Abstract:
An air rescue assembly ( 20 ) having a balloon ( 110 ) adaptable to be filled with a gas to suspend an object ( 138 ) in the atmosphere for a predetermined amount of time is disclosed. The air rescue apparatus includes a shroud ( 120 ) substantially enclosing the balloon, a harness ( 136 ) selectively attachable to the object, and an attachment assembly ( 130 ) extending between the shroud and the harness.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to an airborne ejection and recovery apparatus and, more particularly, to an air rescue apparatus that will suspend an object in the atmosphere to facilitate an air to air rescue.  
         BACKGROUND OF THE INVENTION  
         [0002]    Aircraft crew, such as pilots, rely on typical air rescue devices, such as parachutes, to provide for a safe descent to the ground when the abandoning of an aircraft becomes necessary. Although a typical parachute can slow the decent of an aircrew member to a safe velocity, it cannot eliminate the descent altogether. There are times when it is desirable to retrieve an aircrew member prior to its ultimate descent to the ground, such as when it is necessary to eject over hostile or inhospitable territory.  
           [0003]    In order to prevent landing in hostile or inhospitable territory, an air-to-air rescue can be effected by a nearby rescue aircraft if the aircrew member&#39;s descent can be significantly slowed or eliminated altogether. By suspending the aircrew member at a specific altitude, the rescue aircraft can intercept and retrieve the aircrew member in an air-to-air rescue, thereby minimizing the possibility of the aircrew member landing in hostile territory after bailing out of an aircraft. Thus, there exists a need for an airborne rescue apparatus that suspends an aircrew member at a predetermined range of altitudes for an air-to-air rescue.  
         SUMMARY OF THE INVENTION  
         [0004]    In accordance with one embodiment of the present invention, an air rescue apparatus is provided. The air rescue apparatus includes a balloon adaptable to be filled with a gas to suspend an object in the atmosphere at a predetermined range of altitudes. The air rescue apparatus also includes a shroud substantially enclosing the balloon, and a harness selectively attachable to an object. The air rescue apparatus also includes an attachment assembly extending between the shroud and the harness.  
           [0005]    In certain embodiments of the present invention, the balloon is a nonextensible balloon, such as a superpressure balloon. Such a nonextensible balloon does not expand as it rises, like a conventional balloon, but maintains a substantially fixed volume regardless of exterior pressure or interior pressure beyond a particular threshold. Because the total volume of the balloon does not vary with altitude, the balloon will naturally be suspended at the altitude where its volume displaces an equivalent mass of air as the mass of the payload. In this state of equilibrium, the apparatus will remain at this altitude for an extended period of time.  
           [0006]    In accordance with other embodiments of the present invention, the balloon can be deployed with helium gas or hydrogen gas. In still yet other embodiments, the apparatus can be calibrated to seek a specific target altitude once deployed. In one particular embodiment, the air rescue apparatus is calibrated to maintain an altitude of 10,000 feet. At this altitude, the suspended object is an easy target for aerial recovery without being a target for ground fire. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The foregoing aspects and many of the attendant advantages of this invention will become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
         [0008]    [0008]FIG. 1 is an environmental view of an air rescue apparatus formed in accordance with one embodiment of the present invention;  
         [0009]    [0009]FIG. 2 is an environmental view of a pilot ejecting from an aircraft and deploying an air rescue apparatus formed in accordance with one embodiment of the present invention; and  
         [0010]    [0010]FIG. 3 illustrates an environmental view of a pilot suspended by an air rescue apparatus formed in accordance with one embodiment of the present invention awaiting air-to-air interception and retrieval. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0011]    [0011]FIG. 1 illustrates one embodiment of an air rescue assembly  20  formed in accordance with one embodiment of the present invention. The air rescue assembly  20  includes a balloon  110 , a shroud  120  enveloping the balloon  110 , and an attachment assembly  130  attached to the shroud  120 . The balloon  110  is suitably five meters in diameter and is capable of being inflated with gas. Although five meters is a suitable dimension for the balloon  110 , it should be apparent that the size of the balloon depends upon the mass of the object to be suspended. As a non-limiting example, the diameter, and therefore, the volume of a balloon used to suspend a single person will be less than that of a balloon used to suspend an object of substantially greater mass. Thus, while a balloon of five meters in diameter is suitable for purposes of the present invention, balloons of greater or lesser diameter are also within the scope of the present invention.  
         [0012]    In one embodiment, the balloon  110  is made of an extensible material. An extensible material will stretch to assume a volume, wherein the weight of the volume of gas inside the balloon  110  is equivalent to the weight of air displaced by the volume of the balloon  100 .  
         [0013]    In another embodiment, the balloon  110  is made of a non-extensible material. A nonextensible material has a substantially constant volume and, therefore, the volume of the balloon will not vary. (To overcome the diurnal cycle, a non-extensible material maintains the temperature of gas within the balloon, such that it does not heat up excessively during the day nor cool down at night. Variations in the air pressure caused by the heat of the sun or cool of the night produce changes in the internal gas pressure, but the volume of the balloon remains fixed.) So long as the balloon remains under pressure, it continues to float at its predetermined constant density level. The gas used to inflate the balloon  110  is preferably helium in one particular embodiment. Although helium is preferred, any gas lighter than the ambient air to a degree capable of suspending the total weight of a payload and the air rescue apparatus, such as hydrogen, is also within the scope of the present invention.  
