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The Future of Flight
Roland Piquepaille writes "With "High Times," the Economist delivers a very long and extremely well-documented article about the future of aviation during the next fifty years. It tells us about pilotless planes, with 32 countries currently developing more than 250 models of unmanned aerial vehicles (UAV), primarily for combat purposes. The article also looks at future civilian pilotless planes and at the future of personal aviation. But what captivated my attention in this article was the last part about future commercial supersonic and hypersonic (at least five times the speed of sound) planes. In particular, the Economist describes the HyperSoar. "The HyperSoar is a concept for a craft flying at ten times the speed of sound and able to reach any point on the globe within two hours." This overview contains more details and references about the HyperSoar which would fly from Los Angeles to New York in 35 minutes."
planes!? Where are the flying cars? I was promised flying cars!
Esoteric reference.
hmm, I thought High Times was a publication of a different sort...
Enough said.
"Eve of Destruction", it's not just for old hippies anymore...
gee, just like the pop science article i read as a kid 30 years ago...can't wait !! (maybe they will have the 100 mile per gallon carb additive to - no wait, no more carbs !!!!)
But even with that fact HyperSoar which would fly from Los Angeles to New York in 35 minutes. How long would you have to wait at the airport to get on the plane?
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The only fly in HyperSoar's ointment is that its success is highly dependent upon Hyper-X. Note how similar the designs are.
Additionally, Hyper-X is designed to use the engine block as a heatsink. It will run for a few minutes (which is all it needs to do to get up to speed) and then the engine will melt and the aircraft will splash into the Pacific. I don't think that would be a good thing for a passenger aircraft.
I've read about the hypersoar before, and it's supposed to skim along the surface of the atmosphere. While the specs are impressive, i'm sure this means alternating between positive g, negative g and weightlessness. Great for the rollercoaster generation, but obviously not for everyone.
I've done a few tests in X-Plane and came to the conclusion that with today's rockets and advanced materials it might be fairly easy to make a suborbital plane that can go from Paris to New-York in under an hour. I've got three different designs that could do it. The one obstacle is leading edge temperature at supersonic and hypersonic speeds, but shockwave shaping and the use of cryogenic fluid (liquid hydrogen ?) like on the 70s' XB-70 Valkyrie can overcome it.
Maybe we deserve this world ?
To bad all the major airlines don't want faster planes because of the effect it would have on the schedules of flights. Faster planes have been available for years and it still takes about 4 hours between NY and LA on commercial flights. Not to mention the sonic boom of faster than sound travel not being allowed (one of the reasons the Concorde was never used across the US).
What fuels are we supposed to use for civil flight in 50 years?
Today, the commersial airlines do not pay any environmental fees whatsoever on their fuel (correct me if I am wrong - I would like to be).
The energy cost for travel by flight is much higher than for other transport methods.
I guess that especially super/hyper-sonic flight will not be considered before the environmental issues (noise, not the least) are completely resolved.
In 50 years, I hope we have airplanes fueled by hydrogen produced in nuclear facilities.
Considering it takes about 90 minutes to orbit the earth at LEO (or 45 min to go 'anywhere'), getting anywhere in 2hrs is very impressive. I wonder if it flies inverted so that its lift prevents it from entering orbit.
HyperSoar which would fly from Los Angeles to New York in 35 minutes.
...be able to claim coast-to-coast on one battery.
*coast-to-coast claim only valid when flying at over 5 times the speed of sound.
"It tells us about pilotless planes, with 32 countries currently developing more than 250 models of unmanned aerial vehicles (UAV), primarily for combat purposes" and what about planes that are designed to do stuph BESIDES killing ppl/things? oh yea, war pays..right.... cryo
Depending on how development of transverse fans works out, blended wing subsonic commercial craft could be a huge thing in the next 50 years. Odd that they didn't mention it...
Mach5 is about 1500 m/s. Escape velocity (the speed at which you need to go to leave earth and go to space without accelerating more) is 1100 m/s. Would that mdan that a hypersonic plane must fly uside down so is not to fly out into space?
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
It's 2004, practically, and people still die when 1950s failures happen in aircraft.
I remember shortly after Sep 11th, there was a discussion about parachutes for aircraft -- apparently a working concept had been demonstrated for a 737. I'm sure there are other possibilities.
Flying cars are great, but what that will probably do is bring the highway accident rate (combined with the air accident death rate) to our airspace. Unless we get dramatically better at safety, of course.....
Tweet, tweet.
As if flying wasn't scary enough! Before I just worried about engine failure and crashing into the earth, now I have to worry about the engine firing a little too long and throwing me into orbit (or worse)?
wow, I think that if this Plane is developed, we may see the beginning of cross country commutes every day, much like we see train commuters in Connecticut.
"honey, Im gonna be late for work!!! my Editor at the LA Times sad that if I was 5 minutes late again that I would be fired!!"
"ok, just make sure you get to the subway on time this time so you can catch the 6 o' clock train to JFK"
weird.
I am the Alpha and the Omega-3
Although the article did a good job of discussing flight technology, they did not say enough on the market forces that might drive different scenarios. Its not clear whether Boeing's vision of direct point-to-point travel or Airbus's visions of mass-transit hub-and-spoke will be the future of air travel. On the one hand, the decline in business travel hurts the economics of offering quick direct flights to everywhere while new technologies like free flight aid point-to-point travel. On the other hand, its not clear whether people will tolerate multiple connections and long boarding processes required for larger aircraft like the A380.
Two wrongs don't make a right, but three lefts do.
commercial airlines have an accident rate of 0.06 crashes per million hours of flying whereas the Northrop Grumman Global Hawk UAV used by the US military has 1600 crashes per million hours of flying. This shows that the UAVs have a long way to go before we can trust our lives to this tecnology.
All I'd like to do is to be able to fly across the country in 2 hours for about $200, please.
I'd like to visit family more often. You can zip up and down the east coast or west coast cheap and quickly, but cross country is still $500 and an all-day affair, typically.
When they were designing the SR-71, the Skunk Works had a hell of a time designing the life support systems for the pilot-- and that's just one guy in a space suit. At Mach 3, the heat generated by air friction is sufficient that if the cockpit air conditioning system fails, he's in deep shit. If you're reading this and you think in your lifetime you're going to see passengers flying in casual clothes more than three times faster than the SR-71, you'd better think again.
Even if it does become technically feasible, so few people will be able to afford it that it would be completely impractical to try to build a passenger transportation business around it.
~Philly
There is a joke in the airline industry that the future crew of an airliner will consist of a pilot and a dog. The pilot's job is to watch all the computers, and the dog's job is to bite the pilot if he tries to touch anything.
umm, well, that would be why you invest your education in the future and not in current technology.
I am the Alpha and the Omega-3
Just strap me to an ICBM it'll be safer, and they have better targeting systems to boot.
