Abstract:
The invention generally relates to a method of using a pod to rapidly deploy defensive countermeasures from a wide variety of manned aircraft. The method includes using a configurable pod for dispensing different types of infrared countermeasure (IRCM) devices and different types of radio frequency countermeasure (RFCM) devices at a rapid rate. The primary purpose of this method is to rapidly dispense IRCMs and RFCMs is to protect the host aircraft while ingress and egress maneuvers are performed in a hostile area. A secondary use of the method is for use in defending commercial aircraft from missile threats.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention generally relates to a method of using a pod to rapidly deploy defensive countermeasures from a wide variety of manned aircraft. The method includes using a configurable pod for dispensing different types of infrared countermeasure (IRCM) devices and different types of radio frequency countermeasure (RFCM) devices at a rapid rate. The primary purpose of this method is to rapidly dispense IRCMs and RFCMs is to protect the host aircraft while ingress and egress maneuvers are performed in a hostile area. A secondary use of the method is for use in defending commercial aircraft from missile threats. 
         [0003]    2. Description of the Prior Art 
         [0004]    It is well known that a variety of countermeasures are available to provide a defense against a variety of missile types. It is necessary for an aircraft to be configured to deploy a countermeasure that is specific to the missile threat expected to be encountered. Modern missile seeker heads are sensitive to infrared information generated by aircraft engines, fuselage leading edge surfaces or to reflected radar signals. Handheld surface to air missiles designed to attack low flying aircraft are referred to as Manpads and are prolific, effective and come in a number of variants. During the conflict between Russia and Afghanistan it is estimated that the Russian forces lost more than three hundred helicopters and more than one hundred and ten fixed wing aircraft to Manpad systems. 
         [0005]    Domestic and foreign military forces using aircraft in low level combat operations have devised a number of systems to deploy both IRCM and RFCM devices. A typical countermeasure system will first use a missile launch detector to alert the aircrew that the aircraft is under attack. The countermeasure system or aircrew will then determine the type of missile that is to be defended against, IR or RF. The aircrew will then have the option of making evasive maneuvers or deploying an appropriate countermeasure. 
         [0006]    The survivability rate for this type of attack is highly weighted towards the effective use of countermeasures when compared to the use of evasive maneuvers. Evasive maneuvers are not possible when a troop transport and their escorting aircraft need to ingress to drop troops or cargo and then safely egress. A typical mission scenario produces ten minutes of vulnerability broken down as an ingress lasting four minutes followed by two minutes on the ground to complete the deployment portion of the mission and then four minutes to safely egress. Defensive coverage against manpads is provided by a flare launched every three seconds. The typical mission scenario requires dispensing twenty flares per minute for ten minutes which requires two hundred flares. Mission scenarios are dependent upon the theater of operation and the intelligence information particular to that theater of operation. The threat parameters, the cargo to be delivered and the aircraft type selected for a particular mission scenario will drive the type and quantity of flares to be dispensed. 
         [0007]    The United States military has developed and deployed a number of countermeasure systems and has used pods as housings. The pods that have been used to house the countermeasure systems are customized for each dispensing system and then customized to each aircraft type. This has lead to an inventory of pods that are not adaptable to new dispensing systems and are not adaptable to multiple service aircraft. This invention will lead to a reduction in the variety of pods needed to be maintained in the military logistics system because of the commonality in the mechanical and electrical interfaces. 
         [0008]    Current countermeasure pod systems are not capable of deploying countermeasure devices at the rate or the quantity necessary to effectively defend against multiple manpad attacks. Currently, there is not a reusable lightweight package that is suitable for mounting on a number of aircraft types which contains all of the components necessary to rapidly deploy IRCM and RFCM devices. A low cost countermeasure dispensing system interfaced to an aircraft&#39;s digital countermeasure suite that is easily modified is not currently available. Given the current manpad threat to civilian aviation this invention is suitable for installation on both commercial and private aircraft. 
       SUMMARY OF THE INVENTION 
