Abstract:
A partial blended wing body airplane configuration combining the advantages of a pure blended wing configuration with the advantages of conventional aircraft design. A blended tri-body airplane configuration wherein three pressurized body elements are connected by and blended with a pressurized centerwing element. The sidebodies and centerbody are blended into the wing structure, producing a multi-body airplane whose body sections are interconnected utilizing wing payload carrying sections.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/215,371, filed Jun. 29, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to multiple-body aircraft and more particularly to a tri-body aircraft.  
           [0004]    2. Description of the Prior Art  
           [0005]    Patent Literature  
           [0006]    U.S. Pat. No. 3,869,102 to Carroll, issued Mar. 4, 1975 is illustrative of a cargo aircraft having a non-pressurized hull which can comprise a number of substantially identical hull modules defining a rectangular cargo area.  
           [0007]    U.S. Pat. No. 4,735,381 to Wood, issued Apr. 5, 1988 shows a multi-body aircraft with an all-moveable center fuselage which translates relative to two side fuselages without coupling between pressurized multi-body volumes.  
           [0008]    Publications  
           [0009]    American Institute of Aeronautics and Astronautics publication No. 98-0440 titled “An Airplane Configuration with an Inboard Wing Mounted Between Twin Fuselages, a paper provided at the 36 th  Aerospace Sciences Meeting &amp; Exhibit Jan. 12-15 1998 at Reno, Nev. A wing is shown mounted between twin tip fuselages.  
         PROBLEM SOLVED BY THE PRESENT INVENTION  
         [0010]    Future large airplanes, in order to be economically successful, should satisfy the following requirements:  
           [0011]    1. Provide lower fuel burn per seat mile and lower Total Airplane Related Operating Costs (TAROC) per seat mile relative to current large aircraft viz. The Boeing 747.  
           [0012]    2. Maximize cruise Lift to Drag ratio (L/D), to help enable lower fuel burn per seat mile.  
           [0013]    3. Provide low wetted area per seat and low Overall Empty Weight (OEW) per seat, to help enable lower fuel bum per seat mile.  
           [0014]    4. Provide large cabin volume per wetted area and large volume per wetted area, to maximize profit potential.  
           [0015]    5. Provide combination use or “combi” capability to convert some passenger capacity to cargo capacity for some airlines for which revenue cargo is important and for which passenger seat count needs are not as large as for other airlines.  
           [0016]    6. Provide a low to modest level of technical risk and certification risk.  
         BRIEF SUMMARY OF THE INVENTION  
         [0017]    The present invention provides a blended wing multiple-body airplane comprising a plurality of fuselage elements which are aerodynamically and structurally blended with a connecting wing element which also carries payload.. The wing body blending provides reduced wetted area, and span loading resulting in reduced OEW (Overall Empty Weight) per seat. Large loads are placed where lift is located. The present invention provides conventional flying qualities without need for critical SAS (Stability Augmentation Systems). Fuel burn reduction results from the hereinafter described 3 engines with no aft engine and less weight. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0018]    [0018]FIG. 1A is a plan view and FIG. 1B is a rear view of a blended tri-body airplane according to the present invention;  
         [0019]    [0019]FIG. 2A is a plan view and FIG. 2B is a rear view is a door arrangement and evacuation slide arrangement for the blended tri-body airplane configuration shown in FIG. 1A and FIG. 1B;  
         [0020]    [0020]FIG. 3A is a plan view and FIG. 3B is a rear view of a dual-body configuration which is a variant of the airplane of FIG. 1A and FIG. 1B without forebody;  
         [0021]    [0021]FIG. 4A is a plan view and FIG. 4B is a rear view of a second blended tri-body airplane differing from the embodiment of FIG. 1A and FIG. 1B comprising a single deck forebody and having double deck sidebodies;  
         [0022]    [0022]FIGS. 5A, 5B, and  5 C and further FIGS. 6A, 6B, and  6 C show plan views which are further illustrative of further embodiments of blended tri-body airplanes;  
         [0023]    [0023]FIGS. 7A, 7B and  7 C illustrate plan views of “combi” compartments which may be utilized in the hereinbefore described blended wing multi-body airplanes.  
