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Successful Supersonic Jet Launch
Cave_Monster writes "Japan has hailed the test of a supersonic jet in South Australia's outback as a success. Unlike the attempt in 2002, this test saw the jet launch successfully from Woomera, South Australia." From the article: "Data gained through the test will be used in joint research by Japan and France towards a next-generation supersonic jet. No budget projections have yet been made for the entire project, which Japanese hope will produce a supersonic passenger jet capable of flying from Tokyo to New York in just under six hours - less than half the current time of a Concorde." We reported on the plan to do this, earlier.
This is the ultimate dupe...the "Tokyo Express" was conceived in the late 60s, IIRC. The US Gov't offered plane builders a million dollars per mach number in hopes of having a supersonic, near orbital plane get from New York to Tokyo in a few hours. It never got done.
Or as Ben Rich, former head of the Skunk Works, said it wouldn't matter if it was a billion dollars per mach number.
After you wait another century for it to be built. The Blackbird pilots (~ Mach 3) wore a rather complex suit to stay alive, it got up to several hundred degrees (F) in the cockpit. The cooling system needed for a Mach 3 or (or 5!) passenger (businessmen in thin shirts) would be ridiculously large/heavy, if even possible.
Considering that NewYork and Tokyo are just about on opposite sides of the world, i would suggest that they do an "over the top shot" and go via the North Pole.
By going that route, so long as the plane could pass the required regulations for minimum safe distance from a landing zone ( sorry i cant remember what its called ) , they would be able to do just about the entire flight with out coming anywhere near land at all.
Take off and landing aside.
I think it would be cool to travel Mach 2 on a commercial airliner.
:)
So do I. Incidentally, the concorde flew at mach 2
tm
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http://www.google.com/search?q=boomless+supersonic +flight
Aint Google a wonderful thing.
For those, like me, who had trouble visualizing the flight path, here's the great cirle route. To my surprise, the most direct route is mainly over land.
Sooo... flying from NY to say London and going over that "nice warm" North Atlantic Ocean is soooo much safer..
m l
8 45.htm
.. you have a greater chance of dying by "driving your car" to the airport, than you have of dying by the plane falling out of the air.
look at the odd's , crunch the numbers.
the USA has about 40K ppl die per year from car crashes, and about 25 - 30 K from assaultings ( shootings , stabbings etc )
http://www.the-eggman.com/writings/death_stats.ht
** snip **
In the US, each year there are about 40,000 deaths per year in automobile
accidents vs. about 200 in air transport. To put this in perspective, the
chance of dying in an automobile accident is about 1000 times more than
winning a typical state lottery in a year.
http://www.newton.dep.anl.gov/askasci/gen99/gen99
Sooo yeah
but even with that said, if you did go down in the North Atlantic, at least you wouldnt have to worry about the pain for more than about 3 or 4 mins.
Actually, "over the top" flights are the standard procedure for the suggested New York to Tokyo and similar flights. Happens every day.
The people who would take a flight like this, at least initially, would be the kinds of people who could be given a special pass to speed through security and baggage check: business executives, financiers, wealthy celebs, politicians (excepting senior senators from Massachusetts), and the like. In a world population of six and a half billion, there's only a few thousand of these people, maybe a couple tens of thousands at most, who would be using this flight as a speedier replacement for private or company jets. With this relatively miniscule customer base, it wouldn't be hard to prescreen them all.
Hell, airlines already have the apparatus in place with existing programs: "When they make the cut, Global Services members are issued a black Global Services card, a leather-bound welcome kit and phone numbers of agents trained to see after their needs. Then the fun begins. The chosen ones are escorted through the security line and ushered into secret waiting lounges..."
And besides, for some of these people, time is the most valuable asset they have. Shaving a few hours off a flight, even supposing they still have to endure the rubber gloved finger in the ass, is a priceless extra few hours they can spend with their families, their consorts, or whatever.
At Mach 10, you're talking a shade over 1 hour, 10 minutes. This assumes that the Australians (the only ones with a working Scramjet) can build a commercial version. If you're having to rely on a conventional ramjet, efficiency drops dramatically above mach 6.
The Americans abandoned the advanced passanger airliner project (which was blended-wing) in the late 90s, and there is no obvious indication that NASA has done much work on waveriders - some, mostly by being beaten to it by a bunch of Scots (and they were amateur rocket enthusiasts at that!) - but really not much. The US military seems to be much more interested in slow-moving ROVs and fully-automated robots, so don't look to them for producing anything worthwhile any time soon.
The Australians have the Scramjet, but nothing to speak of to put it on. The joint efforts by the Russians and the ESA to produce an orbiter seem to be stymied by the religious belief in rockets for everything. What we need is either someone who can get these two groups together (a particle accelerator might overcome the repelling forces) OR a non-aligned group with sufficient financial and intellectual backing to reverse-engineer from existing work a combined solution.
Last one to hypersonic mass transit is a chicken!
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
A typical flight from NRT (Tokyo/Narita) to JFK (John F Kenedy Airport, NYC) mapped here.
As you can see, the great circle distance goes over the north pole. Even if you turn on ETOPS-120, most of the ride is north of the 48 contigious states. It does go over Alaska, but I think they would be able to maintain supersonic speeds until it starts to cross over populated areas of Canada (the last 10% of the flight).
The Doormat
If you're not outraged, then you're not paying attention.
