CN114306980B - Aerial fire extinguishing system - Google Patents

Abstract

An embodiment of a fire suppression apparatus for suppressing fires from an aircraft is disclosed having water and foam held in separate containers that when mixed form a fire retardant in the separate water containers, a pump driven by a first electric motor, the pump including an intake valve positioned at a pump inlet where air and fire retardant are drawn into the inlet and pressurized by the pump simultaneously, an intake pump driven by a second electric motor to introduce fire retardant to the inlet prior to activating the pump, an inverter controlling activation of the first electric motor, and a targetable cantilever connected to the pump by a conduit, the cantilever including a nozzle on a distal end of the cantilever from which pressurized water/foam/air fire retardant solution is applied toward a target. The vertical mounting plate may attach the device to the opposite side of the helicopter.

Description

Aerial fire extinguishing system

The present application is a divisional application of patent application with international application date of 2016, 8 and 9, international application number of PCT/US2016/046191, national application number of 201680088290.7 entering the national stage of china, and the name of "air fire extinguishing system".

Background

This application relates generally to systems for applying liquids from aircraft, and more particularly to fire suppression systems that may be used with aircraft such as fixed wing aircraft and rotorcraft.

The design and implementation of fire protection systems for use in aircraft is a difficult endeavor at least because of the limited volume and payload capacity of aircraft such as fixed-wing aircraft and rotorcraft (i.e., helicopters), and because such systems are subject to stringent government certification requirements to protect the safety of personnel flying on such aircraft and to protect personnel and properties on the ground. Accordingly, the air fire protection system should be relatively small and light, simple and safe to operate, with minimal impediment to government certification, while providing as long a durability and as best an effect as possible at the fire site.

Compressed Air Foam Systems (CAFS) are known in the fire industry for extinguishing ground traffic tools and platforms. Such systems include the use of a foaming agent that, when combined or mixed with water, enhances the fire suppression capacity of water alone. For example, when applied to a fire, the water/foam mixture has the advantage of adhering to both horizontal and vertical surfaces of the structure as a surfactant to resist re-ignition of the fire for a long period of time, limiting damage to floors below the fire from water in the case of multi-story buildings, and improving the fire extinguishing quality of the water up to 7 times, as compared to water alone.

Known CAFS systems for land vehicles and fire platforms may include compressed air or an inert gas injected into the water/foam mixture to inflate the water/foam mixture and spray the water/foam mixture from a nozzle at a relatively high velocity toward a relatively far target. The compressed air or inert gas used for this purpose is typically provided in the form of a pressurized tank or bottle or by one or more mechanical air compressors.

However, the use of pressurized tanks or bottles or air compressors as a source of pressurized air can consume valuable space and energy on an aircraft vehicle, which are relatively heavy, thereby reducing the payload of consumable fluids such as water, foam, and fuel, and increasing the risk of accidents due to hazards associated with the pressurized system. In addition, the pressurized tanks must be securely attached to the fuselage, which may extend the turnaround time when changing depleted air tanks. In addition, structural and weight limitations prevent pressurization of one or more water tanks carried on an aircraft or rotorcraft that could otherwise be used to propel water or water/foam mixtures toward a remote target.

What is needed is a fire protection system configured for use in an aircraft that overcomes the above-described limitations of existing CAFS systems.

Disclosure of Invention

Disclosed is an embodiment of a fire extinguishing apparatus for extinguishing a fire from a helicopter, the fire extinguishing apparatus comprising: (a) A tank assembly configured for attachment to an underside of the helicopter, the tank assembly comprising (i) a foam tank for containing foam, (ii) a water tank downstream of the foam tank for containing water, wherein the water tank is configured to receive foam from the foam tank that forms a liquid flame retardant in the water tank when mixed with water in the water tank, and (iii) a tank assembly housing that encapsulates the foam tank and the water tank; (b) A power pack configured for attachment to a side of a helicopter, the power pack comprising (i) a liquid flame retardant pump configured to pump a liquid flame retardant comprising foam and water, the liquid flame retardant pump driven by a first electric motor, the liquid flame retardant pump comprising a pump inlet and an air intake valve positioned at the pump inlet, the air intake valve comprising an electrically variable valve opening, wherein air and liquid flame retardant are drawn together into the pump inlet and pressurized by the liquid flame retardant pump to form a pressurized water/foam/air flame retardant solution; (ii) A liquid introduction pump driven by the second electric motor, the liquid introduction pump configured to introduce liquid flame retardant from the water tank to the pump inlet; (iii) An inverter connected to the first electric motor, the inverter configured to slowly and controllably start the first electric motor to minimize a start current consumed by the first electric motor; and (c) a cannon assembly configured for attachment to an opposite side of the helicopter, the cannon assembly comprising an aimed boom connected by a conduit to a liquid flame retardant pump, the boom comprising a nozzle on a distal end of the boom from which a pressurized water/foam/air flame retardant solution is applied toward a target.

The liquid flame retardant pump and the liquid introduction pump may each be supported on a flat upper surface of the horizontal base. The power pack and the cannon assembly may each be supported by a pair of brackets extending cantilevered from respective vertical mounting plates, each of which may be attached on opposite sides of the fuselage of the helicopter. Each vertical mounting plate may be configured to attach to a structural hard spot located on the exterior surface of the helicopter. The vertical mounting plate may be configured to attach directly to a pair of superstructure hard spots of the helicopter body and to a pair of substructure hard spots of the helicopter body via a pair of adjustable length connecting members that extend from the vertical mounting plate to the substructure hard spots. The pair of adjustable length attachment members may include a clevis on each opposite end of the attachment members for directly attaching the vertical mounting plate to a pair of structural hard points of the helicopter.

The fire suppression apparatus may include a ball valve positioned downstream of and adjacent to the discharge of the liquid flame retardant pump. The intake valve may include an inlet that directly receives unpressurized ambient air. The intake pump discharge conduit may connect the intake pump discharge outlet with a suction conduit positioned upstream of the pump inlet of the liquid flame retardant pump to fill the suction conduit with liquid flame retardant from the water tank before the first electric motor is commanded to rotate. The intake pump inlet conduit may be connected to a water collection area of the water tank.

The cantilever may comprise a carbon fiber composite impregnated with a copper mesh. The boom may include an outboard boom portion, an inboard boom portion, and a coupler portion, wherein the coupler portion connects the inboard boom portion to the outboard boom portion. The coupler portion may include an outer collar, a spring, and a receiver. The outer collar may engage an annular groove of the receiver and the spring may be in compression when the coupler portion is connected to the inboard and outboard cantilever portions.