         [0024]    [0024]FIGS. 8A, 8B,  8 C and  8 DC illustrate plan, front, side and isometric views of yet another preferred embodiment of the invention; and,  
         [0025]    [0025]FIG. 9 illustrates a typical cabin interior arrangement for the embodiment show in FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]    [0026]FIG. 1A is a plan view and FIG. 1B is a rear view of a preferred embodiment of the invention. This configuration features three pressurized body elements  10 ,  12 , and  14  connected by and blended with a pressurized centerwing element  20  which also carries payload (e.g. passengers).In the forward body element comprising forebody  12  is a doubledeck body capable of providing two stacked passenger seating cabins, similar to the forward body of a Boeing Company model 747-400. Dual sidebodies  10  and  14  are single deck bodies similar to the body of Boeing Company model 777. An additional cargo carrying deck is provided in the lower lobe or lower deck areas beneath the passenger seating cabins in both forebody  12  and sidebodies  10  and  14 . In alternative embodiments forebody  12  may include a single deck suitable for accommodating passengers instead of a double deck, and/or sidebodies  10  and  14  may have double decks suitable for accommodating passengers instead of single decks for that purpose. Also further embodiments may feature forebodies and sidebodies of various cross-sectional shapes and sizes, with passenger deck sizes ranging from 2 abreast to 20 abreast.  
         [0027]    In the embodiment of FIG. 1, outerwings  18  and  20  are provided outboard of sidebodies  10  and  14 . Outerwings  18  and  20  comprise state of the art airplane wings and may be high, mid, or low wings (high wings are shown for purposes of illustration). Outerwings  18  and  20  will typically operate at considerably higher lift coefficients than centerwing  20 , but the span-wise distribution can still remain quite smooth since centerwing  20  has considerably more chord than outerwings  18  and  20 . Aerodynamic fairing treatment provides aerodynamic smoothing from the outerwing flow region across the sidebody to the centerwing flow region. Winglets  30  and  32  or other wingtip aerodynamic induced drag reducing treatments may be provided at the outer ends of outer ends of outerwings  18  and  20  as shown. The embodiment shown has a preferred overall span S of around 261 ft., just under the 80 meter limit specified for the ICAO Code F airplane size category. An overall length L well under 80 meters is shown in FIG. 1, and “stretch” body versions may be utilized with increased payload (passenger and cargo) capacity which still fall within an 80 meter or 85 meter length limit. Such stretch body versions are provided by adding constant section fuselage plugs into forebody  12  just ahead of centerwing  20 , and to sidebodies  10  and  14  just behind centerwing  20 .  
         [0028]    The blended tri-body airplane of FIGS  1 A and  1 B may utilize fabrication materials such as metal, composite, or other materials or combinations of materials. Benefits may be achieved through utilization of stitched RFI composite structure for centerwing  20 .  
         [0029]    The airplane of FIGS. 1A and 1B is shown with “T-tail” empennage installations  50  and  54  above the aft ends of sidebodies  10  and  14  for contributing to airplane stability and control (trimmable stabilizer, elevator, and rudder means may be provided for trim and control prposes). Further variations may feature low tails, V-tails, and H-tail or inverted V-tail or other tail configurations connecting between sidebodies  10  and  14  or other tail configurations.  
         [0030]    The airplane of FIG. 1A and FIG. 1B show a nose landing gear  60  which can retract into forebody  12 ,, and main landing gear  62  which can retract into an unpressurized portion of centerwing  20  behind the pressurized portion. A 4-wheel single post nose gear and a 20-wheel, four post main gear are shown for purposes of illustration although other types of wheel and post gear arrangements can be utilized within the spirit and scope of the invention.  
         [0031]    The airplane configuration of FIG. 1A and 1B provides the dual benefits of low drag per seat (due to low wetted area per seat to reduce parasite drag and a large overall span to reduce induced drag) and low OEW per seat (due to low wetted area per seat and due to span load distribution of payloads in addition to engines and fuel).  