Why does the website with the HyperSoar article have the Netscape icon as its site icon?
As an aerospace engineer, I'm always surprised about how many things we are supposed to achieve in the next so-many-years.
People, believe me: It is _not_ going to happen. Period.
Why not?
Well first of all, aerospace as an industry is extremely conservative. Despite it's high-tech image, the facts (and my experience) show differently. Look at the shape of aircrafts for example: Essentially unchanged since the 1930s. The fuselage-wing-tail concept is still the most popular, and all the research on blended wings, canards, double-fuselage, and other stuff people have made up, have not changed a thing (try to find the book by E. Torenbeek, you'll be amazed about how rich a phantasy some people have). That is because it simply is by far the most efficient concept: it's easy to stabilize, and you can put lots of people in it. Blended wings, for example, turn out to be too thin for people to fit in for, say, an aircraft for 100 people. Also, safety is easlier to achieve, and there's lots of room for cargo/luggage and fuel. Boeing's SST and Sonic Cruiser, and even the Concorde, did not fail without a reason. The A380, the "next generation aircraft", still has the same basic design as a DC-3 had 60 years ago. Another example is materials: Aluminum is still the primary construction material. It is _very_ slowly being replaced with composites and laminates (carbon, glass fibre/epoxy, GLARE). Aircraft manufactures can't sell an aircraft until it is absolutely proven that the new aircraft is safe and maintainable and has cheap Direct Operating Costs. So they all play safe and go with trusted concepts/materials. The A380 took about US$15_billion_ to develop. You don't go gable with such amounts. You play safe.
Then there's an economic reason. Profits for airliners are extremely low: 3-5% is not unusual. In fact, very few airlines have made a net profit over the past two decades. In the USA, airlines go bankrupt every 10 years, in Europe they would not survive without government support. Investing in airlines is high risk. This automatically means that investments in aircraft manufacturers is also quite risky. So actual research development of new technologies in the aerospace industry are very low, and usually government-sponsored, related to military applications, or conducted in universities or research institures. The "time to market" of any new technology in the aerospace industry has been estimated to be about 35 years.
This is already too long a story, I could go on for pages. But realy, this kind of views on the future just makes me laugh my pants off.
A friend of mine worked in a local tv station, and she lost her job, and was replaced by a machine. Robotics and automated systems are a curse for the working man (or woman.)
I knew it! Tom Brokow is a robot
L.A city centre -> L.A airport : 50 mins
L.A. ->Tokyo : 30 mins
Tokyo airport -> Tokyo city centre: 1:20h
10 ?"Hello World" life was simple then
On the ground, the sonic boom of a hypersonic transport plane would be on the order of a small earthquake. It would be many times larger than the sonic boom of the Concorde. It would likely break windows and damage structures for many miles on either side of the flight path.
Even if the massive technical and safety issues could be solved, damage caused by the sonic boom would make the aircraft basically useless. Aircraft are not economically feasible if they can't fly over millions of people's houses without damaging them.
The world of tomorrow will not be available until tomorrow.
Also, today was cancelled for lack of interest.
We appologize for the inconvenience.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
You go hopping around from 0G to 1.5G. Basically, this super efficient ride is also a super way to make passengers yak.
I'd spend 50 billion to develop this --- not.
This is my sig.
Before someone posts about how rockets are fuel-inefficient compared to other engines, I'd like to point out that it mostly depends on the cruise speed of the aircraft.
If the plane completes the flight in ten times less time than a conventional subsonic plane, then its engines are burning fuel for ten times less time as well.
Modern high-bypass turbofan engines have a specific fuel consumption (SFC) rate around 0.5 lb of fuel per lb of thrust per hour. Current liquid fuel rockets' SFC is around 10, and solid / hybrid rockets' SFC is around 5. But the concept of "pound of thrust" evolves with speed: for example, a reciprocating engine with a propeller will give you much more (approximately four times as much) pounds of thrust than the number of HP the engine develops, _at low speeds_. At 375 mph, you get one pound of thrust per HP. And beyond, you get much less. That's why high subsonic planes use turbofans and the slower planes still use propellers.
At supersonic speeds the fuel consumption per distance covered of a turbofan engine can grow as high as 3+, but that of a rocket engine does not grow with speed, so there's a given speed beyond which rockets are more efficient than turbofans.
Maybe we deserve this world ?
So basically, we'll be weightless about half the time on the flight? What about the food service then? Will we use the same techniques as astronauts do?
I'm also sure there will be public concerns about the weightlessness.. heck, they even said that this is still far in future. I'm not holding my breath.
"HyperSoar's trajectory follows a skipping pattern. Passengers would feel 1.5 times the force of gravity at the bottom of each skip, and weightlessness out in space. The experience would be comparable to being on a swing, although HyperSoar's motion would be 100 times slower."
Anyone else thinking about investing their life savings into sick bag companies?
I could see UAVs being used for freight long before the public will accept it for holiday flights. Also the piolts are concerned with the collision avoidance abilites of UAVs. This may mean that in the next few years we may see plans for UAV only airports near our lager cities. For this to become anywhere near reality the problems of overcrowded airlanes and over worked air-traffic control staff, need to be resolved. For tis 'free flight' needs to be adopted, it allows piolts to plot their own flight plans and then when airborne onboard computers 'project' a 300km (30 sec)'bubble' around each aircraft, and automatically resolve incursions into the 'bubble'. This method allows more direct and efficent routes to be taken by aircraft and frees up large regions of currently unused airspace. Boeing is backing this move and is also taking an intrest in personal air transport. Yes, that means a flying car.
-- Reality checks don't bounce.
So you don't like that automation is replacing jobs? No problem! Go to some third world country and become a farmer.
Automation is a long way from replacing cheap labor
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
Future 2050 news article summary...
Blah blah blah... disease... blah blah... two million dead... blah blah... spread so quickly... HyperSoar(TM)... blah blah... FreeBSD 14.2.0 is dying.
I hate his drawl, I hate his swagger that borders on arrogance, I hate his "folksy" image, I hate his black and white low-brow ideology and I hate how he mixes religion with politics.
Now I'm beginning to understand the rage Clinton provoked (and still provoke) in some people.
Sure it would be expensive, but we've already seen that several people have been willing to spend millions of dollars for a trip into space despite having to go through extensive training, being stuck in a cramped little Soyuz capsule, and not having anything to do up there.
I'd say you don't need to get it extremely cheap before you could start making money off it.
At 5 times the speed of Concorde, I assume that if you could get down to comparable costs you'd easily see the same passenger volume. And if it could achieve this high enough that sonic booms wouldn't be an issue it would be able to fly a hell of a lot more profitable long haul routes than London/Paris to New York and DC.
