Systems and methods for vertical takeoff and landing aircraft downwash mitigation and energy recapture

Abstract

A final approach and takeoff (FATO) surface for a VTOL aircraft redirects downwash as outwash and may capture outwash from the VTOL aircraft to generate electricity. The FATO surface system may include a central solid plateau configured to capture downwash from the VTOL aircraft to enhance a ground effect for optimal stabilization during takeoff and landing. A floor grate surrounding the plateau may allow outwash to pass through to a subsurface where the outwash is channeled to exhausts or at least one turbine for generating electricity from the outwash. Redirecting the downwash to outwash reduces undesirable effects such as noise and airspeed associated with the VTOL aircraft. The electricity may be used to recharge the VTOL, electric vehicles parked at a vertiport of the FATO surface system, may be used by a building at the vertiport, or may be delivered to a local power grid.

Description

Agent Ref 16163 -0112-00304SYSTEMS AND METHODS FOR VERTICAL TAKEOFF AND LANDING AIRCRAFT DOWNWASH MITIGATION AND ENERGY RECAPTURECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims priority to and the benefit of U.S. Provisional Application No. 63 / 677,981, filed July 31, 2024, titled “SYSTEMS AND METHODS FOR VERTICAL TAKEOFF AND LANDING AIRCRAFT ENERGY RECAPTURE,” the contents of which is incorporated herein in its entirety and for all purposes.TECHNICAL FIELD

[0002] This disclosure relates generally to the field of powered aerial vehicles. More particularly, and without limitation, the present disclosure relates to innovations in takeoff and landing sites for aircraft that use electrical propulsion systems. Certain aspects of the present disclosure generally relate to the management (e.g., mitigation) of the downwash generated by an aerial vehicle upon takeoff or landing. Further aspects of the present disclosure generally relate to energy capture of vertical takeoff and landing (VTOL) aircraft. Other aspects of the present disclosure generally relate to improvements in energy capture that may be used in other types of vehicles but provide particular advantages in aerial vehicles.BACKGROUND

[0003] Vertical takeoff and landing (VTOL) aircraft, such as helicopters and electric aircraft, typically include one or more propellers configured to propel air downward to provide vertical lift for takeoff, landing and hovering. VTOL aircraft may be designed to take off and land from a landing site, such as a final approach and takeoff (FATO) surface system.SUMMARY

[0004] Embodiments of the present disclosure provide a FATO surface system for an aircraft. The FATO surface system may comprise: a plateau configured to receive the aircraft; a floor grate surrounding the plateau and configured to receive the downwash; a subsurface below the floor grate and configured to receive at least some of the downwash of the aircraft and redirect the downwash as outwash, wherein the floor grate comprises a permeable or vented floor surface that allows airflow to pass through to the subsurface.Agent Ref : 16163 -0112-00304

[0005] In some embodiments, the FATO surface system may comprise exhaust ducts configured to exhaust the outwash.

[0006] In some embodiments, the FATO surface system may be further configured to recapture energy used to produce thrust needed to achieve vertical takeoff or landing of the aircraft through capturing of the outwash. For example, the FATO surface system may comprise at least one turbine, the at least one turbine being configured to receive the outwash and generate electricity from the outwash.

[0007] In some embodiments, the FATO surface system may comprise one or more louvers configured to control a direction of exhaustion of the outwash.

[0008] In some embodiments, the FATO surface system may comprise an infrastructure unit, wherein the FATO surface system is located above the infrastructure unit.

[0009] In some embodiments, the floor grate of the FATO surface system comprises a metal grating having a hole size allowing airflow of the downwash while allowing passengers to walk on the floor grate to disembark the aircraft.

[0010] Further embodiments of the present disclosure include a method of providing the FATO surface system.

[0011] Further embodiments of the present disclosure include a method of reducing noise and / or horizontal air speed of an aircraft upon landing or taking off, the method comprising controlling downwash from the aircraft landing on or taking off from the FATO surface system.

[0012] Further embodiments of the present disclosure include a method of generating electricity, the method comprising capturing downwash from an aircraft landing on or taking off from the FATO surface system.BRIEF DESCRIPTIONS OF FIGURES

[0013] Fig. 1A illustrates an example VTOL aircraft in a cruise configuration, consistent with embodiments of the present disclosure.

[0014] Fig. IB illustrates an example VTOL aircraft in a lift configuration, consistent with embodiments of the present disclosure.

[0015] Figs. 2A-2G illustrate example energy capture and downwash mitigation systems for a VTOL aircraft, consistent with embodiments of the present disclosure.

[0016] Fig. 3 illustrates an example chart showing a downwash velocity for a VTOL aircraft, consistent with embodiments of the present disclosure.Agent Ref : 16163 -0112-00304DETAILED DESCRIPTION

[0017] The present disclosure addresses energy capture techniques used during takeoff and landing at a final approach and takeoff (FATO) surface systems for vertical takeoff and landing (VTOL) aircraft, such as electric vertical takeoff and landing (eVTOL) aircraft. A FATO surface system may comprise a defined area over which the final phase of an aircraft approach maneuver to hover or landing is completed, and from which the takeoff maneuver is commenced. The eVTOL aircraft of the present disclosure may be intended for frequent (e.g., over 50 flights per workday), short-duration flights (e.g., less than 100 miles per flight) over, into, and out of densely populated regions. The aircraft may be intended to carry 4-6 passengers or commuters who have an expectation of a clean, low-noise, and low-vibration experience. The distributed propulsion systems of eVTOL aircraft, utilizing a relatively large number of small propellers with zero noxious emissions, may be advantageous for such applications. Their ability to transition between horizontal and vertical flight modes allows the aircraft to utilize wing borne flight while operating out of small-footprint vertiports, offering a combination of versatility and energy efficiency that is not available in conventional aircraft. eVTOL aircraft may offer the promise of a faster, quieter, cheaper, more convenient, and more environmentally friendly means of urban and intercity transportation than what is presently available.

[0018] However, due to the weight of such aircraft, its passengers and cargo, large amounts of thrust are needed during the vertical phases of flight, such as takeoff and landing. Thus, energy consumption threatens to counteract the potential environmental benefits and make such travel less affordable for typical commuters. Therefore, it may be desirable to reduce the net energy consumption of eVTOL aircraft during these phases of increased thrust.

[0019] Furthermore, the large amounts of thrust needed during takeoff and landing may result in unwanted effects at the takeoff and / or landing sites. For example, the downwash of the aircraft may result in excessive amounts of noise or airspeed in the vicinity of the aircraft. In some jurisdictions, limitations are placed on the maximum noise or airspeeds surrounding VTOL takeoff and landing sites. It is therefore desirable to manage and / or mitigate the downwash resulting from an aircraft upon takeoff and / or landing.

