Talk:Supersonic transport

Less Aerodynamic?

"Supersonic airliners are significantly heavier, less aerodynamic..."

I think this comment is weird. Supersonic aerodynamics is different than subsonic aerodynamics. A supersonic airliner should definitely designed by taking supersonic aerodynamics into account, indeed assigning a higher weight to it. This in turn reduces the subsonic efficiency of it. Bu it is not correct to say that it is "less aerodynamic than subsonic aircraft", because it lacks a basis for comparison.

"Less aerodynamic" is either concise to a point of ambiguity or wrong. SST's supersonic aerodynamic qualities do make designing adequate low speed performance difficult, but overall SST require much more stringent aerodynamic features. The entire paragraph (and the entire article, for that matter) seems to have been written by somebody with a negative view on SSTs. Mwace (talk) 08:40, 26 January 2010 (UTC)

A supersonic airliner has of necessity, to spend the majority of it's time in the cruise at supersonic speed, so it's designed to be as efficient as possible at this speed. It's not in any way inferior aerodynamically to a subsonic airliner, they are both flying in completely different regimes. The supersonic airliner is optimised for supersonic cruise, the subsonic one for subsonic cruise. The requirements are substantially different. Any perceived deficiency in efficiency on the supersonics airliner's part is just part of the price paid for the much greater speed/reduced flight time. A supersonic airliner flight gets you there faster than a subsonic one - but you (the customer) have to pay for the greater speed. Greater speed always results in using more fuel. It's been like that since the early days of flight. — Preceding unsigned comment added by 80.4.57.101 (talk) 20:55, 5 December 2011 (UTC)

BTW, Concorde's fuel consumption at subsonic speeds was the same as any subsonic airliner: [1] — Preceding unsigned comment added by 80.4.57.101 (talk) 09:14, 25 December 2011 (UTC)

According to "High Speed Dreams" by E. M. Conway, the state of play at the end of the NASA High-Speed Commercial Transport program in 2000 was that Boeing and other contractors had failed to account for the accelerating trend to reduce aircraft takeoff noise. Each iteration in standards driven by improvements in subsonic transport engines further constrained the design space for the HSCT engineers. The supersonic engines grew in weight, severely impacting airframe and wing design, and ultimately the takeoff weight grew too high to be commercially viable for 250-300 passengers. The other trend was that HSCT engines would always be higher maintenance than subsonic, greatly diminishing time between refurbishment. The airline-imposed constraint that seat costs be only 15-30% higher than subsonic, effectively no discount economy and more business/first seating, could not be reached. The climb-out was also much more protracted than a subsonic because the structure is optimized for supersonic flight. NASA found that one would hear the SST 20 miles away during this phase, transitioning into a muted sonic boom over water as the airplane accelerated to its Mach 2.4 transoceanic cruise. — Preceding unsigned comment added by 24.136.205.244 (talk) 11:31, 3 May 2012 (UTC)

FWIW, the supersonic airliner is probably dead for the simple reason that after the fuss made over Concorde and the subsequent banning of overflights no airline is going to risk money on an airliner that may be 'hobbled' by future flight restrictions by national governments. And because of the possibility of a lack of sales to airlines, no company or companies are going to invest the substantial sums needed in developing a next-generation SST.

So when you are reading this is in the year 2050 on your dreary 6-hour and longer flight to wherever, you know who to thank for the reason why you are still travelling at no more than 600mph. The world had its chance at widespread 1400mph supersonic travel with Concorde, and the world blew it.

In February 1985 a BA Concorde made a trip from Heathrow Airport in London to Sydney Airport on the other side of the world in a total time of 17 hours, 3 minutes.[2]

That meant that you could in theory get from anywhere on Earth, to anywhere else on Earth, in less than 24 hours.

Think about it. No matter where in the world you are, you could get to anywhere in less than a day's travelling.

Concorde could have made the London-Sydney trip in around 15 hours, but had to slow down on some over-land parts of the journey.

As of 2015, that 17-hour London-Sydney trip was thirty years ago. As a flight record, it also still stands. — Preceding unsigned comment added by 95.148.220.131 (talk) 11:20, 13 September 2015 (UTC)

Concorde G-BOAD flight from Vancouver, BC to Kona, Hawaii = 2 hours 54 minutes.

same aircraft - Kona, Hawaii to Nadi, Fiji = 3 hours 2 minutes.

