Abstract:
The RAINSTORM Method applies to helicopters having suspended or built-in liquid reservoir. The innovation lies on the transformation of the fire fighting liquid into artificial rain in the form of an umbrella having diameter approximately equal to the diameter of the helicopter&#39;s propeller, with adjustable density and duration. The rain creation mechanism in both cases consists of a hollow propeller with two wings where the liquid is guided hydraulically. The liquid jets through nozzles which are in counterpoised arrangement causing the initial revolution of the hollow propeller. This rotation is accelerated and stabilized from the downstream of the helicopter&#39;s propeller. The suspended reservoir is adapted by means of a triangular arrangement with three belts through a rectangular stretcher fixed on the helicopter&#39;s hook. The built-in reservoir uses a retractable or inclined metallic pipe at the free end of which a hollow propeller is adapted through a free rotation mechanism.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is an U.S. national phase application under 35 U.S.C. §371 based upon co-pending International Application No. PCT/GR2008/000062 filed on Oct. 16, 2008. Additionally, this U.S. national phase application claims the benefit of priority of co-pending International Application No. PCT/GR2008/000062 filed on Oct. 16, 2008, and Greece Application No. 20070100637 filed on Oct. 18, 2007. The entire disclosures of the prior applications are incorporated herein by reference. The international application was published on Apr. 23, 2009 under Publication No. WO 2009/050524 A1. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The purpose of the present invention, which henceforth will be mentioned for brevity as the RAINSTORM Method, is to create, by means of fire fighting helicopters, conditions of an artificial heavy rainstorm equivalent to a real rainstorm, which one would have wished to break out in reality during the fire. 
         [0004]    The technical implementation field of the RAINSTORM Method is the fire fighting even in locations where firefighting helicopters can not, or are not permitted to operate, i.e. the fringes of inhabited areas, isolated residencies in tree lines, areas with High Voltage transportation pylons, areas with trapped vehicles, people, animals, farming installations, areas where Land Forces operate and in general where there is no risk of damage and loss of life by creating an artificial rain phenomenon of controlled intensity and duration. 
         [0005]    The advantages of the RAINSTORM method allow preventive spraying or decontaminations eve during the night. 
         [0006]    2. Description of the Prior Art 
         [0007]    Present Day Situation: Two types of helicopters are used for fire fighting are under use today: Those which carry water inside the fuselage, similar to the equivalent airplanes, and those which use suspended buckets. 
         [0008]    In both cases dropping of water takes place in a few seconds with the form of a waterfall and, if we take into consideration, in many cases, the unfavorable conditions of visibility, it is very likely and/or inevitable to miss the target, which is translated in loss of the entire water load as well as in precious time, within which the fire gains ground. 
         [0009]    Moreover this way of fire fighting, with great volumes of water falling with high speed to the ground, which cannot be applied in the above mentioned cases, has also the basic disadvantage that only a small percentage of the falling water is used for fire fighting. 
         [0010]    Furthermore, during the violent drop of the water, a vacuum is created attracting air with the form of siphon which revives the fire. 
         [0011]    It must be mentioned and pointed out that the biggest effectiveness of water, when it is used for fire fighting, is achieved with the uniform rainfall above the fire area under form of droplets, so as these to have the largest surface in order to evaporate very rapidly, absorbing from the fire the biggest amount of heat, decreasing respectively the temperature of the area, which in combination with the rarefaction of oxygen, due to the interjection of water vapors, will contribute in the repression and the extinguishment of Fire in the smallest possible time. 
         [0012]    Finally it must also be pointed out that the helicopters, despite their relatively small carrying capacity compared to the Fire fighting airplanes, have two basic and undeniable advantages: Fly with very small speeds—up to hovering speed, as well as to be able to land/descend vertically, in order to be supplied with water and fuel, in relatively very small spaces. 
         [0013]    Furthermore, the RAINSTORM method can be used in cases of preventive spraying with water or retarding liquid, as well as for decontamination of large areas. 
