WO2008054449A2

WO2008054449A2 - Amphibious aircraft

Info

Publication number: WO2008054449A2
Application number: PCT/US2007/002341
Authority: WO
Inventors: Russell Belden
Original assignee: Russell Belden
Priority date: 2006-01-27
Filing date: 2007-01-29
Publication date: 2008-05-08
Also published as: WO2008054449A3; WO2008054449A9

Abstract

A tri-hulled amphibious aircraft includes a center hull located between a starboard outer hull and a port outer hull. The center hull supports a fuselage. The wings can be mounted mid-height to the fuselage and the outer hulls are mounted to the respective wings. The tri-hull configuration makes the aircraft more stable during both take offs from the water and landings on the water. In addition, the outer hulls may support at least some of the weight of the aircraft by displacing water both when the aircraft is stationary and when it is in motion. In one embodiment, the aircraft includes a folding wing to enable the aircraft to dock at docking areas that have limited space.

Description

AMPHIBIOUS AIRCRAFT

BACKGROUND OF THE INVENTION

Field of the Invention

This disclosure generally relates to optionally amphibious aircraft capable of taking off from and landing on both water and land.

Description of the Related Art

Traveling by air through large airport hubs can be frustrating and time consuming for many passengers. According to one industry survey, passenger discontent with the conventional commercial aviation system and infrastructure is at an all-time high (Zagat survey, published in USA Today on November 7, 2005). One of the top complaints, identified by 42% of the respondents, was that there are too many delays, cancellations, and long waiting lines. Another complaint identified by 21% of the respondents was cramped and over-crowded airplanes.

Many airports are at capacity and the hub-and-spoke travel system exacerbates delays. In addition, the majority of airports are often located near populated urban areas. Building new airports and/or runways has become more difficult and expensive due to space and environmental constraints. A good portion of the total travel time for many passengers and even crew is consumed by getting to and from the airport, going through security checkpoints, and finding the requisite departure gate. Because of these infrastructure issues and additional factors, the average travel time to get from one destination to the next has begun to increase.

One additional factor worth noting is that air travel as a mode of transportation for people and cargo continues to grow, although the vast majority of cities do not have feasible, cost-effective plans to accommodate the continued growth or alleviate the dependency on runways. According to one aerospace company, the average growth rate of air travel over the next twenty years is expected to be 5.2% annually (Boeing 2004 Market Outlook). In addition, the Bureau of Transportation reports that each month in the United States over 52 million travelers take more than 850,000 flights, with an average flight distance of 619 miles.

Amphibious aircraft could be used to alleviate some of the congestion described above, but conventional amphibious aircraft are not designed to fly long distances or carry enough passengers to make flights commercially viable. In addition, conventional amphibious aircraft have a number of structural drawbacks, one of which is the spray generated while the aircraft is moving on the water. This spray can and often does damage engines, propellers, and movable airfoil (e.g., ailerons, flaps, elevator, rudder) surfaces.

Some turboprop aircraft, such as the Cessna Caravan, have an amphibious version that can be fitted with floats for taking off from and landing on water. These aircraft, however, are quite noisy, un-pressurized, fly at relatively slow air speeds, and are not well suited for the rigors and issues that come with repeated take offs, landings, and storage in a marine environment.

Thus, it is desirable to have a versatile, passenger-carrying aircraft that can achieve higher air speeds, be flown from point-to-point even where no runways are available, and incorporate features that make the aircraft less susceptible to damage from water spray when landing on or taking off from water.

SUMMARY OF THE INVENTION

At least one embodiment generally relates to a tri-hulled amphibious aircraft having a center or main hull located between a starboard outer hull and a port outer hull. This tri-hull configuration may provide advantages over conventional amphibious and float-type aircraft with respect to the aircraft's ability to take off from and land on water (even small bodies of water), the aircraft's aerodynamic efficiency, and/or the aircraft's stability on the water.

