US Supersonic Transport(SST) Program post-1971

[chornedsnorkack]

Blackkite, sure, but the 707s were economically viable from the start... and airlines HAD interest. Chornedsnorkack: actually, the 2000-7 was still further from theoretical viability than the 2707-300. In the last phases (Phase IIC and III) of the SST competition, calculated fuel consumptions went up and the Lockheed entry was already at its limit in growth potential (there were no more space to put the additional fuel....).

Interesting. Concorde had some room for extra tanks on the Concorde B version... but I gather that Concorde B was getting just 10 % extra range for that.

 

[Skybolt]

I suspect we are in the wrong thread/topic to discuss this.. :
Anyway, to answer the last reply, and other people with that, the selection committee thought that Lockheed would have had to redesign the 2000-7 and scale up for allow for more fuel. In reality, the problem wasn't range per se, but endurance. The airlines went in panic mode circa 1966 for the enormous increment in missed schedules and air traffic congestion around major airports in the US. So they wanted the SSTs be able to stay aloft in subsonic mode doing nothing but wait their turn to land (orbiting). BTW, the FAA was cognizant form the beginining that a mass introduction of SSTs would force a redesign of the ATC system. To Blackkite. Sure, Lockheed tried to design a very efficient aircraft, but as all know, in aeronautics don't allow for growth (e.g. weight growth) is like courting disaster. Lockheed had some growth potential in their design, but this was consumed in successive weight increments (due to engine less than ideal efficiency due to noise constraints and other corrections). When the airlines screamed for more subsonic endurance, the configuration of the L-2000-7 proved less efficient (in calculations) than the variable geometry of the Boeing, and so the request for extra fuel exceeded the residual growth potential. Fly-off: it was discussed time and again, but the money wasn't available, and barely available for one candidate to fly. Johnson didn't signed because it wasn't necessary to do it. FAA had full authority an that technical question, and the funds would have come from the Congress anyway. Moreover, the SST that would have been built was the 2707-300, by which time the competition was over since more than a year and Lockheed had no interest in renewing it (they had their hands full with the L-1011, this another very efficient and refined design tath had a lot of problems to allow for growth, and C-5). For the 2707-300 Johnson didn't asked prototype funds simple because he was retiring, and wanted not to leave such an hot potato to his successor (who, for all he knew, could have well been his Vice-President, Spiro Agnew).

 

[blackkite]

Hi chorendsnorkack!
But where was the space for improvement?

There are many way for improvement,Blended wing body concept, CCV technology, FBW, FBL, natural laminar flow wing design technology, light weight composite materials for non high temperature structure, light weight instrument, visual system instead of moving windshield,non after burning jet engine, engine improvement, etc.(Also LH2 fuel, bi-plane for low sonic boom.)
To Skybolt! It's very interesting for me that we eventually return to this topic. My knowledge about SST increase very much through the discussion with you(Boeing SST designer!!!),KJ,flateric and other air enthusiasts. Now I realize the demerits of double delta SST.
1. Double delta SST can't have high lifting device except leading edge flap. It need high angle of
attack in low speed, and increase drag,increase fuel consumption, clime rate is small. This is the
reason why Lockheed wants to apply JTF17A fan engine which fuel consumption is small in low
speed.
2.Landing noise is big because it enter thrust-drag back side region in landing, to lower the speed, it
must increase angle of attack, increase drag, then increase power.(To lower the speed it must
increase the power!)
But British Aerospace AST, AEROSPATIALE ATSF and Tu-244 use double delta.
Also Lockheed study double delta SST in 1999!(?????)

 

[chornedsnorkack]

But where was the space for improvement?

There are many way for improvement,Blended wing body concept,

Not improvement

CCV technology,

What is this?

FBW, FBL,

When did those appear?

natural laminar flow wing design technology,

Not an improvement.

light weight composite materials for non high temperature structure,

When did those appear?

light weight instrument, visual system instead of moving windshield,

When did those appear?

non after burning jet engine, engine improvement,

Engine improvement did happen on Concorde A, as well as Tu-144. Dropping afterburner? Concorde B was supposed to drop afterburner and add bypass. But they cruised at M 2,0.

etc.(Also LH2 fuel,

Not improvement.

bi-plane for low sonic boom.)

Not improvement.

Now I realize the demerits of double delta SST.
1. Double delta SST can't have high lifting device except leading edge flap. It need high angle of
attack in low speed, and increase drag,increase fuel consumption, clime rate is small. This is the
reason why Lockheed wants to apply JTF17A fan engine which fuel consumption is small in low
speed.

