Will SST make a comeback?
 

Not going to happen. Ambien actually gets you from SFO to SYD a lot faster. In about 30 minutes....or at least at feels like it.

AND it’s a hell of a lot cheaper.

lol, knock me out, throw me in the cargo hold and wake me up when we get there, just as good as teleportation.

There are several plausible SST's in development right now.

One small-ish airliner and a couple bizjet concepts.

With modern technology, I'm sure you can make an economic case for the bizjet... high-end millionaires and billionaires have literally nothing else to spend their money on.

The FAA is seriously looking at rescinding the speed limit too... NASA and others are researching "low-boom" configurations to soften the boom.

Technology isn't the real challenge here, it's economics. We know how to fly supersonic aircraft, been doing it for nearly 70 years. But how to do it and make a profit?


Regarding the boom, I am betting that the military has figured out a way to neutralize it for their stealth ops.

Yes, technology is enabling more efficient aircraft, especially airframes and engines.

Actually not so much, they haven't bothered. Bombers and attack aircraft are mostly subsonic, or in the case of F/A aircraft they would typically do the attack phase of the mission subsonic. Even if they were supersonic the plane would be on egress before ground forces heard the boom... by definition.

If a deep penetration mission was flown supersonic, the route might be selected to minimize exposure to sites which might detect a boom.

A boom is irrelevant for the fighter mission, nobody in another aircraft is likely to hear a boom under any tactically useful circumstance, and even if they did it would be far too late... the fighter arrived before the boom, and the missiles even sooner (they are very supersonic...).

Some subsonic transport aircraft and helos have noise reduction technology to minimize the risk of alerting ground forces on the objective. But that's not at all related to boom reduction.

What makes an SST impractical is the economy of scale to build it. There just are not than many routes that would benefit from Mach 2 vs. Mach 0.85. All the routes that could support an SST are trans oceanic. I mean even a flight from LAX to JFK would not be materially shortened by supper sonic flight when block time is considered. Taxi time in an SST is the same as a turboprop. Time in the speed restricted environment of terminal airspace is the same for an SST as a high subsonic jet. So, MAYBE a flight from LAX to JFK would cut an hour off of block time. How much is an airline willing to pay for a brand new (unproven) airframe that will require retraining of mx personnel and an additional box of spares just so they can say, "We get you there a little faster"?

So, only ultra long haul routes can justify the cost for the airline. But look at the A380. No real problems with the design, but it isn't selling. Airbus may lose a ton of money building a fine aircraft that nobody buys.

Kinda reminds me of the L1011.

No company will spend the zillions of dollars to design, build, and test an aircraft that will only sell 50 airframes.

They can probably do that for the bizjets. There are way more than 50 billionaires out there, and they'd all like to have one. There are very few more unique toys to spend that kind of money on.

Agree the airliner is a harder case.

Re. the A380... sounds like they might be about to shut that thing down early. Wouldn't surprise me if they end up buying them back eventually, just so they don't have the product support liability. The last one might even arrive at the recycler before the last 74 rolls off the line.

https://boomsupersonic.com

With a similar seating capacity as an E145 (roughly half of the original Concorde), could this be economically feasible?

I've been watching these programs for a while. They are moving forward, and being funded, faster than I expected. Including engine development, which is the real long pole since they can't use an existing engine unless it's a 70-year old fighter engine which would not be environmentally friendly or reliable.

I suspect if the bizjet(s) succeed, that will generate a market of premium travelers who can't afford their own SST but also want to cross the ponds in half the time. There is probably a sufficient over-water market without having to worry about sonic boom regulations (most of the really long stage lengths are over water).