I fully expect to live at least another 40-50 years or so, and 50 years was enough to bring us from no aviation to transatlantic jets - I don't see something like hypersoar at "reasonable" (read "Concorde level") prices to be too unlikely within a timeframe like that. Especially given that there are multiple hypersonic projects already underway, and that there is enough private investment in private space travel that we should see results from that as well within the next decade or two.
This article sounds just like a show that was on NPR the other day http://www.sciencefriday.com/pages/2003/Dec/hour2_ 121203.html
They had 'experts' talking about why supersonic commercial flight isn't hot, explains where our personal aircraft are at, sub orbital flights, etc.
It was an interesting listen!
Sean
Call me nuts, but this is the old Dyna-Soar project, so there's nothing new about it except for will to get it done.
ObJoke1: It's hard to keep a Dyna-Soar extinct.
ObJoke2: That project's so old, it's a Dyna-Soar!
(boo, hiss)
[You have a stable society when some nut guns down a schoolyard and the law doesn't change.]
I missed a zero, sorry. However, I will argue your second point
Flying right side up does prevent you from falling down to earth, and flying upside down should provide downward thrust (unless you change the angle of attack of the wings). So it should allow you to go at faster than the escape velocity.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
Atleast its being researched. I know a few of the guys working on the software models for the conflict detection and resolution aspect of the project.
Didnt I read this in a Heinlen novel already?
-- 'The' Lord and Master Bitman On High, Master Of All
RTFA:The g forces would vary between 1.5g and weightlessness
This is not a bad thing in the long run. In the short term, yes, unemployment is bad. But is anyone still hurting because buggy whip makers are all out of business? What are the people doing now that would have been employed making buggy whips, had cars not come along and taken away their jobs? Sure, some of them are probably doing jobs that will eventually be replaced by machines. However -- might some of them be, say, working out the latest cure for cancer?
Technological automation of repetetive tasks frees humans up to do things that only humans can do. Flying is 90% sitting around, making repeated checks of the horion to make sure you're not about to crash. I'm a little bit surprised it's taken this long to automate it.
--- 11 meters/second, or 24 miles per hour - the airspeed velocity of an unladen European swallow. Really.
Technology aside (assume it will exist) the economics are going to be tough. The Concorde went under because no one wanted to pay that kind of transatlantic fare, which meant the plane was always operating in the red. Any new technology such as a 35 Min NY-LA plane would need tends to be very expensive at first, so ticket prices would be sky high. Not to mention getting something like that FAA certified to carry passengets (so it and they can be insured) would be a nightmare and very expensive. With high-speed Internet access so cheap, you can hold a LOT of video-meetings for the price of one plane ticket. Then if you really need to go in person to close the deal, you take the lowest cost flight. In fact, most employers require you take the lowest cost flight unless it would make you arrive too late. It would be very hard to justify a (guessing here) $25,000 ticket just to save 4 hours time unless someone made $6,000/hr. I can see cases where it would pay but they are not prevalent enough to subsidize the operational costs. One positive aspect is that donor organs could be shipped anywhere for transplant, versus some limits now due to flight times. That might be worth $25,000!! Of course, a Government could give the firm an operating subsidy which would help prices to be lower. If you were looking at it strictly as a free market venture you likely wouldn't make it.
Anyone here ever see Deal of the Century?
- Preferences: Solaris 10 (servers), Ubuntu (desktops), Solaris 11 (personal servers) -
You are one fucked up idiot - How can something be marked redundant when it is the only comment of its kind????
I am in a profession that uses remote sensing imagery, mainly from aerial photographs, but also from satellites (QuickBird, IKONOS). This type of data is invaluable, but it becomes dated very quickly in fast growing urban areas and this type of data are pricey (an unnamed seller of satellite imagery quoted us $3 million for statewide coverage, and could not guarantee less than 20% cloud cover). UAVs could potentially reduce the cost of imagery by cutting the cost of flying. If it's cheaper to fly new imagery, we could potentially get "spot" updates on areas of high growth or concern (as in the US-Mexico border). Of course, this technology wouldn't do any favors for pilots and camera operators!
There are some businesses for which conservative practices are appropriate. I think it's a damned fine thing that the airline industry is one of them, given how devastating failures are.
The safety record of the airline industry is rather remarkable when you think about it. Doubly so when you see them cutting corners in maintenance and still getting away with it.
Now consider the somewhat less conservative auto market. We've got BMW's with engines that sieze up because of software bugs. Not the end of the world when driving (usually), but not something a plane can handle.
Faster planes that fly about 10-20% faster than existing planes (like Boeing's late Sonic Cruiser) would mess up airline schedules, for example an overnight flight from East Asia to Europe would arrive too early in the morning, before the airports open, or would have to leave late to be convenient for departures. Planes that fly an order of magnitude faster are a whole different story. Forget overnight flights... forget tight schedules. The 35 min that it takes to fly from LA to NY is much shorter than the time it would take to prep the plane and load/unload passengers.
Sonic boom is a non-issue with this plane because it flies between the upper atmosphere and space. There's not enough air up there to create a sonic boom.
That said there will be some big issues with this. Two hours from Tokyo to LA means it will be like being teleported from night to day. NASTY jet lag. The aircraft will alternate between 1.5g and 0g every two minutes. Guess that rules out any kind of in-flight service, trips to the restroom or anything. You get in, strap yourself to the seat and unless you feel up to a two hour roller-coaster ride and have had a light meal you take air-sickness pills. I doubt most people will even be able to sleep under these circumstances.
Realistically, I see this being used for cargo and military applications more than anything else for a while. Maybe they will be able to increase the period of the oscillation to, say, 30 minutes instead of 2 minutes and then it will be fit for passeger travel.
The prototype "Hyper-X" vehicle was destroyed over the Pacific ocean a couple years ago. The Pegasus rocket it was mounted on malfunctioned and the airframe was destroyed.
It'd be some fun to fly the HyperSoar profile, every few minutes your laptop would float away.
gigantino.tv - Heavy but weighs nothing.
Talk of hypersonic flight and trips from "San Francisco to London in under two hours" is nothing new. Over a decade ago, the late NASA/DOD National Aerospace Plane project (NASP) promised to deliver a craft capable of suborbital, hypersonic flight for use in both military and commercial transport, but was cancelled in 1993 due to technical issues and cost overruns. Maybe HyperSoar can deliver where NASP failed, maybe not. But I'll wait until the project produces a working prototype before I get my hopes up; as the Economist article points out, "HyperSoar is little more than an idea".
Oh gosh. The 21st century is bringing us some of the dumbest scientists in history.
People -- mostly afraid already of flying in the first place -- want more weightlessness and swinging up and down violently 15,000 feet at a time.
Right.
The next comment I write will be ready soon, but subscribers can beat the rush and see it early!