[0020] Embodiments of the present disclosure provide systems and methods for reducing the noise and / or horizontal air speed of an aircraft upon landing or taking off. Further embodiments of the present disclosure provide systems and methods for recovering a portion of the energy expended during takeoff and landing phases of flight. For example, a FATO surface system may be designed to receive downwash of or from an aircraft and redirect theAgent Ref : 16163 -0112-00304 downwash as outwash. A FATO surface system may also be designed to efficiently capture outwash from an eVTOL aircraft during takeoff and landing, without sacrificing safety or comfort in the process. As discussed below, a FATO surface system may comprise a solid central plateau surrounded by a vented floor grate. The central plateau may be made large enough to support a landed eVTOL aircraft, as well as to capture enough downwash to provide a sufficient “ground effect” underneath the aircraft. The “ground effect” may refer to an increase in the amount of lift produced by a rotor due to interactions of the downwash with a nearby ground surface. This ground effect allows the aircraft to maintain stability and control when approaching or leaving the plateau surface, and reduces the amount of energy that is required for taking off, landing, or hovering. A subsurface below the floor grate may be shaped to receive downwash of the aircraft and redirect the downwash as outwash. In other embodiments, a subsurface below the floor grate may be shaped to channel outwash (such as redirected downwash) toward an array of turbines that capture the outwash and generate electricity. This captured electricity may be re-used to reduce the net energy consumption attributable to the aircraft takeoff and landing procedures. For example, the electricity may be delivered to a local power grid, power electrical systems within the vertiport itself, or stored at the vertiport for charging various aircraft and electric vehicles.

[0021] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the disclosure. Instead, they are merely examples of apparatuses and methods consistent with aspects related to the subject matter recited in the appended claims.

[0022] Figs. 1A and IB illustrate a VTOL aircraft 100 in a cruise configuration and a vertical takeoff, landing and hover configuration (also referred to herein as a “lift” configuration), respectively, consistent with embodiments of the present disclosure. Aircraft 100 may include a fuselage 102, wings 104 mounted to fuselage 102, tail 105, and one or more rear stabilizers 106 mounted to tail 105 or the rear of fuselage 102. A plurality of lift propellers 112 may be mounted to wings 104 and configured to provide lift for vertical takeoff, landing and hover. A plurality of tilt propellers 114 may be mounted to wings 104 and may be tiltable between the cruise configuration in which they provide forward thrust to aircraft 100 for horizontal flight, as shown in Fig. 1A, and the lift configuration in which they provide a portion of the lift required for vertical takeoff, landing and hovering, as shown in Fig. IB. As used herein, aAgent Ref : 16163 -0112-00304 lift configuration may refer to a tilt propeller orientation in which the tilt propeller thrust is providing primarily lift to the aircraft. A cruise configuration may refer to a tilt propeller orientation in which the tilt propeller thrust is providing primarily forward thrust to the aircraft. Alternatively, a cruise configuration may refer to a configuration in which a lift propeller is stowed.

[0023] In some embodiments, lift propellers 112 may be configured for providing lift only, with all propulsion being provided by the tilt propellers. Accordingly, lift propellers 112 may be in fixed positions and may only generate thrust during takeoff, landing and hover. Meanwhile, tilt propellers 114 may be tilted to lift configurations in which their thrust is directed vertically for providing additional lift.

[0024] For forward flight, tilt propellers 114 may tilt from their lift configurations to their cruise configurations. In other words, the pitch and tilt angle of tilt propellers 114 may be varied from an orientation in which the tilt propeller thrust is directed vertically (to provide lift during vertical takeoff, landing and hover) to an orientation in which the tilt propeller thrust is directed horizontally (to provide forward thrust to aircraft 100). The tilt propellers may tilt about axes that may be perpendicular to the forward direction of aircraft 100. When aircraft 100 is in full forward flight during the cruise configuration, lift may be provided entirely by wings 104. Meanwhile, lift propellers 112 may be shut off. Blades 120 of lift propellers 112 may be locked in low-drag positions for aircraft cruising. In some embodiments, lift propellers 112 may each have two blades 120 that may be locked for cruising in minimum drag positions in which one blade is directly in front of the other blade as illustrated in Fig. 1A. In some embodiments, lift propellers 112 have more than two blades. In some embodiments, tilt propellers 114 include more blades 118 than lift propellers 112. For example, as illustrated in Figs. 1A and IB, lift propellers 112 may each include, e.g., two blades and tilt propellers 114 may each include, e.g., five blades. In some embodiments, tilt propellers 114 may have, e.g., from 2 to 5 blades.

[0025] In some embodiments, the aircraft may include only one wing 104 on each side of fuselage 102 (or a single wing that extends across the entire aircraft) and at least a portion of lift propellers 112 may be located rearward of wings 104 and at least a portion of tilt propellers 114 may be located forward of wings 104. In some embodiments, all of lift propellers 112 may be located rearward of wings 104 and all of tilt propellers 114 may be located forward of wings 104. According to some embodiments, all lift propellers 112 and tilt propellers 114 may be mounted to the wings — i.e., no lift propellers or tilt propellers may be mounted to the fuselage. In some embodiments, lift propellers 112 may be all locatedAgent Ref : 16163 -0112-00304 rearwardly of wings 104 and tilt propellers 114 may be all located forward of wings 104. According to some embodiments, all lift propellers 112 and tilt propellers 114 may be positioned inwardly of wing tips 109.

[0026] In some embodiments, lift propellers 112 and tilt propellers 114 may be mounted to wings 104 by booms 122. Booms 122 may be mounted beneath wings 104, on top of the wings, and / or may be integrated into the wing profile. In some embodiments, one lift propeller 112 and one tilt propeller 114 may be mounted to each boom 122. Lift propeller 112 may be mounted at a rear end of boom 122 and tilt propeller 114 may be mounted at a front end of boom 122. In some embodiments, lift propeller 112 may be mounted in a fixed position on boom 122. In some embodiments, tilt propeller 114 may mounted to a front end of boom 122 via a hinge. Tilt propeller 114 may be mounted to boom 122 such that tilt propeller 114 is aligned with the body of boom 122 when in the cruise configuration, forming a continuous extension of the front end of boom 122 that minimizes drag for forward flight.

[0027] In some embodiments, aircraft 100 may include, e.g., one wing on each side of fuselage 102 or a single wing that extends across the aircraft. According to some embodiments, at least one wing 104 is a high wing mounted to an upper side of fuselage 102. According to some embodiments, the wings include control surfaces, such as flaps, ailerons or flaperons. According to some embodiments, the wings may have curved wing tips 109 for reduced drag during forward flight.

