Why are there no cargo aircraft with “flying wing” design? Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?Why do aircraft models end their life as freighters?How many active large commercial airplanes are there?Why are there so few aircraft that had inhabited wings?Why are there no blended-wing passenger airplanes in operation?Does cargo heat failure require a diversion? What about if there are live animals in cargo?Why was the A380 built with a gull-wing design?Cargo aircraft temperatureWhy do some cargo aircraft have windows?How are large cargo aircraft loaded at airports?Are there any regulations preventing one from converting an originally cargo aircraft to ferry passengers?Are there any specific weight or structural reasons to choose low vs. high wings for a cargo aircraft?Why do cargo aircraft still have floors?Are cargo aircraft ever ferried empty?

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Why are there no cargo aircraft with “flying wing” design?



Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)
Announcing the arrival of Valued Associate #679: Cesar Manara
Unicorn Meta Zoo #1: Why another podcast?Why do aircraft models end their life as freighters?How many active large commercial airplanes are there?Why are there so few aircraft that had inhabited wings?Why are there no blended-wing passenger airplanes in operation?Does cargo heat failure require a diversion? What about if there are live animals in cargo?Why was the A380 built with a gull-wing design?Cargo aircraft temperatureWhy do some cargo aircraft have windows?How are large cargo aircraft loaded at airports?Are there any regulations preventing one from converting an originally cargo aircraft to ferry passengers?Are there any specific weight or structural reasons to choose low vs. high wings for a cargo aircraft?Why do cargo aircraft still have floors?Are cargo aircraft ever ferried empty?










10












$begingroup$


From that I have seen so far, the "flying wing" design (like the one of B-2 Spirit and Northrop YB-49) has superior performance but also a few notable problems that make it difficult to use for passenger aircraft:



  • It is difficult to control, and the YB-49 crashed even when flown by an elite test pilot. However, computer assistance has been implemented for B-2 and I do not think this is a problem any longer.

  • There are problems related just to the passenger transport: not enough windows, difficult to evacuate.

  • It also cannot be pressurized as easily as a cylinder but for a majority of possible cargo this is probably not a problem. Some cargo may not require pressurization at all and some may only need partial pressurization like in jet fighters.

Hence I understand that there are problems on the way to the flying wing passenger aircraft. However, why there are no cargo aircraft of this kind around?










share|improve this question









New contributor




h23 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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  • $begingroup$
    Very related: Why are there so few aircraft that had inhabited wings?
    $endgroup$
    – Peter Kämpf
    9 hours ago















10












$begingroup$


From that I have seen so far, the "flying wing" design (like the one of B-2 Spirit and Northrop YB-49) has superior performance but also a few notable problems that make it difficult to use for passenger aircraft:



  • It is difficult to control, and the YB-49 crashed even when flown by an elite test pilot. However, computer assistance has been implemented for B-2 and I do not think this is a problem any longer.

  • There are problems related just to the passenger transport: not enough windows, difficult to evacuate.

  • It also cannot be pressurized as easily as a cylinder but for a majority of possible cargo this is probably not a problem. Some cargo may not require pressurization at all and some may only need partial pressurization like in jet fighters.

Hence I understand that there are problems on the way to the flying wing passenger aircraft. However, why there are no cargo aircraft of this kind around?










share|improve this question









New contributor




h23 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$











  • $begingroup$
    Very related: Why are there so few aircraft that had inhabited wings?
    $endgroup$
    – Peter Kämpf
    9 hours ago













10












10








10





$begingroup$


From that I have seen so far, the "flying wing" design (like the one of B-2 Spirit and Northrop YB-49) has superior performance but also a few notable problems that make it difficult to use for passenger aircraft:



  • It is difficult to control, and the YB-49 crashed even when flown by an elite test pilot. However, computer assistance has been implemented for B-2 and I do not think this is a problem any longer.

  • There are problems related just to the passenger transport: not enough windows, difficult to evacuate.