Ummm, do you remember a little old thing called the Concorde, Mach 2 in shirtsleaves in the 70's. Heating is a problem but not as big as you are making out.
Maybe you live in interesting times
Strangely enough we've been seeing similar claims for the last 50 years. Even back in the 50's, magazines such as Popular Science were informing us that "soon" we'd have rocket planes that will take us anywhere in the world in X hours (where X is very small).
Why don't we have them yet then?
Cost. Most people want to fly as cheaply as possible and aren't willing to spend an extra grand in exchange for shaving three hours off their travel time.
In addition, unlike the 50's, business people no longer need to travel everywhere to cut deals. With the advent of email, teleconferening, etc. they don't have to.
Something we geeks need to remember is that just because we can invent a cool new technology doesn't mean there will be any drive to bring it to market.
Damianio
Speaking of sick bags, they used to have one in every seat back. On my last flight I realized I haven't seen a sick back in a long time, and I fly several times a year, so I rooted around the seatback pockets in front of me and found no sick bags.
How do they handle sick bag situations now?
Then again, in my many many flights I have never seen anyone use a sick bag.
On Dec 17th, 1903, the Wright Brothers made history. Flight has come a long way in 100 years.
As far as I can tell the 3 top conncurent (lufthansa, Air France and British Airways) are running without any subsidide. In the case of LH since about 12+ years or so. In the case of Air france the company is in the govt hand *BUT* it is run as a beneficit making company (aka: without subside). As far as I can tell due to the air liberalisation and EU law anyway, you can't subside a company anymore. That is why LH, AF, and BA were so angry at the $$$ the US gave in mass to US airlines, it looked very much like subside (and still does from this side of Atlantic).
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
Even in Star Wars they had pilots. The avionics guys I know used to joke that they were making pilots obsolete. The truth is Airplanes will become obsolete before pilots will.
Pilots are making over a $1000 an hour. Pilotless planes would reduce the cost of flying thus more people would fly and the net effect would be more employement. Would September 11 have occured if the planes were pilotless? I think it would have been much harder to gain control of the plane without a pilot. When one is dead one does not care if it was caused by pilot error or a programming error. It must be determined which will occur more. Can a computer sense it environment faster and better than a human and can it make adjustments for situations nobody ever contemplated?
There doesn't seem to be any R&D towards developing unmanned targets so I'm sure there will be plenty of employment opportunities there. And with GWB as president I'm sure there will be plenty of growth in that field.
from the hypersoar website:
HyperSoar would also have twice the fuel efficiency of commercial airliners, be three to five times more efficient in putting satellites in space than today's launch systems
Wouldn't the first automatically imply the second? Afterall, airline flights aren't exactly in the same order of magnitude of as rocket launches, are they?
...for Google's new remote employees.
Google to Start Research and Development in India
The Mountain View, California, company -- which is widely expected to do an initial public offering in 2004 -- is the latest in a long line of high-technology companies to set up shop in India, which has a large number of educated workers who are paid hourly wages that are significantly lower than in the United States.
A company spokesman said the move aims to take advantage of India's "considerable engineering and technical talent" and is not a cost-cutting move.
Sitting in a modern airliner in the middle of a flight is about the safest place you can possibly be, including (if you count average number of deaths per hour) any place inside your house or apartment. More people die from slipping in their shower than from airline crashes, even when you adjust for the number of people who participate in each activity.
If you want to make things safe, let's make cars safe. Talk about deathtraps, not only for the people in them but for anybody nearby....
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
Heating is a problem but not as big as you are making out.
Mach 2 is not Mach 3. I suggest you read chapter 9 and the beginning of chapter 15 of Skunk Works, which detail the development of the SR-71 and mention the conceptual predecessor to the HyperSoar, respectively.
Here are a few excerpts:
"At the nose the heat would be 800 degrees... 1200 degrees on the engine cowlings... 620 degrees on the cockpit windshield, which was hot enough to melt lead."
"...without effective and fail-safe cooling the pilot could bake a cake in his lap."
"Do you know what would've happened if we tried to fly much faster than [Mach 3.2]? The airplane's surface would have come apart from heat friction. And that was titanium. Do you have something stronger? And by the way, our crew wore space suits and we still worried about boiling them alive if our air-conditioning system failed."
Considering these quotes come from the guy who was the lead thermodynamacist on the SR-71 project, I think it's safe to take them at face value.
~Philly
Concorde does not make a sonic boom. It is very noisy on take-off & landing; but the main reason it was never deployed over the US was at first politics (it's not american) and later cost.
10 ?"Hello World" life was simple then
>Because HyperSoar spends nearly two-thirds of its time out of the atmosphere, it can radiate the heat into space.
But leaving the atmosphere means re-entering the atmosphere. As for the risks of that, I got 1 word for ya: Columbia.
Think about your average commercial airliner bathroom. Now imagine it in zero g.
Picture off.
"I thought they were the dominant species..."
Maybe it's because I am a third generation train junkie, but I have always fantasized about speedy underground railroads. You would use the subterrain railroads to get from city to city, then use the city's subway or bus system to get around.
I know the initial cost is greater than that of using a plane, but in the long run could it be cheaper and less noisy?
Where do I sign up?
Better check your figures, podjo. I don't know of any pilots making $2 million a year.
The idea that pilots are overpaid is something of a myth. Yes, 30-year veterans flying the plum routes in 747s make $150K/year. But the vast majority of commercial pilots can barely make ends meet. That guy flying the Continental 737 between Houston and Atlanta probably makes less money than 90% of his passengers.
What beats me is that in 1902, we couldn't achieve powered flight. Once we could, in 1903, it took only 6 years until someone was able to fly the English Channel. Only another 60 years after that, we built a plane capable of supersonic flight. And then what? Fuck all. 30 something years later and in terms of commercial domestic air travel, we've not moved an extra mile per hour. Think of all the other technological innovation that has happened in that time, and ask the question, "Why not?" It sure beats the hell outa me.
re-invent wheels
Do you mean you simulated your design on a computer or that you physically constructed this airplane and it really flew?
Sorry, don't expect UAVs to be taking you anywhere in the next 100 years. They are great for military application, but UAVs have a horrible record of dealing with anomalies like crosswind landings and takeoffs. They do poorly in common emergencies, not to mention uncommon ones. I am sure the tweaking and coding will continue to improve, but no one would or should feel safe geting aboard a commercial aircraft with 250 passengers run by HAL 9000.
Yes, many GA accidents are pilot error. A good share of passenger accidents are as well. What you don't see in NTSB reports are how many equipment failure and accident avoidance incidents are corrected/saved each year by pilots. You don't hear about the aircraft that manage to land with an onboard fire that incapicates the computers. Those are all future "pilot errors" we can all look forward to in a pilotless cockpit. The day may come when pilots are replaced, but it will be a long time before a pilot (who knows the dangers in the sky) gets aboard one of these planes as a passenger. Why should you be any different.