[0028] In some embodiments, rear stabilizers 106 include control surfaces, such as one or more rudders, one or more elevators, and / or one or more combined rudder-elevators. The wing(s) may have any suitable design. For example, the wings have a tapering leading edge or a tapering trailing edge. In some embodiments, the wings may have a substantially straight leading edge in the central section of wings 104.

[0029] Aircraft 100 may include at least one door 110 for passenger entry and exit. In some embodiments, door 110 may be located beneath and forward of wings 104 as seen in Figs. 1A and IB.

[0030] As discussed above, aircraft 100 may require large amounts of energy to produce the thrust needed to achieve vertical takeoff or a slow, gentle landing. It may be desirable to recapture some of this energy, or to minimize the disruption on the local environment caused by this thrust (e.g., noise pollution or high airspeeds). However, it may be undesirable to excessively diminish the ground effect at a FATO surface system, which could destabilize the aircraft and increase the energy requirements during takeoff and landing. Embodiments of theAgent Ref : 16163 -0112-00304 present disclosure present systems and methods for reducing the noise and / or horizontal air speed resulting from an aircraft, and / or for capturing such energy efficiently and safely.

[0031] Fig. 2A illustrates an example of a FATO surface system 200 for a vertiport, consistent with embodiments of the present disclosure. A cross-sectional view is shown at the top of Fig. 2A, and an exploded perspective view is shown at the bottom. FATO surface system 200 may be configured to accommodate a VTOL aircraft 100 of Figs. 1A and IB. It should be noted that while other aircrafts may utilize FATO surface system 200 for takeoff and landing such as, e.g., helicopters or alternative VTOL aircraft designs, in some embodiments FATO surface system 200 may be optimized for a particular class, dimension or design of an aircraft, such as eVTOL aircraft 100. For example, the sizing, radial distance from the center of FATO surface system 200, number of exhaust ducts / turbines, or the dimensions of various floor surfaces, may be optimized for characteristics of VTOL aircraft 100, such as its dimensions or expected downwash and outwash flow distributions.

[0032] FATO surface system 200 as seen in Fig. 2A may comprise, e.g., a plateau 201 that transitions radially outwardly to a sloped subsurface 202. In some embodiments, plateau 201 may be flat, as seen in Fig. 2A to provide a suitable aircraft landing surface. Plateau 201 and subsurface 202 may form a primary floor surface 204. Primary floor surface 204 may be configured to support the weight of a VTOL aircraft and may be formed of typical aircraft landing surface materials such as, e.g., steel or concrete.

[0033] Plateau 201 may further be surrounded by, and flush with, a floor grate 203. Floor grate 203 may comprise a permeable or vented floor surface that allows airflow to pass through to subsurface 202. For example, floor grate may comprise a metal grating having a hole size that allows sufficient airflow while still allowing passengers to walk on it to board or disembark VTOL aircraft 100. In some embodiments, floor grate 203 may comprise a walkway (not shown) to accommodate foot traffic while allowing a remainder of floor grate to utilize larger openings. In some embodiments, floor grate 203 may be supported by, e.g., a plurality of support structures 205, such as radial or circumferentially oriented ribs extending from subsurface 202. Support structures 205 may further be configured to redirect or guide outwash 211 towards turbines 206 and / or exhaust ducts 208, as well as to smooth out turbulent airflows for optimal energy capture. As shown in Fig. 2A, support structures 205 may be positioned sequentially around subsurface 202. The contained volume formed between support structures 205 may form channels which direct outwash 211 towards turbines 206 and / or exhaust ducts 208. Support structures 205 may be shaped to fill theAgent Ref 16163 -0112-00304 vertical space between subsurface 202 and floor grate 203, to block outwash from moving from one channel to another, and reduce turbulent airflow beneath floor grate 203.

[0034] Subsurface 202 may comprise a sloped subsurface extending radially outward from plateau 201 to channel airflow from VTOL aircraft 100 to receive downwash 210 of the aircraft and redirect downwash 210 as outwash 211. The airflow may be channelled from a generally vertical direction starting from the rotors, to a generally horizontal direction after interaction with subsurface 202. Subsurface 202 may also channel airflow from VTOL aircraft 100 to exhaust ducts 208 configured to exhaust the outwash. In other embodiments, subsurface 202 may channel airflow from VTOL aircraft 100 to at least one or a plurality of turbines 206. For example, turbines 206 may be arranged in a ring-shaped structure, such as within exhaust ducts 208 in a rim 207 of a primary floor surface 204 formed by plateau 201 and subsurface 202. In some embodiments, at least one turbine 206 may comprise at least one microturbine having a small diameter of, e.g., between about 0.5 and 2 m. Microturbines of this size may be advantageous since they help to maximise power generation for a given space. The microturbines and / or turbines may additionally reduce airflow velocity after the outwash has passed through the microturbine and / or turbine. The microturbine and / or turbines may also reduce noise of the airflow. Turbines 206 may capture outwash 211 from VTOL aircraft 100 as it takes off from, lands on, or hovers above plateau 201. In some embodiments, sloped subsurface 202 may comprise a generally downward curved profile. The specific profile shape and depth d of sloped subsurface 202 may be optimized to efficiently channel outwash into turbines 206. For example, a slope shape may be designed to produce a smoother, more energy efficient, less turbulent, or even laminar, airflow and provide a seamless flow transition from plateau 201. The slope shape of the subsurface may follow a curved path. The curved path may be at least linear, parabolic, or exponential in path. The curve may be simple or compound and may comprise one or more curve types to provide optimum airflow. Depth d may be optimized to ensure that outwash velocity is maintained, for example, by minimizing the depth while accommodating the height of exhaust ducts 208 and / or turbines 206 and collecting a sufficient amount of outwash 211. Such shapes and dimension may be determined by, e.g., airflow modelling. The airflow modelling may be based on, e.g. properties of FATO surface system 200 structure, properties of one or more aircraft that are expected to use FATO surface system 200, or local conditions. For example, properties of FATO surface system may comprise, e.g., the hole sizes or other venting properties of floor grate 203, the diameter or surface shape of plateau 201, or the sizing, shape or spacing of support structures 205. Properties of one or moreAgent Ref : 16163 -0112-00304 aircraft that are expected to use FATO surface system 200 may comprise, e.g., the flow velocity or flow distribution of an aircraft, a wingspan or other dimension of an aircraft, or a weighted average of flow velocities, flow distributions or dimensions of multiple aircraft that may be expected to use FATO surface system 200. Local conditions may comprise, expected wind or other weather conditions, local altitude, or typical air conditions such as density, barometric pressure, or temperature.

