View Full Version : Boeing Sonic Cruiser

31st Jul 2002, 09:38
I just been surfing the Boeing web site,and it seems this project might happen..but its a nice decoy from the A380 don`t you think??

Do you think it will ever enter service???

Also,any comments welcome.

admiral ackbar
31st Jul 2002, 13:46
Interesting article (http://www.economist.com/displaystory.cfm?story_id=1247382) in last week's economist about the Sonic Cruiser and other Boeing developments.

They are not too optimistic.

1st Aug 2002, 12:24
I think it was a knee-jerk publicity reaction to the go-ahead on the A380 (ie they grabbed something they were probably working on quietly anyway, and thrust that into the limelight), but the fact remains that you will need more powerful engines (and hence pay more for fuel), and smaller cross sectional area (fewer pax- you can't stretch it much beyong 80 metres -airport constraints), which means the few pax on board (100-150?) would have to stump up big ticket prices..

Nobody at the marketing dept of Boeing is confident that there is enough demand for the project.. (remember A380 mktg hit the same panic for a bit)..

If noone wants it, noone will pay for it.. end of project, technology isn't really a problem, paying for it is.:rolleyes:

King Patience

Flight Safety
2nd Aug 2002, 17:46
I think the Sonic Cruiser would be better built as a low supersonic airliner, say Mach 1.3 or 1.4. This gets the aircraft past the very tricky area of designing for low drag right smack in the middle of the high drag transonic region. Mach 1.3 or 1.4 is in the lowest drag area of supersonic flight, and does not require the power of Mach 2.0 flight. Drag in this speed range is close to the drag of high subsonic flight, and would have only somewhat higher operating costs. The additional costs of Mach 1.3 to 1.4 flight, while higher than subsonic flight but much lower than Mach 2.0 flight, might well be justified to the passenger for the time savings.

An airliner that could fly economically at Mach 1.3 or 1.4 would be an interesting aircraft indeed.

2nd Aug 2002, 22:17
The only advantage of M1.3 is that you can get away without fancy intake geometry. Apart from that it is still right in the transonic drag rise. Once you've sorted the intake it is all downhill because the transonic drag reduces and the intake pressure recovery does lots of the engine's work for it. Personally I reckon they would be better off trying to achieve a high subsonic cruise Mach number, say 0.95 or 0.96. That would get you there ahead of the opposition with minimal extra fuel consumption. Otherwise the next workable solution is M2+ using lots of titanium structure for the hot bits, but that idea proved to be a non-starter because they couldn't get the takeoff noise down to acceptable levels.

5th Aug 2002, 12:15
I visited Boeing at Farnborough two weeks ago, the Sonic Cruiser model displayed there was the very early (2 years old) design. Couldnīt find any person there who wants to talk about this ship. No technical details aviable, no more insformations, nothing new. I think this tells a lot.

Kalium Chloride
5th Aug 2002, 18:41
I think it's interesting that Boeing's CEO is talking about what'll happen if the airlines don't want the SC...basically they'll take the materials technology and look at something a little more conventional.

7th Aug 2002, 19:07
I think patience is right. The timing was very suiting...

10th Aug 2002, 09:16
Yeh M1.3 to 1.4 sounds economicaly feasable but Im certain the aging "anti-Concorde" bozo-rabble of the early 70s and there descendants will reawaken if the SC is redesigned for flight above Mach 1. And unfortunatley those countrys which would have a strong market for such an aircraft also have these "rent-a-bozo" outfits as political base for Green political partys, who only survive and florish on the gullability and unedjamakation of the idealistic Unwashed.

14th Aug 2002, 02:00
Funny, I rather think Boeing have little choice but to pursue the SC as they have lost the last bastion of their dominance of commercial aircraft production to Airbus and the 380. As with the 747 Boeing need to once again "bet the farm" on a project that will IMHO ultimately be the next step up in commercial air transport on planet earth. Airbus may have just about caught Boeing in annual output and sales but they have done so by playing catch up. Boeing won't want to be playing THAT game against their European rivals I am sure. It may take a bit longer than envisaged originally but the SC represents the future of commercial air transport.

17th Aug 2002, 20:15
I've spent the last four months working at board level at a major airline (client confidentiality forbids me from saying who....) and one of their directors gave me a story about the Chronic Snoozer that he had heard from someone in Boeing.....

Apparently, Boeing were SERIOUSLY concerned about the effect that the (at the time) possible formal launch of A380 would have on their share price. So they came up with CS as a way of building some confidence amongst the red-braced dimwits on Wall St that they hadn't screwed up in abandoning 747-XXX where XXX is something pretty huge and heavy. Idea being - few days of good press ("Aren't Boeing just fab?", "Boeing lead the way" etc etc) to rain on Airbus's parade and keep the market boys happy. Then, Boeing could quietly drop the whole thing.

The only fly in this ointment was the airlines, amongst whom there is a small but vocal number who actually WANT the thing, and won't let it die. And of course, Boeing wouldn't dream about offering discounts on possible CS sales if you were to sign up for a 777 or three now..... its payback time.