In one aspect, an amphibious aircraft includes a center hull supporting at least a portion of a fuselage; a first wing having a first inboard wing portion coupled to a first outboard wing portion, the first wing coupled to a first side of the center hull at approximately a mid-height of the fuselage; a first hull having a first mounting portion, the first hull extending down and aft relative to the first mounting portion, the first mounting portion attached to the first wing where the first inboard wing portion is coupled to the first outboard wing portion; a second wing having a second inboard wing portion coupled to a second outboard wing portion; the second wing coupled to a second side of the center hull at approximately a mid-height of the fuselage; and a second hull having a second mounting portion, the second hull extending down and aft relative to the second mounting portion, the second mounting portion attached to the second wing where the second inboard wing portion is coupled to the second outboard wing portion.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings and/or images, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings and/or images are not necessarily illustrated to scale. For example, the shapes of various elements and angles may not be illustrated to scale and some of these elements may be arbitrarily enlarged and positioned to improve the legibility of the drawing and/or image. Further, the particular shapes of the elements as illustrated may not necessarily be intended to convey detailed information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawings and/or images.

Figure 1 is a top, front, left isometric image of a tri-hulled amphibious aircraft, according to one illustrated embodiment.

Figure 2 is a bottom, side isometric image of the tri-hulled amphibious aircraft of Figure 1.

Figure 3 is a bottom, front, left isometric image of the tri-hulled amphibious aircraft of Figure 1.

Figure 4 is a top, front, right isometric view of a tri-hulled amphibious aircraft having a tri-hull configuration.

Figure 5 is a top, rear, left isometric view of the tri-hulled amphibious aircraft of Figure 4.

Figure 6 is a rear elevational view of the tri-hulled amphibious aircraft of Figure 4.

Figure 7 is an isometric image of a tri-hulled amphibious aircraft having a folding wing portion docked at a docking area, according to one illustrated embodiment.

Figure 8 is an isometric image of a tri-hulled, four-seat, amphibious aircraft, according to one illustrated embodiment.

Figure 9 is side elevational image of the tri-hulled, four-seat, amphibious aircraft of Figure 8.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the invention. However, one skilled in the art will understand that the invention may be practiced without these details. In other instances, well-known structures associated with aircraft and methods associated with maneuvering and/or assembling the aircraft may not be shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments of the invention.

Unless the context requires otherwise, throughout the specification and claims which follow, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be construed in an open, inclusive sense, that is as "including, but not limited to."

The headings provided herein are for convenience only and do not interpret the.scope or meaning of the claimed invention.

Figures 1-6 show a tri-hulled amphibious aircraft 100 having a fuselage 102, a starboard wing 104, a port wing 106, and a power plant 108 all arranged in a tri-hull configuration. Each of the wings 104, 106 includes an inboard portion 104a, 106a, and an outboard portion 104b, 106b, respectively. The inboard portions 104a, 106a are respectively coupled to the fuselage 102 at approximately a mid-height portion of the fuselage 102, according to one embodiment. Thus, the wings 104, 106 of the tri-hulled amphibious aircraft 100 do not have to be high-mounted on the fuselage 102 like conventional amphibious aircraft, which are typically high-mounted on the fuselage to reduce the amount of spray on any wing-mounted power plant and/or any flight control surfaces. In addition, wings mid-mounted on the fuselage 102 tend to make the aircraft 100 more aerodynamically efficient, in part, because the wings 104, 106 can be more aerodynamically blended into the fuselage. Additionally or alternatively, the inboard wing portions 104a, 106a may extend along and couple to the fuselage 102 and also extend along and couple to the outer hulls 112, 114 to provide the aircraft 100 with a delta wing surface 120, as best seen in Figure 5. In one embodiment, the wings 104, 106 have wing tip devices 122, 124 mounted at the respective tip portions of the wings 104, 106. In one embodiment, the wing tip devices 122, 124 are aerodynamically shaped to increase the efficiency of the wings 104, 106 at least during certain segments of flight.

The tri-hull configuration comprises a center or main hull 110 located between a starboard outer hull 112 and a port outer hull 114. The outer hulls 112, 114 may also form or house fuel tanks and/or storage compartments for the main landing-gear components when the aircraft 100 is in flight. The tri- hull configuration may provide advantages over conventional amphibious and float-type aircraft with respect to the ability of the tri-hulled amphibious aircraft 100 to take off from and land on water (even small bodies of water), aerodynamic efficiency, and/or stability on the water. Additionally, the fuselage 102 and center hull 110 can have sufficient volume for passenger seating and luggage.