[0035] In the present disclosure, “downwash” 210 (illustrated in solid lines) may refer to the primarily downward-moving rotorwash that travels from the propellers of an aircraft in, e.g., a lift configuration. “Outwash” 211 (illustrated in dashed lines) may refer to the downwash that has been redirected, such as into a primarily horizontal direction, by, e.g., plateau 201 or another ground-level surface, or by subsurface 202. As discussed above, downwash 210 may be responsible for a majority of the ground effect that assists with energy efficiency and stability of aircraft 100 during a takeoff or landing procedure. Therefore, it may be undesirable to directly capture downwash 210 for the purpose of electricity generation before it has interacted with plateau 201, as doing so may diminish the ground effect. However, outwash 211 may have a much smaller impact on the total ground effect, while providing a sufficiently high-velocity airflow to generate a useful amount of electricity.

[0036] As shown in Fig. 2A, plateau 201 may be large enough to accommodate VTOL aircraft 100. For example, in some embodiments, plateau 201 may have a minimum cross- sectional distance that is larger than a maximum separation of landing gear 111. In some embodiments, plateau 201 may have a minimum cross-sectional distance that is larger than a wingspan of VTOL aircraft 100. In some embodiments, plateau 201 may have a minimum cross-sectional distance that is a substantial portion of the wingspan of VTOL aircraft 100 such as, e.g., 60%, 70%, 80% or 90% of the wingspan. In some embodiments, the size of plateau 201 may be configured to accommodate a plurality of expected aircraft dimensions or designs, such as by sizing plateau 201 according to a maximum expected aircraft size or to an average expected aircraft size.

[0037] The diameter of plateau 201 may be selected to support VTOL aircraft 100, as well as to produce a desired degree of ground effect when VTOL aircraft 100 is taking off, landing, or hovering above FATO surface system 200. As mentioned above, enhancing the ground effect can allow an aircraft to boost energy efficiency and achieve optimal stabilization for smooth takeoff and landing. Thus, although shrinking or removing solid plateau 201 may allow more downwash 210 to reach turbines 206 with higher flow velocity, yielding an increase in energy capture, it may be counteracted by increased energy requirements in flightAgent Ref : 16163 -0112-00304 and may come at the expense of stability, safety, and passenger comfort. For this reason, plateau 201 may be configured to deflect a large portion of downwash to produce such ground effect while allowing outwash to be collected at turbines 206 and / or redirected as outwash, optionally exiting via exhaust ducts 208. For example, in some embodiments, plateau may comprise a minimum cross-sectional distance of, e.g., 3 m, 5 m, 10 m or 15 m. Further, to optimize the amount of airflow captured by turbines 206, plateau 201 may comprise a maximum cross-sectional distance as well. For example, in some embodiments plateau 201 may comprise a maximum cross-sectional distance of, e.g., 5m, 10 m, 15 m, or 20 m. In other embodiments, the plateau may have a maximum cross-sectional distance between 5 m and 20 m, the floor grate may have a maximum cross sectional distance of between 10 m and 30 m, and the depth of the subsurface may be between 0.3 m and 2 m. In other embodiments, the plateau may have a cross-sectional distance between 10 m and 15 m, the floor grate may have a maximum cross maximum sectional distance of between 15 m and 30 m, and the depth of the subsurface may be between 0.3 m and 2 m. In other embodiments, the plateau may have a cross-sectional distance between 15 m and 20 m, the floor grate may have a maximum cross sectional distance of between 20 m and 30 m, and the depth of the subsurface may be between 0.3 m and 2 m.

[0038] In some embodiments, floor grate 203 may span the full diameter of the primary surface 204, without a separate plateau 201. A floor grate with a greater surface area may allow for improved downwash capture.

[0039] In some embodiments, at least one turbine 206 or plurality of turbines 206 may be located between a predetermined minimum and maximum radial distances from a center of plateau 201 to optimize the flow velocity of outwash 211 as it passes through turbines 206. For example, in some embodiments a turbine 206 may be located at a radial distance of, e.g., between 5 and 15 m from the center of plateau 201, corresponding to diameters of a full ring of turbines 206 or, e.g., between 10 m and 30 m. Further, it may be desirable to limit the diameter of floor grate 203, or similarly, of rim 207, as these diameters may in some cases dictate the radial distance of turbines 206. For example, in some embodiments, floor grate 203 or rim 207 may comprise a maximum diameter of, e.g., 10 m, 20 m or 30 m. In some embodiments, a depth d of subsurface 202 may be no larger than, e.g., 0.3 m, 0.5 m, 1 m, 1.5 m, or 2 m. A subsurface depth in this range may be preferable to ensure that the outwash generated by the redirected downwash flows smoothly into turbines 206, whilst reducing unwanted noise.Agent Ref : 16163 -0112-00304

[0040] It should be understood that the above diameters may vary depending on the particular aircraft for which a FATO surface system 200 is designed. Therefore, in some embodiments, the minimum and maximum diameters may be greater or less than those described above. However, the parameters governing the choice of diameters may include, e.g., ground effect, aircraft size, outwash flow velocity as a function of distance from the aircraft, etc., as well as the airflow modelling as discussed above.

[0041] Further, while turbines 206 and / or exhaust ducts 208 are illustrated as being arranged in a ring, embodiments of the present disclosure are not limited to this configuration. For example, Fig. 2B schematically illustrates a plan view of a plurality of alternative layouts 251-253, as compared to a circular layout 250 as discussed above. In some embodiments, floor grate 203, subsurface 202 (not shown), turbines 206, or exhaust ducts 208 may be arranged in other shapes to surround the wings, booms, etc. of a VTOL aircraft 100 for a specific expected azimuthal orientation of takeoff or landing. For example, the turbines or exhaust ducts may be arranged in a rectangular layout 251, elliptical layout 252, or bowtie layout 253 In some embodiments, a major axis of these layouts may correspond to an expected orientation of the wings of VTOL aircraft 100 during takeoff or landing as shown in the upper left comer of Fig. 2B. In such cases, a subsurface 202 may be shaped and sloped accordingly to channel airflow to turbines 206 or exhaust ducts 208. In other embodiments, the surface may be configured to prevent the outwash from being exhausted from at least one side, at least two sides, or at least three sides. This may be desirable since, depending on where the FATO surface system is positioned (for example, next to other buildings), it may be necessary not to direct the outwash in certain directions. Alternatively or additionally to the array of smaller turbines 206 discussed above, as shown in Fig. 2C, a single large turbine 206 may be arranged underneath, and parallel to, floor grate 203. Turbine 206 may be configured to rotate around plateau 201 and sloped subsurface 202 to generate electricity from downwash. The downwash may then be directed as outwash 211 and may be exhausted at, e.g., exhaust ducts 208.

