Commercial flights faster than sound

[EdFred]

Thanks. In my mind I saw my original post with the picture garnering one or two "lol's, then everyone would move on. The whole thing caught me off guard. Next time I'll proof-read in fear of making an absolute fool of myself again. (Honestly that's probably why I post so little to begin with.)

It happens, and I wouldn't say it was making a fool of yourself. Had it been posted on one of the pilot forums it would have gotten a laugh. It's just with trying to teach primary students that flying downwind won't cause the plane to stall, and other numerous issues with them trying to wrap their head around ground speed vs airspeed vs stall speed vs landing downwind vs upwind I like to try and correct things early on. Never know when one of the kids on here may take flight lessons and cause issues for their CFI.

[AngelLestat]

Yeah, speed in any flying vehicle will be always wind speed, but I guess they should change it to km/h instead knots as everything else, because we don´t use ropes with knots anymore to measure depth or ship speed.

Well I saw this new supersonic aircraft transport concept from Russia which it looks very cool but it seems pointless (even if they can achieve it)

Although it looks very cool.

Sorry If I derail a little from the original topic but I dont wanna make a new one just for this.

source: http://www.gizmag.com/russia-supersonic-cargo-plane-pak-ta/36693/

Is a military transport vehicle.. But lets be realistic..

What is the point to keep doing weapons? Today the media is in everywhere and what most matter is the public opinion.

So you can not invade any country without a very very good excuse and with the other coutries support.

So any future war will be fought in the economical, media and politic ground.

Edited March 28, 2015 by AngelLestat

[EdFred]

Yeah, speed in any flying vehicle will be always wind speed, but I guess they should change it to km/h instead knots as everything else, because we don´t use ropes with knots anymore to measure depth or ship speed.

But we do use latitude and longitude.

kt = 1 nautical mile/hour

1 nautical mile = 1 minute of arc along a meridian.

[magnemoe]

Yeah, speed in any flying vehicle will be always wind speed, but I guess they should change it to km/h instead knots as everything else, because we don´t use ropes with knots anymore to measure depth or ship speed.

Well I saw this new supersonic aircraft transport concept from Russia which it looks very cool but it seems pointless (even if they can achieve it)

Although it looks very cool.

Sorry If I derail a little from the original topic but I dont wanna make a new one just for this.

https://vimeo.com/103542677

source: http://www.gizmag.com/russia-supersonic-cargo-plane-pak-ta/36693/

Is a military transport vehicle.. But lets be realistic..

What is the point to keep doing weapons? Today the media is in everywhere and what most matter is the public opinion.

So you can not invade any country without a very very good excuse and with the other coutries support.

So any future war will be fought in the economical, media and politic ground.

More an point that is the point of an supersonic military transport, main requirements for them is high cargo capasity, roll on- roll off, fast turnover, being able to land on small and bad airstrips are another very important factor as you can land closer to the front, this require large wings and preferably high mounted wings. You see that all planes have the wings low except military transports. Few other have an rear ramp, most civilian transports are side loaded, yes they rent military if they need to transport huge items.

It makes far less sense than an supersonic passenger plane.

[Torquemadus]

Instead of building a supersonic passenger jet, I would recommend making a SABRE powered sub-orbital rocket plane. Instead of offering a "space tourist" flight, why not take the next logical step and make a spaceplane that provides useful transportation?!

Cutting long-haul flight times down to an hour or less, coupled with fast track check-in to the air/space port, would be a service that many wealthy people would be prepared to pay for. Time is money!

If such services became popular, then technological maturity and mass production would gradually lower costs. There was a time when air travel was only affordable to the wealthy "jet set". The 747 changed that. If someone could devise a spaceplane equivalent, then sub-orbital travel would eventually become commonplace.

[cantab]

I work in the transport industry. Customers will always tell you that shipping speed is of the utmost importance to them. When it's time to pull the wallet, they'll pick the slowest (cheapest) option anyway, with the exception of a very, very select few.

For cargo I agree. If I buy something online I can usually wait for it, if I need something NOW I go to a shop and can come back with it the same day. For passenger travel not so much, I don't want to be spending all my time travelling.

As for the original topic, I once read an interesting viewpoint: Concorde failed not because it was too fast but because in the age of the internet it was too slow.

[PakledHostage]

But we do use latitude and longitude.

kt = 1 nautical mile/hour

1 nautical mile = 1 minute of arc along a meridian.