Yes, and Concorde B was to add leading edge devices.

But British Aerospace AST, AEROSPATIALE ATSF and Tu-244 use double delta.
Also Lockheed study double delta SST in 1999!(?????)

While Concorde has a smoother ogive.

Boeing defeated Lockheed´s fixed delta wing, all 5 abreast plane with a swing-wing, 7 abreast widebody - then this proved unfeasible, returned to a fixed delta smaller plane, which also was impractical.

In 1971, the Boeing 2707 was finally a failure, while both Tu-144 and Concorde had been flying for years. As for Lockheed, Tristar was flying... was there any consideration given to doing the L-2000?

 

[blackkite]

Hi Chorendsnorkack!
1.CCV means Control Configured Vihicle. Using small stabilized and reduce drag. Compensate for lack of
inherent stability with computer control.
2.FBW means Fly By Wire. Instead of hydraulic oil piping to actuate control sufaces, use electric wire
and electric actuater to reduce weight.
3.FBL means Fly By Light using optical fibre instead of electric wire. It also reduce weight.
4.Natural laminar flow design technology is inverse problem method using super computer. Input is
proper pressure distribution along the wing surface, output is wing shape. Output wing shape is
almost covered with laminar flow not turbulent flow and reduce drag. This method is applied Aerion
ssbj.
Sorry for my poor explanation. Please see Wikipedia.

 

[Skybolt]

Chorendsnorkack, Concorde/Tu-144 and the American SST were two different kind of planes: cruise/maximum speed (Mach 2.2 versus Mach 2.7-3.0); range; payload. There was nothing wrong in the 2707-300 technically-wise, AFAWK. In other words, it would have flown and probably operate successfully, but either with a reduced load on 4000 miles routes, or with a full load on the Concorde's routes. Simply, targeting the total performances used to justify the SST program, the operating cost was deemed too high from the airlines and the Government lost interest in front of the campaign against the double offensive from the "greens" on noise and pollution issues and from a part of the Congress, organized around Sen. Proxmire, that questioned the Government involvement in the program. Nixon had other problems, Boeing didn't even lobby for the SST, anyway, the SST lost by a fist of votes, and the "no" to the SST was rather cathartic, BTW. Following votes in the Congress were all in favor of Government involvement in aerospace (I remind just two: Lockheed loan guarantee and Space Shuttle). BTW, Concorde was "successful" from an economic point of view only if you don't consider the development costs in the equation, and only 14 were operating in a very exclusive configuration and tariffs (I'm not sure Air France was operating profitably, though). Even with that provisos, it was a marginal aircraft, stretched from a technical point of view. A great achievement, mind you, but a purely "prestige" venture by any other considerations. And, the UK government wanted to bail out very early, had not for the treaty they had signed without readying the small printings....

 

[mz]

Having read some Lockheed materials on the SR-71 (or whatever the exact variant was) temperature control systems, cruising at Mach 3 is a very hard problem. You need multiple heat exchangers, air-fuel, air-air, refrigeration units and whatnot.
It is incredible that Lockheed did it back then, and it is also understandable that it was not continued.

Continuous high mach cruise is a very hard problem. Higher than shooting for orbit in many regards.

 

[blackkite]

Hi! Please check Useful Links " Boeing 2707-300".

 

[chornedsnorkack]

Chorendsnorkack, Concorde/Tu-144 and the American SST were two different kind of planes: cruise/maximum speed (Mach 2.2 versus Mach 2.7-3.0); range; payload. There was nothing wrong in the 2707-300 technically-wise, AFAWK. In other words, it would have flown and probably operate successfully, but either with a reduced load on 4000 miles routes, or with a full load on the Concorde's routes.

How did the range of 2707 compare against Concorde?

(Tu-144 did suffer from a shorter range).

 

[Skybolt]

Target was 4000 miles plus reserves at full load. i.e. Rome-New York. That's why, for example, Alitalia did option the 2707-300 and not the Concorde.

 

[chornedsnorkack]

Target was 4000 miles plus reserves at full load. i.e. Rome-New York. That's why, for example, Alitalia did option the 2707-300 and not the Concorde.

Concorde A did fly between Heathrow and Bridgetown. 6752 km, plus reserves, plus some foul winds. With reduced payload, though.

 

[Skybolt]

Yep, payload is everything, you know... BTW, payload fractions for SST has always been critical. For example, in the last phases of evolution the 2707-300 had a payload fraction of 7 per cent, and it was at risk to go down to 2 per cent with the extra-weight due to noise-suppression add-ons and related structural stiffening.