         [0014]    The safety of the RAINSTORM method allows the aircraft to operate during the night as well, thus giving a unique advantage. 
       SUMMARY OF THE INVENTION 
       [0015]    In view of the foregoing disadvantages inherent in the known types of helicopter fire fighting systems now present in the prior art, the present invention provides an improved aircraft fire extinguishing system and method, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved aircraft fire extinguishing system and method and method which has all the advantages of the prior art mentioned heretofore and many novel features that result in a aircraft fire extinguishing system and method which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in any combination thereof. 
         [0016]    Fire fighting by means of the RAINSTORM Method. 
         [0017]    The RAINSTORM method was devised, studied and engineered in such a way in order to avoid all disadvantages and weaknesses that we face today during fire fighting with helicopters, and at the same time to exploit in the biggest possible degree the particular abilities of helicopters, as well as, and the fire fighting capabilities of water. 
         [0018]    The Key for confronting the above mentioned disadvantages in the present situation, as well as the combined exploitation of helicopter and water capabilities in fire fighting, in order to obtain the biggest fire fighting Result, constitutes. 
         [0019]    These together with other objects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein: 
           [0021]      FIG. 1  is a side plane view of an embodiment of the aircraft fire extinguishing system constructed in accordance with the principles of the present invention, with the phantom lines depicting environmental structure and forming no part of the claimed invention. 
           [0022]      FIG. 2  is a top elevational view of the aircraft fire extinguishing system of the present invention. 
           [0023]      FIG. 3  is a rear plane view of the aircraft fire extinguishing system of the present invention. 
           [0024]      FIG. 4  is a cross-sectional view of the aircraft fire extinguishing system of the present invention taken along the line  4 - 4  in  FIG. 3 . 
           [0025]      FIG. 5  is a cross-sectional view of the aircraft fire extinguishing system of the present invention taken along line  5 - 5  in  FIG. 4 . 
           [0026]      FIGS. 6A-C  is an in use illustrative view of the aircraft fire extinguishing system and method of the present invention. 
           [0027]      FIG. 7  is a top elevational view of a reservoir suspension device of the aircraft fire extinguishing system of the present invention. 
           [0028]      FIG. 8  is a cross-sectional view of the reservoir suspension device taken along line  8 - 8  in  FIG. 7 . 
           [0029]      FIG. 9  is an in use illustrative view of an alternate embodiment aircraft fire extinguishing system and method of the present invention. 
           [0030]      FIG. 10  is a side plane view of an alternate embodiment of the aircraft fire extinguishing system of the present invention. 
           [0031]      FIG. 11  is a top elevational view of the alternate embodiment aircraft fire extinguishing system of the present invention. 
           [0032]    The same reference numerals refer to the same parts throughout the various figures. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0033]    Referring now to the drawings, and particularly to  FIGS. 1-11 , an embodiment of the aircraft fire extinguishing system and method of the present invention is shown and generally designated by the reference numeral  10 . 
         [0034]    The Water Reservoir with the Artificial Rain Creation Mechanism 
         [0035]    It is a cylindrical reservoir  12 , in the rear side of which the artificial rain creation and dousing mechanism is adapted. The Schematic Diagrams of the Reservoir and the artificial rain creation mechanism  30  are shown in  FIGS. 1-5 . 
         [0036]    The dimensions of the reservoir  12  and its capacity are standardized in sizes respectively with the lifting capability of helicopters used for fire fighting. 
         [0037]    The reservoirs  12  are suspended from the helicopters  60  by means of three wire ropes—belts  68 ,  70 , which are fixed, with couplers easy to dismantle, in three points of the reservoir  18 ,  22 , in triangular arrangement, two coupling points  18  on the sides of reservoir  12  and the third  22  in its rear side. 
         [0038]    The suspended reservoir  12  has two main components connected to each other with a watertight flange  34 , as follows:
       The Water Reservoir Unit  10  which is a cylindrical reservoir  12 , manufactured from material durable in marine water, having a powerful frame in order to withstand all load strains and vibrations caused by the various helicopter maneuvers especially during the dousing phase.       