One nautical mile equals approximately 1 minute of arc along a meridian. It equals exactly 1852 metres. A minute of arc along a meridian varies from about 1,843 metres at the equator to about 1,862 metres at the poles, with a mean value of 1,852.3 metres.

[longbyte1]

From what I see, supersonic flight was actually gaining ground with the Concorde, until of course several accidents happened involving it. Since then, no company has invested any money in the creation of supersonic airliners.

Noise definitely was a problem with the Concorde. Politicians and regulators kept complaining about breaking noise limits on takeoff. (I'm not seeing any data on how loud it was during the flight or inside the cabin, though.) Of course, it's supersonic . So regulators told it not to break the sound barrier while taking off. The pilots also tried to minimize noise by cutting back the throttle considerably until they were high enough and far enough to boost up to Mach 2.

Also, only rich people could afford it at the time, so it essentially a luxury.

We'll probably see SSTO before supersonic at the rate engineers are going

[Technical Ben]

It is not a "misconception." The aircraft is flying 100mph faster than the sound barrier at sea level. Ground speed is important when talking about supersonic travel - the distance from Paris to New York is on the ground, after all.

You completely missed that point.

"Sound barrier" refers specifically to the speed of sound relative to the object.

"768 mph" is a correct term that applies irrespective of altitude, air pressure, wind etc.

It's a bit like talking about lightspeed...

[AngelLestat]

But we do use latitude and longitude.

kt = 1 nautical mile/hour

1 nautical mile = 1 minute of arc along a meridian.

Ok, you got me there.

One nautical mile equals approximately 1 minute of arc along a meridian. It equals exactly 1852 metres. A minute of arc along a meridian varies from about 1,843 metres at the equator to about 1,862 metres at the poles, with a mean value of 1,852.3 metres.

Is not the definition of nautic mile 1 min arc? If is not that, what it is?

Heh, I have sailboat licence but I dont rememeber to learn this.

More an point that is the point of an supersonic military transport, main requirements for them is high cargo capasity, roll on- roll off, fast turnover, being able to land on small and bad airstrips are another very important factor as you can land closer to the front, this require large wings and preferably high mounted wings. You see that all planes have the wings low except military transports. Few other have an rear ramp, most civilian transports are side loaded, yes they rent military if they need to transport huge items.

It makes far less sense than an supersonic passenger plane.

Yeah I am agree, but still.

[Iskierka]

Yeah, speed in any flying vehicle will be always wind speed, but I guess they should change it to km/h instead knots as everything else, because we don´t use ropes with knots anymore to measure depth or ship speed.

Well I saw this new supersonic aircraft transport concept from Russia which it looks very cool but it seems pointless (even if they can achieve it)

Although it looks very cool.

Sorry If I derail a little from the original topic but I dont wanna make a new one just for this.

This vehicle doesn't look supersonic at all. It has no supersonic intake design, and the low-speed electric fans don't appear to be able to be closed off to reduce drag at high speed. Additionally, its wings are very wide and narrow, clearly more designed for high-subsonic speed. It could be quite an efficient fast transport with relatively good STOL performance, but supersonic is quite doubtful for that design, even if there's some rumours that it may be.

Is not the definition of nautic mile 1 min arc? If is not that, what it is?

Heh, I have sailboat licence but I dont rememeber to learn this.

That was its original definition, but variance depending on the meridian and location used caused disagreement, so it was defined as a specific average. It's close enough that you can reliably call it 1 min of arc, but that's not the definition.

Suborbital travel isn't going to be a thing any time soon - even Skylon is only targeting the possibility of around $100,000 per seat, which only the very richest will pay for 55 minutes-to-anywhere flights. $10,000 should be the target price for first-class travel, no matter how fast, which is achievable for supersonic or hypersonic, but not suborbital. $100,000 is only justifiable for people if you're talking about somewhere totally unique, like actually getting to orbit - SS2 selling zero-g flights at $200,000 proves that, but you're not going to get many repeat passengers, so regular travel flights won't go for that.

[Nibb31]

From what I see, supersonic flight was actually gaining ground with the Concorde, until of course several accidents happened involving it. Since then, no company has invested any money in the creation of supersonic airliners.

Concorde flew for 40 years without a single accident (and without gaining much ground either). I'm not sure what accidents you are referring too.

Noise definitely was a problem with the Concorde. Politicians and regulators kept complaining about breaking noise limits on takeoff. (I'm not seeing any data on how loud it was during the flight or inside the cabin, though.) Of course, it's supersonic . So regulators told it not to break the sound barrier while taking off. The pilots also tried to minimize noise by cutting back the throttle considerably until they were high enough and far enough to boost up to Mach 2.

As we explained earlier, US politicians and regulators complained because US aircraft manufacturers hadn't invested in commercial supersonic aircraft. The idea made sense in those pre-1973-Oil-Crisis days and Boeing, McDonnell-Douglas, and Lockheed were afraid of the competition from Europe.

[Coam]

Concorde flew for 40 years without a single accident (and without gaining much ground either). I'm not sure what accidents you are referring too.

It had quite a few incidents through it's service life (as nearly all models of aircraft do.) Here's a list

By the time it had come, it was probably already too late for mass-use unfortunately. Concorde was competitive with the original 707 (It was even quieter on take-off and landing!), just as the age of the 747 was beginning. I believe it was still profitable in British Airways service, though.

Edited March 28, 2015 by Coam

[Iskierka]

It may surprise you, but that is not a particularly bad list, even for a fleet of just 20 aircraft. Most of those are very minor issues that other aircraft won't experience particularly less often, barring components unique to supersonic engines. It also looks like a large fraction were related to tyre failures, which were a relatively common problem for all airliners prior to its 2000 crash - following that incident, new tyres were developed that are totally burst-proof, meaning both that Concorde would be far more reliable and that all other modern aircraft also are, as the new tyres perform so much better that every single airliner has switched over.

[Kulebron]

As a frequent flyer I've calculated time spent on medium range flights, and concluded that faster vehicle won't improve the experience much. You spend 5 hours on a) riding to the airport staying there (you usually come beforehand with a safety margin) c) riding taxiways d) unloading and waiting for the luggage e) riding aeroexpress f) getting home on public transport.

Transatlantic flights takes 7 hrs of flight + 5 = 12 hours. Reducing them to 8 at a huge cost is not a great improvement. I think better procedures and ground infrastructure can cut 5 hours to 3 or less (look at how things work well in Kopenhagen, Munchen or Amsterdam).

Also, I think aviation now looks too much like private minibuses that worked or work in many cities, like in Britain in 1980s, when bus transport was privatized. Airlines play a bit against the passenger with all those non-refundable tickets, alliances that force you to only their connections. Also, isn't it absurd that if you miss your flight, the next one, you can't get on a plane that goes 1h later to the same city, and has empty seats?

I think future of aviation is in making it more transparent and interchangeable like buses in Curitiba or Bogotá (sure flexibilities on planes are more expensive, but one can just introduce additional payments). For a passenger it does not matter a big deal whether you fly up to 3 hours in one company or another, so I think a contract system could be quite viable, with an agency selling tickets and paying to companies for flynig their planes on a route. (I know that planes are expensive to stay on the ground, so several routes are preferrable, but this is doable with good logistics.)

[AngelLestat]

I am agree Kulebron, this will be partially solve if the range increase, so you fly from dubai to san fransisco or between other distant high rate cities. but then due the fuel added, the amount of passagers decrease.

Maybe as Cantab said Internet could have some implications in the final desicion, if you want to reach fast a place and then go back it will be mostly due business reasons.

Right now you can do some kind of business using internet, but if you are traveling for vacation I guess no much people care if the airplane takes 2 or 4 hours less.

Other way is making your travel as part of your vacation, as cruise lines, when the speed does not matter.

[PakledHostage]

Airlines play a bit against the passenger with all those non-refundable tickets, alliances that force you to only their connections. Also, isn't it absurd that if you miss your flight, the next one, you can't get on a plane that goes 1h later to the same city, and has empty seats?

A bit off topic, but I'm going to step in and defend the airlines for a moment: At the end of the day, a seat on a plane is a seat on a plane is a seat on a plane... Baring some obvious perks in business class or whatever premium class an airline may offer, there is no difference in your seat between a cheap economy ticket and an expensive one. The difference between a cheap economy ticket and an expensive one is convenience and flexibility. That is what you are paying for when you buy an expensive ticket.