"Curiosity killed the cat, but for a while I was a suspect."- Steven Wright
Seastead this.
"This overview contains more details and references about the HyperSoar which would fly from Los Angeles to New York in 35 minutes."
Sure the flight would be 35 minutes, but the trip time would be 3 hours, sitting on the runway, sitting on the runway, sitting on the runway, waiting while the FBI takes the person without white skin off the plane, sitting on the runway...
Wings and engines have not changed much in 50 years.
But... New electronics are finding their way into small planes that anyone can learn to fly.
Now GPS makes it hard to get lost. New electronic flight displays are replacing 50 year old "steam gauge" instruments.
Sooner or later, someone will perfect cheap and reliable fly by wire controls that will make small aircraft much simpler to fly and reduce training time and improve safety.
Today, personal flying is a fun way to travel. Just yesterday was a beautiful, sunny day. I flew up to New Hampshire just to enjoy the view.
On warm days, my wife likes to fly with me down to Martha's Vineyard, a small island off the coast of Massachusetts where we can land on a grass strip 50 feet from the beach. When the sun goes down, we just get back in the plane and fly home.
Flying is a very old dream. Anyone can learn to fly, but be warned, once you start, it is very addictive! Flying is not just a way to get from here to there. It is a lot of fun all by itself.
Im currently doing my masters project on the feasibility of the hypersoar concept. In a nutshell, its possible, but with some caveats. One of the main reasons you want to do a periodic trajectory is to reduce drag and heating of the aircraft. If you stay at a constant altitude, all that heat builds up and eventually melts your plane. If you skip out of the atmosphere the heat should radiate to space, reducing your total heat load. The problem comes when you come back in. You go deeper into the atmosphere at a higher temperature than you would at a constant altitute. Ultimately your total heat load is lower, but your maximum temperature is higher by about 20% (in degrees K) which is enough to require some more exotic materials. The other thing is that you require alot of lift for pulling out of the dive at the bottom of your trajectory. So you need a high L/D ratio, which for a hypersonic vehicle is about 4. So you need wings and structure to hold the wings etc. Thirdly, you need an engine with enough thrust to overcome the drag at the bottom of the dive. If your engine isnt pushing harder than the air is pushing back, you just slow down and fall to earth. If its not pushing hard enough to bring you back to your initial velocity, you cant go very far. For my preliminary vehicle design I found that a vechile of ~500 tons with a L/D of 4 needs a thrust of about 2g's or about a million newtons If your vehicle is too light, it cant push far enough into the atmosphere to generate thrust (im using an airbreathing engine) and you crash. If its too heavy you go in to far and burn up. There is a specific range of weights and engine on-off conditions that are required for a successful trajectory. I think Ive got it worked out, but I need to do some more analysis over winter break
"If god had meant us to run around naked, we would have been born that way." - Unknown
The future is NOW!
With interest rates being very low right now, this doesn't seem to be a big deal, but these low interest rates are historically an anomaly.
I predict the first big pandemic that fulfills the fears people had of SARS will tank passenger travel. Terrorism is bad enough, but it just doesn't make sense to ship people all over the world anymore. There is too much human flesh to be eaten by whatever is wanting to evolve in that direction to allow any more of this indulgence in reckless global endangerment from emerging biothreats. The cargo transports are going to be important for a while anyway. The real question in my mind is whether any of this hypersonic stuff will get off the ground before decentralized manufacturing technologies beat them to it. Once you eliminate human transport, the residual demand is for manufacturing transport which will evaporate when the low-capitalization general purpose manufacturing plants are deployed.
Seastead this.
Had you actually RTFA, you'd know that the HyperSoar is able to deal with excess heat by radiatiing it into space at the top of each "skip".
Of course, since this is Slashdot, why would I expect you to read the article you're commenting on in the first place?
A story about Flying the Open Skies with FlightGear http://linux.oreillynet.com/pub/a/linux/2003/12/11 /flightgear.html
this is really going to cause a problem for my mile high club status...every one will have to be a quickie...
We tell the same joke in the phone company biz, except that "the man's job is to feed the dog".
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
A plane that has the effective flight characteristics of the space shuttle will also suffer from some of its safety issues. The thing that happened to Columbia (minor damage leading to disintegration of vehicle) could just as easily happen to any of these super-high speed planes.
The airplane has some interesting scaling laws. The 747, say, gets 60 seat-MPG (you probably have to look at some actual data rather than max range data because max range has reserve for headwinds, diversion to alternate airport, but the 60 seat-MPG is not far from the mark). I am guessing, but I would say a 757 may get close to 100 seat-MPG New York-LA (the 757 is a lighter plane which is lighter per passenger, carries less fuel than a trans Pacific flight, the PW 2037 is a really efficient engine). But if you operate the 757, say Minneapolis to Detroit, I would bet the fuel mileage may drop to 40-50 seat MPG because of the energy cost of climbing to cruising altitude, low-and-slow flight in the landing pattern.
From reading a trucking magazine at a truck stop, I learned that an 18-wheeler with good aerodynamic fairings and a late-model Diesel engine gets about 6 miles per gallon. If you figure 8 miles per gallon for a bus, an intercity bus can give over 300 seat-MPG. As for the train, I am willing to guess that for a transcontinental train like the Chicago-Seattle Empire Builder, what with sleeping and dining cars, U.S. standards that passenger cars be built like tanks to withstand derailments (European passenger cars are much lighter), and all of the mountain passes on the western routes, the train is probably little different than the airplane and at the 50-60 seat-MPG range.
These Diesel commuter trains where they have one locomotive pulling 6 or 7 100-passenger double-decker cars may get something in the 500-600 seat-MPG. But if you go for acceleration and frequent stops such as a subway train, or if you go for high speed, I bet your seat-MPG start working their way back to the car and airplane range.
Interesting that you should mention high-speed rail. Part of what makes my Taurus get 31 highway MPG is that I pretty much stick to 65 MPH. All those dudes passing me doing 75 or 80 are probably getting more like 25 MPG or less. I read that the highly-streamlined but quite fast TGV's are maybe a factor of 2 better than air - I am guessing maybe about 100 seat-MPG. And that 300 MPH Japanese maglev may be comparable to air, perhaps in the 40-50 seat-MPG range.
If you start going fast, think of going at airplane speed but doing it at ground level where the air is thicker. Part of how jets get their efficiency is that they fly high -- the thin air reduces the power on their turbine engines without the losses of throttling, and the thin air allows them to go fast without too much drag. They have to pay for that efficiency with a long climb to cruising altitude. Coupled with large-long range planes being heavier, there is probably a sweet spot in efficiency for perhaps a 1500-3000 mile trip.