       [0009]    The preferred embodiment is a reusable compact lightweight pod containing a digital interface to communicate with an aircraft detection system, countermeasure dispenser sequencers, a number of countermeasure dispensers and is configured to be mounted on a number of aircraft without modifying the pod or the aircraft. 
         [0010]    The pod container which houses the countermeasure dispensing components is externally configured with a number of aircraft mounting lugs. The availability of multiple types of mounting lugs allows the pod to be mounted to a wide variety of aircraft without modifications. The pod container is aerodynamic having a missile shaped body fitted with a nose cone and a tail section. The pod is built with internal structural components and compartments that support internal mounting of the countermeasure dispensing components. 
         [0011]    The preferred embodiment uses an ALE-47 countermeasures dispensing system. All of the dispensing components necessary to deploy the IRCM and RFCM devices are carried within the pod. The dispensing components are a power supply, a microcomputer, a number of sequencers and the dispenser units. The dispensing units are prohibited from premature activation by a number of safety interlocks within the pod that overrides normal control of the pod&#39;s microcomputer. 
         [0012]    The common services pod is unique in that the pod is readily adaptable to accepting new countermeasure dispensing systems by virtue of having reconfigurable internal compartments. The common services pod is also unique in that the pod is readily adaptable to being mounted onto a new type of aircraft simply by incorporating a new mounting lug. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a block diagram of the preferred embodiment&#39;s countermeasure system. 
           [0014]      FIG. 2  is a diagram of the common services pod external features and internal features. 
           [0015]      FIG. 3  is an electrical connection diagram depicting the preferred embodiment&#39;s countermeasure system. 
           [0016]      FIG. 4  is a three dimensional view of the common services pod showing the dispenser unit compartments. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    The common services pod is built to carry and operate a number of dispenser units electrically connected to the host aircraft. The common services pod is missile shaped and mounted to a host aircraft with mounting lugs that allow the dispenser units to have a clear field of operation for dispensing the countermeasure devices when commanded. 
         [0018]    Referring to  FIGS. 2 and 4 , the preferred embodiment is a pod container  201  which has an overall diameter not to exceed fourteen inches and a length not to exceed one hundred inches. The external skin of the main body tube  220  is made of 6061-T6 aluminum that is approximately 0.09 inches in thickness. Any 6000 series aluminum would suffice. The pod container  201  is aerodynamic having a missile shaped main body tube  220  fitted with a nose cone  210  and a tail section  275 . The main body tube  220  contains sequencer compartments ( FIG. 4  item  420 ) in a quantity sufficient to house four sequencer assemblies ( FIG. 2  item  255 ) and dispenser compartments ( FIG. 4  item  410 ) in a quantity sufficient to house eight dispenser assemblies ( FIG. 2  item  280 ). To maintain a center of gravity that is as close to the center of the pod container  201  as possible the sequencer compartments ( FIG. 4  item  420 ) are centered by placing four dispenser compartments ( FIG. 4  item  410 ) on each side. To provide structural integrity for the pod several structural members run the along the length of the main body tube  220 . 
         [0019]    Referring to  FIG. 2 , the pod is built with several internal structural members that run along the length of the main body tube  220  for the purpose of providing strength to support the pod when mounted to the host aircraft and to provide a stable platform for dispensing the countermeasure devices. 
         [0020]    The primary structural member is the strongback  260  to which the mounting lugs (items  240 ,  245  and  250 ) are mounted. The strongback  260  and mounting lugs (items  240 ,  245  and  250 ) in combination attach the pod to the host aircraft. One end of the strongback  260  is connected to a forward bulkhead  215  and the opposite end of the strongback  260  is connected to a rear bulkhead  265 . The mounting lugs and lug adapters chosen for use in the preferred embodiment to support Navy aircraft are the NAVAIR  1380540  lugs  240  and the corresponding lug adapter  241 . The mounting lugs and lug adapters chosen for use in the preferred embodiment to support Air Force aircraft are the MS3314 lugs  250  and the corresponding lug adapter  251 . Use of these two lug types will allow the common services pod  201  to be used on multiple across services aircraft. 