To put things into perspective for yourself, you can dowload just about any major carrier's annual report and divide the annual revenue seat miles by the annual operating costs and you'll get an approximation of the cost per seat mile. The number is typically about 0.12 USD per revenue seat per mile. That means anyone paying less than about $600 USD (plus tax) to fly from LA to New York and back on an airline like Delta or American is being subsidized by someone who's flying on a premium ticket.

Now note that I'm using revenue seat miles not available seat miles. This is important because airlines are already doing everything that they can to increase their load factors. Increasing the proportion of seats you sell on every flight has obvious benefits to the bottom line. There are limits to what is possible, however. Low cost airlines manage higher load factors by flying less frequently and imposing restrictions on passengers to ensure that they actually show up for their flights. Low cost carriers also manage lower cost per mile by flying to airports with lower landing/ground handling fees and paying their staff less.

Large full service airlines can only achieve so much in the load factor department, however. They count on the people who are willing to pay the big bucks for a seat. Those people want convenience and flexibility. If their meeting is done an hour early, they want to be able to jump on the earlier flight. If there isn't an earlier flight, they'll book with the competition that does have more frequencies next time. Unfortunately for the airlines, those extra seats on the more frequent flights then have to be filled up. Sometimes there just aren't enough people who want to fly on a route. Some of the extra capacity is sold below cost (it is better to get something for those seats than nothing), but there is a balance. If you make too many cheap seats available, people will just buy those and be willing to abandon their unused tickets rather than pay a higher price for more flexibility. Too many cheap seats also create an expectation that air travel should be cheap, making it hard to price the expensive tickets sufficiently high that you break even.

No, you've got to create demand for the higher priced expensive tickets. Letting the guy who bought the cheap ticket have the same flexibility and convenience as the guy who bought the expensive ticket erodes the value of the higher priced ticket.

EDIT: I should add that this post is not intended to be an exhaustive treatise on airline economics - just a rough overview of some of the basics. Other factors like demographics and customer loyalty programs (among others) are also important. The key point is that airlines have to impose restrictions to create value and thereby justify their price structure.

And on a note more related to the topic of this thread, BA and Air France created value for Concorde tickets by making it prestigious. It wasnt so much about saving 3 or 4 hours off your 12 hour door to door journey. BA's Concorde operations had its own wing in T4 at Heathrow. You were treated like someone special right from when you entered that part of the terminal. I almost experienced it myself one time, getting as far as buying a one way ticket from LHR to JFK, but I got a refund on my ticket when the amount of money that I'd spent on it sunk in. Round trip at the time was over 20 000 CAD. I got my ticket at a significant discount, but it was still a lot of money. I guess the prestige wasn't worth it to me... I regret that decision in hindsight, but so it goes.

Edited March 29, 2015 by PakledHostage

[longbyte1]

I think we'll be stuck in flying sardine cans for the next 50 years or so.

[KerbMav]

I do not care about costs, but more speed, more fuel, more immissions ...

There will always be enough business jokers willing to pay more - out of the pockets of their companies, for faster trips that save them oh so valuable time ...

But for those we could use nice rocket ships - without parachutes to save time during landings ...

/rant

[EdFred]

I do not care about costs, but more speed, more fuel, more immissions ...

There will always be enough business jokers willing to pay more - out of the pockets of their companies, for faster trips that save them oh so valuable time ...

But for those we could use nice rocket ships - without parachutes to save time during landings ...

/rant

Time IS valuable. I mean, if it wasn't, and we take your position that is isn't we could just let the business "jokers" (and everyone else) use 1800's travel technology to travel. How long would a transoceanic trip take? Weeks. I mean yeah, that wouldn't slow down things in business at all. Oh, you want to take a vacation to Australia? Well, you better save up your entire life for it because it will take months of travel to get there and back, and I don't think you will have a job when you return from it.

[tater]

As just the customer, time in flight is an issue for me on flights above some number of hours… how many is sort of fuzzy. SSTs would not be used over inhabited areas, so we have to confine it to transoceanic travel.

As it is, airliners don't even fly as fast as they did in the '60s, as they fly lower cruise speeds to increase fuel economy (I want to say the average is ~10% slower). That's about 30 minutes on a 5 hour flight, but an hour savings is nothing to sneeze at for a 10 hour long haul.