The problem is low-altitude (approach/departure) airspace around large airports, most large airports today are near capacity. (IFR traffic, which all airline traffic is.) Free flight doesn't buy you anything for approach/departure, which is where all the delays and inefficiencies are.
You might say the advantage of "free flight" is to the pilot -- less pesky knob-twiddling as you go from segment to segment. But the computer is flying the airplane enroute regardless of whether or not they're going direct or by a published route -- the flight computers know all the routes and will fly them all automatically. A "free flight" system has to know about traffic so it can tell the autopilot to take evasive action. That stuff is really, really expensive. (Check out how much TCAS-II systems cost.) How much longer before recreational and research aviation disappears? It's already ridiculously expensive to fly. The airlines are using this as a gambit to "own the airspace" -- make other uses of aviation prohibitively expensive so it's just airline and military flying. First transponders, then Mode C, then Mode S, and now TCAS for "free flight." (Yes, this is a rant -- but it's all true.)
Unlimited growth == Cancer.
There was a Golden Age of private aviation -- perhaps the mid 1960's, when a Piper or a Cessna was competitive with a luxury car. What has happened since then is that liability insurance has driven the light plane manufacturers into the ground and priced light planes out of the market.
We can all get mad at lawyers and call for tort reform and exemptions for plane manufacturers. But flying a light plane is a much riskier activity than driving a car, and the high liability insurance making planes really expensive is society's way of saying that we place a high value on human life, or at least on human life lost in transportation accidents, and the legal system coupled to the market system has perhaps made the correct decision in trying to get people to drive rather than fly themselves.
You mention the "steam gauges" and the need for a glass cockpit in a light plane. The "steam gauges" are there because they are simple and reliable -- and perhaps safer unless there is an enormous breakthrough in light plane avionics.
The engine controls are very primitive and manual: throttle, mixture control, and in some cases, propeller speed: not much more sophisticated than a lawn mower. If you have a turbo engine, you have manual control over boost pressure and have to follow rules for both advancing and retarding the throttle so as to not ruin the engine. In the 1980's there as some attempt at modernization: Porsche came out with an engine with electronic controls and "single-lever power control." But I don't know if this changed the general market trend that light plane manufacturers went out of business or went high-end (half-million dollar plus airplanes), and the only affordable planes are the ones stamped "Experimental" (i.e. I built it myself so I can't sue anybody).
Sure, the plane can get from LA to NY in 35 minutes, but you can't. First, you have to the airport 2+ hours before boarding beings just to be searched for finger nail clippers and eyeglass screwdrivers. Then there is the 10 to 15 minutes of boarding and disembarking. So it still is 3 hours to get from LA to NY, not much better than in 1999.
So, given today's commercial aviation environment and the way the Bush administration has made the US hated by even its friends, why would anyone even care at this point in time?
Too bad we let the terrorists terrorize us into this sad state of affairs.
Why would anyone even consider building a hypersonic plane after the Concorde just went to the dustbin of history for being way too expensive? Do they think new models will need less fuel? Do they think more people will want to use it if it flies even faster? Seems like a case of very bad timing. Sure, the time of such a device may yet come, but in times such as these? Strikes me as rather unlikely...
If a train station is a place where a train stops, what's a workstation?
#ifdef LAZY_BASTARD_WHO_DIDNT_READ_ARTICLE
One of the major points of the article is that for "flying cars" to work, the actual flying will have to be taken out of the hands of a human and given to a computer. Research on such things is well under way. As far as maintenance goes, modern luxury cars do things like monitor tyre pressuers and service intervals. It's trivial to extend this to "refuse to take off unless service has been done".
#endif
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
First year First Officer pay at ASA, Skywest and most other regionals is around $19-$20 an hour... this is based on flight time... around 75-85 a month, but it varies greatly..
...and I only get paid when I am with a student... I could make more money as a waiter! Computers will never fully replace pilots in the cockpit. Heck, even those "drones" the military uses are flown by humans on the ground!
I currently make less than $15 an hour teaching people how to fly
Nathan
Actually, BA operated Concorde in the black for more than 15 years. It was the manufactures that took a major bath.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"Really? Hmm...if thats the case then the argument they used to retire it (too costly) was bogus? I would however like to see some facts to back up that assertion. BA itself may have made money but did the Concorde?
As someone who lived in Cornwall under the French Concorde's flight path I can assure you that it does make a sizeable sonic boom.
On many nights Concorde would try to shave a few minutes off her flight by decelerating as late as possible to sub-sonic flight. Sometimes she would not decelerate until after flying over Cornwall.
It was a very noticeable double boom, sometimes the windows would shake, but nothing more.
but the main reason it was never deployed over the US was at first politics (it's not american) and later cost.
There were also regulatory issues which prevented British Airways and Air France from offering internal flights within the US.
Best wishes,
Mike.
The reason they gave it up was because Air France weren't able to run it profitably, 911 and the French Concorde crash tanked the airline market in general and the SST market specifically and the manufacturers weren't exactly ecstatic about continuing to have to maintain the aircraft. Just a few too many strikes and you're out.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"So it was a purely technical reason that made it possible for a concorde to land and take off from JFK if the other airport was Heathrow or Charles De Gaulle, but impossible if that other airport was LAX???
Columbia was traveling at orbit speeds. It used the atmosphere to slow down. You can instead slow down to below orbit speeds above the atmosphere, and then decend into the atmosphere (you have to "hover" like a helocopter but with rocket). I have no clue how you would get that much fuel into orbit, but you if you did, you would have no heat problem on re-entry.
It is possible that this plane wouldn't even reach orbit speeds, I'm not sure if a normal human body can take the acceleration needed to go NY-LA while reaching orbit speeds.
P.S. Technially the Space shuttle doesn't get outside the earth's atmosphere, but there is so little that it isn't useful for anything other than a lot of drag if you try to stay up there for a while (read ISS has lots of problems from the atmosphere, but it is useless for wings or breathing). Hard to define where the Earth's atmosphere ends though, as it just tappers off.
That plane can reach anywhere in the world in 2 hours! Is that total time? I thought you could spend more than an hour just getting from your car/cab to the end of the runway.
Well I guess I haven't kept up with what is happening in the light plane market these days -- perhaps there are brighter horizons ahead.
Except there won't be any jobs there either.
Obligatory book plug: The End of Work: The Decline of the Global Labor Force and the Dawn of the Post-Market Era by Jeremy Rifkin.
The basic argument is this: In every generation technological improvements have led to decline in employment in one sector of the economy, but those same or similar technological changes have created large new sectors of the economy to absorb the burgeoning masses of unemployed workers (i.e., farm laborers migrated to cities and got jobs in factories).
The problem is that the new technologies are still creating new industries, but those industries simply can't employ the number of workers being down-sized, regardless of whether or not they have the requisite skills. Even if by some miracle we were able to re-train every unemployed autoworker in the country and give them a PhD, how many of them would the biotech industry (one of the new big "growth sectors") be able to employ?
Now that even the service industries are being automated to replace flesh and blood workers, where will the new jobs be?
In many ways, we are finally beginning to see the beginnings of the Star Trek fantasy of nobody working - unfortunately, it isn't panning out quite like we imagined, since the spoils of all this newfound wealth and leisure time are not being shared, but rather hoarded by a privileged few.
fuck you.
Well, when the hysteria you saw in nascent form during the SARS scare actually hits home none of your rhetoric will mean anything to you or anyone else.
Seastead this.
aerospace engineer Preston Carter has invented a concept for a next-generation hypersonic aircraft
Hey, I've got another concept right here: how about an aircraft that flies at 50 mach, takes 1000 passengers and 200 tons of cargo and makes an Earth round trip on less than a gallon of fuel ? Oh, it's also able to take off and land on a regular highway and it's silent. You may start booking tickets.
Seriously, is the above THAT more riduculous than the article-proposed ?
"The speed of today's aircraft has limited the growth of this market," says Carter.
Excuse me, but I don't buy it. I see only two situations when your business requires delivering stuff to the other side of the earth in an hour. One - you are a country at war. Two - you are an ISP. Since IP packets don't travel on planes, good luck with your super-hyper-sonic-next-gen-bomber.
I like my outfit, it's inexpensive, but cool -- April Ryan
The fact of the lift being upside or downside only depends on the angle of attack of the flight. You can always produce negative lift by flying upside but with a negative angle of attack (as measured from the zero-lift line)
All this is going to hinge on the development of a hyperspeed engine. Without same - nothing much happens. Of course there are projects underway that are making progress.
One of the issues one runs into is this. If one slows the air stream before initiating ignition then we have a situation where we lose fuel energy both through the compression and the reaccleration phases. In addition we are limited to what velocity the hot gasses can be ejected at. Of course - this happens in a jet engine as well because the turbine has to provide the power for the compressor and the blades have to be able to withstand the temperatures.
If we do not compress the air stream then we have very little time to burn the fuel. For example, lets take the projected 3 km/sec = 3000 m/sec. Since the craft is 25 m long we have about 1/120 seconds to burn the fuel before it is passed out the rear end. That corresponds to 8.3 milliseconds. If it takes this long to burn the fuel we'll probably get zero efficency since it will be out the rear end before any work can be done.
We can contrast this to an internal combustion engine. Since the burn is only useful on the down stroke, a burn time of 8.3 ms is equal to a time of 16.67 ms for a complete revolution. 16.67 ms per revolution = 1/16.67 revolution per ms x 1000 = 60 revolutions per second x 60 = 3600 rpm.
But this assumes the combustion section of the hyperspeed plane is 25 meters long which clearly is absurd. Suppose the combustion chamber is say 5 meters long - then we have 5/25 the burn time so this is equivalent to 5x the rpm and 3600 x 5 = 18,000 rpm.
By doing calculations like this one can see that high speed really imposes serious issues because you need to build a really long engine.
As for flying into space... the orbital velocity is about 27000 kph at 100 miles so we can see that our hyperspeed engine looks as if it has to be able to perform at probably 3x the speed contemplated.
IIRC it used to be the case that non-US airlines could fly to one city inside the US, but not offer onward legs or connecting flights within the US. I believe this has been relaxed somewhat in recent years, but foreign airlines are not able to compete properly in the US domestic market, nor are they able to buy controlling interests in American airlines.
Best wishes,
Mike.
Oh, I see... It's not specific to the US, btw. And even if the practice is theoretically allowed it remains possible for a country to keep protecting domestic airlines by keeping a tight hand on airport slots. But that's mostly politics in my eyes.
As far as I know, a Concorde used something like 10% of it's fuel to run the airconditioner, because it was pushing the thermal barrier (where the friction of the air heats plane to the point where the people inside get cooked).
:)
The Concorde was already a high flyer, to get less air friction, and considering the "air breathing" approach they mention in the article, I can't imagine they can go into much thinner air than the Concorde.
Or what?
If someone knows, educate me! point me to a link!
I remember reading about people studying how dolphins skin has the ability to counteract turbulance in the water flowing over their skin, which allows them to swim with an extremely low energy cost compared to many other aquatic animals.
Maybe mimicking this with nano-materials?
Give me liberty or give me kill -s 9
Most of the heating occurs at the leading edges, nose, wings, engine cowlings, windshield. With a larger passenger craft there is far more aircraft volume/leading edge ratio to aid dissipation of heat. Perhaps they can use some of it to warm the coffee better than tepid
The idea is also to fly far higher than an SR-71 (between 35 and 60km) so there will be less frictional heating. The article the article talks about the craft skipping across the top of the atmosphere like a stone skimmed accross a pond, you did read the article ?
Insulation on the leading edges does not need to be stronger than titanium, look at how the shuttle copes (mostly) with re entry at hypersonic velocities. The insulation is not that strong but protects the structural elements from the extreme heat.
All in it is a very different beast undoubtedly with a multitude of problems (Air breathing H2 engines are not exactly ten a penny) but just to claim it is impossible because the blackbird almost baked its crew in pie is probably not one of them.
Cheers,
R.
Maybe you live in interesting times
There are conductorless subways already, and nobody seems to mind much.
There will be pilotless aircraft sooner or later.
There is a powerful incentive to design pilotless fighters:
Current AA missiles can maneuver at 30g and a piloted aircraft is limited to about 10g lest its pilot passes out. There will come a time when piloted aircraft will be sitting ducks for missiles.
Once the technology has been developped for the military, it will only be a matter of time for it to migrate to commercial planes, just as was the case for fly-by-wire a couple decades ago.
There was also the fact that the planes were getting old and maintenance costs were escalating.
A Mach-2 plane requires a lot more attention than a subsonic one, and it's much more expensive to prolong its life.
Airplanes are becoming more automated already, and we can hope software will become more reliable in the future (really?), but as the article points out, in fully automated civil flight the individual aircraft will be only a piece of a larger systems puzzle:
So the bigger picture will include a radically "overhauled" traffic control system One with more traffic, doing more kinds of different things than today (such as free flight for example). And the question (in my mind) is: how does a fully automated airplane fit into this picture?
The airplane's computers will have to interact in non-trivial ways with the traffic control computers and --in the free flight scenario-- with the computers on nearby aircraft. These in turn will interact with other ancillary computer systems providing things like weather, data link, etc.
