Will supersonic aircraft ever be commercially viable?

Great Debates
21

The biggest problem with the SSTs that were designed in the early 1970s was that they were not a fundamental improvement in technology. They achieved increased speed simply by having narrower cross sections and more powerful engines- in other words, they were race horses, not work horses. Jets replaced prop planes for long-distance travel because turbofan engines had higher thrust for their weight and at high-subsonic speed could operate as efficiently as propeller planes, primarily due to flying at high altitude against lower air resistance.

A “true” SST would be one that had some fundamental improvement in engine design that would allow it to function efficiently at very rarified altitudes, cutting drag (and therefore fuel consumption) to the minimum. You would know it had happened when you achieved a design that was actually more efficient for distances of over three thousand miles than a subsonic plane.

22

That’s hilarious. That one paragraph is enough to tell you that this is a crackpot notion. The idea that a supersonic jet which still has ‘much design work to be completed’, and which doesn’t even have a manufacturer lined up, could be delivered to customers in 7 years is beyond fanciful.

In comparison, the Airbus A380, a very conventional if large jet, had its design frozen in 2001, was already budgeted and had facilities being constructed for manufacture by Airbus at that time, and even so the first one didn’t enter service until the end of 2007. And that’s a remarkably fast turnaround for a large jet. And that was only possible because so many off-the-shelf parts could be used.

I can’t imagine how long it would take just to get through the certification trials for an SST today, and how long it would take to ramp up production for a jet that is all new from nose to tail, and for which existing simulators and flight dynamics software don’t exist.

My guess is that if there was a prototype of an SST already under construction today, you might be lucky if you saw the first production model enter service by 2020.

23

Aerion is taking the most sensible approach currently, businesswise. I wouldn’t recommend investing in them, either, though.

There might still be a marketable speed advantage for bizjets over the Pacific, but it won’t come free - count on smaller, less-comfortable cabins in the meanwhile for the Captains of Industry who might buy it, compared to a Gulfstream V or such. And what’s the advantage, in the age of satellite Internet hookups available even from a plane?

24

I think that they will become commercially viable because I think that the costs of fuel will continue to shrink. Yes, avgas has gotten more expensive in the short run, but over the long term, the trend has been for energy to become cheaper and for aircraft to become more efficient. I have to think that, someday, those curves will intersect in a way that makes SST cheap enough for commercial use.

Maybe not in our lifetimes, though.

25

Have you been inside a Gulfstream? They’re incredibly small - I can’t stand up straight in some of them.

26

It makes a nice model, though. Multiplex released a foam kit (named “Sonic Liner”) which has had a bit of a following. :slight_smile:

27

Before Concorde went into commercial operation the R.A.F. flew over urban areas at supersonic speed deliberately to test the effects of sonic booms on ordinary people.

I in fact heard one of these and it was a pretty much a non event.

No pregnant women going into labour,no stampeding herds of cattle or even the odd driver colliding with something in shocked startlement at the immensity of the sound.

It was reminiscent of all the warnings given by people about the effect that steam trains would have on livestock etc.when the first railway was being constructed.

Rightly or wrongly many people on this side of the pond believed that the U.S. government was indulging in a little bit of protectionism at the behest of Lobbyists for the American Aerospace industry.

28

You may be underestimating American NIMBYism and prissiness. It is just about impossible to get anyone in the U.S. to agree to such necessary things as landfills, refineries, nuclear reactors, let alone a not-obviously-necessary thing such as an SST flying over them.

Plus, the anti crowd would have available to them the latest theories about nitric oxide emissions being very very bad in the stratosphere, which would not necessarily have been a talking point available back in the '60s and '70s.

Although of course I agree with you it’s not that bad.

29

True, time is money - but the really expensive time is time spent out of touch with one’s work, not time in transit. It used to be that this distinction wasn’t important - if you’re traveling, you’re out of touch. Now, however, that simply isn’t so.

Here’s my low-end example, as a student. I’ve got an interview in NYC in a couple weeks. (Hurray!) I have a choice between a $40 round-trip bus ride from DC, roughly four hours each way, or a plane hop, which is less than an hour each way, but over $100 round-trip. (I could also take Amtrak, but that’s almost as expensive as the plane, and little faster than the bus.)