The fire suppression apparatus may include one or more electronic controllers in operative communication with the first electric motor and the air intake valve, wherein the one or more electronic controllers may be configured to automatically open the air intake valve upon activation of the liquid flame retardant pump. The fire suppression apparatus may include a foam pump configured to pump foam from the foam tank to the water tank, wherein the tank assembly housing may encase the foam pump. Each of the foam tank and the water tank has an inner space for containing a fluid, and the inner space of the foam tank is 5% to 10% of the inner space of the water tank.

The inverter may provide current from zero ampere to about 65 amperes linearly to the first electric motor for a period of 2 to 3 seconds.

In another embodiment, a fire suppression apparatus for suppressing a fire from a helicopter is disclosed that includes a power pack configured for attachment to a fuselage of the helicopter via a vertical mounting plate. The vertical mounting plate is directly attachable to a pair of upper structural hard points of the helicopter body and to a pair of lower structural hard points of the helicopter body via a pair of adjustable length connecting members extending from the vertical mounting plate to the lower structural hard points. The power pack includes a liquid flame retardant pump configured to pump a liquid flame retardant including foam and water. The liquid flame retardant pump is driven by a first electric motor. The liquid flame retardant pump includes a pump inlet and an air intake valve positioned at the pump inlet. The intake valve includes an electrically variable valve opening in which air and liquid flame retardant are drawn together into a pump inlet and pressurized by a liquid flame retardant pump to form a pressurized water/foam/air flame retardant solution. The power pack includes a liquid intake pump driven by the second electric motor. The liquid introduction pump is configured to introduce liquid flame retardant from the water tank to the pump inlet. The power pack also includes an inverter connected to the first electric motor. The inverter is configured to supply current to the first electric motor to start the first electric motor in a period of 2 to 3 seconds to minimize a starting current consumed by the first electric motor.

In another embodiment, a fire extinguishing apparatus for extinguishing a fire from a helicopter is disclosed, the fire extinguishing apparatus comprising a cannon assembly configured for attachment to a fuselage of the helicopter via a vertical mounting plate. The vertical mounting plate is directly attachable to a pair of upper structural hard points of the helicopter body and to a pair of lower structural hard points of the helicopter body via a pair of adjustable length connecting members extending from the vertical mounting plate to the lower structural hard points. The gun assembly includes an aimed boom connected by a conduit to a liquid flame retardant pump, the boom including a nozzle on a distal end of the boom from which pressurized flame retardant, including water, foam and air, discharged by the liquid flame retardant is applied toward a target. The aimable boom includes (a) a carbon fiber composite material impregnated with a copper mesh for transmitting electrical energy from a lightning strike to a fuselage of the helicopter, and (b) an outboard boom portion, an inboard boom portion, and a coupler portion, wherein (i) the coupler portion connects the inboard boom portion to the outboard boom portion, (ii) the coupler portion includes an outer collar, a spring, and a receiver, (iii) the outer collar engages an annular groove of the receiver, and (iv) the spring is in compression when the coupler portion is connected to the inboard boom portion and the outboard boom portion.

Drawings

FIG. 1 is a schematic diagram illustrating one embodiment of an aerial fire suppression system.

Fig. 2A and 2B illustrate exploded perspective views of one embodiment of an aerial fire suppression system of the present disclosure.

Fig. 3 is a front perspective view of an exemplary power pack of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 4 is a rear perspective view of an exemplary power pack of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 5 is a bottom perspective view of an exemplary power pack of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 6 is an exploded front perspective view of an exemplary power pack of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 7 is another exploded front perspective view of the exemplary power pack of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 8 is a front perspective view of an exemplary cannon assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 9 is a rear perspective view of an exemplary cannon assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 10 is a bottom perspective view of an exemplary cannon assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 11 is an exploded front perspective view of an exemplary cannon assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 12 is another exploded front perspective view of the exemplary cannon assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 13A and 13B illustrate partial front perspective views of an exemplary power pack of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 14 illustrates an exemplary operator station for use in conjunction with the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 15 illustrates an exploded front perspective view of an exemplary turret portion of a turret assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 16 illustrates a partial front perspective view of the tank assembly of the aerial fire suppression system shown in fig. 2A and 2B.

Fig. 17 illustrates another partial front perspective view of the tank assembly of the aerial fire suppression system shown in fig. 2A and 2B.

FIG. 18 illustrates a partially exploded perspective view of the boom of the aerial fire suppression system shown in FIGS. 2A and 2B;

fig. 19 illustrates a partial cross-sectional view of the cantilever of the aerial fire suppression system shown in fig. 2A and 2B.

Detailed Description

While the figures and this disclosure describe one or more embodiments of a fire suppression system for an aircraft, those of ordinary skill in the art will appreciate that the teachings of this disclosure will not be limited to such a system, but will also have utility on ground platforms and on-board platforms used in other industries, or wherever it is desired to transport a volume of water, water mixture, or any type of fluid from a starting platform to a remote target. In one embodiment, the system of the present disclosure may be used to extinguish fires in buildings and structures of all shapes and sizes, including fires on high rise buildings and oil rigs. In another embodiment, the system of the present disclosure may be used to extinguish a wildfire. In another embodiment, the system of the present disclosure may be used to clean all shapes and sizes of buildings, including mosque, water towers, and high rise buildings. In another embodiment, the system of the present disclosure may be used to clean high voltage line insulators on electrical towers and windmills. In another embodiment, the system of the present disclosure may be used for cleaning or deicing structures, such as aircraft, windmills, power lines, and the like. In another embodiment, the system of the present disclosure may be used to clean areas, provide crowd control (crowd control), or provide oil leak remediation.

Turning now to the drawings, wherein like reference numerals denote like elements. Fig. 1-19 illustrate an exemplary aerial fire suppression system 10 configured for use on an aircraft, such as an aircraft or helicopter, for extinguishing wildfires or high-rise fires, and the like.

In one embodiment, the system 10 includes (a) a tank assembly for containing water, water/foam solution, or any other fire retardant, (b) a power pack for extracting water, water/foam solution, or other fire retardant from the tank assembly and for pressurizing the water, water/foam solution, or other fire retardant, (c) a cannon assembly for delivering pressurized water, water/foam solution, or other fire retardant to a target downstream of the cannon assembly, and (d) an operator station for controlling operation of the system 10, including operation of the power pack and aiming points of the cannon assembly. The system 10 may also include various piping, wiring, fittings, and structural supports to connect the aforementioned components to each other and/or to the aircraft.