The trouble with something that cruises at M0.98 is that it will go supersonic if the air changes temperature, or the crew are a bit heavy handed at top of climb..... and going from M0.98 to M1.01 does strange things to the airflows...

I'd bet there are engineers at Boeing just praying this thing will die..... shades of 2707 all over again.


16th Sep 2002, 14:54
It seems to me that the economics of the industry are against this project as opposed to the A380. The success of the 747 is largely down to the fact that the operating costs for each flight don't rise as quickly with the size of the aircraft as the revenue from each flight (defined by the number of pax) does - in economist speak, the marginal cost of transporting a passenger rises less quickly with increasing load than the marginal revenue. The condition for economic efficiency in perfect competition is production where marginal cost=marginal revenue. That is to say, it is efficient to build bigger aircraft until the higher operating costs catch up with the higher revenues per-flight.

We aren't dealing with pure economics but with economics and engineering, so this point will be defined by a limiting factor which is sufficiently costly to overcome that it outweighs the gains from a further move up in size. At the moment, the first limiting factors for aircraft size are the terminal facilities required to handle very large aircraft. (The A380 design brief included a condition that the aircraft must be able to use terminals designed for 744- sized aircraft.) The next would probably be connected with handling very large loads of pax on the ground before engineering restrictions were reached.

The reasons for all this are in the cost-structure of airline operations. The cost of transporting a planeload of pax includes overhead costs that have to be met to begin with and are either fixed or semi-variable (like the cost of capital), costs which vary per-flight (i.e. staff, landing charges, air traffic charges, tax, and fuel as far as it is determined by mileage), and costs per-pax, like passenger handling, meals, and a proportion of fuel. The biggest chunk of the costs is made up of the fixed and per-flight costs. Therefore, larger loads per aircraft (bigger planes) win out over more flights with smaller aircraft, all things being equal. Whereever this holds, (i.e. main-line routes) larger aircraft win out.

In the future, we can expect that the price to airlines(in a market solution) or the availability (in an administrative solution) of flights (i.e. slots, landing fees, terminal capacity, air traffic charges, green taxes) is going to be squeezed. This is a consequence of rapid growth in air traffic combined with environmental problems. The current generation of airports and air-traffic arrangements are filling up, and expanding capacity is becoming politically very difficult. It is to be expected that the environmental costs of aviation will be an issue. Therefore, there will be some form of demand-management of the number of flights. This may be achieved through a free market in airport slots or by setting an administrative cap on their number. Given that passenger numbers rise faster than economic growth, the pressure will go somewhere.

Boeing's solution with the SC appears to involve smaller numbers of passengers - i.e. larger numbers of aircraft (wouldn't you!) - serving larger numbers of airports. This last idea seems very unlikely as widespread airport development will be even more unpopular than concentrating at the hubs (where only the people who currently whinge will whinge!). Generally, Boeing SCs will use the short-supply resources - the per-flight costs - much more than A380s and lift fewer pax on each flight. It don't take John Maynard Keynes to work out that this means less revenue and higher costs - so either no profit or very high ticket prices. Which means very few SCs!

Notso Fantastic
19th Oct 2002, 16:01
The thing's a turkey, and will never see the light of day! High subsonic cruise is difficult. Airflow will go supersonic in places above about M.92 resulting in vibration and fatigue. We used to take VC10s up to M.93 in training and there was signifiant vibration. It wasn't designed for those speeds, but the higher airflow speeds will still occur. Can you see what a mess a world full of jetty operators will make of those pretty foreplanes? The powerplant installation doesn't seem to be fully thought through. It doesn't look efficient or satisfactory. The area ruled fuselage will be expensive to manufacture. In short, a highly expensive, inefficient machine operating in a high drag transonic speed area and nobody wants to talk about it!

28th Oct 2002, 14:04
I'm currently trying to design a SC as a final year project at university ( 11 of us in the group) and can tell you that there are many many difficulties arising all over the place, which we are sure Boeing hasn't got around either.

Even if the Boeing SC does appear to work, the estimates for flight-time savings are also optimistic. The thing is going to be flying in a high drag region, at a marginally higher speed than a 747-400 for example, and will probably need a lot of fuel to keep it going. Hmmmmmm

If anyone is able and willing to provide any help with the design of the aircraft, we will be very grateful. All aerofoil sections we have looked at cannot produce enough lift at the required speed. Area ruling has also been considered, but will pose structural problems, difficult to stretch the design, etc

Cheers !!


[email protected]

Notso Fantastic
3rd Nov 2002, 21:28
Jason- a fairly high payload, high fuel load aeroplane with a wing optimised for high speed cruise, two engines.......the mind boggles about a single engine climb out at low speed/high weight! Nah! It's an Easter Bunny! (I actually think it was a design for one of those Far East childrens' toys with a blue light on top and giant wheels to be towed by a 4 year old!)