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A New Engine Could Bring Back Supersonic Air-Travel (economist.com)
An anonymous reader shares a report (may be paywalled): Every morning, time once was, a giant roar from Heathrow Airport would announce the departure of flight BA001 to New York. The roar was caused by the injection into the aircraft's four afterburners of the fuel which provided the extra thrust that it needed to take off. Soon afterwards, the pilot lit the afterburners again -- this time to accelerate his charge beyond the speed of sound for the three-and-a-half hour trip to JFK. The plane was Concorde.
Supersonic passenger travel came to an end in 2003. The crash three years earlier of a French Concorde had not helped, but the main reasons were wider. One was the aircraft's Rolls-Royce/Snecma Olympus engines, afterburners and all, which gobbled up too much fuel for its flights to be paying propositions. The second was the boom-causing shock wave it generated when travelling supersonically. That meant the overland sections of its route had to be flown below Mach 1. For the Olympus, an engine optimised for travel far beyond the sound barrier, this was commercial death.
That, however, was then. And this is now. Materials are lighter and stronger. Aerodynamics and the physics of sonic booms are better understood. There is also a more realistic appreciation of the market. As a result, several groups of aircraft engineers are dipping their toes back into the supersonic pool. Some see potential for planes with about half Concorde's 100-seat capacity. Others plan to start even smaller, with business jets that carry around a dozen passengers. The chances of such aircraft getting airborne have recently increased substantially.
Supersonic passenger travel came to an end in 2003. The crash three years earlier of a French Concorde had not helped, but the main reasons were wider. One was the aircraft's Rolls-Royce/Snecma Olympus engines, afterburners and all, which gobbled up too much fuel for its flights to be paying propositions. The second was the boom-causing shock wave it generated when travelling supersonically. That meant the overland sections of its route had to be flown below Mach 1. For the Olympus, an engine optimised for travel far beyond the sound barrier, this was commercial death.
That, however, was then. And this is now. Materials are lighter and stronger. Aerodynamics and the physics of sonic booms are better understood. There is also a more realistic appreciation of the market. As a result, several groups of aircraft engineers are dipping their toes back into the supersonic pool. Some see potential for planes with about half Concorde's 100-seat capacity. Others plan to start even smaller, with business jets that carry around a dozen passengers. The chances of such aircraft getting airborne have recently increased substantially.
30 minutes to any city on earth sounds pretty good, and I am pretty sure SpaceX will be getting at least one such commercial flight out in the next five years or so... they also can carry 100 people at a time, and passengers get a free sub-space visual to boot.
Even supersonic would look pokey next to that.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
So you just need to scale up the F-22 to carry 100 people!
Would still be a cheaper program than the F-35
The only thing necessary for evil to triumph is for it to be pitted against a slightly greater evil
Slashdot remains a target-rich environment filled with consumers who are easily persuaded by flimsy promises
What is flimsy about such a prediction? The BFR is flying just next year. It's not hard to see them putting up at least one commercial flight within the next five as a test of viability, after all it has a huge attraction for flights like NYC to Australia which otherwise take a very long time. Tickets would sell like hotcakes.
Why don't we go ahead an speculate on which flying cars we'll have in five years while we're at it?
That's actually about five to ten years out, made possible by self driving car tech. it was never going to happen when humans were the ones flying the car, which is why we've never really see that come about even tough every now and then you read about flying car designs. Just like self driving cars, the first applications will be taxis more than personal transport, though that too will come.
What never ceases to amaze me about Slashdot is that people used to technology, can be such negative luddites despite years and years of being shown technology can make amazing advances quickly when conditions are right.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Drag is really bad from just about Mach 0.8 to about 1.8 or so. That doesn't have anything to do with the engines or anything else you can control. It's a constant known as cD that isn't largely independent of aircraft design.
Meaning you need to cruise at about Mach 2 to have reasonable efficiency in terms of drag.
Supersonic flight isn't just "subsonic flight, but faster". The design of a high speed aircraft is all about how the air flows around the aircraft and through the engines. At Mach 1, which is kinda like "the maximum speed of air", that totally changes. Things work completely differently.
So you have to design your engine for Mach 2, your airframe, etc. All of these will be designed very differently than they would be for subsonic flight. Especially if you intend to fly over land, you're going to need to fly subsonic a significant portion of the time (plus you need to take off and land, and you're not landing at supersonic speeds).
So you have a problem. You need a plane designed to work very well at Mach 2, and it has to be designed to work well subsonic. These are two very different designs. It's hard to have the same plane do well with both. It's kinda like designing an ocean-going ship that's also a bicycle.
TFS does list a handful of the issues with commercial supersonic flight, and I do think that there may be room for those smaller planes. However, supersonic flights have increased competition...
1.) "The cost of three hours". NY to Heathrow is a 7-8 hour flight using standard jets. NY to Heathrow at mach 1.4 is 3-4 hours. If the cost of a ticket is triple, then those three hours have to be worth thousands of dollars *and* there has to be a reason why "fly the day before and book a hotel" isn't practical.
2.) First Class. For the cost of a supersonic flight where every seat is basically a coach seat, passengers can get posh seats that go completely horizontal and get good food and entertainment. A better flight experience can make the 3 hour difference far more tolerable. Concorde didn't have that, and the cost of a first class seat on a supersonic flight would be so exorbitant that it could only be afforded by people who probably have their own private jet anyway.
3.) Telecommuting. Some things still need to be done in person, but Zoom and WebEx have made it possible to have multi-continent, real-time teleconferences. A meeting that would cost a company tens of thousands of dollars to arrange to get everyone in the same room in such a tight timetable that a three hour difference is worth the cost *might* happen once or twice a year, but dozens of teleconferences in between make those cases exceptional at best.
4.) Fuel costs. It takes a LOT more fuel to run a plane at supersonic speeds. Even a small change in fuel costs will drastically impact per-passenger profitability for a flight that's as fuel hungry as supersonic. Yes, planes are lighter now, and yes, this is less of a deal on the smaller planes, but it's still a big deal to airlines, and the tightrope walk between "keeping it profitable" and "keeping the costs low enough to justify using this service over the other options" may very well mean that even a modest bump in fuel costs turns a 1% profit into a 1% deficit.
Commercial supersonic flight is very, very difficult to do profitably.
London-NY subsonic: 7.5 hours
London-NY supersonic: 3.5 hours
Waiting at the check-in desk, checking in, waiting in line at the airport for the security theater, walking the airport's corridors, waiting at the gate, boarding, taxiing, landing, disembarking, walking some more, waiting at the baggage claim, etc: 3 hours if you're lucky. That's assuming flying supersonic isn't reserved for rich fucks who get to fast-track the whole process of course...
Conclusion: if you want people to travel faster, it would make more economic sense to reduce the time it takes *before* and *after* the flying proper.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Concord supercruised as well. That capability wasn't sufficient to make it profitable.
The term "supercruise" isn't all that well defined. There are several military aircraft that can sustain supersonic speed without afterburner given enough altitude and limited or no external stores. The F-22 is just a new degree of supersonic capability; it can perform most of its mission above supersonic speed including weapon deployment and aggressive maneuvers at lower altitudes that previous combat aircraft.
Maw! Fire up the karma burner!
F-22 has engines that provide so much efficient thrust, it can cruise at supersonic speeds without using the afterburner.
So did the concorde.
It didn't need afterburners to accelerate Mach 1, it was simply more efficient to do so. The concorde cruised at Mach 2.2 without afterburners running, which is somewhat faster than the F-22 can supercruise.
SJW n. One who posts facts.