  • It also cannot be pressurized as easily as a cylinder but for a majority of possible cargo this is probably not a problem. Some cargo may not require pressurization at all and some may only need partial pressurization like in jet fighters.

Hence I understand that there are problems on the way to the flying wing passenger aircraft. However, why there are no cargo aircraft of this kind around?










share|improve this question









New contributor




h23 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




From that I have seen so far, the "flying wing" design (like the one of B-2 Spirit and Northrop YB-49) has superior performance but also a few notable problems that make it difficult to use for passenger aircraft:



  • It is difficult to control, and the YB-49 crashed even when flown by an elite test pilot. However, computer assistance has been implemented for B-2 and I do not think this is a problem any longer.

  • There are problems related just to the passenger transport: not enough windows, difficult to evacuate.

  • It also cannot be pressurized as easily as a cylinder but for a majority of possible cargo this is probably not a problem. Some cargo may not require pressurization at all and some may only need partial pressurization like in jet fighters.

Hence I understand that there are problems on the way to the flying wing passenger aircraft. However, why there are no cargo aircraft of this kind around?







aircraft-design cargo blended-wing






share|improve this question









New contributor




h23 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









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share|improve this question




share|improve this question








edited 42 mins ago









fooot

54.5k18174329




54.5k18174329






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asked 11 hours ago









h23h23

5315




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h23 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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  • $begingroup$
    Very related: Why are there so few aircraft that had inhabited wings?
    $endgroup$
    – Peter Kämpf
    9 hours ago
















  • $begingroup$
    Very related: Why are there so few aircraft that had inhabited wings?
    $endgroup$
    – Peter Kämpf
    9 hours ago















$begingroup$
Very related: Why are there so few aircraft that had inhabited wings?
$endgroup$
– Peter Kämpf
9 hours ago




$begingroup$
Very related: Why are there so few aircraft that had inhabited wings?
$endgroup$
– Peter Kämpf
9 hours ago










5 Answers
5






active

oldest

votes


















14












$begingroup$

Flying wings can be made to have acceptable flying qualities without any artificial assistance. Just look at the Jim Marske glider designs.



The principal downfall of flying wings is that stability in pitch is pretty much achieved the same way as with a conventional tail, with a down force balancing out the center of gravity forward of the fulcrum of the center of lift, but it's all being done over the very short moment arm of the wing chord itself. In other words the "tail" has been moved forward to the trailing edge of the main wing.



There are a lot of issues that result from this, pitch sensitivity and damping issues and all that, but the biggest one from a cargo aircraft's perspective is a very narrow center of gravity range. Not a big deal on a bomber with a concentrated bomb bay load, or a glider that doesn't have to cope with loading variations, but a bigger deal on a freighter. You are forced to spread the load, and the fuselage volume, laterally, creating way more frontal area than necessary (you're in effect turning the fuselage sideways), so you end up cancelling out the drag benefit of doing away with the tail in the first place, and still end up with a "temperamental" configuration.



enter image description here






share|improve this answer











$endgroup$








  • 2




    $begingroup$
    Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
    $endgroup$
    – Peter Kämpf
    5 hours ago










  • $begingroup$
    That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
    $endgroup$
    – John K
    2 hours ago


















11












$begingroup$

Cargo aircraft (outside the military) almost always started life as passenger aircraft. The ratio of active large cargo aircraft to passenger aircraft is in the single percentages. Therefore, nobody develops a pure cargo aircraft from scratch.



That does not mean that many have tried. Especially for cargo, large flying wings have been proposed which store their cargo in containers along the wingspan - hence their name: Spanloaders. Below is an artist impression from the 1970s.



Boeing Model 759-159 distributed load freighter concept from the 1970s



Boeing Model 759-159 distributed load freighter concept from the 1970s (picture source)





share









$endgroup$








  • 4




    $begingroup$
    And to the military, soldiers are just another kind of cargo.
    $endgroup$
    – jamesqf
    6 hours ago






  • 1




    $begingroup$
    Where would that thing park?
    $endgroup$
    – Azor Ahai
    5 hours ago






  • 1




    $begingroup$
    Not at the airport it's flying over, certainly...
    $endgroup$
    – Roger Lipscombe
    4 hours ago






  • 1




    $begingroup$
    Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
    $endgroup$
    – Skyler
    3 hours ago


















4












$begingroup$

For a start, with what it costs to design and certificate a new aircraft type, if a transport craft can't be reconfigured to carry either passengers or freight it won't make it off the napkin. The conventional transports we have can be switched from cargo to passenger and back, some in just a few hours. For a non-passenger transport to compete, it would have to be much cheaper (to buy and to operate) than a multi-purpose airframe.






share|improve this answer









$endgroup$




















    2












    $begingroup$

    In addition to the other answers, a reason for the lack of flying wings in civil aviation in general is that they need to compete in an environment that has grown alongside conventional, fuselage-and-wings aircraft and is ill-suited for flying wings.



    This means they need to use the same airports (turning radii, RWY widths), fit into the same parking envelopes (wingspan) and be serviced by the same ground vehicles (bay heights, wing clearances). Because redesigning an entire industry worth of ancillary equipment and infrastructure has been deemed not worth the minor efficiency gains to be had from flying wings.






    share|improve this answer









    $endgroup$




















      1












      $begingroup$

      It's all about CG range and how much abuse the design can take. Take a look at the C-130 Hercules. It has a huge Hstab to cope with a wide range of CG. Really a bi-plane. So is the Chinook helicopter. Holding the table up with 4 legs (6 with a canard).



      So, what do we do to get to a viable flying wing? Sweep back offers improvement in pitch stability as (with washout) you lengthen the aircraft. Control surfaces can be placed at the wing tips. Reflexed camber airfoils also help. How to cope the loss of a longer fuselage/Hstab pitch torque arm? Have the cargo bay set on a roller at CG.
      Pull it forward until it tips. Secure, cargo balanced! Fuel tanks can be arranged to drain evenly. Assuming a subsonic design with near neutral static stability, it may even fly without computers.



      But the all important shift in Clift with change in AOA or airspeed must be accounted for.
      So a small tail, like birds have, may help build a better safety margin for the design, with or without computers. Ditto for lower aspect wings. Interestingly, a bird sweeping its wings back becomes ... a delta. Sweep them back out ... an F-111?



      It is possible to reduce tail size in cargo, and passenger planes.






      share|improve this answer











      $endgroup$













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        5 Answers
        5






        active

        oldest

        votes








        5 Answers
        5






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        14












        $begingroup$

        Flying wings can be made to have acceptable flying qualities without any artificial assistance. Just look at the Jim Marske glider designs.



        The principal downfall of flying wings is that stability in pitch is pretty much achieved the same way as with a conventional tail, with a down force balancing out the center of gravity forward of the fulcrum of the center of lift, but it's all being done over the very short moment arm of the wing chord itself. In other words the "tail" has been moved forward to the trailing edge of the main wing.



        There are a lot of issues that result from this, pitch sensitivity and damping issues and all that, but the biggest one from a cargo aircraft's perspective is a very narrow center of gravity range. Not a big deal on a bomber with a concentrated bomb bay load, or a glider that doesn't have to cope with loading variations, but a bigger deal on a freighter. You are forced to spread the load, and the fuselage volume, laterally, creating way more frontal area than necessary (you're in effect turning the fuselage sideways), so you end up cancelling out the drag benefit of doing away with the tail in the first place, and still end up with a "temperamental" configuration.



        enter image description here






        share|improve this answer











        $endgroup$








        • 2




          $begingroup$
          Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
          $endgroup$
          – Peter Kämpf
          5 hours ago










        • $begingroup$
          That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
          $endgroup$
          – John K
          2 hours ago















        14












        $begingroup$

        Flying wings can be made to have acceptable flying qualities without any artificial assistance. Just look at the Jim Marske glider designs.