In one embodiment, the hulls 112, 114 provide improved stability and are configured to contain water spray generated by the center hull 110 while the aircraft 100 is moving along the water, such as during take off, landing, and/or taxiing. Such water spray has been known to damage or at least be problematic for moveable airfoil surfaces, such as flight control surfaces (e.g., ailerons, flaps, elevators, rudder) and/or wing-mounted power plants. The height and length of the hulls 112, 114 are configured to enhance the stability of the aircraft while on the water, both when the aircraft is at rest and when moving on the water. Further, the outboard hulls 112, 114 are capable of absorbing at least some impact upon landing, thus reducing the amount of impact absorbed by the center hull, which in turn may help protect or at least provide a softer landing for any passengers and/or crew members in the fuselage.

The main hull 110 supports the fuselage 102 and provides the majority of surface area for displacing water when the aircraft is at rest or moving on the water. The two outer hulls 112, 114 stabilize the aircraft at low and high speed on the water. While the aircraft is moving along the water at low speed, the outer hulls 112, 114 are in contact with the water to provide additional displacement and stabilization for the aircraft. While the aircraft is moving along the water level and at high speed, the outer hulls 112, 114 lightly touch the water, keeping the aircraft 100 more stable than conventional amphibious aircraft that merely have wing tip floats. Thus, the outer hulls 112, 114 are wetted (i.e., a portion is below the water line) during level takeoffs, landings and/or taxiing. The center hull 110 and the outer hulls 112, 114 are simultaneously wetted by the water during at least one the operations consisting of when the aircraft is at rest, taking off, landing, and taxiing.

The outer hulls 112, 114 displace enough water to support a range of about 1% - 50% of the total weight of the aircraft 100 while the aircraft 100 is at rest on the water. It is understood that although wider hulls 112, 114 may support more weight, the wider hulls 112, 114 will also decrease aerodynamic efficiency (i.e., cause drag). Accordingly, the height, length, and width of the outer hulls 112, 114 may be customized for individual aircraft 100 based on a customer's specification. Similarly, the center hull 110 is sized to support up to 99% of a total weight of the aircraft via water displacement while the aircraft is stationary in water. The wing tip floats of conventional amphibious aircraft provide little to no appreciable water displacement to help support the weight of the aircraft.

In one illustrated embodiment, the outer hulls 112, 114 of the aircraft 100 each include a vertical stabilizer 116, 118. Conventional amphibious aircraft require a substantial amount of tail area and a horizontal stabilizer to make the aircraft sufficiently stable. Having the vertical stabilizers 116, 118 coupled to the outer hulls 112, 114, however, permits the tri-hulled amphibious aircraft 100 to be more stable with less tail area and without incorporating a discrete horizontal stabilizer. Reducing the tail area and eliminating the horizontal stabilizer may advantageously reduce the overall weight of the tri-hulled amphibious aircraft 100.

Figure 7 shows a tri-hulled amphibious aircraft 200 having a fuselage 202, a starboard wing 204, a port wing 206, and a power plant 208 all arranged in a tri-hull configuration with a center hull 210, a starboard outer hull 212, and a port outer hull 214. In the illustrated embodiment, the port wing 206 includes an outer folding portion 216 that is rotationally and structurally coupled with the port outer hull 214. In another embodiment, both the starboard and port wings 204, 206 include outer folding wing portions. The outer folding wing portion 216 permits the aircraft 200 to be conveniently docked at a variety of docking areas and to include stationary and/or floating docking structures located on the water and where space around the docking area may be limited.

The tri-hulled amphibious aircraft may be manufactured with various passenger carrying and/or cargo-carrying capabilities, from a twin-seat kit plane up to and beyond a fifty-seat regional-transport aircraft. Figures 8 and 9 show a four seat tri-hulled amphibious aircraft 300, according to one embodiment. Further, the aircraft may be configured with various types of power plants (e.g., turbine, propeller, etc.) and the power plants may be fuselage-mounted or wing-mounted.

