Supersonic and hypersonic commercial flights firmly in view [Boom Supersonic/Aerion]

It's a fairly small aircraft, with a length of just 21 meters (68.8 feet). But after a tough year for the airline industry, it symbolizes a big step forward in aviation history as the first privately built supersonic aircraft.

Every other supersonic aircraft up to this point — the European Concorde flown until 2003 and the Soviet Tu-144 flown until 1999, as well as many fast military aircraft — was funded by billions from state coffers and built with government mandates.

Startup Boom Supersonic from Denver in the US is different. It unveiled the first privately manufactured supersonic jet last October. The single-seat XB-1 is nicknamed Baby Boom. […]

The aim is to validate the aerodynamic concept and then basically build the same thing on a bigger scale — to result in the Overture passenger airliner for up to 75 passengers. By the second half of this decade, it is supposed to become a smaller-scale successor to the Concorde, which had a capacity of 100 passengers. The Overture will zip passengers from London to New York in 3½ hours at Mach 2.2 (about 2,700 km/h), faster than the Concorde. The company says it will use aviation fuel produced in a CO₂-neutral way. […]

Just before Easter, Aerion made an announcement that stunned industry observers. By the end of this decade, the company plans to make a quantum leap in fast air transportation with its AS3, another new jet. Up to 50 passengers will be able to travel for a maximum of 13,000 kilometers at Mach 4 (about 5,000 km/h) or even faster. This would mean an airliner would finally reach the low hypersonic region, which starts at Mach 5. …

No, that’s a good data point.

Note that the TFE-1042 was and is a military engine; no one has really adapted it to civil use, although it’s been proposed. F119 is a very good example of a supersonic fan jet and further makes my case.

Would note that this design is mid-80s, and Lockheed had no idea they were going to win the fighter, it came as a shock. But the engine/airframe match was really what USAF was looking for. Since then, they have not pushed into the civil world with the idea. At least not publicly. Guess they’re happy the AF is happy.

A civil supersonic jet need not be so agile, nor stealthy. And a civil version of F119 would be decades out of date now, but the basics would be the same in any upgrade/variant. Everyone knows how to do it these days.

So I agree, it’s an engine AND airframe from which “lessons learned” (eeek a Systems Engineering phrase!) can be used to create a viable high thrust, medium pax supersonic jet.

Until of course that Musk fellow finds his magical 400 Wh/kg Li+ battery and mates it to a high Tc electric motor...

If you ignore the F-22 and its super-cruise capability (its engines are a big part of its super-cruise capability).

The JP-8+100 fuel additive is critical and requires special handling when it comes to filtering water out of fuel. It works well in fighters since you can offload their entire fuel quantity into a truck and then into another fighter but airliner quantities would pose problems for the storage tanks and pipelines to the pits.

Um, I really don’t have time to debate the reality of supersonic cruise engines but with a little websearching, you can find many current examples, all of them with very good SFC and decades of flight history in their predecessor engines.

The Concorde also Supercruised for most of it's flight. Yes, it had afterbruning engines, but it did not use afterbruners for it's entire time above Mach 1.

https://en.wikipedia.org/wiki/Supercruise

One of the best known examples of an aircraft capable of supercruise was Concorde. Due to its long service as a commercial airliner, Concorde holds the record for the most time spent in supercruise; more than all other aircraft combined.

Yeah...the ideal is that you wouldn’t have to go to A/B at all but that’s impractical since you don’t want to have excess power just for the transonic drag rise portion (note the Cd(M) plot..), why not just burn through it. It comes down to “how long do we want to do that” and what’s the fuel consumption trade.

So Concorde with the old Olympus blow torches still qualifies as “supercruise” because they had enough power to maintain speed after the A/B shutdown, but only when far enough along the drag rise curve to make that effective.

From both a cycle perspective (and thus aerodynamic design) and operating economics the ultimate goal is to negate the need for an A/B, and the newer engines get pretty close. Some may meet this goal, note that was the case with some of the examples in the link.

So even a hoary old bird like Concorde proves the point...we have what we need to get there, just need the right mix for the market and the regulators (no pun intended).

Older Baby Boomers might remember “sonic booms” but few of our younger cohorts will have any clue.

Jets flying faster than the speed of sound create a shock wave in the air, and this shock wave causes a loud “boom” across the land area below. And I mean a BOOOOMMM!! The noise would make you jump, then you’d look around for a smoke cloud to make sure it wasn’t an explosion, or worse a nuclear detonation. Yeah, that kind of loud.

I don’t know the year that the U.S. Air Force outlawed supersonic flight over the continental U.S. but before then it was pretty common to hear the boom.

Don’t tell that to the Navy. They have already turned seawater into jet fuel and flew a mini with it. They are scaling up as we speak why? Because they have nukes and it’s cheaper to brew fuel onboard then tanker it half way around the planet with an AOR steaming 25 knots next to you. The cost can be $400 a gallon for fuel delivered to an FOB and easily $25 for an underway replenishment. The point is the technology is well proven to make liquid hydrocarbons from CO2,CO, and H2 gasses the Germans did it by the millions of gallons in WWII the South Africa’s do it by the 50,000 bbl a day every day at market prices from gassified coal. AUDI is making synthetic diesel from wind and solar and also synthetic natural gas you can buy an AUDI in Europe and fuel it 100% on wind power they add in to the national gas grid and then the CNG stations pull out an equivalent amount for the AUDI to use. It’s just chemistry not all that difficult chemistry at that it’s 1930s technology. Cost has always been the issue. Germany had plenty of coal and little oil, same for South Africa. AUDI is going after the greens who are willing to pay a premium for designer fuels. The Navy has a cost and tactical advantage to using synthetic kerosene. These airlines also are going after the rich greens who won’t even blink at spending an extra $500 or $1000 for designer fuels when the ticket prices will be like Concorde which in inflation adjusted money got as high as $13000 one way fares like that are not for the plebs so it doesn’t matter if they add 15% to the fuel cost for “green” fuels it’s a selling point that has more value to their target clientele which is not anyone on this board very few here can afford a 20,000 dollar trip which is what a mach 4 trip would cost if not more.

Successful or not, the real innovation here is that these are private sector efforts. In the fifties and sixties even the US was big into central planning for anything new like supersonic transport and space travel.

As a result, it only took a few lies circulating in congress to kill or sabotage such efforts. Elon Musk is a lot more resistant to some outlandish environmental whacko’s absurd fantasies about the ozone than your average room temperature IQ congress critter who only cares about cash and getting laid.

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