 
         [0040]    In the upper front compartment of the reservoir there is a specifically shaped and elevated intake orifice  14  used for the replenishment of the reservoir  12  with water, which, if required, opens and closes automatically during the three phases of operation of the reservoir  12 , i.e.: Water filling (Open), Transportation of water (Closed) and fire fighting (Open). 
         [0041]    The caudal reinforcing fin  20  is fixed in the upper rear side of the reservoir  12 . This fin  20  retains the rain creation mechanism  30  from above, in the top of which exists the third point of suspension  22 .
       The Rain Creation/Dousing Unit  30 , manufactured from stainless material, which includes:   The Conical Pipe  32  which channels the water to the Hydraulic Mechanism  36 .   The Hydraulic Mechanism-Water Turbine  36  of the propeller  50 , as best illustrated in  FIGS. 4 and 5  which is fitted with the bladed trunnion  38  with ports  40  for channeling the pressurized water to the rain creation mechanism (propeller)  50 , and   The Rain Creation Mechanism  50 , which consists of the hollow propeller  52 , that is water tightly connected to the trunnion  38  of the Hydraulic Mechanism-Water Turbine  36 . The hollow propeller  52  has sufficient number of nozzles  54  in each blade having the appropriate diameter, in order that in correlation with the speed and the flight height of the helicopter  60 , the desired diameter and density of the rain droplets in the umbrella  66  that will take shape in the dousing phase will be achieved, thus ensuring, after experimenting, the biggest fire fighting result (Creation of Tables).       
 
         [0046]    Note: The direction of water centrifugation can be combined with the helicopter propeller in order to obtain a better interaction. 
         [0047]    The fire fighting process with the RAINSTORM Method includes the following stages, as best illustrated in  FIGS. 6A-6C :
       Filling up of the Reservoir with Water ( FIG. 6A ). This is achieved with the following ways:   From the Sea, Lakes and rivers, as the current practice.   From man made Reservoirs of large capacity, having a depth of at least 2.5 m, which either exist or will be constructed near specifically protected areas as: archaeological sites, open air theaters, zoos, gardens, mountains etc.   In the above two cases the helicopter  60  is flown over the supply source  62  and with the help of a winch, operated from within the helicopter  60 , the third wire rope  70  which is hooked to the caudal fin  20  is set into operation, lifting thus the tail of the reservoir  12  until its longitudinal axis reaches an angle of approx. 45° to the water leve. The helicopter  60  is then lowered progressively and the reservoir  12  sinks under its own weight, and starts to fill up from the wide orifice  14  located at the elevated front end. As soon as the replenishment of the reservoir  12  is completed within a few seconds the caudal wire rope  70  is lifted, the reservoir  12  assumes the horizontal position, as best illustrated in  FIG. 6B , the helicopter  60  is lifted and flies to the fire  64 .   In addition to the above mentioned methods, the RAINSTORM Program gives the possibility to transport backup reservoirs  12  near the fire  64 , placing them in open areas (stadiums, fields etc.). These backup reservoirs  12  will be filled up by water tank vehicles of the local authorities and/or private individuals. In this way the helicopters will leave the empty reservoirs for replenishment and pick up in minimum time the filled ones in order to return very rapidly to the fire, thus multiplying the fire fighting force of the helicopters. This is equivalent to a bigger helicopter fleet.   Flying to the Scene of Fire. During this phase, the reservoir  12  is at the horizontal position, as best illustrated in  FIG. 6B , in order not to waste any water during transportation from the filling orifice  14 , which is also equipped with a non return mechanism  16 , as well from the rain creating mechanism  30  which is located over the highest water level of the reservoir  12 .   Rain Creation and Fire Fighting. As soon as the helicopter  60  approaches the scene of fire  64  and assumes the proper flight height, the caudal wire rope  70  is slackened until the reservoir  12  assumes the vertical position and the rain creating mechanism  50  is horizontal, as best illustrated in  FIG. 6C .       