Unless it could be more cost effective, somehow, it seems like an unlikely choice for an airline to make on small margins driven by cost competition. There might be a model where all long-haul flights are either SST or current systems. Current would become all coach (increasing margins), and the SSTs would get all business(?) and certainly all first class seats. Right now business class costs what 1st used to cost, and 1st class (say to asia from the US) has no analog to 1st class even a decade or 2 ago. Stateroom-like 1st class is a new invention. $17,000 to asia might be profitable on an SST, I have no idea.

For mass use it would require a sea change in the way the cost structures work, I think.

[magnemoe]

As just the customer, time in flight is an issue for me on flights above some number of hours… how many is sort of fuzzy. SSTs would not be used over inhabited areas, so we have to confine it to transoceanic travel.

As it is, airliners don't even fly as fast as they did in the '60s, as they fly lower cruise speeds to increase fuel economy (I want to say the average is ~10% slower). That's about 30 minutes on a 5 hour flight, but an hour savings is nothing to sneeze at for a 10 hour long haul.

Unless it could be more cost effective, somehow, it seems like an unlikely choice for an airline to make on small margins driven by cost competition. There might be a model where all long-haul flights are either SST or current systems. Current would become all coach (increasing margins), and the SSTs would get all business(?) and certainly all first class seats. Right now business class costs what 1st used to cost, and 1st class (say to asia from the US) has no analog to 1st class even a decade or 2 ago. Stateroom-like 1st class is a new invention. $17,000 to asia might be profitable on an SST, I have no idea.

For mass use it would require a sea change in the way the cost structures work, I think.

New dreamliner is faster again, think its close to 1000 km/h as cruise speed.

Overland SST is not an problem with modern aerodynamic who manages to cancel out the shock wave pretty well so you will not hear anything on ground then flying at cruise speed.

If you wanted an SST business model it would be the trans pacific routes and Europe to Asia, here the trip length will get past most peoples comfort zones even in business/ first class.

And the long trip would make additional plane changes acceptable.

You would also need enough customers to run all business class trips, note that business class is cheaper than Concorde.

This might be something for Dubai airlines they use Dubai as an hub and use the huge airbus

[cpast]

Not really. The Dreamliner is maybe a *bit* faster optimum cruise than the 777, but it isn't way faster. Most widebodies like to cruise between 0.80 and 0.85 Mach.

[Nibb31]

Time IS valuable. I mean, if it wasn't, and we take your position that is isn't we could just let the business "jokers" (and everyone else) use 1800's travel technology to travel. How long would a transoceanic trip take? Weeks. I mean yeah, that wouldn't slow down things in business at all. Oh, you want to take a vacation to Australia? Well, you better save up your entire life for it because it will take months of travel to get there and back, and I don't think you will have a job when you return from it.

Yeah, but there's this thing called diminishing returns. In the 90's Boeing came out with the Sonic Cruiser proposal. The idea was to fly at Mack 0.95 instead of Mack 0.85 like most airliners. This incurred an increase in of 20% in kerosene consumption for a 10% increase in speed. It could have brought the average transatlantic flight down from 8 hours to 7 hours, but when you add in the check-in and boarding time at the airport, it simply wasn't worth it. Of course, the idea was abandoned because it simply wasn't what the airlines wanted. So Boeing went on with the 787 Dreamliner.

And then as soon as you go supersonic, everything gets even more complicated and therefore orders of magnitude more expensive, again for little gain in term of total transit time. So basically we are at a sweet spot in terms of cost/speed. Going any faster costs a lot more. Going slower doesn't save a lot.

New dreamliner is faster again, think its close to 1000 km/h as cruise speed.

Not really. The Dreamliner, like most modern airliners, is all about lower fuel usage, not speed. Mach 0.85 seems to be the sweet spot for air travel and is likely to remain that way until some magical new technology makes supersonic flight economical (but don't count on that for the foreseeable future).

Edited March 31, 2015 by Nibb31

[Kulebron]

As it is, airliners don't even fly as fast as they did in the '60s, as they fly lower cruise speeds to increase fuel economy (I want to say the average is ~10% slower). That's about 30 minutes on a 5 hour flight, but an hour savings is nothing to sneeze at for a 10 hour long haul.

I watched Flightradar24 carefully and noticed that long-haul flights usually fly 10% faster than those on short flights. In a short flight, cruise is just about 50-70% of time, so 10% faster means 5..7% faster flight. On long flights, cruise is about 90% of time.