         [0032]    [0032]FIG. 2A is a plan view of a door and slide arrangement for the Airplane of FIG. 1A. The arrangement shown utilizes  8  pairs of type A doors ( 4  on each side) with slides or slide-rafts  104 , and optionally one underbody slide  102  (or alternatively one underbody stairway). Assuming a limit of  110  passengers per pair of type A doors, the door exit limit capacity of this configuration should be 935 (or 880 even if no credit is taken for the underbody slide). The illustrated door arrangement is intended to meet the 60 ft. maximum longitudinal separation between door edges rule, and to enable safe evacuation of passengers from the airplane in the required 90 seconds. Alternate door arrangements and escape slide arrangements are possible within the spirit and scope of the invention.  
         [0033]    [0033]FIG. 3A is a plan view and FIG. 3B is a rear view of the aircraft of FIG. 1A and 1B but without a forebody however retaining the aforementioned advantages of a blended wing mutiple-body airplane. A cockpit  200  is located in or near the forward apex of centerwing  20  or in the alternative in or near the forward end of a sidebody  10  or  14 .  
         [0034]    [0034]FIG. 4A is a plan view and FIG. 4B is a rear view of a second blended tri-body configuration. This configuration differs from the configuration of FIGS. 1A and 1B in several aspects including utilization of a single deck forebody  200  and aft double deck sidebodies  202  and  204 .  
         [0035]    [0035]FIGS. 5A, 5B, and  5 C and further FIGS. 6A, 6B, and  6 C show plan views of features which are variants of the hereinbefore described blended wing multi-body airplanes and include:  
         [0036]    swept-forward outerwings;  
         [0037]    swept-forward centerwing;  
         [0038]    centerwing with swept-aft leading edge and swept-forward trailing edge;  
         [0039]    aftbody instead of forebody on the airplane centerline (i.e., centerbody behind instead of ahead of sidebodies);  
         [0040]    extended body lengths;  
         [0041]    several engines exceeding two; and,  
         [0042]    various tail/empennage configurations, including T-tails, split V-tails or low tails, an H-tail or inverted V-tail or further tail configurations connecting between the two sidebodies.  
         [0043]    [0043]FIGS. 7A, 7B, and  7 C are illustrative of plan views of “combi” compartments which may be utilized on the present blended wing multi-body airplane configuration, which compartments are suitable for carrying cargo in pallets e.g.  201  and  202  or which airplane may be converted back to passenger carrying configurations.  
         [0044]    In the preferred embodiment of FIG. 8, sidebodies  10  and  14  are forward of and along the length of centerwing  20 . Centerwing  20  has forward swept leading and trailing edges. Variations of the centerwing  20  sweep are forward swept leading edge with aft swept trailing edge, aft swept leading edge with forward swept trailing edge and aft swept leading and trailing edges. The cockpit is located in the forward section of one of the sidebodies  10  and  14 .  
         [0045]    Center engine  41   a  is shown mounted center and forward of centerwing  20  on a pylon. An alternative installation of center engine  41   a  is in the vertical tail structure similar to a McDonnell Douglas DC 10.  
         [0046]    Aft body  12   a  is connected to centerwing  20  and extends aft to support the empennage. The interior of aft body  12   a  is connected to the pressurized section of centerwing  20  allowing the free movement of passengers. The cross section of  12   a  may consist of a single passenger deck with lower cargo deck or may consist of double passenger decks with lower cargo deck similar to a Boeing 747.  
         [0047]    Nose landing gears  60   a  are shown in an unpressurized bay in each of sidebodies  10  and  14 . Main landing gear  62  are attached to the structure of centerwing  20  and retract into unpressurized gear bays at the rear of centerwing  20 .  
         [0048]    While certain preferred embodiments of the invention have been described with reference to the attached figurers, it should be understood that further variations and modifications are possible within the spirit and scope of the invention as defined in the claims below: