Boeing believes mach 5 hypersonic passenger planes might have better economics than mach 2 supersonic

Boeing has selected mach 5.0 as the top speed for a hypersonic passenger jet because that greatly simplifies the structural materials and the propulsion. Standard titanium alloys used in aircraft and jet engines today are strong enough to survive the surface temperatures ranging up to 600°C (1,100°F).

A mach 5 hypersonic plane would also use standard Jet-A fuel. Liquid methane or some combination of those fuels are also options for the commercial aircraft.

A mach six aircraft requires a supersonic combustion ramjet (or “scramjet”) engine, a technology that still isn’t mature after decades of research and demonstration. A mach five might be able to just modify the lockheed spyplane engine technology.

The Lockheed SR-71A spyplane flew at speeds up to Mach 3.2 using two Pratt & Whitney J58 engines. The J58 featured a unique configuration called a turboramjet. The engine functioned like a turbojet up to about M2, then diverted air from the compressor into ducts that emptied in the afterburner.

Boeing’s hypersonic airliner also would use a turboramjet configuration, with some variations compared to the J58. Instead of ducting only a portion of the airflow around combustor over M2, Boeing’s concept might bypass all of the airflow around the engine core at higher speeds.

A mach five hypersonic passenger airliner could cross the Atlantic four or five times a day with the same crew versus twice with a mach 2 supersonic plane. The increased utilization rate could make the hypersonic airliner more economical than a supersonic jet.

124 thoughts on “Boeing believes mach 5 hypersonic passenger planes might have better economics than mach 2 supersonic”

  1. For an ocean-going ground effect plane, waves could be an issue too. I mean, doesn’t a ground effect plane need a reasonably flat surface underneath?

    Reply
  2. For an ocean-going ground effect plane waves could be an issue too. I mean doesn’t a ground effect plane need a reasonably flat surface underneath?

    Reply
  3. It’s not the airlines driving this, it’s their customers. For most, the ticket price is the primary factor driving their decision to choose a particular flight, therefore airlines need to compete mainly on price. Unless and until customers become willing to pay more for a better experience, airline seats will continue to get smaller and less comfortable.

    Reply
  4. It’s not the airlines driving this it’s their customers. For most the ticket price is the primary factor driving their decision to choose a particular flight therefore airlines need to compete mainly on price. Unless and until customers become willing to pay more for a better experience airline seats will continue to get smaller and less comfortable.

    Reply
  5. My understanding is that the winds are stronger at altitude, but gustier near the ground. It’s the changes in wind speed that get you.

    Reply
  6. My understanding is that the winds are stronger at altitude but gustier near the ground. It’s the changes in wind speed that get you.

    Reply
  7. Only compared to those airliners that happen to be above the clouds. (Not sure but the winds might be stronger than near the surface.)

    Reply
  8. Only compared to those airliners that happen to be above the clouds. (Not sure but the winds might be stronger than near the surface.)

    Reply
  9. But who knows what safety risks would be from flying so many people so low.” Not falling out of the sky but landing on water if there’s an issue…

    Reply
  10. But who knows what safety risks would be from flying so many people so low.””Not falling out of the sky but landing on water if there’s an issue…”””

    Reply
  11. Boeing is never going to build this plane (unless others have done it before). It is like all those car companies showing concept cars. It is just marketing hype, a way to show to people that they are relevant, modern and cool. Boeing is become a stale company that is stiffling competition and innovation rather then encouraging it. Look how they tried to keep SpaceX out of government contracts or the equally dismal pace of innovation in aircraft industry.

    Reply
  12. Boeing is never going to build this plane (unless others have done it before). It is like all those car companies showing concept cars. It is just marketing hype a way to show to people that they are relevant modern and cool. Boeing is become a stale company that is stiffling competition and innovation rather then encouraging it. Look how they tried to keep SpaceX out of government contracts or the equally dismal pace of innovation in aircraft industry.

    Reply
  13. The problem is that airlines could already give you twice the leg room they do now, the reason that they don’t give it to you is that increasing the number of seats per airplane makes more money for them than they think they could get by charging you a higher ticket price in exchange for the room. Thus, if they did buy large capacity wing-in-ground effect craft, they would probably use the extra room to crowd in more seats and you would have a 10 or 12 hour trans-Atlantic trip with the same (crappy) amount of (lack of) legroom as now, but on the plus side, tickets might well cost half what they do now. Although I might be wrong about this, this approach seems to be the revealed preference of airlines based on present trends.

    Reply
  14. The problem is that airlines could already give you twice the leg room they do now the reason that they don’t give it to you is that increasing the number of seats per airplane makes more money for them than they think they could get by charging you a higher ticket price in exchange for the room. Thus if they did buy large capacity wing-in-ground effect craft they would probably use the extra room to crowd in more seats and you would have a 10 or 12 hour trans-Atlantic trip with the same (crappy) amount of (lack of) legroom as now but on the plus side tickets might well cost half what they do now. Although I might be wrong about this this approach seems to be the revealed preference of airlines based on present trends.

    Reply
  15. Actually Mach 3.2 was regarded as the peak efficiency around plus or minus 80 altitude. One combined data graph associated with J-78 went above Mach 4. Not saying the aircraft wouldn’t suffer *cough* glow-red-in-the-dark.

    Reply
  16. Actually Mach 3.2 was regarded as the peak efficiency around plus or minus 80 altitude. One combined data graph associated with J-78 went above Mach 4. Not saying the aircraft wouldn’t suffer *cough* glow-red-in-the-dark.

    Reply
  17. I think the idea is that for long hauls, one plane would generate so many more passenger*miles per day, that ticket prices would be lower than expected, based on the cost of the plane. As far as comfort, it’s not the crowding that gets me, it’s the screaming baby, and the kid kicking the back of my seat.

    Reply
  18. I think the idea is that for long hauls one plane would generate so many more passenger*miles per day that ticket prices would be lower than expected based on the cost of the plane. As far as comfort it’s not the crowding that gets me it’s the screaming baby and the kid kicking the back of my seat.

    Reply
  19. Yeah, but what will get me from the front door to the plane in 1/2 hour, like back in the good old days(1990s). It would be ironic to take longer to get from the parking lot, to the airplane, than to get from NYC to London.

    Reply
  20. Yeah but what will get me from the front door to the plane in 1/2 hour like back in the good old days(1990s). It would be ironic to take longer to get from the parking lot to the airplane than to get from NYC to London.

    Reply
  21. If Boeing and Lockheed could pool together their resources again, maybe they could come up with a hypersonic flyback booster for ULA to operate.

    Reply
  22. If Boeing and Lockheed could pool together their resources again maybe they could come up with a hypersonic flyback booster for ULA to operate.

    Reply
  23. But who knows what safety risks would be from flying so many people so low. Might make for a decent SyFy Channel movie though, if a giant shark could be worked into the plot. How about something like the Aeroscraft instead?

    Reply
  24. But who knows what safety risks would be from flying so many people so low. Might make for a decent SyFy Channel movie though if a giant shark could be worked into the plot.How about something like the Aeroscraft instead?

    Reply
  25. Personally, I’d be more interested in a craft that could cross the Atlantic in twice the time with more leg room, at half the price, than one that could cut the trip time to a fraction at multiples of the price. MOST people have more time than money. Maybe there would be a market for a ground effect passenger liner with a cruising speed of about 450-500 kph, instead of the 880 kph of a 747. And *comfortable* cabins.

    Reply
  26. Personally I’d be more interested in a craft that could cross the Atlantic in twice the time with more leg room at half the price than one that could cut the trip time to a fraction at multiples of the price. MOST people have more time than money. Maybe there would be a market for a ground effect passenger liner with a cruising speed of about 450-500 kph instead of the 880 kph of a 747. And *comfortable* cabins.

    Reply
  27. Dismal pace of innovation…” What should they be pursuing that they are not pursuing? Incremental evolutionary improvement and a great safety record not good enough?

    Reply
  28. The increase utilization rate only works if there isn’t an increased maintenance rate to go with it. And there is also the issue of increased fuel use and the increase cost of the hypersonic jet in the first place.

    Reply
  29. High ocean waves can reach 10-15 m. Rogue waves can reach 30 m. It would need to have a pretty large wing span to satisfy “flight altitude is significantly less than the wing span”.

    Reply
  30. No, it doesn’t (necessarily) need a flat surface underneath. You may be thinking of a hovercraft, however, which definitely does. “Wing in ground effect” flight delivers a high dynamic lift to drag ratio when the flight altitude is significantly less than the wing span. As long as that altitude is above wave height, variations in the surface don’t much matter. But colliding with a tall wave would be a disaster.

    Reply
  31. Dismal pace of innovation…””What should they be pursuing that they are not pursuing? Incremental evolutionary improvement and a great safety record not good enough?”””

    Reply
  32. The increase utilization rate only works if there isn’t an increased maintenance rate to go with it. And there is also the issue of increased fuel use and the increase cost of the hypersonic jet in the first place.

    Reply
  33. High ocean waves can reach 10-15 m. Rogue waves can reach 30 m. It would need to have a pretty large wing span to satisfy flight altitude is significantly less than the wing span””.”””

    Reply
  34. No it doesn’t (necessarily) need a flat surface underneath. You may be thinking of a hovercraft however which definitely does. Wing in ground effect”” flight delivers a high dynamic lift to drag ratio when the flight altitude is significantly less than the wing span. As long as that altitude is above wave height”””” variations in the surface don’t much matter. But colliding with a tall wave would be a disaster.”””

    Reply
  35. Remember that airlines DO offer you the choice of paying more for more legroom. It’s right there as an option on most flights. And most people choose not to pay the extra. Unless you are already buying business or first class you don’t really have a leg to stand on. (Pun intended as always.)

    Reply
  36. Even worse, you get presented with some beautiful creation, high performance, innovative layout, everything. THEN they announce it’s actually going into production. And 3 years later it appears. But for safety regulations reasons the swoopy curvaceous shape is now the same lozenge box as everything else. For cost reasons the variable compression ratio, 12k rpm V10 is now a turbo four. And to make it more acceptable to a focus group of 7 blind people the innovative layout has been abandoned. And so we are actually left with a camry with a new grill and an in-car video game in which the rear seat passengers can play a game in which they are driving the original concept vehicle. But not when the car is moving because it might distract the driver.

    Reply
  37. Remember that airlines DO offer you the choice of paying more for more legroom. It’s right there as an option on most flights.And most people choose not to pay the extra.Unless you are already buying business or first class you don’t really have a leg to stand on.(Pun intended as always.)

    Reply
  38. Even worse you get presented with some beautiful creation high performance innovative layout everything.THEN they announce it’s actually going into production. And 3 years later it appears. But for safety regulations reasons the swoopy curvaceous shape is now the same lozenge box as everything else. For cost reasons the variable compression ratio 12k rpm V10 is now a turbo four. And to make it more acceptable to a focus group of 7 blind people the innovative layout has been abandoned. And so we are actually left with a camry with a new grill and an in-car video game in which the rear seat passengers can play a game in which they are driving the original concept vehicle. But not when the car is moving because it might distract the driver.

    Reply
  39. They have weather radar. The Caspian Sea Monster was most efficient at 20 metres, which should be enough to cross the Arctic ice, but most of the wigs are capable of fling much higher, if necessary.

    Reply
  40. Airliners have to lift half their weight as fuel, and they have to be pressurised to 40,000 feet. A wing in ground effect craft operates at sea level pressure, so it could be much roomier at a lower cost. It also carries more weight for the same power, and doesn’t have the same runway restrictions. I’m hopeful that they could be nuclear powered, but even just using jet fuel, it would be putting all its emissions into the lower troposphere, instead of the stratosphere. That alone would reduce the climate effects considerably, even if the wig used more fuel.

    Reply
  41. They have weather radar. The Caspian Sea Monster was most efficient at 20 metres which should be enough to cross the Arctic ice but most of the wigs are capable of fling much higher if necessary.

    Reply
  42. Airliners have to lift half their weight as fuel and they have to be pressurised to 40000 feet. A wing in ground effect craft operates at sea level pressure so it could be much roomier at a lower cost. It also carries more weight for the same power and doesn’t have the same runway restrictions. I’m hopeful that they could be nuclear powered but even just using jet fuel it would be putting all its emissions into the lower troposphere instead of the stratosphere. That alone would reduce the climate effects considerably even if the wig used more fuel.

    Reply
  43. There would be great benefit from planes that make less noise, a hybrid plane might work. The development of supersonic planes or something like the skylon or SpaceX BFR that travels trough space. The era of the 747 started in 1970, we almost half a century later and i would say we are still in the 747 era.

    Reply
  44. There would be great benefit from planes that make less noise a hybrid plane might work. The development of supersonic planes or something like the skylon or SpaceX BFR that travels trough space. The era of the 747 started in 1970 we almost half a century later and i would say we are still in the 747 era.

    Reply
  45. Because the higher you go, the faster you have to go to keep the engines running, and to generate enough lift to stay in the air. And when you hit the air at that ever higher speed, it gets *hot*. Eventually you reach an altitude where it’s just too hot to stay up in the air.

    Reply
  46. Because the higher you go the faster you have to go to keep the engines running and to generate enough lift to stay in the air. And when you hit the air at that ever higher speed it gets *hot*.Eventually you reach an altitude where it’s just too hot to stay up in the air.

    Reply
  47. But your ground effect airplane / double the travel time idea provides the airline with a second opportunity to lower cost – double the capacity. As was described in other comments, sure with your idea they could leave the price the same and double the travel time; or they could double the travel time AND leave the leg room the same, and half the price. More people will pay half the price for the same legroom and double the duration than will pay the same for double the duration, same price and double the legroom. Cost supercedes comfort in airline economics, regardless of duration.

    Reply
  48. Ironic, but not unsellable. And there are plenty of people living in places where it’s fairly easy to get to the airport. Granted, it was 2 and a half hours drive and walking through endless terminals for me growing up, and today it’s nearly the same, but for a couple million people in the DC-Baltimore area, it’s just an hour on the metro. And that’s just my knowledge of the US. I’m sure the same is true of many other metropolitan areas.

    Reply
  49. Boeing manufactures airplanes, not interest. When an industry wants something, Boeing will design it. Why do you think commercial spaceflight has taken so long to mature? You don’t research, design and manufacture a product that nobody is asking for. You need to understand the industry you’re talking about a little more first.

    Reply
  50. Yeah, I was just suggesting I’d be willing to go slower to increase the amount of legroom I could afford. Since I “have more time than money”.

    Reply
  51. But your ground effect airplane / double the travel time idea provides the airline with a second opportunity to lower cost – double the capacity. As was described in other comments sure with your idea they could leave the price the same and double the travel time; or they could double the travel time AND leave the leg room the same and half the price. More people will pay half the price for the same legroom and double the duration than will pay the same for double the duration same price and double the legroom. Cost supercedes comfort in airline economics regardless of duration.

    Reply
  52. Ironic but not unsellable. And there are plenty of people living in places where it’s fairly easy to get to the airport. Granted it was 2 and a half hours drive and walking through endless terminals for me growing up and today it’s nearly the same but for a couple million people in the DC-Baltimore area it’s just an hour on the metro. And that’s just my knowledge of the US. I’m sure the same is true of many other metropolitan areas.

    Reply
  53. Boeing manufactures airplanes not interest. When an industry wants something Boeing will design it. Why do you think commercial spaceflight has taken so long to mature? You don’t research design and manufacture a product that nobody is asking for. You need to understand the industry you’re talking about a little more first.

    Reply
  54. Yeah I was just suggesting I’d be willing to go slower to increase the amount of legroom I could afford. Since I have more time than money””.”””

    Reply
  55. You’re right nobody asked for reusable rockets and then SpaceX made them and blew the competition away. With a big leap it can go the other way it creates new possibilities that didn’t exist before. The space industry will grow like never before as a consequence. After a while the big companies become massive drains on talent and government resources that has a negative impact on society. Lockheed is no better with their F35 many nations where very happy to buy F16s from the US now they are dragging their because F35 is so expensive and buggy that it is seen as a risky investment.

    Reply
  56. Because the higher you go, the faster you have to go to keep the engines running, and to generate enough lift to stay in the air.” That’s an advantage. Also, sparser air: less drag. “And when you hit the air at that ever higher speed, it gets *hot*. ” Perhaps. But I can’t get my head around why. I would imagine you could just go higher to for the sparser air to generate the same amount of lift and heating as it does at low speeds nearer the surface. What effect causes extra heating?

    Reply
  57. I would add that legroom isn’t clearly advertised AFAIK, so consumers don’t have effective tools to choose the roomier option even if they wanted to (short of opting for business class).

    Reply
  58. You’re right, nobody asked for reusable rockets and then SpaceX made them and blew the competition away. With a big leap it can go the other way, it creates new possibilities that didn’t exist before. The space industry will grow like never before as a consequence. After a while the big companies become massive drains on talent and government resources, that has a negative impact on society. Lockheed is no better with their F35, many nations where very happy to buy F16s from the US, now they are dragging their because F35 is so expensive and buggy that it is seen as a risky investment.

    Reply
  59. Because the higher you go the faster you have to go to keep the engines running” and to generate enough lift to stay in the air.””That’s an advantage. Also”””” sparser air: less drag.””””And when you hit the air at that ever higher speed”””” it gets *hot*. “”””Perhaps. But I can’t get my head around why. I would imagine you could just go higher to for the sparser air to generate the same amount of lift and heating as it does at low speeds nearer the surface. What effect causes extra heating?”””

    Reply
  60. I would add that legroom isn’t clearly advertised AFAIK so consumers don’t have effective tools to choose the roomier option even if they wanted to (short of opting for business class).

    Reply
  61. If Boeing actually got enough interest from the airlines they’d build anything! Of course no airline is probably wanting to stick their neck out that far. I’d also like to point out that it’s harder to suppress a sonic boom at mach 5 than it is at mach 2.

    Reply
  62. If Boeing actually got enough interest from the airlines they’d build anything! Of course no airline is probably wanting to stick their neck out that far. I’d also like to point out that it’s harder to suppress a sonic boom at mach 5 than it is at mach 2.

    Reply
  63. But why is friction heating more significant if you go faster in appropriately sparse air to generate the same lift as jetliners travelling much slower in much denser air?

    Reply
  64. But why is friction heating more significant if you go faster in appropriately sparse air to generate the same lift as jetliners travelling much slower in much denser air?

    Reply
  65. But why is friction heating more significant if you go faster in appropriately sparse air to generate the same lift as jetliners travelling much slower in much denser air?

    Reply
  66. If Boeing actually got enough interest from the airlines they’d build anything! Of course no airline is probably wanting to stick their neck out that far. I’d also like to point out that it’s harder to suppress a sonic boom at mach 5 than it is at mach 2.

    Reply
  67. “Because the higher you go, the faster you have to go to keep the engines running, and to generate enough lift to stay in the air.”

    That’s an advantage. Also, sparser air: less drag.