In one embodiment, the tri-hulled amphibious aircraft is a fifteen seat passenger plane capable of flying express point-to-point routes, for example from one city to the next, without the need for airports, runways, or other expensive infrastructure. By way of example, the tri-hulled amphibious aircraft could provide passenger and/or cargo transportation service from San Francisco to Seattle. When transporting cargo only, for example, the tri-hulled amphibious aircraft can deliver the cargo directly, via water take offs and landings, to a docking area located adjacent or proximate to a cargo ship that will carry the cargo overseas. When transporting passengers, the tri-hulled amphibious aircraft provides an efficient and quick mode of transportation between dozens of waterfront cities and may get the passengers to and from their destinations in less time than if the travelers flew on conventional aircraft taking off and landing at conventional airports. In addition to the tri-hulled amphibious aircraft's ability to take off from and land on water, the aircraft may also be utilized to transport passengers and/or cargo between small cities and towns with small runways.

Advantages

The tri-hulled amphibious aircraft may be more aerodynamically efficient than conventional amphibious and/or float-type aircraft. The tri-hulled amphibious aircraft may be manufactured according to a variety of configurations, such as delta wing, straight wing, swept wing, tailless, with canards, and/or some combination of the above.

The various embodiments described above can be combined to provide further embodiments. All of the above U.S. patents, patent applications and publications referred to in this specification are incorporated herein by reference. Aspects can be modified, if necessary, to employ devices, features, and concepts of the various patents, applications, and publications to provide yet further embodiments.

These and other changes can be made in light of the above detailed-description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but should be construed to include all types of aircraft, and in particular amphibious aircraft, that operate in accordance with the claims. Accordingly, the invention is not limited by the disclosure, but instead its scope is to be determined entirely by the following claims.

Claims

CLAIMS What is claimed is:

1. An amphibious aircraft, comprising: a fuselage having a center hull portion; at least one wing coupled to the fuselage, the at least one wing having an area and shape that produces lift sufficient to maintain an altitude the amphibious aircraft in the atmosphere when the amphibious aircraft is at an operational airspeed; a first outer hull spaced laterally outboard of the center hull portion in a first direction; and a second outer hull spaced laterally outboard of the center hull portion in a second direction, different from the first direction, where the first hull, the second hull and the center hull portion are each wetted when the amphibious aircraft is at rest.

2. The amphibious aircraft of claim 1 wherein a first wing extends in the first direction from the fuselage and a second wing extends in the second direction from the fuselage.

3. The amphibious aircraft of claim 2 wherein the first outer hull extends generally downward from the first wing and the second outer hull extends generally downward from the second wing.

4. The amphibious aircraft of claim 2 wherein the first outer hull extends generally downward from the first wing inboard of an wingtip portion of the first wing and the second outer hull extends generally downward from the second wing inboard of an wingtip portion of the second wing.

5. The amphibious aircraft of claim 2 wherein each of the first outer hull, the second outer hull and the center hull portion are elongated and have longitudinal axes that are generally parallel to one another.

6. The amphibious aircraft of claim 1 , further comprising: a first vertical stabilizer extending vertically upward from an aft portion of the fuselage.

7. The amphibious aircraft of claim 1 , further comprising: a second vertical stabilizer extending vertically upward from an aft portion of the fuselage.

8. The amphibious aircraft of claim 1 wherein the first and the second outer hulls are sized and positioned to substantially preclude water spray generated by the center hull portion from impacting on outboard portions of the at least one wing during take off of the amphibious aircraft.

9. The amphibious aircraft of claim 1 , further comprising: a first wing tip fence and a second wing tip fence extending from the at least one wing proximate a respective one of a first and a second wing tip.

10. The amphibious aircraft of claim 1 wherein the center hull portion supports at least 99% of a total weight of the amphibious aircraft while the amphibious aircraft is stationary in water.

11. The amphibious aircraft of claim 1 wherein the at least one wing is coupled to the fuselage at approximately a mid height of the fuselage.

12. The amphibious aircraft of claim 1 wherein the at least one wing is foldable.