In one embodiment, as schematically shown in, for example, fig. 1, the system 10 includes a tank assembly 15 including a water tank 20 for storing water 24, one or more foam tanks 30 for storing foam (or foam concentrate) 34, and one or more foam pumps 32 for pumping foam (or foam concentrate) 34 from the one or more foam tanks 30 to the water tank 20 to produce a water/foam solution 38 for suppressing a fire in the water tank 20. The water tank 20, or one or more foam tanks 30, or both, may include one or more bladders positioned within the tank assembly 15 for holding water, foam, and/or water/foam solutions. In the embodiment shown in the figures, two foam tanks 30 are positioned within the tank assembly 15, one on the port side and one on the opposite starboard side of the tank assembly 15, for maintaining the center of gravity along the longitudinal centerline of the tank assembly 15. The water 24 of the water tank 20 may be located in a space within the tank assembly 15 not occupied by two foam tanks 30 or other conduits, tank structures, etc., and thus may be located at least partially in contact with one or more foam tanks 30 and/or partially surrounding one or more foam tanks 30. Foam (or foam concentrate) 34 may be pumped from one or more foam tanks 30 to water tank 20 by one or more foam pumps 32 to create a batch of water/foam solution 38 in water tank 20 to create the flame retardant. As described more fully below, after the flame retardant is applied from the system 10 toward the target and while the aircraft is in its mission, pumping water from an open water source to a water tank may be used 20, for example, a telescoping or non-telescoping pump system to supplement the water 24, more foam (or foam concentrate) 34 may then be pumped into the water tank 20 to create another batch of flame retardant for application from the system 10. This cycle may be repeated as long as consumables such as aircraft fuel and foam (or foam concentrate) 34 remain on board the aircraft. In one embodiment of the system 10, the one or more foam tanks 30 comprise from about 5% to about 10% by volume of the water carried in the water tank 20. Suitable foams areClass WD 881A foam, available from ICL Performance ProductsLP company, st.

In addition to housing or supporting the water tank 20, one or more foam tanks 30, and one or more foam pumps 32, the tank assembly 15 may be configured to house or support system piping and tubing, baffles, sensors, interfaces, interconnects, and the like. For example, tank assembly 15 may include an interface 262 and associated piping connected thereto, including conduits 268 and 270 for communicating water/foam solution 38 from water tank 20 to main water/foam pump 62 of power pack 50, and an interface 264 and associated piping connected thereto for receiving water/foam solution 38 discharged from main water/foam pump 62 and communicating water/foam solution 38 to conduit 266 and ultimately to cantilever 100 for discharge toward a target. One or more of the conduits 266, 268, 270, 278, 280 may be configured as flexible conduits or non-flexible conduits. The tank assembly 15 may include a check valve 272, the check valve 272 being positioned near the water-collecting end of the conduit 270 to prevent backflow into the water tank 20.

The tank assembly 15 may also include a cavitation prevention device mounted within the water tank 20 at the lowest point of the water tank 20 to allow the main water/foam pump 62 to pump the water/foam solution 38 without cavitation of the main water/foam pump 62. In the case of a helicopter, the lowest point in the water tank 20 may be located at the tail of the tank when the helicopter is in hover mode.

Additionally, as schematically illustrated in FIG. 1, the system 10 includes a power pack 50 that includes (a) a gas generator 60 and (b) a purge manifold 80. The gas generator 60 of the power pack 50 may be configured to introduce air into the water/foam solution 38 pumped from the tank assembly 15 to inflate the water/foam solution 38 to obtain an optimal composition of flame retardant, as described more fully below.

The gas generator 60 may include an electric motor 64, a main water/foam pump 62, an intake pump 68 for pressurizing the water/foam solution 38, an intake valve 70 for filling and/or filling the intake conduit with the water/foam solution 38 from the water/foam tank 20 prior to opening the electric motor 64, an intake valve 70 for introducing a controlled amount of air into the intake of the main water/foam pump 62, and housings 75, 76 for protecting these components from damage, the electric motor 64 being powered by the inverter 66 to slowly and controllably activate the electric motor 64 and rotate the electric motor 64 to minimize current consumption and/or spikes in current consumption. In one embodiment, inverter 66 is configured to achieve a rotation of electric motor 64 of about 8000RPM over a span of about 2 to 3 seconds by providing a linearly increasing amount of current starting from zero amps to about 85 amps. In this embodiment, the current drawn by the electric motor 64 when operating at about 8000RPM is about 85 amps. In some embodiments, the rate (i.e., slope) and amount of rise of the current delivered to the electric motor 64 is fully programmable. In some embodiments, the current available from the aircraft may be above or below 85 amps. In these cases, inverter 66 may be programmed to deliver the available current for a programmed period of time to bring electric motor 64 to a desired operating speed. In one embodiment, the available current is 65 amps.

The power pack 50 is configured to provide pressurized flame retardant including pressurized water/foam/air solution 74 to the cantilever 100 at about 20 to about 150 gallons per minute (gpm). The housing 75 may be configured as a plurality of individually removable, lightweight, yet sturdy panels or panel assemblies to enclose or partially enclose the power pack 50. The housing 76 may be configured to house a ball valve under the base 176.

The primary water/foam pump 62 of the gas generator 60 is configured to draw the water/foam solution 38 from the water tank 20 and pressurize it for discharge from the cantilever 100 toward the target. The main water/foam pump 62 is configured to draw atmospheric air through the air intake valve 70 and to pressurize the air with the water/foam solution 38. More specifically, the gas generator 60 of the system 10 includes a manually or automatically adjustable intake valve 70 positioned at the suction inlet end of the main water/foam pump 62, which is driven by the electric motor 64. The main water/foam pump 62 is triggered "on" to draw water/foam solution 38 from the water tank 20 in accordance with an indication by an operator using, for example, one of the controls for the operator station 240 discussed herein. At the same time, the intake valve 70 may be commanded to its "open" position, either automatically or manually, such that atmospheric air 72 is drawn into the suction port end 63 of the main water/foam pump 62 at a rate of about 30CFM to about 50 CFM. In one embodiment, the intake valve 70 includes an electrically variable valve opening that is controllable by an operator or automatically according to a preprogrammed controller to vary the amount of air introduced into the intake end 63 of the main water/foam pump 62 as the main water/foam pump 62 is driven at a constant speed.