[0042] Alternatively or additionally, plateau 201 or sloped subsurface 202 may comprise shape profiles other than what is represented in Fig. 2A. For example, as shown in Fig. 2D, plateau 201 may be slightly convex in some embodiments to better redirect downwash as outwash 211 along sloped subsurface 202. It is noted that VTOL aircraft may utilize landing gear 111 having, e.g., three discrete points instead of the elongated skids seen on helicopters. Therefore, a VTOL may be capable of safely and comfortably landing on surface that are more complex than a simple flat plane. This may allow for additional design degrees ofAgent Ref : 16163 -0112-00304 freedom in plateau 201, such that outwash may be efficiently channeled in a smooth transition from plateau 201 to sloped subsurface 202. Furthermore, in some embodiments, sloped subsurface 202 may not comprise a monotonically decreasing downward slope. For example, the subsurface may comprise a local minimum, or upward-facing curve, 212. Upward-facing curve 212 may be configured to concentrate outwash 211 as it reaches turbines 206 to improve air velocity at the point of electricity generation.

[0043] As seen in Fig. 2E, the power generated by turbines 206 may be combined at junction box 220 and transmitted to, e.g., a storage unit 221 such as a battery station. Storage unit 221 may supply electricity via power supply 222 to the vertiport for, e.g. charging aircraft or parked electric vehicles, or to power electrical systems in the vertiport itself. In some embodiments, the generated electricity may be transmitted to a local power grid.

[0044] Further, turbines 206 and / or exhaust ducts 208 may be quiet enough to operate in close proximity to passengers without disturbing them. For example, in some embodiments, primary floor surface 204 may be arranged above an infrastructure unit 215, such as a passenger waiting area, or other facility. Therefore, to fit primary floor surface 204 in a compact arrangement, a depth of subsurface 202 may be sized just large enough to fit the diameter of turbines 206 and / or exhaust ducts 208. For example, in some embodiments, a depth d of subsurface 202 may be no larger than, e.g., 1.1, 1.2, 1.5, 2, or 3 times a diameter of turbines 206 or exhaust ducts 208.

[0045] Alternatively or additionally, the FATO surface system may comprise one or more slats, such as louvers 209, configured to further direct the outwash. Fig. 2F illustrates a FATO surface in accordance with embodiments of the FATO surface systems described herein, comprising one or more louvers 209. Louvers 209 are illustrated on one side of the FATO surface system, however, they may be repeated around at least part of or all of the perimeter of the surface such that any or all of the outwash may be directed by one or more louvers 209. Although not depicted, the louvers may be present in any of the other figures described herein. Louvers 209 may be configured to provide redirecting surfaces positioned within the outer extremities of the FATO surface system and accommodate the throughflow of outwash 211 channelled from subsurface 202. The inclusion of louvers 209 contributes to a smooth airflow through turbines 206 and / or exhaust ducts 208 if present. Louvers 209 may direct the outwash in a direction which is a continuation of the path of the subsurface, for example the substantially horizontal airflow shown in Fig. 2F may be exhausted through louvers 209 in a horizontal direction. Alternatively, louvers 209 may be angled to change the direction of the airflow, for example the louvers may be angled upwards to direct the outwashAgent Ref : 16163 -0112-00304 upwards. In other embodiments, for example as shown in Fig. 2D, subsurface 202 may curve upwards as it nears the edge of the FATO surface system. In such an embodiment, louvers 209 may be angled upwards such that that redirected outwash continues in an upwards direction. Louvers 209 may be fixed, or adjustable such that the direction of outwash may be adjusted when required, for example to adapt outwash to suit different locations. Adjustment of the louvers may be electrically and / or mechanically actuated. For example, the louvers may be actuated by one or more electro-mechanical actuators, such as electric motors configured to change the slant angle of the louver. Alternatively, or additionally, the louvers may be adjusted mechanically, using manual mechanical adjustment such as adjusting fixings and adjusting the slant angle of the louver. The slant angle of the louvers may further be adjusted dependent on the velocity of the outwash received. For example, the louvers may be electrically controlled to increase slant angle as outwash velocity increases. Alternatively, the louvers may be biased into a preset slant angle, the bias being overcome by increased outwash velocity, which may impart increased slant angle corresponding to increased outwash velocity. The louvers may be angled downwards to direct the downwash downwards. All of the louvers may be configured to the same slant angle, or one or more of the louvers may be configured to different slant angles. A combination of slant angles may be required to provide different outwash zones. Redirection of the outwash using louvers 209 enables improved control of the outwash to create zones of controlled outwash outside of the FATO surface system. Further details of outwash zones are described below in relation to Fig. 2G

[0046] Fig. 2G illustrates a FATO surface system arranged above an infrastructure unit 215, for example, a passenger waiting area. In Fig. 2G, an aircraft 100 is shown on the FATO surface system, the direction of the airflow is shown as it moves from vertical downwash 210 to outwash 211 after interacting with subsurface 202 as described in relation to Figs. 2A to 2F. The configuration of FATO surface system of Fig. 2G provides zones exposed to varying outwash velocity. Outwash 211 expelled directly from the FATO surface system results in a zone of higher velocity outwash 223. Higher outwash velocity zone 223 may be directed away from unwanted areas, such as infrastructure unit 215 or areas with passengers. The zone below the FATO surface system, shown as 224 in Fig. 2G is protected from higher velocity outwash 211 by the redirection of airflow provided by the FATO surface system and subsurface 202 configuration. Zones 223, 224 may be affected by one or a combination of at least the direction of louvers 209, the overhang of subsurface 202 in relation to infrastructure unit 215, the slope of subsurface 202, the maximum thrust of aircraft 100, the wingspan ofAgent Ref : 16163 -0112-00304 the aircraft, or the outwash velocity reduction achieved by turbines 206. For example, a lower velocity outwash zone 224 may be increased in size by adjusting louvers 209 to direct outwash in a more upwards direction. A greater overhang of subsurface 202 in relation to infrastructure unit 215 may reduce the need for further redirection of outwash. An aircraft 100 with a wider wingspan may require a subsurface slope and louver configuration which includes a more upwards redirection of outwash to direct the outwash into higher velocity outwash zone 223. The zone of lower velocity outwash 224 may be of a velocity suitable for accommodating passengers. The velocity of the outwash in lower velocity outwash zone 224 may be between 16 kph (10 mph) and 55.5 kph (34.5 mph). In a preferred embodiment, the zone of lower velocity outwash may not exceed 55.5 kph (34.5 mph). Although Fig. 2G depicts a passenger waiting area, the FATO surface system may alternatively be located above other types of infrastructure, such as residential units, storage units, or utility units. Lower velocity outwash and / or higher velocity outwash zones 223, 224 may be exposed to other airflows such as downwash.