        The principal downfall of flying wings is that stability in pitch is pretty much achieved the same way as with a conventional tail, with a down force balancing out the center of gravity forward of the fulcrum of the center of lift, but it's all being done over the very short moment arm of the wing chord itself. In other words the "tail" has been moved forward to the trailing edge of the main wing.



        There are a lot of issues that result from this, pitch sensitivity and damping issues and all that, but the biggest one from a cargo aircraft's perspective is a very narrow center of gravity range. Not a big deal on a bomber with a concentrated bomb bay load, or a glider that doesn't have to cope with loading variations, but a bigger deal on a freighter. You are forced to spread the load, and the fuselage volume, laterally, creating way more frontal area than necessary (you're in effect turning the fuselage sideways), so you end up cancelling out the drag benefit of doing away with the tail in the first place, and still end up with a "temperamental" configuration.



        enter image description here






        share|improve this answer











        $endgroup$








        • 2




          $begingroup$
          Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
          $endgroup$
          – Peter Kämpf
          5 hours ago










        • $begingroup$
          That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
          $endgroup$
          – John K
          2 hours ago













        14












        14








        14





        $begingroup$

        Flying wings can be made to have acceptable flying qualities without any artificial assistance. Just look at the Jim Marske glider designs.



        The principal downfall of flying wings is that stability in pitch is pretty much achieved the same way as with a conventional tail, with a down force balancing out the center of gravity forward of the fulcrum of the center of lift, but it's all being done over the very short moment arm of the wing chord itself. In other words the "tail" has been moved forward to the trailing edge of the main wing.



        There are a lot of issues that result from this, pitch sensitivity and damping issues and all that, but the biggest one from a cargo aircraft's perspective is a very narrow center of gravity range. Not a big deal on a bomber with a concentrated bomb bay load, or a glider that doesn't have to cope with loading variations, but a bigger deal on a freighter. You are forced to spread the load, and the fuselage volume, laterally, creating way more frontal area than necessary (you're in effect turning the fuselage sideways), so you end up cancelling out the drag benefit of doing away with the tail in the first place, and still end up with a "temperamental" configuration.



        enter image description here






        share|improve this answer











        $endgroup$



        Flying wings can be made to have acceptable flying qualities without any artificial assistance. Just look at the Jim Marske glider designs.



        The principal downfall of flying wings is that stability in pitch is pretty much achieved the same way as with a conventional tail, with a down force balancing out the center of gravity forward of the fulcrum of the center of lift, but it's all being done over the very short moment arm of the wing chord itself. In other words the "tail" has been moved forward to the trailing edge of the main wing.



        There are a lot of issues that result from this, pitch sensitivity and damping issues and all that, but the biggest one from a cargo aircraft's perspective is a very narrow center of gravity range. Not a big deal on a bomber with a concentrated bomb bay load, or a glider that doesn't have to cope with loading variations, but a bigger deal on a freighter. You are forced to spread the load, and the fuselage volume, laterally, creating way more frontal area than necessary (you're in effect turning the fuselage sideways), so you end up cancelling out the drag benefit of doing away with the tail in the first place, and still end up with a "temperamental" configuration.



        enter image description here







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited 9 hours ago









        ymb1

        70.4k7226373




        70.4k7226373










        answered 9 hours ago









        John KJohn K

        25.5k13678




        25.5k13678







        • 2




          $begingroup$
          Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
          $endgroup$
          – Peter Kämpf
          5 hours ago










        • $begingroup$
          That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
          $endgroup$
          – John K
          2 hours ago












        • 2




          $begingroup$
          Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
          $endgroup$
          – Peter Kämpf
          5 hours ago