The main water/foam pump 62, which may include an axially inflow and radially outflow centrifugal impeller, then pressurizes and mixes the air 72 with the water/foam solution 38 to about 125psi and causes the pressurized fire retardant including the pressurized water/foam/air solution 74 to pass through a ball valve 77 having a ball valve discharge 78 and exit the pump discharge 79 through a discharge conduit 278 at about 150 gpm. The discharged fire retardant is then delivered to the cannon assembly 90 via cross-feed conduit 280 positioned in the water tank 20, the cross-feed conduit 280 being between interfaces 262 and 264 positioned on both sides of the tank assembly 15, and ultimately leading from the tank assembly 15 to the cannon assembly 90 via conduit 266. Introducing air 72 for mixing with water/foam solution 38 and pressurizing water/foam solution 38 through system 10 for delivery to cantilever 100 through conduit 266 helps to create tight-formed foam bubbles of optimal size for the flame retardant prior to ejecting the flame retardant from nozzle 130 of cantilever 100 and helps to achieve the furthest possible distance of nozzle 130 from the flame retardant in the emission direction. Because the centrifugal impeller of the main water/foam pump 62 rotates at a relatively high speed of about 8000RPM, it does not significantly lose suction when sucking about 30-50CFM of air 72 and water/foam solution 38. And because air 72 is an infinite resource when drawn from the atmosphere, the time to air standby above a target such as a fire will be limited to the amount of other consumables such as water, foam, or fuel carried on the aircraft. Thus, the system 10 including the gas generator 60 provides a simplified, efficient means for providing a compressed air foam on board an aircraft for engaging a target.

In one embodiment of the system 10 including the gas generator 60, wherein the water tank 20 is sized to hold about 800 gallons of water, the one or more foam tanks 30 are sized to hold about 80 gallons of foam or foam concentrate, the dry weight of the system 10 is about 1015lbs, and the weight of the system 10 when fully loaded with consumables such as water and foam is about 7580lbs. The system 10 with this configuration was able to stand-by in the air for 5 minutes at a foam to water ratio of about 0.5%.

As best shown in fig. 13A-13B, the intake pump 68 may be configured to work in combination with a purge manifold 80 to fill the intake line with a flame retardant agent including the water/foam solution 38 from about the water collection area of the water tank 20 to the inlet 63 of the main water/foam pump 62. In one embodiment, the intake pump 68 is configured to fill the intake line in about 15 seconds. When ball valve 77 is closed, during filling of the suction line (such as conduit 268) with flame retardant, air displaced from the suction line may be vented from the system prior to engaging electric motor 64 to drive main water/foam pump 62. With the suction line filled or nearly filled with liquid flame retardant, a smooth and efficient start-up of the main water/foam pump 62 can be achieved, especially when the impeller of the main water/foam pump 62 has limited suction performance. For example, purging manifold 80 may include a manifold 82 and a solenoid valve 86, manifold 82 positioned atop main water/foam pump 62, wherein a water sensor 84 is positioned on manifold 82 for confirming the presence of liquid fire retardant at the manifold after the suction line and main water/foam pump 62 are substantially full of fire retardant, solenoid valve 86 is positioned on the manifold and configured to be commanded to an open position to allow air from the suction line to vent to atmosphere as the fire retardant fills the suction line. The intake pump 68 may be commanded to operate as long as the water sensor 84 does not indicate liquid at the sensor. As shown, the flame retardant is pumped by the intake pump 68 from the water collection end of an intake conduit 274 located in the water tank 20 and delivered to the introducer supply and discharge lines 87, 88, the discharge lines 87, 88 being located at ports 276 from outside the water tank 20 to the base of the conduit 268 located near the interface 262, respectively.

As further shown schematically in fig. 1, the system 10 may include a cannon assembly 90. The cannon assembly 90 of the system 10 includes a turret 110, a boom 100 having a nozzle 130 at a distal end, and optionally, an infrared vision device 115 and a distance measurement device 120. As shown in fig. 15, the turret 110 of the system 10 includes a linear actuator 212 and a rotary actuator 214 that may be programmed to control the direction and speed of movement of the boom 100 and turret 110, respectively, via a joystick 250 (see, e.g., fig. 14). Turret 110 includes a base 225, which base 225 in turn is supported by supports 227 and 228 (see, e.g., fig. 8-12) for supporting and mounting the cannon assembly 90 to the fuselage of helicopter 150.

The turret 110 includes a rotary drive system 230, the rotary drive system 230 being coupled to the rotary actuator 214 for rotating the turret 110 along a generally vertical axis to move the boom horizontally. The turret 110 includes bearings upon which the housing 222 and the remainder of the turret 110 are supported. Thus, when the rotary actuator 214 engages the rotary drive system 230, the housing 222 and the remainder of the turret 110 rotate relative to the base 225 in the direction of travel of the rotary actuator 214.

To move the cantilever 100 vertically, the linear actuator 212 is connected to a pivot arm, which in turn is connected to the cantilever 100. The compound (diagonal) motion of the cantilever 100 may be achieved by simultaneously engaging the linear actuator 212 and the rotary actuator 214, perhaps at different speeds. An actuator 232 is connected to the cantilever 100 to assist the linear actuator 212 in returning the cantilever 100 to a horizontal position, such as in the event of a power failure. To automatically stow the turret 110 and boom 100 in the event of an emergency, or in the event of a power supply failure or interruption of the system 10, or a mechanical failure or electrical failure of any component of the system 10, such as the actuator 212, and return to a safe, forwardly projecting, locked configuration for evacuation of the aircraft, the turret 110 of the system 10 may be configured with a mechanical turret return system. The mechanical turret return system may be configured to wind the roller chain on a plate located on the tail end of the turret 110 to compress one or more gas struts positioned on the tail end of the turret 110. For example, if the power to the cannon assembly 90 is turned off, the gas strut releases the energy stored therein, which causes the plate to freewheel and loosen the roller chain. In the process, turret 110 is caused to rotate to its original position, in which the cantilever is aimed in a forwardly projecting manner with the aid of actuator 232.

As previously described, the infrared vision apparatus 115, including the infrared camera 117, may be mounted on the turret 110 or elsewhere on the cannon assembly 90. Likewise, the distance measurement device 120, including the laser used to determine the distance between the aircraft and any obstacle or building, is shown mounted on the base 225, but may be mounted on any structure of the system 10 or on the aircraft itself.

As described above, upon exiting the power pack 50, the mixed and pressurized flame retardant comprising the pressurized water/foam/air solution 74 is delivered to the cantilever 100 via the conduits 278, 280, and 266 and is applied from the cantilever 100 via the nozzle 130 toward the aiming point of the cantilever 100. Cantilever 100 may comprise a lightweight material and be adapted to allow for a relatively long cantilever 100 geometry while providing a fluid flow rate sufficient to extinguish fires that are quite distant from the aircraft. For example, boom 100 may be constructed from one or more pieces, and may be constructed from a composite material to provide sufficient stiffness and withstand excessive bending or deflection along its length, such as, especially in the case of rotor down-wash when mounted on a helicopter.