    “And when you hit the air at that ever higher speed, it gets *hot*. ”

    Perhaps. But I can’t get my head around why. I would imagine you could just go higher to for the sparser air to generate the same amount of lift and heating as it does at low speeds nearer the surface. What effect causes extra heating?

    Reply
  68. I would add that legroom isn’t clearly advertised AFAIK, so consumers don’t have effective tools to choose the roomier option even if they wanted to (short of opting for business class).

    Reply
  69. You’re right, nobody asked for reusable rockets and then SpaceX made them and blew the competition away. With a big leap it can go the other way, it creates new possibilities that didn’t exist before. The space industry will grow like never before as a consequence. After a while the big companies become massive drains on talent and government resources, that has a negative impact on society. Lockheed is no better with their F35, many nations where very happy to buy F16s from the US, now they are dragging their because F35 is so expensive and buggy that it is seen as a risky investment.

    Reply
  70. But your ground effect airplane / double the travel time idea provides the airline with a second opportunity to lower cost – double the capacity. As was described in other comments, sure with your idea they could leave the price the same and double the travel time; or they could double the travel time AND leave the leg room the same, and half the price. More people will pay half the price for the same legroom and double the duration than will pay the same for double the duration, same price and double the legroom. Cost supercedes comfort in airline economics, regardless of duration.

    Reply
  71. Ironic, but not unsellable. And there are plenty of people living in places where it’s fairly easy to get to the airport. Granted, it was 2 and a half hours drive and walking through endless terminals for me growing up, and today it’s nearly the same, but for a couple million people in the DC-Baltimore area, it’s just an hour on the metro. And that’s just my knowledge of the US. I’m sure the same is true of many other metropolitan areas.

    Reply
  72. Boeing manufactures airplanes, not interest. When an industry wants something, Boeing will design it. Why do you think commercial spaceflight has taken so long to mature? You don’t research, design and manufacture a product that nobody is asking for. You need to understand the industry you’re talking about a little more first.

    Reply
  73. Because the higher you go, the faster you have to go to keep the engines running, and to generate enough lift to stay in the air. And when you hit the air at that ever higher speed, it gets *hot*.

    Eventually you reach an altitude where it’s just too hot to stay up in the air.

    Reply
  74. There would be great benefit from planes that make less noise, a hybrid plane might work. The development of supersonic planes or something like the skylon or SpaceX BFR that travels trough space. The era of the 747 started in 1970, we almost half a century later and i would say we are still in the 747 era.

    Reply
  75. They have weather radar. The Caspian Sea Monster was most efficient at 20 metres, which should be enough to cross the Arctic ice, but most of the wigs are capable of fling much higher, if necessary.

    Reply
  76. Airliners have to lift half their weight as fuel, and they have to be pressurised to 40,000 feet. A wing in ground effect craft operates at sea level pressure, so it could be much roomier at a lower cost. It also carries more weight for the same power, and doesn’t have the same runway restrictions. I’m hopeful that they could be nuclear powered, but even just using jet fuel, it would be putting all its emissions into the lower troposphere, instead of the stratosphere. That alone would reduce the climate effects considerably, even if the wig used more fuel.

    Reply
  77. Remember that airlines DO offer you the choice of paying more for more legroom. It’s right there as an option on most flights.
    And most people choose not to pay the extra.
    Unless you are already buying business or first class you don’t really have a leg to stand on.
    (Pun intended as always.)

    Reply
  78. Even worse, you get presented with some beautiful creation, high performance, innovative layout, everything.
    THEN they announce it’s actually going into production.
    And 3 years later it appears. But for safety regulations reasons the swoopy curvaceous shape is now the same lozenge box as everything else. For cost reasons the variable compression ratio, 12k rpm V10 is now a turbo four. And to make it more acceptable to a focus group of 7 blind people the innovative layout has been abandoned. And so we are actually left with a camry with a new grill and an in-car video game in which the rear seat passengers can play a game in which they are driving the original concept vehicle. But not when the car is moving because it might distract the driver.