         [0014]    The shroud  120  is a typical rescue parachute that envelopes the balloon  110 , and is suitably formed from a well known material, such as ripstop nylon. The shroud  120  is draped over the balloon  110 , such that the edge of the shroud  120  hangs down toward a suspended payload below. In one particular embodiment, the edge of the shroud  120  hangs down past the lower surface of the balloon  110 . Connected to the edge of the shroud  120  is the attachment assembly  130 .  
         [0015]    The attachment assembly  130  includes a plurality of reins  132 , an aerial retrieval portion  140 , and a bridle  134 . Each rein  132  is suitably formed as a cord from a high strength material. One end of each rein  132  is connected to the edge of the shroud  120  by a well known fastener, such as an eye ring. The other end of each rein  132  is fastened to one end of the aerial retrieval portion  140  by a well known fastener. The reins  132 , as attached, assist in securing the shroud  120  around the lower surface of the balloon  110 , thereby substantially encasing the balloon  110  within the shroud  120 .  
         [0016]    The aerial retrieval portion  140  is suitably a cord of high strength material. The aerial retrieval portion  140  extends between the reins  132  and the bridle  134 . In one embodiment of the present invention, the aerial retrieval portion  140  is 25 meters in length. It should be apparent that while the preferred length of the aerial retrieval portion  140  is 25 meters, other lengths sufficient to provide a safe aerial recovery of a suspended object are also within the scope of the present invention. Factors considered in determining a sufficient length of the aerial retrieval portion include minimizing the risk of a suspended object from becoming entangled with the aircraft and providing a target that permits both day and nighttime recovery of the suspended object by the recovery aircraft. An aerial retrieval portion  140  of such lengths distances an air crew member from the balloon, such that an aircraft  320  may make an air-to-air recovery of the aircrew member  130 , as is described in more detail below.  
         [0017]    The bridle  134  is connected to the harness  136  that in one embodiment is adaptable to support the aircrew member  138 . Although it is preferred that the harness  136  is adapted to support the weight of a human, it should be apparent that harnesses adapted to support other objects, such as a piece of cargo, are also within the scope of the present invention.  
         [0018]    One or more tanks of pressurized gas  142  are used to fill the balloon  110  with gas when the air rescue assembly  20  is deployed. Each of the tanks of pressurized gas  142  is suitably disposed within the balloon  110 . Although the present embodiment of the air rescue assembly  20  illustrates one tank of pressurized gas  142  as being disposed within the balloon  110 , the invention is not intended to be so limited. Thus, it should be apparent that the location of any of the tanks of pressurized gas  140  are not important to the invention and, therefore, any tank of pressurized gas  140  may be located in other locations to optimize the invention.  
         [0019]    After deployment, the air rescue assembly  20  will seek a state of equilibrium in the atmosphere. Because the gas inside the balloon  110  is lighter than air, the entire system and the payload will be suspended at an altitude whereby the mass of the air rescue assembly  20 , including the aircrew member  138 , is equal to the mass of air that is displaced by the balloon  110 . In one particular embodiment, the altitude sought to be deployed at is 10,000 feet above sea level. At this altitude, the suspended payload in an easy target for an air-to-air interception and retrieval without being a target for ground fire. A suitable range of altitudes is 100 feet above sea level to 50,000 feet above sea level.  
         [0020]    [0020]FIG. 2 illustrates an aircrew member  138  ejecting from the aircraft  220  and deploying the air rescue assembly  20 . Deployment of the air rescue assembly  20  may be accomplished either manually or automatically upon actuation of an ejection sequence. Before the air rescue assembly  20  is deployed, it may be stowed in a wearable backpack. In another embodiment, the air rescue assembly  20  may be stowed behind the pilot and attached to the pilot&#39;s aircraft seat. The air rescue assembly  20  remains dormant until ejection from the aircraft  220 . Upon ejection from the aircraft  220 , the tank of pressurized gas  142  fills the balloon  110  with the gas, thereby rapidly filling the volume of the balloon  110 .  
         [0021]    Once the air rescue assembly  20  has been deployed and the apparatus has reached a state of equilibrium, i.e., the altitude in which the total weight of the balloon and payload is equivalent to the weight of the volume of air that is displaced, the payload is in a position to be intercepted and retrieved by a rescue aircraft via an air-to-air rescue. This is depicted in FIG. 3. A rescue aircraft  320 , shown as a C-130, can be equipped with a catching assembly  322 , whereby the rescue aircraft  320  flies in a path above the balloon  110  and “catches” the aerial retrieval portion  140  in a net connected to the catching assembly  322 . After the aerial retrieval portion  140  is intercepted by the net, the payload can be retrieved into the rescue aircraft  320 . The air rescue assembly  20  enables a payload to remain at a predetermined altitude thereby significantly increasing the accuracy and success rate of an air-to-air rescue.  
         [0022]    While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.