[0047] Fig. 3 illustrates an example chart showing a downwash velocity for VTOL aircraft, consistent with embodiments of the present disclosure. For example, the chart may correspond to a rotorwash (such as, e.g., downwash or outwash) velocity near ground level as a function of radial distance from a VTOL aircraft (such as VTOL aircraft 100) for a given height. In the example chart, the VTOL aircraft may have a mean propeller height of, e.g., approximately 3 m. As seen in Fig. 3, the velocity of rotorwash increases outwardly from a center of VTOL aircraft 100 until it reaches a primary velocity peak 301 at a first radial distance, after which the velocity tapers off and builds again to a secondary velocity peak 302 at second radial distance. In some embodiments, it may be desirable to position turbines 206 or floor grate 203 to capture this maximum flow velocity at primary velocity peak 301, or, in the case of exhaust ducts 208, to reduce the noise and / or airspeed at primary velocity peak 301. In some embodiments, it may be desirable to select a plateau 201 radius such that primary velocity peak 301 falls within the radius of plateau 201, thus preserving it for achieving a stable ground effect instead. For example, in some embodiments it may be desirable to position turbines 206 or floor grate 203 to capture secondary velocity peak 302, or to position exhaust ducts 208 to effectively redirect it as outwash 211. In general, an optimization between energy capture and ground effect may be chosen based on the considerations illustrated in Fig. 3 and discussed above.

[0048] Embodiments of the FATO surface system described herein may also not include any turbines or microturbines. In such embodiments, the airflow may include downwashAgent Ref : 16163 -0112-00304 redirected into outwash as described in relation to Figs. 2A to 3, but without the outwash subsequently passing through turbines or microturbines, and instead exiting the FATO surface system through exhaust ducts or other means.

[0049] Further embodiments relate a method of providing a FATO surface system as described above. The FATO surface system may be assembled in one piece and then transported to a desired location, or may come in prefabricated sections that are then assembled on site. As previously noted, the materials used in the FATO surface system are not particularly limited, so long as they can support the weight of the VTOL aircraft. For example, steel and concrete may serve as suitable materials. If using turbines, the FATO surface system may be assembled with or without these. It is preferable if turbines are removable for ease of replacement and / or maintenance.

[0050] Other embodiments of the disclosure relate to methods of reducing the noise and / or horizontal air speed of an aircraft upon landing or taking off, the methods comprising controlling downwash of the aircraft landing on or taking off from a FATO surface system as described above. In this method, the downwash from the aircraft is redirected as outwash, whereupon it then exits the FATO surface system, optionally by exhaust ducts. Outwash produces less noise and / or lower air speed in the vicinity of the aircraft than downwash, and is therefore preferable.

[0051] Further embodiments of the disclosure relate to methods of generating electricity, the methods comprising capturing downwash of an aircraft landing on or taking off from a FATO surface system. As described above, if the FATO surface system comprises turbines, these may capture the energy of the downwash and / or redirected outwash and convert this to electricity.

[0052] The foregoing description has been presented for purposes of illustration. It is not exhaustive and does not limit the disclosure to the precise forms or embodiments disclosed. Modifications and adaptations of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein.