        • $begingroup$
          That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
          $endgroup$
          – John K
          2 hours ago







        2




        2




        $begingroup$
        Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
        $endgroup$
        – Peter Kämpf
        5 hours ago




        $begingroup$
        Admittedly, without a long fuselage there will not be much length along which the cargo can be distributed. I'd call it a wash.
        $endgroup$
        – Peter Kämpf
        5 hours ago












        $begingroup$
        That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
        $endgroup$
        – John K
        2 hours ago




        $begingroup$
        That's what I meant by having to spread the loading laterally. But even within the space envelope you would have just within a flying wing stump fuselage or center section, the available loading range is pretty narrow. Bring your knees to your chest in a FW glider, where the allowable range is couple of inches, and you might find yourself aft of the rear limit.
        $endgroup$
        – John K
        2 hours ago











        11












        $begingroup$

        Cargo aircraft (outside the military) almost always started life as passenger aircraft. The ratio of active large cargo aircraft to passenger aircraft is in the single percentages. Therefore, nobody develops a pure cargo aircraft from scratch.



        That does not mean that many have tried. Especially for cargo, large flying wings have been proposed which store their cargo in containers along the wingspan - hence their name: Spanloaders. Below is an artist impression from the 1970s.



        Boeing Model 759-159 distributed load freighter concept from the 1970s



        Boeing Model 759-159 distributed load freighter concept from the 1970s (picture source)





        share









        $endgroup$








        • 4




          $begingroup$
          And to the military, soldiers are just another kind of cargo.
          $endgroup$
          – jamesqf
          6 hours ago






        • 1




          $begingroup$
          Where would that thing park?
          $endgroup$
          – Azor Ahai
          5 hours ago






        • 1




          $begingroup$
          Not at the airport it's flying over, certainly...
          $endgroup$
          – Roger Lipscombe
          4 hours ago






        • 1




          $begingroup$
          Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
          $endgroup$
          – Skyler
          3 hours ago















        11












        $begingroup$

        Cargo aircraft (outside the military) almost always started life as passenger aircraft. The ratio of active large cargo aircraft to passenger aircraft is in the single percentages. Therefore, nobody develops a pure cargo aircraft from scratch.



        That does not mean that many have tried. Especially for cargo, large flying wings have been proposed which store their cargo in containers along the wingspan - hence their name: Spanloaders. Below is an artist impression from the 1970s.



        Boeing Model 759-159 distributed load freighter concept from the 1970s



        Boeing Model 759-159 distributed load freighter concept from the 1970s (picture source)





        share









        $endgroup$








        • 4




          $begingroup$
          And to the military, soldiers are just another kind of cargo.
          $endgroup$
          – jamesqf
          6 hours ago






        • 1




          $begingroup$
          Where would that thing park?
          $endgroup$
          – Azor Ahai
          5 hours ago






        • 1




          $begingroup$
          Not at the airport it's flying over, certainly...
          $endgroup$
          – Roger Lipscombe
          4 hours ago






        • 1




          $begingroup$
          Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
          $endgroup$
          – Skyler
          3 hours ago













        11












        11








        11





        $begingroup$

        Cargo aircraft (outside the military) almost always started life as passenger aircraft. The ratio of active large cargo aircraft to passenger aircraft is in the single percentages. Therefore, nobody develops a pure cargo aircraft from scratch.



        That does not mean that many have tried. Especially for cargo, large flying wings have been proposed which store their cargo in containers along the wingspan - hence their name: Spanloaders. Below is an artist impression from the 1970s.



        Boeing Model 759-159 distributed load freighter concept from the 1970s



        Boeing Model 759-159 distributed load freighter concept from the 1970s (picture source)





        share









        $endgroup$



        Cargo aircraft (outside the military) almost always started life as passenger aircraft. The ratio of active large cargo aircraft to passenger aircraft is in the single percentages. Therefore, nobody develops a pure cargo aircraft from scratch.



