform refueling, rearming and/or servicing of the aircraft  12 . In other embodiments the mother ship  14  may include an autonomous refueling/rearming/servicing system, and could even be completely unmanned. 
     In certain embodiments the mother ship  14  may be a converted cargo airlifter, such as the Boeing C-17 shown in  FIG. 1 . However, in certain other embodiments the mother ship  14  may be specifically designed and built for the purpose of airborne launch and recovery. Similarly, the aircraft  12  may comprise an existing aircraft that is modified to be compatible with the present system  10  for airborne launch and recovery, or it may be an aircraft specially designed and built for this purpose. While in the illustrated embodiment the aircraft  12  is an unmanned air vehicle (UAV) those of ordinary skill in the art will appreciate that the present system  10  is also configured for airborne launch and recovery of manned air vehicles. 
     In embodiments where the mother ship  14  is a converted cargo airlifter certain embodiments of the present system  10  may provide a self-contained and loadable pallet containing all of the hardware needed to perform airborne launch and recovery. The pallet may be configured to engage existing pallet rails and locking mechanisms on the floor of the airlifter. 
     The aircraft  12  is advantageously capable of assuming a zero-lift or near zero-lift configuration. For example, the aircraft&#39;s wings  28  may include spoilers (not shown) or other apparatus configured to change the profile or plan area of the wings  28  in order to decrease the lift that they provide. In other example embodiments the wings  28  may be capable of morphing, and/or they may be foldable or stowable. In embodiments having foldable or stowable wings  28  the aircraft  12  may advantageously have a very wide wingspan for flight, and then fold or stow its wings  28  in order to fit within the mother ship  14 . In certain embodiments the wings  28  may also be jettisonable. In embodiments in which the wings  28  may be jettisoned, they may also be constructed of materials having low density, such as foam, so that they drift slowly to Earth and land without causing damage. 
     In the zero-lift or near zero-lift configuration, the aircraft  12  is configured to be supported by the tension in the flexible tether  16 . Thus, as explained in further detail below, during launch and recovery the aircraft  12  may embody the zero-lift or near zero-lift configuration. As it translates along the flexible tether  16  and toward the mother ship  14  during recovery it transitions from “clean” air, to a turbulent wake and boundary layer surrounding the mother ship  14  and finally to dead air within the mother ship  14 . As it translates along the flexible tether  16  and away the mother ship  14  during launch it transitions through these areas in reverse order. These transitions would significantly affect the aircraft&#39;s motion if it were not in the zero-lift or near zero-lift configuration. This configuration enables the aircraft  12  to smoothly pass through the transitions without wildly pitching up and down due to rapidly changing lift forces acting on the wings  28 . This configuration also reduces roll and/or yaw movements of the aircraft  12  caused by rapidly changing differential lift forces acting on the wings  28 . 
     The flexible tether  16  may be constructed of any material having suitable strength, weight and flexibility characteristics. For example, the flexible tether  16  could be KEVLAR®, one or more metals, such as steel, alloys and/or polymers, such as nylon. The material may also comprise woven fibers. The flexibility of the flexible tether  16  advantageously reduces the forces to which the mother ship  14  and the aircraft  12  are subjected as compared to prior art systems including a rigid arm extending from the mother ship. In such prior art systems, forces acting on either the mother ship or the aircraft are transferred through the rigid arm to the structure at the other end. The longer the arm is, the greater the moments created at the points where the arm connects to the mother ship and to the aircraft. With the present flexible tether  16 , forces acting on either the mother ship  14  or the aircraft  12  are absorbed in the flexible tether  16  as it flexes. 
     The flexible tether  16  can also advantageously be extended farther behind the mother ship  14  as compared to a rigid arm. The comparatively larger and heavier rigid arm is more limited in its length, due to concerns about storage space and weight aboard the mother ship  14 . The relatively more compact and light flexible tether  16  can be rolled up into a compact size for storage, and unreeled to greater lengths than a rigid arm. The longer flexible tether  16  enables the aircraft  12  to engage at a point far removed from the mother ship  14  where airflow is less turbulent. The longer flexible tether  16  also enables more than one aircraft  12  to engage the flexible tether  16  at once. Further, the drag device  20  at the distal end  18  of the flexible tether  16  creates tension in the flexible tether  16  that enables the aircraft  12  to be held steady when it is engaged with the flexible tether  16  and as it translates along the flexible tether  16 . 
     The flexible tether  16  may also include one or more sensors and/or guidance apparatus (not shown) to assist the aircraft  12  in locating and capturing the flexible tether  16  during recovery. The sensors and/or guidance apparatus may comprise, for example, optical sensors and apparatus, such as visible, infrared and/or ultraviolet lights, etc. Alternatively, or in addition, the aircraft  12  may include light detection and ranging (LIDAR) apparatus. Further details of the present recovery methods are described below. 