[0053] Embodiments of the present disclosure may also be described using the following clauses:1. A final approach and takeoff (FATO) surface system for an aircraft, the FATO surface system comprising: a plateau configured to receive the aircraft; a floor grate surrounding the plateau and configured to receive downwash from the aircraft; andAgent Ref : 16163 -0112-00304 a subsurface below the floor grate and configured to receive at least some of the downwash from the aircraft and redirect the downwash as outwash; wherein the floor grate comprises a permeable or vented floor surface that allows airflow to pass through to the subsurface.2. The FATO surface system of clause 1, wherein the plateau is substantially flat.3. The FATO surface system of clause 1, wherein the plateau is convex.4. The FATO surface system of any of clauses 1 to 3, wherein the plateau has a minimum cross-sectional distance larger than a maximum separation of a landing gear of the aircraft.5. The FATO surface system of any of clauses 1 to 4, wherein the plateau has a minimum cross-sectional distance that is larger than a wingspan of the aircraft.6. The FATO surface system of any of clauses 1 to 4, wherein the plateau has a minimum cross-sectional distance which is 60%, 70%, 80%, or 90% of a wingspan of the aircraft.7. The FATO surface system of any of clauses 1 to 6, wherein the plateau has a minimum cross-sectional distance of 3 m, 5 m, 10 m, or 15 m.8. The FATO surface system of any of clauses 1 to 7, wherein the plateau has a maximum cross-sectional distance of 5 m, 10 m, 15 m, or 20 m.9. The FATO surface system of any of clauses 1 to 8, wherein the floor grate has a maximum cross-sectional distance of 10 m, 20 m, or 30 m.10. The FATO surface system of any of clauses 1 to 9, wherein a depth of the subsurface is sized to maintain a flow velocity of the outwash at a predetermined level.11. The FATO surface system of any of clauses 1 to 10, wherein the depth of the subsurface is no greater than 0.3 m, 0.5 m, 1 m, 1.5 m, or 2 m.12. The FATO surface system of any of clauses 1 to 11, wherein the plateau has a maximum cross sectional distance between 5 m and 20 m, the floor grate has a maximum cross sectional distance of between 10 m and 30 m, and the depth of the subsurface is between 0.3 m and 2 m.13. The FATO surface system of any of clauses 1 to 11, wherein the plateau has a cross sectional distance between 10 m and 15 m, the floor grate has a maximum cross maximum sectional distance of between 15 m and 30 m, and the depth of the subsurface is between 0.3 m and 2 m.14. The FATO surface system of any of clauses 1 to 11, wherein the plateau has a cross sectional distance between 15 m and 20 m, the floor grate has a maximum cross sectionalAgent Ref : 16163 -0112-00304 distance of between 20 m and 30 m, and the depth of the subsurface is between 0.3 m and 2 m.15. The FATO surface system of any of clauses 1 to 14, further comprising exhaust ducts configured to exhaust the outwash.16. The FATO surface system of clause 15, wherein the exhaust ducts are configured to exhaust the outwash away from the FATO surface system.17. The FATO surface system of clauses 15 or 16, wherein a depth of the subsurface is no greater than 1.1, 1.2, 1.5, 2, or 3 times a diameter of the exhaust ducts.18. The FATO surface system of any of clauses 1 to 17, further configured to recapture energy used to produce thrust needed to achieve vertical takeoff or landing of the aircraft through capturing of the outwash.19. The FATO surface system of clause 18, further comprising at least one turbine, the at least one turbine being configured to receive the outwash and generate electricity from the outwash.20. The FATO surface system of clause 19, comprising a plurality of turbines.21. The FATO surface system of clauses 19 or 20, wherein the at least one turbine is arranged within exhaust ducts in a rim of a floor surface formed by the plateau and subsurface.22. The FATO surface system of any of clauses 19 to 21, wherein the at least one turbine comprises at least one microturbine having a diameter of between about 0.5 m and 2 m.23. The FATO surface system of any of clauses 19 to 22, wherein the at least one turbine is located at a radial distance of between 5 m and 15 m from the center of the plateau.24. The FATO surface system of any of clauses 19 to 23, wherein a depth of the subsurface is no larger than 1.1, 1.2, 1.5, 2, or 3 times a diameter of the at least one turbine.25. The FATO surface system of any of clauses 19 to 24, wherein the at least one turbine comprises a plurality of turbines arranged in a ring-shaped structure.26. The FATO surface system of any of clauses 19 to 24, wherein the at least one turbine comprises a plurality of turbines arranged in rectangular, elliptical, or bowtie layout.27. The FATO surface system of clause 19, wherein the at least one turbine is a single turbine arranged underneath, and parallel to, the floor grate; or the FATO surface system of any of clauses 20 to 26, wherein the FATO surface system further comprises a single turbine arranged underneath, and parallel to, the floor grate.28. The FATO surface system of clauses 27, wherein the single turbine is configured to rotate around the plateau and the subsurface.Agent Ref : 16163 -0112-0030429. The FATO surface system of any of clauses 1 to 28, wherein the floor grate is positioned to capture the maximum flow velocity of the downwash at a primary velocity peak.30. The FATO surface system of any of clauses 1 to 29, wherein the floor grate is positioned to capture the maximum flow velocity of the downwash at a second velocity peak.31. The FATO surface system of any of clauses 1 to 30, wherein the floor grate comprises a metal grating having a hole size allowing airflow of the downwash while allowing passengers to walk on the floor grate to disembark the aircraft.32. The FATO surface system of any of clauses 1 to 30, wherein the floor grate comprises a walkway to accommodate foot traffic while allowing a remainder of the floor grate to utilize larger openings for receiving the downwash.33. The FATO surface system of any of clauses 1 to 32, wherein the floor grate is supported by a plurality of support structures extending from the subsurface.34. The FATO surface system of clause 33, wherein the support structures are configured to redirect or guide the downwash towards exhaust ducts and / or turbines of the FATO surface.35. The FATO surface system of clauses 33 or 34, wherein the support structures are configured to smooth turbulent airflows of the downwash for optimal energy capture.36. The FATO surface system of any of clauses 33 to 35, wherein the support structures comprise circumferentially oriented ribs extending from the subsurface.37. The FATO surface system of any of clauses 1 to 36, wherein the floor grate has a rectangular shape.38. The FATO surface system of any of clauses 1 to 37, configured to prevent the outwash from being exhausted from at least one side.39. The FATO surface system of any of clauses 1 to 38, wherein the subsurface is sloped and comprises a generally downward curved profile.40. The FATO surface system of any of clauses 19 to 39, wherein the subsurface comprises a sloped surface extending radially outward from the plateau to channel downwash from the aircraft as the outwash to one of the at least one turbine.41. The FATO surface system of any of clauses 18 to 40, further configured to combine power generated at a junction box, and transmit the power to a storage unit.42. The FATO surface system of any of clauses 1 to 41, wherein the plateau and the subsurface form a floor surface configured to support a weight of a vertical takeoff and landing (VTOL) aircraft.Agent Ref : 16163 -0112-0030443. The FATO surface system of clause 42, wherein the floor surface is formed of steel and / or concrete.44. The FATO surface system of any of clauses 1 to 43, further comprising one or more louvers configured to control a direction of exhaustion of the outwash.45. The FATO surface system of clause 44, wherein the louvers are angled to change the direction of the outwash.46. The FATO surface system of clause 44 or clause 45, wherein the louvers are fixed or adjustable.47. The FATO surface system of any of clauses 44 to 46, wherein the louvers are positioned and configured to receive the outwash after the outwash has passed through exhaust ducts and / or turbines of the FATO surface.48. The FATO surface system of any of clauses 44 to 47, wherein the louvers are repeated around at least part or all of a perimeter of the FATO surface system.49. The FATO surface system of any of clauses 1 to 48, further comprising an infrastructure unit, wherein the FATO surface system is located above the infrastructure unit.50. The FATO surface system of clause 49, wherein the infrastructure unit is a passenger waiting area.51. A method of providing a FATO surface system according to any of clauses 1 to 50.52. A method of reducing noise and / or horizontal air speed of an aircraft upon landing or taking off, the method comprising controlling downwash from the aircraft landing on or taking off from a FATO surface system according to any of clauses 1 to 50.53. A method of generating electricity, the method comprising capturing downwash from an aircraft landing on or taking off from a FATO surface system according to any of clauses 18 to 50.

Claims

Agent Ref : 16163 -0112-00304CLAIMS:

1. A final approach and takeoff (FATO) surface system for an aircraft, the FATO surface system comprising: a plateau configured to receive the aircraft; a floor grate surrounding the plateau and configured to receive downwash from the aircraft; and a subsurface below the floor grate and configured to receive at least some of the downwash from the aircraft and redirect the downwash as outwash; wherein the floor grate comprises a permeable or vented floor surface that allows airflow to pass through to the subsurface.

2. The FATO surface system of claim 1, wherein the plateau is substantially flat.

3. The FATO surface system of claim 1, wherein the plateau is convex.

4. The FATO surface system of any of claims 1 to 3, wherein the plateau has a minimum cross-sectional distance larger than a maximum separation of a landing gear of the aircraft.

5. The FATO surface system of any of claims 1 to 4, wherein the plateau has a minimum cross-sectional distance that is larger than a wingspan of the aircraft.

6. The FATO surface system of any of claims 1 to 4, wherein the plateau has a minimum cross-sectional distance which is 60%, 70%, 80%, or 90% of a wingspan of the aircraft.

7. The FATO surface system of any of claims 1 to 6, wherein the plateau has a minimum cross-sectional distance of 3 m, 5 m, 10 m, or 15 m.

8. The FATO surface system of any of claims 1 to 7, wherein the plateau has a maximum cross-sectional distance of 5 m, 10 m, 15 m, or 20 m.

9. The FATO surface system of any of claims 1 to 8, wherein the floor grate has a maximum cross-sectional distance of 10 m, 20 m, or 30 m.

10. The FATO surface system of any of claims 1 to 9, wherein a depth of the subsurface is sized to maintain a flow velocity of the outwash at a predetermined level.