        That does not mean that many have tried. Especially for cargo, large flying wings have been proposed which store their cargo in containers along the wingspan - hence their name: Spanloaders. Below is an artist impression from the 1970s.



        Boeing Model 759-159 distributed load freighter concept from the 1970s



        Boeing Model 759-159 distributed load freighter concept from the 1970s (picture source)






        share











        share


        share










        answered 9 hours ago









        Peter KämpfPeter Kämpf

        162k12411658




        162k12411658







        • 4




          $begingroup$
          And to the military, soldiers are just another kind of cargo.
          $endgroup$
          – jamesqf
          6 hours ago






        • 1




          $begingroup$
          Where would that thing park?
          $endgroup$
          – Azor Ahai
          5 hours ago






        • 1




          $begingroup$
          Not at the airport it's flying over, certainly...
          $endgroup$
          – Roger Lipscombe
          4 hours ago






        • 1




          $begingroup$
          Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
          $endgroup$
          – Skyler
          3 hours ago












        • 4




          $begingroup$
          And to the military, soldiers are just another kind of cargo.
          $endgroup$
          – jamesqf
          6 hours ago






        • 1




          $begingroup$
          Where would that thing park?
          $endgroup$
          – Azor Ahai
          5 hours ago






        • 1




          $begingroup$
          Not at the airport it's flying over, certainly...
          $endgroup$
          – Roger Lipscombe
          4 hours ago






        • 1




          $begingroup$
          Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
          $endgroup$
          – Skyler
          3 hours ago







        4




        4




        $begingroup$
        And to the military, soldiers are just another kind of cargo.
        $endgroup$
        – jamesqf
        6 hours ago




        $begingroup$
        And to the military, soldiers are just another kind of cargo.
        $endgroup$
        – jamesqf
        6 hours ago




        1




        1




        $begingroup$
        Where would that thing park?
        $endgroup$
        – Azor Ahai
        5 hours ago




        $begingroup$
        Where would that thing park?
        $endgroup$
        – Azor Ahai
        5 hours ago




        1




        1




        $begingroup$
        Not at the airport it's flying over, certainly...
        $endgroup$
        – Roger Lipscombe
        4 hours ago




        $begingroup$
        Not at the airport it's flying over, certainly...
        $endgroup$
        – Roger Lipscombe
        4 hours ago




        1




        1




        $begingroup$
        Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
        $endgroup$
        – Skyler
        3 hours ago




        $begingroup$
        Perhaps it doesn't park, or even land - just flies endlessly while smaller craft ferry fuel and cargo between it and the ground.
        $endgroup$
        – Skyler
        3 hours ago











        4












        $begingroup$

        For a start, with what it costs to design and certificate a new aircraft type, if a transport craft can't be reconfigured to carry either passengers or freight it won't make it off the napkin. The conventional transports we have can be switched from cargo to passenger and back, some in just a few hours. For a non-passenger transport to compete, it would have to be much cheaper (to buy and to operate) than a multi-purpose airframe.






        share|improve this answer









        $endgroup$

















          4












          $begingroup$

          For a start, with what it costs to design and certificate a new aircraft type, if a transport craft can't be reconfigured to carry either passengers or freight it won't make it off the napkin. The conventional transports we have can be switched from cargo to passenger and back, some in just a few hours. For a non-passenger transport to compete, it would have to be much cheaper (to buy and to operate) than a multi-purpose airframe.






          share|improve this answer









          $endgroup$















            4












            4








            4





            $begingroup$

            For a start, with what it costs to design and certificate a new aircraft type, if a transport craft can't be reconfigured to carry either passengers or freight it won't make it off the napkin. The conventional transports we have can be switched from cargo to passenger and back, some in just a few hours. For a non-passenger transport to compete, it would have to be much cheaper (to buy and to operate) than a multi-purpose airframe.






            share|improve this answer









            $endgroup$



            For a start, with what it costs to design and certificate a new aircraft type, if a transport craft can't be reconfigured to carry either passengers or freight it won't make it off the napkin. The conventional transports we have can be switched from cargo to passenger and back, some in just a few hours. For a non-passenger transport to compete, it would have to be much cheaper (to buy and to operate) than a multi-purpose airframe.