... and Nadi, Fiji to Sydney, Australia = 1 hour 59 minutes.— Preceding unsigned comment added by 2.31.130.71 (talk) 18:47, 19 January 2016 (UTC)

Tu-44

The article fails to mention that the TU-144 was the first supersonic passenger jet, airborne 2 months before the Concorde. Also, the Russian plane did go into regular, if domestic only, service. It was used on weekly Moscow-AlmaAta flights.

European Supersonic Research

Can a knowledgeable person update the paragraph on the "European Supersonic Research Program"? I am sure it needs updating -- I just removed the note that it was aiming to create a reference configuration in 1999. Google search for "European Supersonic Research Program" returns 29 hits.

"The main advantage appeared to be practical, these designs would be flying at least three times as fast as existing subsonic designs, and would be able to three planes and thereby lower costs in terms of manpower and maintenance."'
This sentence does not make sense, can someone correct it?
Adrian Pingstone 22:43, 2 Dec 2003 (UTC)

Thanks for correcting that sentence.

Adrian Pingstone 21:07, 20 Dec 2003 (UTC)

Damage to the Ozone Layer

Regarding the following text in the section "Damage to the Ozone Layer": "The high altitude flight makes such damage theoretically more likely than with traditional aircraft. However, research showed that the comparatively tiny quantity of nitric oxides generated in the exhaust actually boosts the ozone layer."

The webpage http://www.npi.gov.au/database/substance-info/profiles/67.html (which was cited in Nitric Oxide) contains the following information on the effects of nitric oxide on the ozone layer:

"In the stratosphere, oxides of nitrogen play a crucial role in maintaining the level of ozone. Ozone is formed through the photochemical reaction of nitrogen dioxide and oxygen. However, too little nitrogen dioxide results in too little ozone being formed, On the other hand, too much nitric oxide reduces the level of ozone because of an increase in the reaction of ozone to convert nitric oxide to nitrogen dioxide."

Ozone: "The latter reaction (O₃ + O → 2 O₂) is catalysed by the presence of certain free radicals, of which the most important are hydroxyl (OH), nitric oxide (NO) and atomic chlorine (Cl) and bromine (Br)."

Ozone-oxygen cycle: "Certain free radicals, the most important being hydroxyl (OH), nitric oxide (NO), and atoms of chlorine (Cl) and bromine (Br), catalyze the recombination reaction, leading to an ozone layer that is thinner than it would be if the catalysts were not present."

From all these sources, I have concluded that NO has a very important role in the ozone cycle, but greater amounts of Nitric Oxide in the stratosphere would do nothing to boost the ozone layer. If anyone else with a slightly greater understanding of this comes along and happens to agree with my conclusions here, the text of that section should definitely be changed. Ph0t0phobic 22:36, 26 May 2007 (UTC)

USAF SST program

Im no expert in this but the article fails to go into any detail about the huge work by the USAF - e.g. the Blackbird program/SR71 built by Lockheed's skunkworks flew at record speeds during this timeframe (1960-85) at 3,600 MPH routinely. http://www.aviationexplorer.com/sr-71_facts.htm

Also Gen Gibbs headed up the USAF SST program developing an SST which resulted in the superconic bomber the ? B1.

http://en.wikipedia.org/wiki/B-1_Lancer —Preceding unsigned comment added by 76.216.68.78 (talk • contribs)

They're not SSTs they're just supersonic aircraft. An SST is for transporting people around commercially.WolfKeeper 23:06, 13 September 2007 (UTC)

• Before the SR-71 and B-1 was the B-70 Valkyrie, a proposed Mach 3 bomber. Its XB-70 prototypes were used in SST flight testing. -Fnlayson 23:10, 13 September 2007 (UTC)

Airline desirability of SSTs

"Since supersonic aircraft use more fuel, this translates into higher ticket prices, but since this is borne by the customers, this is not of itself a disadvantage to the airline. However, because more of the ticket price is fuel, variations in the price of oil cause greater elasticity in the price of a ticket, and hence in the numbers of passengers, and having to fly aircraft partly empty is rarely cost-effective."

This is convoluted, I kind of get where it's going but it's really not correct in several ways. Costs don't translate into prices except very indirectly. Most business costs are "borne by" consumers, unless the business is unprofitable - the cost of staffing HR people in the airline headquarters is also "borne by" ticket buyers and if that cost goes up with nothing else changing, that's typically not a positive thing for an airline. Profits are revenues - costs. A fuel cost increase in and of itself is a bad thing for airlines and their profits. There are lots of other factors that would play into whether ticket prices (and revenues) could change as a result of the cost increase - the competition, the substitutes, the elasticity of demand, the ability to schedule more or fewer flights, etc., but they're not simple.

Also, variations in the price of oil wouldn't naturally cause greater price elasticity of demand for a ticket. The price elasticity is already there, it's an attribute of the market for tickets. The variations in price cause variations in demand corresponding to the elasticity.

Probably better to just say that supersonic aircraft have higher per-passenger fuel costs and leave it at that. Xetnauq2 (talk) 21:46, 27 December 2008 (UTC)

I think the correct sentence is "Supersonic aircraft have higher fuel costs for passenger but if there are sufficient number of customers who are ready to pay more for traveling faster, this is not itself a disadvantage to the airline." Gokaydince (talk) 21:39, 23 September 2009 (UTC)

This whole section is unsourced and poorly written. It is not a question of what airlines want; it is a question of what consumers want. For today's international air travelers, if you asked them: "Would you rather have the same flight time with half the cost, or the same cost with half the flight time?", the vast majority would opt for the same flight time with half the cost. In other words, reducing cost is more important than reducing flight time to the vast majority of airline consumers. Thus, there are no more Concorde's, but instead B787's, A350's, and other planes using advanced composite materials and highly-efficient engines. The market wants lower cost more than it wants faster flight. --Westwind273 (talk) 16:07, 8 September 2011 (UTC)

Westwind273, what is written here is not contradictory with what you say. Just think about it: What do we mean by "consumer" or "customer"? Any aircraft manufacturing company does not sell any aircraft to air travelers. From their point of views, customers are airlines. So, from manufacturer point of view, the important thing is the airlines' demand. Of course the airlines' demand is driven primarily by travelers' demand, but there are some other driving factors such as conservative approaches (We are already making good money, why take the risk of trying totally different things) etc. Gokaydince (talk) 22:08, 16 October 2011 (UTC)

Yes, if you assume that airlines are simply responding to their customer demand, it is only a semantic point. The more important point is, what does the market want? The market wants lower cost flight much more than it wants faster flight. --Westwind273 (talk) 19:37, 6 March 2012 (UTC)

You are basically right. But, indeed, demand of customer is not independent of service providers' behaviour. Sometimes, demand of customers is driven by what is presented to them. If customers don't demand something very strongly, this doesn't necessarily mean that they don't really want it. It may mean that they are simply not aware of it, because it has never been presented to them. This may be the case for supersonic travel. In reality, supersonic travel was only for a very very small minority - not a very good public awareness. But, maybe if you make it more widely available, when they taste it, they will demand it. I agree that today the biggest ambition of air travelers is to find cheaper and cheaper tickets. However, I don't think that it would be the same today if that "low cost airline" concept was not created by someone until now. They tasted it and they demand it. So, I still think that, it is an issue of "airline desirability", not "passenger desirability." Airlines' conservative approach is to blame, not the passenger demand.Gokaydince (talk) 22:43, 11 December 2012 (UTC)

If you have an airliner that is twice as fast as it's competitors then you can schedule twice as many flights per-day. So although the overall fuel costs are higher, you cover that with increased passengers carried, i.e., it's twice as productive. That's why the SST was thought desirable by airlines at the time. This was before various countries started to make an issue over sonic booms, so it was assumed that supersonic travel would be the next milestone in civil aviation. It was also before the majority of air travellers had become the budget-conscious holidaymakers who are seeking the lowest fares possible that led the worldwide increase in air travel in the 1970s and 80s. The fact is that the airline market was different at the time the SST was being considered.

As regards running costs, IIRC Concorde had the same running costs - both subsonic and supersonic - as a Boeing 707, so it wasn't that expensive to run - the other, later wide-bodied subsonic airliners just became even cheaper. — Preceding unsigned comment added by 80.7.147.13 (talk) 16:44, 14 February 2013 (UTC)

A 1964 article "Concord Customer" on SSTs by an American Airlines representative in Flight here [3] — Preceding unsigned comment added by 80.7.147.13 (talk) 11:26, 20 February 2013 (UTC)

Ticket prices

Does anyone have information on how much a ticket Paris-New York cost during the Concorde's lifetime? Some reference would be good as well, i.e. how much was a ticket for a subsonic flight at that time?

Concorde 1984 British Airways fares here; [4]

Unfortunately no Paris-New York figures only London ones:

• Concorde London-New York return = £2,399
• Subsonic London-New York First Class return = £1,986
• Concorde London-Washington return = £2,426
• Subsonic London-Washington First Class return = £2,258

All Concorde seats were First Class.

Profitability

These two sentences are somewhat misleading:

"Now that commercial SST aircraft have stopped flying, it has become clearer that Concorde made substantial profit for British Airways."

"Since Concorde stopped flying it has been revealed that over the life of Concorde, the plane did prove profitable, at least to British Airways. Concorde operating costs over nearly 28 years of operation were approximately £1 billion, with revenues of £1.75 billion."

So was the Concorde profitable or not? Costs of 1 bn GBP compared to revenues of 1.75 bn GBP sound profitable to me -- am I missing something here?

Concorde started out unprofitable due to being operated by the-then state-owned British Airways (BA), however under Mrs Thatcher BA was privatised in the 1980s and the new director found that the Concorde operation had previously been run at a loss, with many people assuming that the ticket prices were much higher than they actually were. He therefore put the ticket prices up nearer to what the market would bear - the majority of its passengers were businessmen who had the fare paid for by their companies, to the point where Concorde was making money for BA and this remained so until Concorde was retired in 2003.

So in answer to your question, it didn't at first because the tickets were underpriced when BA was state-owned, once the ticket cost was increased it made a continuous profit for BA from then on. As for Air France, I don't know.

Businessmen/women are what the aeroplane was originally intended for as for them time is money, so to them getting across the Atlantic in three hours meant that they could do a day's business in the US and then fly home the same day. Three hours there, three hours back. Although because of the fuss that was kicked up in the US about the noise and suchlike, it was never possible to schedule the flights to make that possible in practice. It was never intended for tourists and other 'leisure' passengers. Back then if you wanted to make a deal with someone you met them face-to-face, no internet or widespread tele-conferencing until much later. — Preceding unsigned comment added by 80.4.57.101 (talk) 20:33, 5 December 2011 (UTC)

After Concorde was re-branded in the 1980's the British Airways fleet of seven Concordes generated up to 25% of BA's profits, a figure of around £500,000,000 (half a billion) pounds net profit.[5]

In their time in service Concorde carried around 2.5 million passengers with BA, Air France Concorde's carried just over 2 million. — Preceding unsigned comment added by 95.149.173.43 (talk) 20:07, 4 August 2016 (UTC)

add Gen Gibbs

see above paragraph, unresolved, ab USAF SST program, so im' here suggesting again, to add Gen Gibbs, pioneer in SST aviation... and adding also his son Lt Jim Gibbs, pioneer in USAF OTH, the mountain R&D, aka the "criminal" Jim Gibbs, etc lil darpa sr !!! 69.121.221.97 (talk) 16:25, 24 July 2011 (UTC)

Greater efficiency?

The lead states "Supersonic airliners' greater speed and efficiency over their conventional counterparts have made them objects of numerous recent and ongoing design studies". I don't see any supporting evidence for the greater efficiency claim. I will remove it in due course. - Crosbie 21:04, 1 March 2013 (UTC)

Where supersonic commercial transports have the opportunity to be competitive with subsonic transports is in productivity. During NASA's High-Speed Research Program, it was claimed that a supersonic vehicle could fit two flights per day for the majority of city pairs, whereas a subsonic vehicle would only have one. So even though the supersonic airplane has, say, fewer seat miles per gallon than a subsonic airplane, it would still be attractive for an airline to buy. – AeroJeff, 8 September 2013

Concorde super-cruised across the Atlantic at Mach 2.0 on ~40,000lb of thrust, around the equivalent in power of a single early RB211. — Preceding unsigned comment added by 2.31.130.17 (talk) 14:21, 1 March 2015 (UTC)

Concordski

I would like to point out that footnote 187 on the Concorde's page cites a reference from the Times concering the use of the word Concordski. --Arkansawyer96 (talk) 18:34, 2 April 2013 (UTC)

Laws and Regulations against supersonic transport

This article is highly deficient in that it has no links and very few references to the effect of regulations banning supersonic flights on the federal level in the United States as well as regulations and laws banning flight routes in parts of Asia both in the 1970s as well as later. 71.214.125.228 (talk) 20:20, 25 July 2014 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Supersonic transport/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

could use some more inline refs

Last edited at 21:28, 22 February 2007 (UTC). Substituted at 07:21, 30 April 2016 (UTC)

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Dates have been passed

Article currently contains predictions for dates such as 2019 which have passed. Andrewa (talk) 18:37, 21 December 2020 (UTC)

See also https://www.quora.com/Were-old-jetliners-in-the-60s-flying-faster-than-today-Was-it-due-to-the-use-of-turbojet-engines-or-turbofan-with-lower-bypass-ratio/answer/Matthew-Bekaert-1 for some of what we have been missing. Andrewa (talk) 00:12, 22 December 2020 (UTC)

https://boom-press-assets.s3-us-west-2.amazonaws.com/United+Adding+Supersonic+Speeds+with+New+Agreement+to+Buy+Aircraft+from+Boom+Supersonic.pdf is of course a primary source, and CNET and others have based articles on it but these are still technically primary sources.