     In the illustrated embodiment, the drag device  20  comprises a ballute. However, in other embodiments the drag device  20  may comprise, for example, a parachute or any other device configured to create drag at the distal end  18  of the flexible tether  16 . The drag device  20  may be constructed of, for example, a synthetic material such as nylon or an aramid such as KEVLAR®. In certain embodiments, characteristics of the drag device  20  may be changed while the drag device  20  is deployed at the end of the flexible tether  16 . For example, the drag device  20  may be deflated or otherwise rendered ineffective so that the flexible tether  16  can more easily be reeled into the mother ship  14 . Also, the amount of drag created by the drag device  20  may be adjusted upward or downward in order to adjust an amount of tension in the flexible tether  16 . 
     In the illustrated embodiment, the reel  22  is configured to take up and let out the flexible tether  16  by, for example, winding and unwinding the flexible tether  16  from a rotatable member  30 . However, those of ordinary skill in the art will appreciate that alternate apparatus may be used to take up and let out the flexible tether  16 . In the illustrated embodiment, the reel  22  is located in an aft portion  32  of a cargo hold  34  in the mother ship  14 . In certain embodiments the reel  22  may be located on a cargo ramp  36  at the aft  32  of the mother ship  14 . However, those of ordinary skill in the art will appreciate that the reel  22  could be located elsewhere. 
     With continued reference to  FIG. 1 , in the present system  10  the aircraft  12  includes a capture mechanism  26  configured to engage the flexible tether  16 . In the illustrated embodiment, the capture mechanism  26  comprises a latching hook  38  located on a dorsal portion  40  of the aircraft  12 . The hook  38  may be configured to extend and retract so that it can reach out to the flexible tether  16  and draw the flexible tether  16  toward the aircraft  12  once it has been captured. Those of ordinary skill in the art will appreciate that the capture mechanism  26  may not be a hook  38 , but may have some other shape and/or configuration. Those of ordinary skill in the art will appreciate that the capture mechanism  26  need not be located on the dorsal portion  40  of the aircraft  12 , but may be located elsewhere, such as on the port or starboard sides. The capture mechanism  26  and/or the aircraft  12  may also include one or more sensors or guidance apparatus (not shown) to assist the aircraft  12  in locating and capturing the flexible tether  16 , as discussed in further detail below. 
     While the tension in the flexible tether  16  supports the aircraft  12  when it is in the zero-lift or near zero-lift configuration, the flexible tether  16  does not overcome the drag forces acting on the aircraft  12 . Thus, in certain embodiments the present system  10  may also comprise a shuttle  42  configured to translate along the flexible tether  16 . The shuttle  42  may selectively engage the aircraft  12  to control movement of the aircraft  12  along the flexible tether  16 . The aircraft  12  may include apparatus (not shown) for engaging and temporarily securing the shuttle  42  and the aircraft  12  to one another. The shuttle  42  may be configured to move along the flexible tether  16  under its own power. For example, the shuttle  42  may include motorized friction wheels (not shown) that engage the flexible tether  16  to allow the shuttle  42  to propel itself. Alternatively or in addition, the shuttle  42  may be connected to a shuttle line  44  that controls its movement. For example, a proximal portion  46  of the shuttle line  44  may be anchored about a second reel associated with the mother ship  14 . As the second reel draws in the shuttle line  44  it pulls the shuttle  42  toward the mother ship  14 . In certain alternative embodiments apparatus for controlling movement of the aircraft  12  along the flexible tether  16  could be integrated into the aircraft  12 , negating the need for the shuttle  42 . 
     With reference to  FIG. 5 , in one embodiment of the present methods for airborne launch of the aircraft  12 , the flexible tether  16  is deployed from the airborne mother ship  14 , as shown at step S 500 . The drag device  20  may first be deployed/inflated so that the drag it creates draws the flexible tether  16  off of the reel  22 . Alternatively, the flexible tether  16  may be let out and the drag device  20  deployed/inflated at a point distant from the mother ship  14 . A launch device (not shown) may assist in the process of deploying the drag device  20 . When the flexible tether  16  is deployed, the aircraft  12  is translated rearward along the flexible tether  16  away from the mother ship  14 , as shown at step S 502 . The weight of the aircraft  12  is transferred from the flexible tether  16  to the wings  28 , as shown at step S 504 . In some embodiments the weight of the aircraft  12  may be transferred from the flexible tether  16  to the wings  28  as the aircraft  12  translates rearward along the flexible tether  16 . In other embodiments the weight of the aircraft  12  may be transferred from the flexible tether  16  to the wings  28  after the aircraft  12  has reached a desired launch point and further movement of the aircraft  12  has been halted. In certain embodiments a system check may be performed on the aircraft  12  before or after its weight is transferred from the flexible tether  16  to the wings  28 . If a problem is discovered during the system check, the launch may be aborted and the aircraft  12  recovered. If, however, all systems are go, the aircraft  12  may be released from the flexible tether  16  and it may proceed to fly under its own power and begin its mission. 