            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered 11 hours ago









            Zeiss IkonZeiss Ikon

            3,502418




            3,502418





















                2












                $begingroup$

                In addition to the other answers, a reason for the lack of flying wings in civil aviation in general is that they need to compete in an environment that has grown alongside conventional, fuselage-and-wings aircraft and is ill-suited for flying wings.



                This means they need to use the same airports (turning radii, RWY widths), fit into the same parking envelopes (wingspan) and be serviced by the same ground vehicles (bay heights, wing clearances). Because redesigning an entire industry worth of ancillary equipment and infrastructure has been deemed not worth the minor efficiency gains to be had from flying wings.






                share|improve this answer









                $endgroup$

















                  2












                  $begingroup$

                  In addition to the other answers, a reason for the lack of flying wings in civil aviation in general is that they need to compete in an environment that has grown alongside conventional, fuselage-and-wings aircraft and is ill-suited for flying wings.



                  This means they need to use the same airports (turning radii, RWY widths), fit into the same parking envelopes (wingspan) and be serviced by the same ground vehicles (bay heights, wing clearances). Because redesigning an entire industry worth of ancillary equipment and infrastructure has been deemed not worth the minor efficiency gains to be had from flying wings.






                  share|improve this answer









                  $endgroup$















                    2












                    2








                    2





                    $begingroup$

                    In addition to the other answers, a reason for the lack of flying wings in civil aviation in general is that they need to compete in an environment that has grown alongside conventional, fuselage-and-wings aircraft and is ill-suited for flying wings.



                    This means they need to use the same airports (turning radii, RWY widths), fit into the same parking envelopes (wingspan) and be serviced by the same ground vehicles (bay heights, wing clearances). Because redesigning an entire industry worth of ancillary equipment and infrastructure has been deemed not worth the minor efficiency gains to be had from flying wings.






                    share|improve this answer









                    $endgroup$



                    In addition to the other answers, a reason for the lack of flying wings in civil aviation in general is that they need to compete in an environment that has grown alongside conventional, fuselage-and-wings aircraft and is ill-suited for flying wings.



                    This means they need to use the same airports (turning radii, RWY widths), fit into the same parking envelopes (wingspan) and be serviced by the same ground vehicles (bay heights, wing clearances). Because redesigning an entire industry worth of ancillary equipment and infrastructure has been deemed not worth the minor efficiency gains to be had from flying wings.







                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered 9 hours ago









                    AEhereAEhere

                    1,516519




                    1,516519





















                        1












                        $begingroup$

                        It's all about CG range and how much abuse the design can take. Take a look at the C-130 Hercules. It has a huge Hstab to cope with a wide range of CG. Really a bi-plane. So is the Chinook helicopter. Holding the table up with 4 legs (6 with a canard).



                        So, what do we do to get to a viable flying wing? Sweep back offers improvement in pitch stability as (with washout) you lengthen the aircraft. Control surfaces can be placed at the wing tips. Reflexed camber airfoils also help. How to cope the loss of a longer fuselage/Hstab pitch torque arm? Have the cargo bay set on a roller at CG.
                        Pull it forward until it tips. Secure, cargo balanced! Fuel tanks can be arranged to drain evenly. Assuming a subsonic design with near neutral static stability, it may even fly without computers.



                        But the all important shift in Clift with change in AOA or airspeed must be accounted for.
                        So a small tail, like birds have, may help build a better safety margin for the design, with or without computers. Ditto for lower aspect wings. Interestingly, a bird sweeping its wings back becomes ... a delta. Sweep them back out ... an F-111?