Now, I’m actually fairly busy, even though I’m still living the care-free (hah!) law student life. I don’t want to be out of touch with my classes, clinic, etc, longer than I have to. But here’s the thing: the bus has free WIFI, and power outlets. That means I won’t be out of touch - I can do my work, and even collaborate with classmates, on the bus. I can’t do that on a puddle-jumper to NYC, and I have to pay to do that in an airport. So, the bus is the more attractive option - it’s slower, but it’s also cheaper, and most importantly, the time that I can’t communicate with other people is almost nill.

The same calculus holds true, I suspect, for international flights. Given a choice between paying more money for a faster flight, in which I’ll still be incommunicado, and paying a smaller premium for a slower flight with internet access (or even power outlets!), the latter option is much more attractive.

30

Question about the Sonic Cruiser - it seems like the big challenge with that thing would be keeping it below Mach 1. I mean, if your cruising speed is just a hair below the speed of sound, isn’t there a real danger that you’ll nudge a bit over fairly over? Or am I missing something obvious? IANAAE (I Am Not An Aeronautical Engineer.) Academic, I guess, since the thing won’t be built. Shame, though - it’s a pretty airplane.

31

The speed of sound is 770 mph. The maximum proposed speed for the Sonic Cruiser was Mach .98, or about 754 mph. Given that aircraft ramp up to their cruising speeds pretty slowly, that 16 mph gap should be pretty easy to maintain. I would imagine there are lots of reasons (air traffic control, fuel conservation, avoidance of stall) why modern aircraft have pretty precise avionics that allow very precise monitoring and control of airspeed.

32

Isn’t there a pretty dramatic nonlinearity in power needed to increase speed once you apprach the sound barrier? I.e. that last 16mph is pretty hard to do even if you wanted to?

The other thing mitigating against SSTs is that nowadays airports are shitholes. Congestion on the way there, delays, security, crowds, the lot. Given the choice between:
[ul][li] a small semi-private airfield at each end with only a few minutes separating limo and plane, plus a six-hour flight in a well-appointed private jet[/li][li]a huge crowded TSA-infested commercial hub at each end and a three-hour flight in a small but still public SST[/li][/ul]
Many people in the target market would prefer to go with the first option.

On the other hand:

These people all went bust by trying to run a biz-class operation from shitty airports which were miles outside London. All those bankers objected to the lack of fripperies which they expect for spending thousands of other peoples money.

Personally I’m waiting to see if BA manage to get their planned LCY-JFK route off the ground - they were hoping to use an all-business A320, which into LCY would be :eek::eek::eek::eek::eek:

33

If you want more info on the device, google “quiet spike”. I’m not sure what is public knowledge at this point, but there’s alot out there.

Have you? Other than a G100? The GIV’s and GV are anything but “incredibly small”. Unless you’re taller than 6’ you should have no trouble standing up in them.

34

Stansted is not utterly ridiculous, given that there’s an express train there, and when I’ve flown through there, I’ve found it relatively friendly (of course that is compared to the horror that is LHR security).

But calling Luton a “London” or even “London-area” airport was a bridge too far.

Had not heard about the LCY proposal but it does look as though BA is trying to mimic some of what the other three failed at – they note in the below article that they are going to allow you to show up as late as 15 minutes before takeoff, which several of the all-business airlines also offered. I note as well that they are actually using something smaller than a A320 – it is an A318, which is sufficiently small that they are going to need to refuel in Shannon on a Westbound flight (it’s nonstop Eastbound). Sounds kind of nice, and I know BA has a pretty good BC/FC product.

http://www.elitetraveler.com/news_detail.html?nid=432

35

Kubla Khan was born too soon. :slight_smile:

36

Well, I get the feeling he did all right for himself down on the banks of Alph, what with the slave girls and such.

But this is not too shabby either:

37

I used to work at their maintenance depot in Luton. :slight_smile: A lovely place to work, BTW. We saw all sorts.

I didn’t have much to do with the aircraft themselves, but I had to go into them from time to time.

I’m 6’4". :frowning:

BTW when you go in, you have to take off your shoes if you’re not wearing the special shoes, and I was still to tall.

38

Ah, the lovely stansted “express”. Not used it lately, but it used to be dirtier and more crowded than my regular commuter train, and only the Brits could call something an Express which takes 45mins to cover 50km.