     Certain embodiments of the present methods for airborne launch of the aircraft  12  may include additional steps. For example, prior to any of the steps outlined above the mother ship  14  may transport the aircraft  12  to an area of operations, such as a battlefield. Sometime prior to launch the aircraft  12  may be moved from a storage rack (not shown) inside the mother ship  14  to a launch position. The aircraft  12  may be secured to the flexible tether  16 , perhaps along with the shuttle  42  ( FIG. 1 ), and then pushed out of the cargo hold or off of a launch ramp (which may be the cargo ramp  36 ). As the aircraft  12  translates rearward along the flexible tether  16 , it may be pulled away from the mother ship  14  by its own drag and by the lower dynamic pressure in the freestream. Once the aircraft  12  reaches the desired launch position, its movement may be arrested. For example, the shuttle  42  and the shuttle line  44  may halt further movement of the aircraft  12 . Prior to the aircraft&#39;s release, its wings  28  may be deployed if they had been folded or stowed. After the aircraft&#39;s release, the shuttle  42  may be recovered. For example, the shuttle line  44  may be drawn back into the mother ship  14 , pulling the shuttle  42  along with it. After all aircraft  12  have been launched and/or recovered, the flexible tether  16  may be retracted into the mother ship  14 . Before, after or during retraction of the flexible tether  16 , the drag device  20  may be deflated or otherwise rendered ineffective. 
     With reference to  FIG. 6 , in one embodiment of the present methods for airborne recovery of the aircraft  12  the flexible tether  16  is deployed from the airborne mother ship  14  as described above and as shown at step S 600 . The aircraft  12  engages the flexible tether  16  at step S 602  and the weight of the aircraft  12  is transferred from the wings  28  to the flexible tether  16  at step S 604 . The aircraft  12  is translated forward along the flexible tether  16  toward the mother ship  14  at step S 606 . In some embodiments the weight of the aircraft  12  may be transferred from the wings  28  to the flexible tether  16  before the aircraft  12  begins translating forward along the flexible tether  16 . In other embodiments the weight of the aircraft  12  may be transferred from the wings  28  to the flexible tether  16  as the aircraft  12  translates forward alone the flexible tether  16 . In some embodiments the aircraft  12  may translate forward under its own power, and in other embodiments the aircraft  12  may translate forward under the influence of a shuttle  42  secured to the aircraft  12  and to the flexible tether  16 . 
     Certain embodiments of the present methods for airborne recovery of the aircraft  12  may include additional steps. For example, prior to engaging the flexible tether  16  the aircraft  12  may locate the mother ship  14  and/or the flexible tether  16  using sensors and/or guidance apparatus such as those described above. Prior to or during the aircraft&#39;s translation forward along the flexible tether  16  the shuttle  42  ( FIG. 1 ) may translate rearward along the flexible tether  16  to engage the aircraft  12 . The shuttle  42  may be attached to the shuttle line  44  that can be reeled in to pull the aircraft  12  back into the mother ship  14 . During or after the step of transferring the weight of the aircraft  12  from the wings  28  to the flexible tether  16  the aircraft&#39;s wings  28  may be folded or stowed. Once inside the mother ship  14 , the aircraft  12  may be refueled, rearmed and/or serviced. These processes may be carried out by personnel aboard the mother ship  14  or by machines. When refueling, rearming and/or servicing are complete, the aircraft  12  may be re-launched. Prior to re-launch, a new pilot may board the aircraft  12 . If the aircraft  12  is not to be re-launched, it may be powered down and stowed in the cargo hold  34  of the mother ship  14 . After all aircraft  12  have been launched and/or recovered, the flexible tether  16  may be retracted into the mother ship  14 . Before, after or during retraction of the flexible tether  16 , the drag device  20  may be deflated or otherwise rendered ineffective. The mother ship  14  may then return to base with the recovered aircraft  12 . 
     As the present description illustrates, embodiments of the present system  10  and methods for airborne launch and recovery of aircraft provide myriad advantages. The system  10  enables aircraft to be recovered and re-launched so that their missions can be extended indefinitely. Missions no longer need be limited in duration by the fuel capacity of the aircraft, exhaustion of weaponry, pilot fatigue or the need to perform aircraft maintenance. Aircraft may be recovered and launched smoothly without being significantly affected by turbulent airflow near the mother ship. 
     The above description presents the best mode contemplated for carrying out the present system and methods for airborne launch and recovery of aircraft, and of the manner and process of making and using them, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which they pertain to make this system and use these methods. This system and these methods are, however, susceptible to modifications and alternate constructions from those discussed above that are fully equivalent. Consequently, this system and these methods are not limited to the particular embodiments disclosed. On the contrary, this system and these methods cover all modifications and alternate constructions coming within the spirit and scope of the system and methods as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the system and methods.