And there are at least two other commercial SSTs under development. Andrewa (talk) 09:48, 4 June 2021 (UTC)

Under Development / Previous Concepts

I moved a couple of things around to get Aerion out of the 'Under Development' section but there's quite a bit more work to be done here if someone has the chance to tackle it. Lots of confusing info and a table that doesn't belong here as it includes long-gone airplanes. Retswerb (talk) 08:46, 21 June 2021 (UTC)

"they were already more efficient than their subsonic turbofan counterparts" - unclear?

The "Engines" section confuses me.

I think I understand what is meant by turbojet engines potentially being more efficient at supersonic speeds than other engines are at subsonic speeds - even if they use more fuel for a given thrust, they are going faster, so that thrust needs to be sustained for a shorter time.

But then this section talks about high-bypass turbofans making the advantage of supersonic turbojets disappear - "One major advantage of the SST disappeared.", right after saying, "subsonic jet engines immediately became much more efficient, closer to the efficiency of turbojets at supersonic speeds." This makes it unclear whether high-bypass turbofans eliminated the supersonic turbojet efficiency advantage or merely narrowed it.

But the last paragraph of the section ends in a way that seems even less clear to me. It goes:

"For example, the early Tu-144S was fitted with a low bypass turbofan engine which was much less efficient than Concorde's turbojets in supersonic flight. The later TU-144D featured turbojet engines with comparable efficiency. These limitations meant that SST designs were not able to take advantage of the dramatic improvements in fuel economy that high bypass engines brought to the subsonic market, but they were already more efficient than their subsonic turbofan counterparts."

What does "already more efficient than their subsonic turbofan counterparts" mean? It isn't clear whether it is referring to low-bypass turbofans (just mentioned only in a supersonic context), or whether it is saying that high-bypass turbofans, for all their efficiency, still were not as efficient as supersonic turbojets.

Boatman4 (talk) 18:16, 26 January 2022 (UTC)

Gas turbine engines are at their most fuel-efficient when operating at 100 (dry) power which Concorde's engines operated at continuously during cruise flight at Mach 2. Unlike piston engines, fuel consumption does not reduce with lower throttle settings, but in fact, increases. Hence most aeronautical gas turbines burn proportionally more fuel when cruising than they do at take-off, i.e., the fuel consumption actually increases over that at take-off. Obviously the take-off is only a small proportion of the flight and so this efficiency in a subsonic aeroplane cannot be used, not-withstanding the technical difficulties of requiring an engine that can, in effect, operate at take-off power for long periods. Fuel consumption while taxying or idling is also the highest, as the engine is operating at it's most inefficient throttle setting. Usually this does not matter as these periods of a journey are normally only a small proportion of the flight and can usually be ignored.

In addition, the best propulsive (Froude) efficiency for a gas turbine or rocket motor is obtained when the forward motion of the aircraft or vehicle exactly equals the velocity of the fluid (gas or air) being ejected rearwards by the engine. This is why the different aircraft speed ranges utilise different methods of propulsion, e.g., piston-propeller, propeller-turbine, turbofan, turbo jet, rocket engine.

Thus for supersonic flight, which roughly matches the rearward velocity of the jet efflux of a turbojet, the turbojet is more propulsively and fuel efficient, all other things being equal. — Preceding unsigned comment added by 86.8.126.91 (talk) 07:23, 4 August 2022 (UTC)

Explain how my edit about the North American NAC-60 is vandalism

Please explain how my edit about the North American NAC-60 is vandalism. I have reverted the reversion which was NOT done in good faith. --KJRehberg (talk) 03:47, 12 March 2022 (UTC)

I didn't call it vandalism, as it wasn't vandalism, just unnecessary. I've reverted it again with a more complete explanation. Please assume good faith. BilCat (talk) 05:05, 12 March 2022 (UTC)

Please try to do better next time. --KJRehberg (talk) 18:27, 12 March 2022 (UTC)

American Airlines Supersonic Boom

I believe an update is necessary to the article to keep it accurate, namely the american airlines purchase of 20 supersonic boom SSTs. DropBear42 (talk) 15:11, 17 August 2022 (UTC)