You know, if it was as easy as you make it sound, we would have done it by now. Not only are there problems with the technology (a large one being heating of the skin due to aerodynamic friction), but just by the nature of the physics, it'll always cost you several times more fuel to fly at high mach numbers than at low ones. You don't even need to be an aerodynamicist to understand it. Drag goes up with the square of velocity, you figure out what that does to fuel consumption. Existing turbofan engines are extremely efficient, yet airlines still can't turn a profit. You think the solution is to make airplanes that are even less efficient?
A deep unwavering belief is a sure sign you're missing something...
IIRC there's also a problem with heating. The SR-71 Blackbird (~Mach 3) for instance had the fuselage lined-up properly only when heated up by in-flight air friction (and as a consequence it leaked fuel on the runway, as the fuel sealing had a similar problem handling temperature variations) This could probably be fixed, but will require a cheap enough and easily maintainable thermal shield - unlike the shuttle's tiles. Not to mention that it will make for a hell of a hot plane upon landing, which for commercial uses can be ... cumbersome to handle.
All in all, the engineering challenges for going at Mach 3+ are quite impressive.
in JAXA's home page you can find a video of the launch and some more technical info.
Airbus is likewise trying to get EU funding for the 350 (which is a 787 clone), but it is illegal per a deal that clinton cut (basically allow Airbus one last gov. funded, but then no more). What is interesting is that Airbus is still getting subsidies even though they (and american gov.) say otherwise. Roughly, we acted tough for the last 5 years, but the EU gov. is still subsidizing it via low-key approachs. But you we are now proclaiming a victory (kind of like Sadaam proclaiming that he won against us).
This is completely wrong. The US and the EU agreed in 1992 (the Trans Atlantic Aerospace Agreement) that launch aid was limited to 33% of hte projects cost, funded at Government borrowing rate + 1% and was capped relative to the manufacturers gross income at any one time. Airbus has simply been using LEGAL funding under that agreement (which was available to all manufacturers on both sides of the Atlantic). Noone has claimed that Airbus hasnt received loans from the EU governments.
On October 6th, 2004 the US withdrew from this agreement but it contains a 12 month termination clause, allowing the EU to offer funding for the A350 program. EADS, the main Airbus shareholder, has already said that it will forgoe launch aid on the A350 and fund it entirely inhouse.
The FAA restricts the noise not the speed of aircraft going over the US, so keep it quiet and you can go as fast as you want.
Wrong. Take a look at Federal Aviation Regulation 91.817
91.817 Civil aircraft sonic boom.
(a) No person may operate a civil aircraft in the United States at a true flight Mach number greater than 1 except in compliance with conditions and limitations in an authorization to exceed Mach 1 issued to the operator under appendix B of this part.
So, even if you manage to solve the sonic boom issue, you still need to obtain an authorization from the FAA to operate at supersonic speeds over the US.
Kevin Horton
Some smaller airports does not have any problems with the security and baggage. On my local International Airport I have never used more then 15 minutes from leaving the plane, to standing on the platform for the airport express train. Same with checking in. I have never used more then 5 minutes in line to get to the plane.
Why is this not possible on a larger airport?
Is it a airport design flaw? Is it because you have to screen your hand luggage multiple times? Or show your passport 4 times? What are they actually looking for in the 2 seconds they are checking? Oki, my name was not "Saddam" or "Osama" when the first security guard checked it. Do they think I changed my passport while waiting in line for the next check? Does it take exponentially more time to handle more people? Please tell me what the problem is!
So I take it the pictures of British streets strewn with shattered glass during the Concorde's high speed trials are just figments of the worlds collective imagination?
According to this source, the overpressure of the Concorde was about 16 pounds per sqare foot (PSF), or a little more that 0.1 psi. This level "will not cause material damage to any structure in a reasonable state of repair", subject to their definitions of material damage and reasonable state of repair. That level of overpressure, combined the short-duration square-wave nature of the pressure signal tend to make the impact somewhat more significant than the 30-mph (50 kph) wind they compare it to. It also doesn't account for the presence of other factors, ie: a window that is already stressed by a 30 mph wind will shatter more easily than a window that is not stressed.
Finally, there were designs on the drawing board for an American SST, but Congress pulled to funding. And the real money (particularly now) for airlines has been on international routes because various bi-lateral agreements limit capacity and city-pairs, driving up fares. Domestically, the mid-course speed benefits of an SST are mitigated by the more fixed-speed ground and departure/approach legs of the flight (fly United and listen in on the ATC comms, flying into San Francisco you might hear orders to reduce speed for 'traffic flow' somewhere over Utah).
With numbers (and some assumptions):
Wikipedia gives speed of sound at 29,000 m (where the X-43 flew) as 301 m/s. Mach 10 would therefore be 3010 m/s.
1g is 9.81 m/s^2. Assume a constant acceleration of 0.35g, so we don't spook the elderly. 3010/(9.81*0.35) = 877 seconds to get to Mach 10.
Double that because you have to accelerate and decelerate. 1753 seconds. Average speed is Mach 5 for acceleration and deceleration periods. 5*301*1753 is 2639km travelled accelerating and decelerating. If you're flying New York to Frankfurt, that leaves (6205-2639)=3566 km to travel at top speed. That takes 1184 seconds. So you'd spend 19.75 minutes flying at top speed, and 29 minutes accelerating and decelerating for a total trip of just under fifty minutes, which ain't bad no matter how you slice it.