         [0021]    Also mounted to the strongback  260  is a set of bomb rack sway braces  245 . The bomb rack sway braces  245  are used to provide aerodynamic stability between the host aircraft and the pod  201  during periods of high speed or high g maneuvers. The bomb rack sway bracing used in the preferred embodiment are of the type MAU-12×/A. 
         [0022]    There are at least seven body longerons  230  which run the length of the main body tube  220 . One end of each of the body longerons  230  is connected to the forward bulkhead  215  and the opposite end of each of the longerons  230  is connected to the rear bulkhead  265 . The longerons  230  serve as stiffeners for the main body tube  220  while two of the lower longerons  230  serve as a structure to which a housing mounting rack  225  is attached. The dispenser assemblies  280  are mounted between the housing mounting rack  225 . 
         [0023]    It is well known in the arts that a flat aluminum sheet can be bent in the shape of a “U” to create a channel that will increase the overall stiffness of the aluminum sheet making it resistant to bending. This technique is used in producing the stiffening longerons  230  from aluminum sheeting. 
         [0024]    In preferred embodiment, the countermeasure dispenser compartment ( FIG. 4  item  420 ) has a volume sufficient to mount an ALE-47 countermeasure dispenser assembly also known as a bucket ( FIG. 2  item  280 ). Each dispenser compartment  420  holds one or more buckets depending upon the flare type. The buckets are standard containers that hold the flares or chaff and have fixed external dimensions. Since the flares and chaff vary in size the internal configuration of the bucket changes with the load. A bucket for MJU-10 flares would hold six flares. Forty eight MJU-10 flares would be a full pod load. Eight buckets each holding six flares equates to forty eight MJU-10 flares per pod. A bucket for M206 flares would hold thirty flares. Two hundred forty flares would be a full pod load. Eight buckets each holding thirty flares equates to two hundred forty flares. 
         [0025]    Referring to  FIG. 2 , the preferred embodiment uses an Air Force ALE-47 countermeasures dispensing system. All of the components that comprise the ALE-47 countermeasures dispensing system are carried within the pod. The dispensing components carried within the pod are a power supply  210  mounted to the forward bulkhead  215 , a HiDAN PC-104 microcomputer  270  mounted to the rear bulkhead  265 , four sequencers  255  and the eight dispenser assemblies  280 . The common services pod is not constrained to the use of the ALE-47 system. 
         [0026]    Other embodiments of the invention include the use of an ALE-29 countermeasure dispensing system and the Navy version of the ALE-47 dispensing system. The ability of the common services pod to adapt to any suitable dispensing unit system provides the flexibility to configure an aircraft to deploy defensive countermeasures, this is the essence of this invention. The adaptability is provided by the compartments and mounting surfaces that define the common services pod. 
         [0027]      FIG. 1  is a functional block diagram showing the major components of a generic countermeasures dispensing system  100 . The common services pod host aircraft interface  105 , accepts from the host aircraft power and control signals  115 , accepts input from a safety switch  110  and accepts input from an arm and safety relay  120 . The aircraft interface  105  is connected to a computer processor  130  that is part of the countermeasure dispensing system  100  which controls the sequencer unit  140 . The sequencer unit  140  in turn sends control signals to multiple dispenser units ( 155  and  160 ). 
         [0028]      FIG. 3  is an ALE-47 electrical connection diagram  300  depicting the connections for the preferred embodiment. For the sake of clarity, only three of the four sequencer assemblies are shown and only six of the eight dispenser assemblies are shown. A terminal block  375  is mounted to the rear bulkhead ( FIG. 2  item  265 ) and is the main interface between the host aircraft and the pod. The terminal block  375  accepts through an umbilical connection  380  aircraft power and control signals. The pod must accommodate 115 volt, three phase power at a frequency of 400 Hz (5 amperes per phase) as well as positive 28 volts direct current. The aircraft power is routed to a power supply ( FIG. 2  item  210 ) which supplies power to the ALE-47 components. Also connected to the terminal block are safety signals. 
         [0029]    The dispensing assemblies (items  310 ,  320 ,  330 ,  340 ,  350  and  360 ) are prohibited from premature activation by a number of safety interlocks within the pod that override control by the pod&#39;s microcomputer. The first safety interlock is an arm and safety relay  370  signal that is used to energize a relay that close the normally open safety switch contacts. The second safety interlock is a hardware safety switch  365  that is in opens the path of the sequencer control signal present in wiring harness  385 . In another embodiment the hardware safety switch  365  is replaced by a safety pin (not shown). 