For example, the boom 100 may also be configured to extend beyond the rotor tip diameter of the helicopter to avoid undesirable pre-dispersion or atomization of the water/foam/air solution 74. In one embodiment, boom 100 is about 6.7 to 7.3 meters long and extends at least about 1 meter beyond the end of the rotor. In some embodiments, at least the distal end of cantilever 100 may be constructed of one or more materials that provide electrical insulation properties to prevent conduction and transmission of electricity if cantilever 100 is used in or adjacent to a power line, such as when extinguishing a fire near the power line, or when cleaning a power line insulator on a power line tower, for example. In addition to composite materials, cantilever 100 may be constructed of other materials that provide the foregoing and other desired characteristics and functions, including wound carbon and glass fibers, matt resins, aluminum, and the like. Given the length of boom 100 beyond the rotor tip, boom 100 may be formed in a relatively light yet sturdy and deflection-resistant structure to avoid excessive shifting of the center of gravity of the aircraft and to avoid deflection of the distal tip of boom 100 into the path of the rotor blades.

Boom 100 may be configured to allow for its telescopic extension and retraction to provide compact loading, for example, during ground operation and during flight, while also providing the ability to position the distal end of nozzle 130 beyond the tip of the rotor during use and in-flight at fire locations. Alternatively, the cantilever 100 may be configured to be of a fixed length.

Cantilever 100 may be configured to operate in a "wet" configuration or in a "dry" configuration. For operation in a "wet" configuration, a working fluid, such as a water/foam solution, is communicated through the cantilever 100 to the nozzle 130, causing the inner surface of the cantilever 100 to become "wet". In contrast, cantilever 100 may be configured in a "dry" configuration in which an inner hose communicates working fluid therein to nozzle 130. The "dry" configuration involving the inner hose may not readily allow the boom 100 to also have a telescoping configuration, while a boom 100 having a "wet" configuration in combination with a telescoping configuration may result in binding of the telescoping elements of the boom 100 or leakage through the telescoping elements of the boom 100.

The cantilever 100 may be aimed in any He Shui direction defined by rotation of the turret 110 via the rotary drive system 230 and in any vertical direction defined by movement of the cantilever via the linear actuator 212. If a dedicated operator of system 10 is located on an aircraft or is remotely operating system 10, the operation of cantilever 100 may reduce pilot workload, thereby allowing the pilot to maneuver the aircraft while improving the ability of the firefighter to target a fire independent of the motion of the aircraft. Side deployments may help pilots locate and orient the aircraft for optimal flight characteristics, and may facilitate use of emergency escape routes, as the aircraft points away from the fire, possibly in the intended direction of travel. In contrast, forward deployment of boom 100 in a rotorcraft may negatively impact the stability of the rotorcraft, as tailwind may be created by the consumption of air by the flame.

In one embodiment, as shown in fig. 18 and 19, the boom 100 may be a wet boom comprised of a two-piece carbon fiber composite material impregnated with a copper mesh capable of transporting electrical energy from a lightning strike from the distal end of the boom to the proximal end to dissipate the energy through the rotor. In this embodiment, boom 100 includes an outboard boom portion 101, an inboard boom portion 102, a coupler portion 103 configured to connect outboard boom portion 101 to inboard boom portion 102, and a stiffening tube 104 positioned on an inner diameter to provide rigidity to the connected coupling. Coupler portion 103 includes outer collar 105, spring 106, and receiver 107. Outer collar 105 is configured with an adapter 108 to engage annular groove 109 of receiver 107 and shear pin 135 while being biased apart by spring 106. A plurality of O-rings 138 may be positioned in circumferential grooves on one or more of the inner components to ensure a water seal. The receiver 107 and bolt 140 may be constructed of metal to transfer lightning-induced electrical energy from the copper mesh of the outboard cantilever portion 101 to the inboard cantilever portion 102 for transfer to the aircraft for dissipation.

Turning to fig. 14, the system 10 may include an operator station 240, which is shown to include a set of controls and a computer display. An operator may manipulate the aiming point of cantilever 100 using, for example, joystick 250. The joystick 250 is electrically connected to the linear actuator 212 and the rotary actuator 214 to provide horizontal, vertical, and diagonal movement of the turret 110. The operator station 240 and/or joystick 250 also include a number of controls to activate or deactivate various aspects of the system 10. For example, the operator station 240 and/or joystick 250 may include one or more triggers, switches, or buttons connected to one or more valves or solenoids to turn on, off, or alter the flow of the water 24, the water/foam solution 38, the operation of the intake pump 68, and the pressurized water/foam/air solution 74 delivered by the boom 100 toward a target. The operator station 240 and/or the joystick 250 may also include a switch or trigger connected to the solenoid for releasing the turret 110 from the locked and/or stowed positions. The lever 250 also includes a switch or trigger for opening or closing the intake valve 70. One of ordinary skill will appreciate that other means for turning on or off aspects of the system 10 may be used in addition to buttons, switches, etc., such as a software-driven user interface deployed on a touch screen, as described below.

The operator station 240 also includes controls that allow an operator to, for example, open, close, or change the flow of foam from the one or more foam tanks 30 to the water tank 20 via the one or more foam pumps 32. The operator station 240 may also have controls for varying the concentration of foam or foam concentrate to achieve a desired foam concentration in the water tank 20.

The operator station 240 may include one or more displays for displaying information and providing an interface for an operator to control one or more aspects of the system 10. For example, the display 258 may report data from the infrared vision device 115, data from the distance measurement device 120, position and movement data of the boom 100, flow rates, amounts, and remaining amounts of consumable fluids, data regarding calculated remaining time of flight life, including alert information indicating one or more operating parameters of the cannon assembly 90 that fall outside predetermined limits, data relating to atmospheric conditions such as wind direction and speed, temperature, humidity, and barometric pressure, and data relating to altitude, attitude, and other performance parameters of the aircraft itself.

The display 258 may also provide or include a user interface for receiving operator commands regarding the operation of the system 10. For example, the display 258 may be configured with a touch-sensitive screen for receiving operator input to control or monitor one or more aspects of the system 10. The display 258 may be connected to one or more CPUs, memories, data buses, and software configured to respond to and/or execute operator commands.

The system 10 may additionally be configured for remote monitoring or operation of one or more aspects of the system 10, such as the cantilever 100. For example, the system 10 may be configured to transmit and receive wireless data signals via satellite, cellular, or Wi-Fi in real-time, including, for example, any or all of the information displayable on the display 258, to a remote operator or monitor located on the ground or in the air.

The system 10 may include piping for fluidly communicating fluid to and from various elements of the system 10, valves including pressure relief valves, temperature sensors, pressure sensors and position sensors, flow meters and controllers. The system 10 may include other similar elements without departing from the scope or principles of the present disclosure.

Turning again to fig. 2A-2B, an exemplary integration of the system 10 with the helicopter 150 is shown. The tank assembly 15 of the system 10 is shown externally mounted to the helicopter 150 along the underside of the fuselage. The gun assembly 90 with the turret 110 and boom 100 is shown with the boom 100 in a stowed position along the starboard side of the helicopter, with the nozzle 130 of the boom 100 pointing in the nose direction of the helicopter 150. Power pack 50 is shown mounted to the port side of helicopter 150, opposite cannon assembly 90, to balance the weight of cannon assembly 90. The system 10 is positioned at or near the center of gravity of the helicopter at the tail of the nose of the helicopter 150. The system 10 is configured to optimize the flight characteristics of the helicopter 150 to which the system 10 is attached during operation of the system 10 and the helicopter 150.

In the embodiment shown in the figures, the cannon assembly 90 is mounted to and supported on one side of the fuselage of the helicopter 150, while the power pack 50 is mounted to and supported on the opposite side of the fuselage of the helicopter 150. As such, the weight of cannon assembly 90 can be balanced by the weight of power pack 50. To connect the cannon assembly 90 and power pack 50 to respective sides of the fuselage of helicopter 150, system 10 may include a cannon assembly interface mounting plate 160 and a power pack interface mounting plate 170.

As shown in fig. 2A-12, the cannon assembly interface mounting plate 160 and the power pack interface mounting plate 170 are configured to attach to a hard spot 190 available on the helicopter 150. These hard points 190 are provided by the helicopter manufacturer as standard interfaces to transfer external mounting loads to the internal load bearing structure of the aircraft. Thus, adapting the system 10 to be installed to an existing hard spot 190 via the cannon assembly interface mounting plate 160 and the power interface mounting plate 170 provides ease of installation and other cost savings.

Fig. 3-7 illustrate an exemplary power pack interface mounting plate 170 and associated mounting system in more detail. For example, the power pack interface mounting plate 170 may include a pair of upper clevis/pin joints 183 and a plurality of adjustable length connecting members 180, with clevis/pin joints 182 at both ends of the connecting members 180 for connecting the power pack interface mounting plate 170 to a plurality of aircraft hard points 190. In this embodiment, a pair of adjustable length connecting members 180 may be used to connect the power pack interface mounting plate 170 to each of the two lower aircraft hard points 190, and a pair of upper clevis prongs/pin joints 183 may be used to directly connect the power pack interface mounting plate 170 to each of the two upper aircraft hard points 190. The pair of connection members 180 may be positioned on respective lower corners of the power pack interface mounting plate 170 to enable positional adjustment of the power pack 50 relative to the aircraft fuselage.

The power pack 50 of the system 10 includes a base 176, which base 176 is in turn supported by supports 177, 178 (see, e.g., fig. 5) for supporting and mounting the power pack 50 to the fuselage of the helicopter 150. The supports 177, 178 may be configured with upper and lower hooks 184 and locking pins 185 for quick-connect and securing the supports 177, 178 to corresponding upper and lower pin mounts 186 of the power pack interface mounting plate 170. Thus, once the power pack interface mounting plate 170 is secured to the fuselage of the helicopter 150, the power pack 50 including the supports 177, 178 pre-mounted to the base 176 may be lifted or elevated adjacent the power pack interface mounting plate 170, and the supports 177, 178 may be quickly and easily hooked onto the power pack interface mounting plate 170 and secured to the power pack interface mounting plate 170 adjacent the power pack interface mounting plate 170.

Fig. 8-12 illustrate an exemplary cannon assembly interface mounting plate 160 and associated mounting system in greater detail. For example, the cannon assembly interface mounting plate 160 may include a pair of upper clevis/pin joints 165 and a plurality of adjustable length connecting members 162, with clevis/pin joints 164 at both ends of the connecting members 162 for connecting the cannon assembly interface mounting plate 160 to a plurality of aircraft hard spots 190. In this embodiment, a pair of adjustable length connecting members 162 may be used to connect the cannon assembly interface mounting plate 160 to each of the two lower aircraft hard points 190, and a pair of upper clevis/pin joints 165 may be used to directly connect the cannon assembly interface mounting plate 160 to each of the two upper aircraft hard points 190. The pair of attachment members 162 may be positioned on respective lower corners of the cannon assembly interface mounting plate 160 to enable positional adjustment of the cannon assembly 90 relative to the aircraft fuselage.

Gun assembly 90 of system 10 includes a base 225, which base 225 in turn is supported by supports 227, 228 (see, e.g., fig. 10) for supporting and mounting power pack 50 to the fuselage of helicopter 150. The supports 227, 228 may be configured with upper and lower hooks 166 and locking pins 167 for quick connection and securement of the supports 227, 228 to the corresponding upper and lower pin mounts 168 of the cannon assembly interface mounting plate 160. Thus, once the cannon assembly interface mounting plate 160 is secured to the fuselage of the helicopter 150, the cannon assembly 90, including the supports 227, 228 pre-mounted to the base 225, may be jacked or lifted adjacent the cannon assembly interface mounting plate 160, and the supports 227, 228 may be quickly and easily hooked onto the cannon assembly interface mounting plate 160 and secured to the cannon assembly interface mounting plate 160.

The system 10 may be configured to deliver pressurized fire retardant including pressurized water/foam/air solution 74 from the nozzle 130 at relatively low pressure but at relatively high volume to extinguish a fire in an emission direction. The pressure for the low pressure configuration of the system 10 may be in the range of about 50 to about 200 pounds per square inch (psi) depending on how far the water/foam mixture or other fluid is desired to be delivered in the emission direction. In one embodiment, the system 10 is configured to deliver the water/foam mixture from the nozzle 130 at a flow rate of about 150gpm at about 125psi to a distance of about 132 feet from the nozzle 130, which corresponds to about 150 feet from the proximal end of the cantilever 100 if the cantilever 100 is about 7 meters long. In this manner, the system 10 may be used to extinguish fires that are quite distant from fire fighter platforms, including buildings located in urban areas, such as high rise buildings and warehouses. In another embodiment, the system 10 is configured to deliver the water/foam mixture from the nozzle 130 to a distance of about 65 feet from the nozzle 130 at a flow rate of about 20gpm at about 125 psi.