    Reply
  79. “Dismal pace of innovation…”

    What should they be pursuing that they are not pursuing? Incremental evolutionary improvement and a great safety record not good enough?

    Reply
  80. The increase utilization rate only works if there isn’t an increased maintenance rate to go with it. And there is also the issue of increased fuel use and the increase cost of the hypersonic jet in the first place.

    Reply
  81. High ocean waves can reach 10-15 m. Rogue waves can reach 30 m. It would need to have a pretty large wing span to satisfy “flight altitude is significantly less than the wing span”.

    Reply
  82. No, it doesn’t (necessarily) need a flat surface underneath. You may be thinking of a hovercraft, however, which definitely does.

    “Wing in ground effect” flight delivers a high dynamic lift to drag ratio when the flight altitude is significantly less than the wing span. As long as that altitude is above wave height, variations in the surface don’t much matter. But colliding with a tall wave would be a disaster.

    Reply
  83. It’s not the airlines driving this, it’s their customers. For most, the ticket price is the primary factor driving their decision to choose a particular flight, therefore airlines need to compete mainly on price. Unless and until customers become willing to pay more for a better experience, airline seats will continue to get smaller and less comfortable.

    Reply
  84. Heh, that’s why I stopped going to the auto shows. Too many beautiful cars you knew would never, ever be sold. “Here’s what we COULD be selling! Now eat your identical lozenge shaped boxes, peasants!”

    Reply
  85. “But who knows what safety risks would be from flying so many people so low.”

    Not falling out of the sky but landing on water if there’s an issue…

    Reply
  86. Boeing is never going to build this plane (unless others have done it before). It is like all those car companies showing concept cars. It is just marketing hype, a way to show to people that they are relevant, modern and cool. Boeing is become a stale company that is stiffling competition and innovation rather then encouraging it. Look how they tried to keep SpaceX out of government contracts or the equally dismal pace of innovation in aircraft industry.

    Reply
  87. The problem is that airlines could already give you twice the leg room they do now, the reason that they don’t give it to you is that increasing the number of seats per airplane makes more money for them than they think they could get by charging you a higher ticket price in exchange for the room. Thus, if they did buy large capacity wing-in-ground effect craft, they would probably use the extra room to crowd in more seats and you would have a 10 or 12 hour trans-Atlantic trip with the same (crappy) amount of (lack of) legroom as now, but on the plus side, tickets might well cost half what they do now. Although I might be wrong about this, this approach seems to be the revealed preference of airlines based on present trends.

    Reply
  88. Actually Mach 3.2 was regarded as the peak efficiency around plus or minus 80 altitude. One combined data graph associated with J-78 went above Mach 4. Not saying the aircraft wouldn’t suffer *cough* glow-red-in-the-dark.

    Reply
  89. I think the idea is that for long hauls, one plane would generate so many more passenger*miles per day, that ticket prices would be lower than expected, based on the cost of the plane.
    As far as comfort, it’s not the crowding that gets me, it’s the screaming baby, and the kid kicking the back of my seat.

    Reply
  90. Yeah, but what will get me from the front door to the plane in 1/2 hour, like back in the good old days(1990s). It would be ironic to take longer to get from the parking lot, to the airplane, than to get from NYC to London.

    Reply
  91. But who knows what safety risks would be from flying so many people so low. Might make for a decent SyFy Channel movie though, if a giant shark could be worked into the plot.

    How about something like the Aeroscraft instead?

    Reply
  92. Personally, I’d be more interested in a craft that could cross the Atlantic in twice the time with more leg room, at half the price, than one that could cut the trip time to a fraction at multiples of the price. MOST people have more time than money.

    Maybe there would be a market for a ground effect passenger liner with a cruising speed of about 450-500 kph, instead of the 880 kph of a 747. And *comfortable* cabins.

    Reply

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