 
         [0055]    In this position, under the pressure of the, above water column, the Hydraulic Mechanism Water Turbine  30  is set into automatic operation simultaneously setting the propeller  52  into rotation, while at the same time the incoming water is channeled towards the counterbalancing nozzles  54  and dashes out through them with great momentum intensifying the propellers rotation, and contributing thus in the better centrifugation of water and in the enlargement of shaped rain umbrella  66 . 
         [0056]    Note: The relative experiments will show which is the optimum number of nozzles, their diameter as well as the reservoir water drop duration, so that in function with the flight level and the helicopters speed, to achieve maximum firefighting results in the ground. Fire Fighting Helicopter Method of Operation 
         [0057]    In order to have the best possible results in fire fighting with the RAINSTORM Method, the helicopters must operate in a Systematic Manner, depending on the pattern, the extend and the intensity of the fire. 
         [0058]    The way of operation will be decided each time by the responsible person in charge of the Command and Control Center, according to the relative information reported. 
         [0059]    As an example, when the front of the fire is relatively narrow, then the helicopters (2 or 3) will attempt one behind the other, maintaining a safety distance, and will fly in a row above the fire front. If however the width of fire front is relatively wide, then the helicopters will fly in shapes, in such a way that the rain umbrellas will cover the whole rain front, Le. in triangular arrangement with one helicopter in front and two behind, or two helicopters in front and three behind and so on. 
         [0060]    What has particular importance and must be enforced during all the air missions is the detailed coordination in order to achieve best results with minimum cost. This of course must not go against all security measures, which must at any rate be applied in order to minimize possible disasters and loss of life. 
         [0061]    As best illustrated in  FIGS. 7 and 8 , a reservoir suspension device  80  can be used to suspend and control the angle of the cylindrical reservoir from the aircraft  60 . The reservoir suspension device  80  consists of a rectangular shaped frame or stretcher  82  which is removably connected to a hook  61  of the aircraft  60 . The stretcher  82  has a general dimension of, but not limited to, 2.00 m (length)×1.00 m (width)×0.20 m (height). The purpose of the stretcher  82  is to strap the three (3) belts  68 ,  70  from which the cylindrical reservoir is suspended in a triangular arrangement. 
         [0062]    The stretcher  82  is fitted with a 12V servomechanism or winch  84 , powered from within the aircraft  60 . The servomechanism  84  is operated by means of a simple controller located in the aircraft&#39;s  60  cockpit. 
         [0063]    The servomechanism  84  moves two parallel shafts  86  located on each side of the stretcher  82 . One shaft includes drums  88  located at each end thereof with belts  68  wound therearound, and the other shaft includes one drum  88  with belt  70  wound therearound. The belts  68 ,  70  have a free end of approximately, but not limited to, 70-80 cm. At the end of each belt  68 ,  70  is included a fast coupler which connects the stretcher  82  with the cylindrical reservoir. The belts  68 ,  70  have an approximate length of, but not limited to, 10-12 m. 
         [0064]    This arrangement allows the rotation of the drums  88  of the stretcher  82  by means of approximately three (3) rotations of the servomechanism  84 . This elevates and descends the belts  68 ,  70  approximately, but not limited to, 70-80 cm, thereby tilting the longitudinal axis of the cylindrical reservoir ±45°, without shifting its center of gravity. 
         [0065]    As best illustrated in  FIG. 9 , the present invention can also be adapted to be used with aircrafts or helicopters  60  having a built-in liquid reservoir  100 . A rain creation mechanism and dousing unit  90  includes rotating hollow propellers  92  for the centrifugation of water. The rain creation mechanism and dousing unit  90  has an immediate implementation with heavy fire fighting helicopters or aircrafts that posses a built-in liquid reservoir with a capacity, such as but not limited to, 3-15 m 3 . In these cases only common industrial equipment can be used. 