Alternatively, the system 10 may be configured to provide a relatively low volume of fluid at relatively high pressures, for example, for precisely cleaning insulation on an electrical high voltage tower, for cleaning windmills, etc., or for deicing structures, vehicles, etc. In one embodiment, the system 10 may be configured for cleaning high voltage wire insulators to deliver fluid from the nozzle 130 at about 1500psi to provide about 5.5 to about 6.0gpm of fluid to a distance of about 12 to about 14 feet from the nozzle 130, which exceeds the distance of about 3 to about 6 feet from the nozzle currently provided by known cleaning systems.

An operator, whether a pilot, an onboard operator, or a remote operator connected to the aircraft via one or more wireless communication protocols (such as, for example, cellular, satellite, wi-Fi, or a closed wireless network), may manipulate the aiming point of cantilever 100 using, for example, a joystick. In another embodiment, the operator may manipulate the aiming point of the cantilever 100. The boom 100 may be connected to a turret 110, and the turret 110 may or may not include a drive system for moving together or at least assisting in the movement of the boom 100 under the direction of an operator. The turret 110 may additionally be configured to load the boom 100 in a "home position" when not in use to enhance safe operation of the aircraft during flight operations, and to allow easy and safe ingress and egress from a fire location, for example.

The linear and rotary actuators may be programmed to control the direction and speed of movement of the boom 100 and turret 110, respectively, via a joystick or other steering device. The compound (diagonal) motion of the cantilever 100 may be achieved by simultaneously engaging the linear actuator and the rotary actuator, perhaps at different speeds. In one embodiment, during fire extinguishing operations, the rotational movement of cantilever 100 may range from approximately the nose (i.e., forward) directed toward the aircraft for loading during transport of the aircraft to approximately 110 degrees at the tail. In an embodiment for rotorcraft applications, the vertical movement of boom 100 may range from approximately horizontal (to avoid interference with the rotor) to about 40 degrees down. For aircraft applications, the vertical movement of the cantilever 100 may range from approximately horizontal to about 40 degrees downward. A mechanical lock or an electromechanical lock may be applied to stow the boom 100 for loading for transport of the aircraft. One or more position sensors may be employed to provide one or more signals corresponding to the position of cantilever 100. One or more signals may be used to disengage or engage one or more of the linear actuator and the rotary actuator, thereby moving the cantilever 100.

In one or more embodiments, the system 10 may include an infrared vision device 115, a distance measurement device 120, and an anti-cavitation device in the water tank 20, the distance measurement device 120 including a laser for determining the distance between the aircraft and any obstacle or building, the anti-cavitation device being used to minimize the chance of air, rather than water 24, being drawn from the water tank 20 by the main water/foam pump 62. The infrared vision device 115 may include an infrared camera 117, such as an EVS3 9Hz infrared camera available from FLIR Systems, inc. of golita (CA 93117), calif., to aid in identifying fire hotspots by fog, dust and smoke, as well as in complete darkness. In one embodiment, as shown in FIG. 15, an infrared camera 117 may be mounted on the boom 100. In another embodiment, infrared camera 117 may be mounted elsewhere on a component of system 10 or a component of the aircraft. In one embodiment, images from one or more infrared cameras 117 may be supplied to a display 162 mounted on the turret 110 or near the turret 110 for viewing by an operator of the turret 110. Alternatively, images from one or more infrared cameras 117 of system 10 may be supplied to multiple displays in real-time. Such displays may include displays for use in the cockpit of a pilot, displays on helmets mounted with vision systems worn by the pilot or by one or more crew members on the aircraft or operators of system 10, displays on the ground or in another aircraft that are remote from the aircraft, and displays associated with any number of handheld devices, including cell phones or tablet computer devices.

As indicated by an operator using one of the controls discussed above, for example, at the operator station 240, a known amount of foam or foam concentrate is pumped from one or more foam tanks using one or more foam pumps 32 and added to a known amount of water in the water tank 20 to produce a batch of water/foam mixture having a desired foam to water concentration in the range of about 1% to about 10% relative to water concentration.

In the configuration of the system 10, the one or more foam tanks 30 comprise from about 5% to about 10% by volume of the amount of water carried in the water tank 20. As noted above, for system 10, the ratio of foam to water of system 10 may range from about 0.1% to about 10.0% wet foam to dry foam, as directed by the operator of system 10. Alternatively, the foam to water ratio of the system 10 may be in the range of about 0.4% to about 1.0%.

The power to the operating system 10 or any portion thereof (including the turret 110 and boom 100, electric motor 64, intake pump 68, intake valve 70, solenoid valve 86, etc.) may originate from an unnecessary electrical bus of the aircraft, from a generator connected to an engine or transmission of the aircraft, or from an Auxiliary Power Unit (APU).

All of the fluid pumps described above may be electrically driven using electricity from the sources mentioned above, or may be mechanically driven through a mechanical connection to an on-board engine. For example, the main water/foam pump 62, one or more foam pumps 32, and the intake pump 68 may be mechanically or electrically powered by an aircraft or rotorcraft system. In one embodiment, each or any of the main water/foam pumps 62, one or more of the foam pumps 32 and the intake pump 68 may be configured as electrically driven pumps that consume electrical current from the aircraft or the rotorcraft's unnecessary electrical buses, or from a generator connected to the rotor or engine system, or from a separate Auxiliary Power Unit (APU).

The system 10 may be configured to include a system for supplementing the water supply in the water tank 20 while the aircraft is in flight. For example, the system 10 may include a retractable or non-retractable refill system configured for use on or with a rotorcraft or fixed-wing aircraft. In one embodiment, the system 10 may include a coiled pump system including a water pump at the far end of a conduit of sufficient length to reach a reservoir, lake or other water source beneath the aircraft to pump water from the water source to the water tank 20.

Alternatively, the system 10 may be configured to include a retractable pump system for deploying and retracting a collapsible flexible hose to draw water from a water source, such as a pond or lake, into the water tank 20 as the aircraft spirals over the water source. In one embodiment, the retractable pump system may include a housing or structure for supporting the motorized reel and reversible motor and a motor controller for deploying and retracting the collapsible hose from and to the reel. The housing may include a panel secured to cage elements to form the structure of the housing. A water pump may be positioned at the distal end of the collapsible hose, and the inlet of the water pump may be covered with a shield for pumping water from a water source to the water tank 20. The retractable pump system may be mounted to an aircraft or to one side of the tank assembly 15 to direct water from the collapsible hose to the water tank 20 via conduit 282. In either case, a check valve 284 may be positioned at the proximal end of the conduit 282 to minimize leakage of water from the water tank 20 of the tank assembly 15.