11. The FATO surface system of any of claims 1 to 10, wherein the depth of the subsurface is no greater than 0.3 m, 0.5 m, 1 m, 1.5 m, or 2 m.

12. The FATO surface system of any of claims 1 to 11, wherein the plateau has a maximum cross sectional distance between 5 m and 20 m, the floor grate has a maximum cross sectional distance of between 10 m and 30 m, and the depth of the subsurface is between 0.3 m and 2 m.

13. The FATO surface system of any of claims 1 to 11, wherein the plateau has a cross sectional distance between 10 m and 15 m, the floor grate has a maximum cross maximumAgent Ref : 16163 -0112-00304 sectional distance of between 15 m and 30 m, and the depth of the subsurface is between 0.3 m and 2 m.

14. The FATO surface system of any of claims 1 to 11, wherein the plateau has a cross sectional distance between 15 m and 20 m, the floor grate has a maximum cross sectional distance of between 20 m and 30 m, and the depth of the subsurface is between 0.3 m and 2 m.

15. The FATO surface system of any of claims 1 to 14, further comprising exhaust ducts configured to exhaust the outwash.

16. The FATO surface system of claim 15, wherein the exhaust ducts are configured to exhaust the outwash away from the FATO surface system.

17. The FATO surface system of claim 15 or 16, wherein a depth of the subsurface is no greater than 1.1, 1.2, 1.5, 2, or 3 times a diameter of the exhaust ducts.

18. The FATO surface system of any of claims 1 to 17, further configured to recapture energy used to produce thrust needed to achieve vertical takeoff or landing of the aircraft through capturing of the outwash.

19. The FATO surface system of claim 18, further comprising at least one turbine, the at least one turbine being configured to receive the outwash and generate electricity from the outwash.

20. The FATO surface system of claim 19, comprising a plurality of turbines.

21. The FATO surface system of claims 19 or 20, wherein the at least one turbine is arranged within exhaust ducts in a rim of a floor surface formed by the plateau and subsurface.

22. The FATO surface system of any of claim 19 to 21, wherein the at least one turbine comprises at least one microturbine having a diameter of between about 0.5 m and 2 m.

23. The FATO surface system of any of claims 19 to 22, wherein the at least one turbine is located at a radial distance of between 5 m and 15 m from the center of the plateau.

24. The FATO surface system of any of claims 19 to 23, wherein a depth of the subsurface is no larger than 1.1, 1.2, 1.5, 2, or 3 times a diameter of the at least one turbine.

25. The FATO surface system of any of claims 19 to 24, wherein the at least one turbine comprises a plurality of turbines arranged in a ring-shaped structure.

26. The FATO surface system of any of claims 19 to 24, wherein the at least one turbine comprises a plurality of turbines arranged in rectangular, elliptical, or bowtie layout.

27. The FATO surface system of claim 19, wherein the at least one turbine is a single turbine arranged underneath, and parallel to, the floor grate; or the FATO surface system ofAgent Ref : 16163 -0112-00304 any of claims 20 to 26, wherein the FATO surface system further comprises a single turbine arranged underneath, and parallel to, the floor grate.

28. The FATO surface system of claim 27, wherein the single turbine is configured to rotate around the plateau and the subsurface.

29. The FATO surface system of any of claims 1 to 28, wherein the floor grate is positioned to capture the maximum flow velocity of the downwash at a primary velocity peak.

30. The FATO surface system of any of claims 1 to 29, wherein the floor grate is positioned to capture the maximum flow velocity of the downwash at a second velocity peak.

31. The FATO surface system of any of claims 1 to 30, wherein the floor grate comprises a metal grating having a hole size allowing airflow of the downwash while allowing passengers to walk on the floor grate to disembark the aircraft.

32. The FATO surface system of any of claims 1 to 30, wherein the floor grate comprises a walkway to accommodate foot traffic while allowing a remainder of the floor grate to utilize larger openings for receiving the downwash.

33. The FATO surface system of any of claims 1 to 32, wherein the floor grate is supported by a plurality of support structures extending from the subsurface.

34. The FATO surface system of claim 33, wherein the support structures are configured to redirect or guide the downwash towards exhaust ducts and / or turbines of the FATO surface.

35. The FATO surface system of claim 33 or 34, wherein the support structures are configured to smooth turbulent airflows of the downwash for optimal energy capture.

36. The FATO surface system of any of claims 33 to 35, wherein the support structures comprise circumferentially oriented ribs extending from the subsurface.

37. The FATO surface system of any of claims 1 to 36, wherein the floor grate has a rectangular shape.

38. The FATO surface system of any of claims 1 to 37 configured to prevent the outwash from being exhausted from at least one side.

39. The FATO surface system of any of claims 1 to 38, wherein the subsurface is sloped and comprises a generally downward curved profile.

40. The FATO surface system of any of claims 19 to 39, wherein the subsurface comprises a sloped surface extending radially outward from the plateau to channel the downwash from the aircraft as the outwash to one of the at least one turbine.Agent Ref : 16163 -0112-0030441. The FATO surface system of any of claims 18 to 40, configured to combine power generated at a junction box, and transmit the power to a storage unit.

42. The FATO surface system of any of claims 1 to 41, wherein the plateau and the subsurface form a floor surface configured to support a weight of a vertical takeoff and landing (VTOL) aircraft.

43. The FATO surface system of claim 42, wherein the floor surface is formed of steel and / or concrete.

44. The FATO surface system of any of claims 1 to 43, further comprising one or more louvers configured to control a direction of exhaustion of the outwash.

45. The FATO surface system of claim 44, wherein the louvers are angled to change the direction of the outwash.

46. The FATO surface system of claim 44 or claim 45, wherein the louvers are fixed or adjustable.

47. The FATO surface system of any of claims 44 to 46, wherein the louvers are positioned and configured to receive the outwash after the outwash has passed through exhaust ducts and / or turbines of the FATO surface.

48. The FATO surface system of any of claims 44 to 47, wherein the louvers are repeated around at least part or all of a perimeter of the FATO surface system.

49. The FATO surface system of any of claims 1 to 48, further comprising an infrastructure unit, wherein the FATO surface system is located above the infrastructure unit.

50. The FATO surface system of claim 49, wherein the infrastructure unit is a passenger waiting area.

51. A method of providing a FATO surface system according to any of claims 1 to 50.

52. A method of reducing noise and / or horizontal air speed of an aircraft upon landing or taking off, the method comprising controlling downwash from the aircraft landing on or taking off from a FATO surface system according to any of claims 1 to 50.

53. A method of generating electricity, the method comprising capturing downwash from an aircraft landing on or taking off from a FATO surface system according to any of claims 18 to 50.

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