         [0030]    The terminal block  375  is connected to wiring harness  385  which contains the control signals to operate the sequencers ( 315 ,  335  and  355 ). Sequencer  315  is connected to dispenser  310  by wiring harness  314  and is also connected to dispenser  320  by wiring harness  316 . Sequencer  335  is connected to dispenser  330  by wiring harness  334  and is also connected to dispenser  340  by wiring harness  336 . Sequencer  355  is connected to dispenser  350  by wiring harness  354  and is also connected to dispenser  360  by wiring harness  356 . In order to have adequate wiring harness access for connection and maintenance in the sequencer compartment ( FIG. 4  item  420 ) it is necessary to stagger the placement of the sequencers ( 315 ,  335  and  355 ). 
         [0031]    Referring to  FIG. 2 , the preferred embodiment orientation of the common services pod  201  when mounted to an aircraft is critical and is completely dependent upon proper positioning of the lugs ( 240  and  250 ) and lug adapters ( 241  and  251 ). The proper positioning of the lugs ( 240  and  250 ) and lug adapters ( 241  and  251 ) is perpendicular to a plane that is parallel to the dispenser assembly  280  opening. This will assure that that the flares leave the dispenser assemblies at an angle to clear the aircraft safely and to travel in the general direction of the attacking missile. 
         [0032]    In another embodiment of the invention the proper positioning of the lugs ( 240  and  250 ) and lug adapters ( 241  and  251 ) is offset by 30 degrees relative to the plane that is parallel to the dispenser assembly  280  opening. This will assure that that the flares leave the dispenser assemblies at an angle to clear the aircraft safely and to travel in the general direction of the attacking missile. 
         [0033]    The preferred embodiment of the common services pod is loaded with only one type of flare per mission. This limitation is a characteristic of the dispensing system and not of the common services pod. A fully loaded common services pod  201  has a center of mass and an overall weight for three flare types in accordance with the physical properties load out in Table 1. A three dimensional Cartesian coordinate system is used to identify the center of mass coordinates relative to the geometric center of the common services pod. A y axis extends axially through the nose cone  205  in the positive y direction and extends axially through the tail section  275  in the negative y direction. The z axis is perpendicular to the y axis and has a positive z direction that extends through the main body tube  220  in the direction of the sway braces  245 . The z axis has a negative direction that extends through the main body tube  220  in the direction of the dispenser assemblies  280 . The x axis is perpendicular to the y axis and extends through the side walls of the main body tube  220 . The positive x axis is towards the viewer when viewing  FIG. 2 . 
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                   
                 Center of 
                 Center of 
                 Center of 
               
               
                   
                   
                   
                 Loaded 
                 Mass in 
                 Mass in 
                 Mass in 
               
               
                   
                 Flare 
                 Number 
                 Pod 
                 inches 
                 inches 
                 inches 
               
               
                 Flare 
                 Weight 
                 of 
                 Weight 
                 X 
                 y 
                 z 
               
               
                 Type 
                 in lbs. 
                 Flares 
                 in lbs. 
                 direction 
                 direction 
                 direction 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 MJU-10 
                 2.5 
                 48 
                 433 
                 −0.014 
                 52.070 
                 0.158 
               
               
                 M206 
                 0.81 
                 240 
                 515 
                 −0.003 
                 52.009 
                 −0.277 
               
               
                 MJU- 
                 1.9 
                 120 
                 546 
                 −.0029 
                 51.980 
                 −0.409 
               
               
                 7/13 
               
               
                   
               
             
          
         
       
     
         [0034]    The common services pod is unique in that the pod is readily adaptable to accepting new countermeasure dispensing systems by virtue of having a series of reconfigurable internal compartments. The common services pod is also unique in that the pod is readily adaptable to being mounted onto a new type of aircraft simply by incorporating a new mounting lug.