The retractable pump system may be controlled by a pilot of the aircraft or an operator at the operator station 240. During operation, the reversible motor of the telescoping pump system may be commanded by an operator, which command is received by the motor controller, which in turn energizes the reversible motor to cause the spool to rotate in a desired direction to wind and retract the collapsible hose to the spool, or unwind and unwind from the spool. 1. Once the remotely located pump is submerged in the water source after the collapsible hose is unwound from the spool, the operator can place the pump "on" to cause water to be pumped from the water source to the water tank 20 via the collapsible hose, internally through the hub of the spool, and via conduit 282. Alternatively, the conduit 282 may be adapted to connect with additional pipes which in turn are connected to the water tank 20 to communicate water to the water tank 20. At the completion of the fill cycle, the operator may command the pump to be placed in its "off" position to stop pumping water. The operator may then command the reversible motor to reverse the rotation of the spool to retract the collapsible tube and wind the collapsible tube onto the spool. The deployment and retraction of the collapsible hose may be initiated as the aircraft spirals over the water source, or transitions to and from hover, respectively. One or more steps of deploying the collapsible hose to, for example, a predetermined length, turning on and off the water pump for pumping water, and retracting the collapsible hose may be automatically performed using sensors and/or appropriate software control algorithms included in the system 10. When the collapsible hose is fully wound on the spool, the retractable pump system may be configured to avoid interference with normal landing operations of the aircraft.

In embodiments including rotorcraft, the refilling cycle time using the retractable or non-retractable system described above may range from about 25 seconds to about 60 seconds when hovering over a water source, such as a reservoir or lake, to reload the water tank 20 with water. In embodiments, depending on the ratio of foam to water used, it may be desirable to refill the foam after about 5 to about 10 water cycles.

Although specific embodiments have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the present disclosure is to be considered as illustrative and not restrictive in scope, and all aspects of the appended claims and any equivalents thereof should be given.

Claims (13)

1. A fire extinguishing device for extinguishing a fire from a helicopter, the fire extinguishing device comprising:

a water tank for containing water, the water tank being configured to be externally attached to the helicopter along an underside of the helicopter body;

a foam tank for containing foam, the foam tank being disposed in the water tank, wherein the water tank is configured to receive foam from the foam tank, forming a liquid flame retardant in the water tank when the foam is mixed with water in the water tank;

A liquid flame retardant pump configured to pump the liquid flame retardant comprising the foam and water, the liquid flame retardant pump driven by a first electric motor, the liquid flame retardant pump comprising a pump inlet and an air intake valve positioned at the pump inlet, the air intake valve comprising an electrically variable valve opening, wherein air is drawn into the pump inlet with the liquid flame retardant and pressurized by the liquid flame retardant pump to form a pressurized water/foam/air flame retardant solution;

a liquid introduction pump driven by a second electric motor, the liquid introduction pump configured to introduce the liquid flame retardant from the water tank to the pump inlet;

an inverter connected to the first electric motor, the inverter configured to slowly and controllably start the first electric motor to minimize a start current consumed by the first electric motor;

wherein the liquid flame retardant pump, the liquid intake pump, and the inverter are supported by a base supported by a pair of brackets extending cantilevered from a vertical mounting plate configured to be attached to the helicopter fuselage, wherein each of the brackets comprises:

Upper and lower hooks configured to be detachably engaged with respective upper and lower pin mounts located outwardly facing of the vertical mounting plate; and

upper and lower laterally mounted locking pins configured to removably secure the upper and lower hooks to the respective upper and lower pin mounts, an

Wherein the vertical mounting plate is configured to be directly attached to a pair of upper structural hard points of the helicopter body via a pair of clevis/pin joints located at opposite upper corners of the vertical mounting plate and to a pair of lower structural hard points of the helicopter body via a pair of adjustable length connecting members extending horizontally from a second pair of clevis/pin joints at opposite lower corners of the vertical mounting plate to the lower structural hard points.

2. The fire suppression apparatus of claim 1, wherein the foam is a foam concentrate.

3. The fire extinguishing apparatus according to claim 1, wherein the foam tank is defined by a bladder for containing the foam.

4. The fire suppression apparatus of claim 1, comprising a foam pump configured to pump the foam from the foam tank to the water tank.

5. The fire extinguishing apparatus according to claim 1, wherein the foam tank and the water tank each have an inner space for containing a fluid, and the inner space of the foam tank is 5% to 10% of the inner space of the water tank.

6. The fire suppression apparatus of claim 1, comprising a ball valve positioned downstream of and adjacent to a discharge of the liquid flame retardant pump.

7. The fire suppression apparatus of claim 1, wherein an intake pump discharge conduit connects an intake pump discharge outlet with a suction conduit positioned upstream of a pump inlet of the liquid flame retardant pump to fill the suction conduit with liquid flame retardant from the water tank before the first electric motor is commanded to rotate.

8. The fire suppression apparatus of claim 7, comprising a purge manifold configured to cooperate with the liquid intake pump to expel air from the suction conduit.

9. The fire suppression apparatus of claim 8, wherein the purge manifold comprises

A manifold positioned on top of the liquid flame retardant pump,

a water sensor positioned on the manifold for confirming the presence of the liquid flame retardant at the manifold after the intake conduit and the liquid flame retardant pump are substantially full of the liquid flame retardant,

A solenoid valve is positioned on the manifold and configured to be commanded in an open position to allow air from the intake conduit to vent to atmosphere as the liquid flame retardant fills the intake conduit.

10. The fire extinguishing apparatus according to claim 1, comprising a conduit extending from an inlet of the intake pump to a water collecting area of the water tank.

11. The fire suppression apparatus of claim 1, wherein the intake valve includes an inlet that directly receives unpressurized ambient air.

12. The fire suppression apparatus of claim 1, comprising one or more electronic controllers in operative communication with the first electric motor and the air intake valve, wherein the one or more electronic controllers are configured to automatically open the air intake valve upon activation of the liquid flame retardant pump.

13. The fire suppression apparatus of claim 1, wherein the inverter provides current from zero amperes to about 65 amperes linearly to the first electric motor for a period of 2 to 3 seconds.