Suppose there are only 2 aircraft (A and B) in the sky in a given area. Computer A needs to interact with Computer B, and vice versa, so there are two interactions going on here. Add a third aircraft and since they all need to interact with one another the number leaps to 6 paths (A to B and C, C to B and A, B to A and C). Add an air traffic control computer (and yes, there will still be need for those even with free flight) and now we have 9 paths and so on. As more elements are added to the system, the complexity grows geometrically. And with it, the probability of a software error somewhere in this system also grows geometrically. There would also be a higher potential for cascading errors propagating through the system.
I think that getting a handle on that kind of complexity is likely to be a big challenge; even the 20 to 30 year time horizon the article mentions might be too optimistic.
For the technically inclined, the page on Computer-Related Incidents with Commercial Aircraft makes interesting reading.
- Gregg
We have found the enemy and he is us. - Pogo
They weren't that old though; their airframes were less than half of their estimated maximum lifespan. It was more to do with the fact that there were so few of them because they weren't all that popular in the first place; that was pushing up their maintenance costs- and nobody except British Airways made them pay, so they would have been maintaining them on their own. And after the crash, they suddenly weren't as popular, so even BA couldn't make them pay. If BA itself had been financially stronger they would have ridden it out, but post 911 there was no chance.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"The real reason they don't want supersonic flight is because these planes consume more fuel (which makes up most of the ticket price). Experience has shown that people are not willing to pay much more for faster travel. If a supersonic technology was available that was actually cheaper I'm sure the scheduling issues could be resolved really quickly.
Sonic boom is a real issue in flight over land.
By the way, there is *no* law of nature which says that a supersonic vehicle must produce shockwaves. In fact, there is a sniper bullet shaped to generate no sonic boom. It relies on symmetry for eliminating shockwaves so it cannot produce any lift. A shockwave-free supersonic glider is impossible but a powered vehicle could theoretically use some of the engine power to simultaneously provide thrust, lift and shockwave elimination.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
Planes that automatically change shape and repair themselves huh? Didn't we find something that could do this in the deserts of roswell, new mexico in the summer of 1947? With that stuff that looked like tinfoil that would unfold itself if you folded it up with no markings in it afterwards. Makes me wonder where we got the basic idea for this... :) We're still using the technology found their today. And still they deny it ever happened.
12 MWH/tonne of fuel is assuming 100 percent thermal efficiency. The TGV is electric powered (from a nuclear power plant in France?), but assume you generate that power in a Diesel-electric locomotive, perhaps 30 percent thermal efficiency is reasonable, and then you are in the range of 130 passenger-MPG, which is not too far off the capabilities of perhaps a propfan powered medium range airliner. If you are going to go that fast that close to the ground, it is going to take some power.
Fuel efficiency has a everything to do with the total weight, the lift/drag ratio, and the efficiency of the engines. A short range configured B-757 or Airbus A-320 comes in at around 1000 lb gross weight per seat (structure, fat U.S. passenger, baggage, fuel) while the longer range 747 comes in around 2000 lb/seat (more business class seats, cargo, more fuel load, the bigger plane takes more structure per seat than the smaller plane). The lift to drag work out to about 18:1 given current aspect ratios on wings -- boost the lift to drag and the weight goes up. A really good engine, like the PW 2037 on the 757 comes in at around .55 lb fuel per pound of thrust per hour. Assume jet fuel to be 6.5 lb/gallon (density .8). Assume cruise at 500 MPH. The 757 has 56 lb drag/seat, consumes 31 lb fuel/seat-hour, 4.7 gallons per seat-hour, or 106 seat-miles/gallon. The 747 comes in at half that -- around 53 seat-miles/gallon -- because it is heavier. Now the 757 is not going to achieve that on short range trips -- the taxi, climb, approach pattern fuel usage probably knocks it down to the 50-60 seat-miles/gallon range.
The Taurus gets 31 MPG average on the highway. It has about 100 lb of drag at the speeds I drive. If the engine was efficient as the PW 2037, the Taurus would be getting 60 MPG on the highway. The Taurus engine has to be oversized or I would have to be downshifting through several gears with every hill just like an 18-wheeler. Half of the Carnot-efficiency power is driving the wheels and overcoming rolling and aero resistance -- the other third is oil-bearing friction in the oversized engine with the remaining sixth the "pumping loss" for throttled engine operation. The 757 throttles its engines without pumping loss by flying at high altitude in thin air, and turbine engines don't have the friction losses of piston engines so they can operate "part load" using atmospheric "throttling" very efficiently.
Now for the train. The train is hyper efficient at slow speeds where aero drag is minimal and on flat level ground and with a minimum of starts and stops. When you make the train heavy (Federal safety standards), draggy (the only Amtrak train that is highly streamlined is the Acella), and have it climb the Western mountains, it starts using fuel.
L.A. Marre (1995) The Contemporary Diesel Spotter's Guide 2nd Edition, Kalmbach, Waukesha, Wisconsin, p 294 states that Amtrak experimented with a 9300 gallon fuel tender car to allow the Empire Builder to go Chicago-Seattle nonstop. Allow another 300 gallons for the tanks in two EMD F-40's, assume a 10 car train carrying 400 passengers (maybe 80 seats in a Hi-level coach, fewer in sleeping cars, no revenue seats in the lounge and dining cars), 2500 mile trip and you are at 81 seat-MPG at full load, and that train is generally sold out at least during the summer.
As I said, a single Diesel engine pulling a string of double-decker commuter cars probably checks in at 400 seat-MPG, but that is high-density seating, no dining car, slower speeds, and level ground. But if you pack a family of 4 into a minivan (25 highway MPG), you don't have to feel guilty about not taking the Empire Builder.
Private aviation does not have a safety record on the level of cars, and I believe a lifetime of driving can give you 1 in a 100 odds of dying in a car crash, so what does that may private flying?
Let me tell you why I mentioned John F Kennedy Jr. The accident has had enough celebrity notariety that the details of it are widely known. And the details speak volumes of the safety problems of private aviation. I am sure every Harry and Moe hanging around the local FBO is saying, "Yeah, like he shouldn't have tried a water-crossing flight with his level of experience" or "he should have called Flight Planning and they would have told him VFR flight not recommended." Tom Wolfe called it "the Right Stuff" -- the notion that Harry bought the farm but I Larry have nothing to worry because I would never do anything that bone-headed as Harry in an airplane.
From what I had heard, if JFK Jr. had left according to his original plan, he would have been OK, but he got delayed waiting for his wife and/or sister-in-law to get their rears in gear, and he took off into the sunset where the ocean and sky melted into a pool of hazy red sunset. Guess what -- you do the most rigorous flight planning and you get thrown off your game by the requirements of passengers or the have-to-be-there demands of family.
The worst part of it is driving from New York to Cape Cod takes what, 4-5 hours? Yes he could have been in a car smashup, but private aviation is indeed a high-risk undertaking.
Planes will crash resulting in loss of life. If you can't tell, I'm the glass-half-empty type.
-=- Many seek good nights and lose good days.