                        It is possible to reduce tail size in cargo, and passenger planes.






                        share|improve this answer











                        $endgroup$

















                          1












                          $begingroup$

                          It's all about CG range and how much abuse the design can take. Take a look at the C-130 Hercules. It has a huge Hstab to cope with a wide range of CG. Really a bi-plane. So is the Chinook helicopter. Holding the table up with 4 legs (6 with a canard).



                          So, what do we do to get to a viable flying wing? Sweep back offers improvement in pitch stability as (with washout) you lengthen the aircraft. Control surfaces can be placed at the wing tips. Reflexed camber airfoils also help. How to cope the loss of a longer fuselage/Hstab pitch torque arm? Have the cargo bay set on a roller at CG.
                          Pull it forward until it tips. Secure, cargo balanced! Fuel tanks can be arranged to drain evenly. Assuming a subsonic design with near neutral static stability, it may even fly without computers.



                          But the all important shift in Clift with change in AOA or airspeed must be accounted for.
                          So a small tail, like birds have, may help build a better safety margin for the design, with or without computers. Ditto for lower aspect wings. Interestingly, a bird sweeping its wings back becomes ... a delta. Sweep them back out ... an F-111?



                          It is possible to reduce tail size in cargo, and passenger planes.






                          share|improve this answer











                          $endgroup$















                            1












                            1








                            1





                            $begingroup$

                            It's all about CG range and how much abuse the design can take. Take a look at the C-130 Hercules. It has a huge Hstab to cope with a wide range of CG. Really a bi-plane. So is the Chinook helicopter. Holding the table up with 4 legs (6 with a canard).



                            So, what do we do to get to a viable flying wing? Sweep back offers improvement in pitch stability as (with washout) you lengthen the aircraft. Control surfaces can be placed at the wing tips. Reflexed camber airfoils also help. How to cope the loss of a longer fuselage/Hstab pitch torque arm? Have the cargo bay set on a roller at CG.
                            Pull it forward until it tips. Secure, cargo balanced! Fuel tanks can be arranged to drain evenly. Assuming a subsonic design with near neutral static stability, it may even fly without computers.



                            But the all important shift in Clift with change in AOA or airspeed must be accounted for.
                            So a small tail, like birds have, may help build a better safety margin for the design, with or without computers. Ditto for lower aspect wings. Interestingly, a bird sweeping its wings back becomes ... a delta. Sweep them back out ... an F-111?



                            It is possible to reduce tail size in cargo, and passenger planes.






                            share|improve this answer











                            $endgroup$



                            It's all about CG range and how much abuse the design can take. Take a look at the C-130 Hercules. It has a huge Hstab to cope with a wide range of CG. Really a bi-plane. So is the Chinook helicopter. Holding the table up with 4 legs (6 with a canard).



                            So, what do we do to get to a viable flying wing? Sweep back offers improvement in pitch stability as (with washout) you lengthen the aircraft. Control surfaces can be placed at the wing tips. Reflexed camber airfoils also help. How to cope the loss of a longer fuselage/Hstab pitch torque arm? Have the cargo bay set on a roller at CG.
                            Pull it forward until it tips. Secure, cargo balanced! Fuel tanks can be arranged to drain evenly. Assuming a subsonic design with near neutral static stability, it may even fly without computers.



                            But the all important shift in Clift with change in AOA or airspeed must be accounted for.
                            So a small tail, like birds have, may help build a better safety margin for the design, with or without computers. Ditto for lower aspect wings. Interestingly, a bird sweeping its wings back becomes ... a delta. Sweep them back out ... an F-111?



                            It is possible to reduce tail size in cargo, and passenger planes.







                            share|improve this answer














                            share|improve this answer



                            share|improve this answer








                            edited 8 hours ago

























                            answered 8 hours ago









                            Robert DiGiovanniRobert DiGiovanni

                            2,8751316




                            2,8751316




















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