         [0066]    The rain creation mechanism and dousing unit  90  further includes a reclined or retractable telescopic pipe  94  having a total length of approximately, but not limited to, 3.00 m. The pipe  94  is adapted to and in fluid communication with the helicopter&#39;s  60  reservoir, and at the end of which is fitted the hollow propellers  92  through a free rotating mechanism  96  that is in a substantially vertical position to the pipe  94 . 
         [0067]    The rain creation mechanism and dousing unit  90  can be raised and lowered into position be a hydraulic mechanism  98 . 
         [0068]    A water pump  100  is used to pump water or liquid from the built-in reservoir  102  to a first element of the telescopic pipe  94 , thus protracting the pipe and setting the hollow propellers  92  into rotation. This rotation is accelerated by the downstream air of the helicopter&#39;s rotors. 
         [0069]    A 12V servomechanism or winch  104  is fitted to the helicopter&#39;s floor. A cable  106  connected and operated by the servomechanism  104  is connected to the end of the pipe  94 . The cable  106  follows the movement of the pipe  94  during the extension phase, and retracts the pipe once the operation is complete. 
         [0070]      FIGS. 10 and 11  best illustrates an alternate embodiment water reservoir and artificial rain creation mechanism  110 . This embodiment includes a cylindrical reservoir  112  having an artificial rain creation and dousing mechanism located on a rear side thereof. 
         [0071]    The dimensions of the reservoir  112  and its capacity are standardized in sizes respectively with the lifting capability of helicopters used for fire fighting. 
         [0072]    The reservoir  112  includes two pivoting suspension assemblies located adjacent to each end of the reservoir  112 . Each suspension assembly includes a pair of pivoting suspension arms  116  located on opposite sides of the reservoir  112 . Each pair of suspensions arms  116  include a cross arm  118  connected to the free ends of the suspension arms, as best illustrated in  FIG. 11 . 
         [0073]    One pair of suspension arms  116  are located at a front end of the reservoir and include a coupling point  120  located at the free ends of each suspension arm. The other pair of suspension arms  116  includes a single coupling point  120  centrally located on said coupling arm  118 . 
         [0074]    The reservoir  112  is suspended from the helicopters by means of three wire ropes or belts  68 ,  70 , which are fixed with couplers to a corresponding coupling point  120 , thereby forming a triangular arrangement. 
         [0075]    The reservoir  112  is manufactured from material durable in marine water, having a powerful frame in order to withstand all load strains and vibrations caused by the various helicopter maneuvers especially during the dousing phase. The rear end of the reservoir  112  is a angled planar surface with an angle of approximately 45°. 
         [0076]    In an upper front compartment of the reservoir  112  there is a specifically shaped and elevated intake orifice featuring a valve  114  used for the replenishment of the reservoir  112  with water. The valve  114  opens and closes automatically during the three phases of operation of the reservoir  112  by way of a spring or line  122  connected to the cross arm  118  of the front end located suspension arms  116 . Thus, when the front end suspension arms  116  are pivoted in one direction, the spring  122  is pulled thereby opening the valve  114 . 
         [0077]    The water reservoir and artificial rain creation mechanism  110  further includes a rain creation and dousing unit, manufactured from stainless material. The rain creation and dousing unit includes an angled conical pipe  124  which channels the water to a hydraulic mechanism and water turbine  36 , and a hollow propeller assembly  50 . The pipe  124  is parallel with the angle of the rear end of the reservoir  112 . 
         [0078]    The hydraulic mechanism and water turbine  36  is fitted with the ported bladed trunnion for channeling the pressurized water to the hollow propeller assembly  50 . The hollow propeller assembly  50  includes a plurality of propellers each with multiple nozzles each having an appropriate diameter to form a rain umbrella that will take shape in the dousing phase. The hollow propeller assembly  50  is watertightly connected and in fluid communication with the hydraulic mechanism and water turbine  36 , and is angle so as to be parallel with the angle of the rear end of the reservoir  112 .