 

[chornedsnorkack]

I found some numbers for weights:

Concorde:
Maximum TOW 185 tons
OEW 78,7 tons
making 42,5 % of MTOW
B2707:
MTOW 306 tons (?)
OEW 130 tons
making also 42,5 %
L-2000-7A
MTOW 276 tons
OEW 108 tons
making 39 %
Sounds L-2000 is more efficient there.

Fuel spent after takeoff at MZFW and MTOW:
Concorde - 93 tons
B2707 - 142 tons
L-2000-7A - 134 tons.

Hm, as Concorde burns, like, 930 kg per passenger while B2707 and L-2000 burn only around 500 kg per passenger, you would expect the B2707 and L-2000 tickets to be twice cheaper than the Concorde ones!
Payload:
Concorde 13,4 tons (100 passengers)
B2707: 34 tons (277 passengers)
L-2000: 273 passengers... presumably also 34 tons

 

[overscan (PaulMM)]

Hmm, but Concorde actually flew, while the figures for the other two designs are purely hypothetical.

 

[Skybolt]

Right. Moreover, it would be interesting to compare the theoretical numbers fro Concorde (apples with apples). I suspect the difference originally wasn't this significant....

 

[chornedsnorkack]

Right. Moreover, it would be interesting to compare the theoretical numbers fro Concorde (apples with apples). I suspect the difference originally wasn't this significant....

How many passengers was Concorde meant for? 128? 144?

 

[Skybolt]

It's not much the number of passenger but the MTOW for that number. For example, at Bourget 1963 the Concorde LR (Long Range) was advertised at 263.000 lbs MTOW with a payload of 20.000 lbs (111 normal number of people on-board) and a max range of 3730 miles and a take-off length of 8500 ft. at ISA +- 10 C. By end of 1970's (FAA certification) the MTOW had risen to 408.000 lbs, with a scant 10 more passengers. The internal arrangement in 1963 had a longer pitch.

 

[blackkite]

Hi! Noise level, mixer ejector for SST engine and U.S. designed engine for SST.
Future SST's engine noise level using mixer ejector will be same as recent quiet jet.

 

[hesham]

Hi,

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940029013_1994029013.pdf

 

[hesham]

Hi,

http://aero.stanford.edu/Reports/vki_kroo_supersonics.pdf

 

[blackkite]

Oh! We need such innovative ideas. Minimize,scatter and interfere.

 

[hesham]

Hi,

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940028947_1994028947.pdf

 

[hesham]

Hi,

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005346_1972005346.pdf

 

[hesham]

Hi,

http://cpair.blogspot.com/2007/02/cp-airs-fleet-of-future.html

 

[Orionblamblam]

Hi,

http://cpair.blogspot.com/2007/02/cp-airs-fleet-of-future.html

I've seen the subsonic design with the oddly bulbous fuselage listed as a Lockheed nuclear powered concept.

 

[hesham]

From Purdue Univ.;
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890006536_1989006536.pdf

 

[blackkite]

Many thanks hesham for nice design! But we need more radical counter measures for sonic boom.
I used to hear it's effective to use plasma for sonic boom reduction. Anyone know the theory and detail of this method?

 

[Sundog]

Thanks for the report Hesham. I didn't know that existed. I was in the Fall Semester that Professor Weisshaar is referring to in that report. I recognize some of those designs that were started in the semester when I took the class. Let me also say, with regard to the team I was in, communication problems were huge as the professor alluded to. It's still cool to see this report, though.

 

[hesham]

The California Univ. SST aircraft;
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940021217_1994021217.pdf

 

[hesham]

By the way,

the previous pictures,the eight one was asymmetric aircraft.
And from NASA;
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890003168_1989003168.pdf

 

[fightingirish]

Hi! Boeing's High Speed Civil Transport study in 1989.
[...]

Hi! Douglas HSCT study.
[...]

Hi folks,
this attached picture shows Boeing's and MDD's High Speed Civil Transport studies. These concepts were shown at Farnborough in 1990. Please notice the "stump canards" and "wingroot spoilers" on the Boeing concept. Did not the Boeing X-32 JSF have also similar spoilers? ???

Source: Flug Revue (+Flugwelt International) - Nr.9/ September 1990 - Page 10

 

[KJ_Lesnick]

Hesham,

What kind of variable cycle engine was to be used for the hypersonic design you depicted? (I.E. Turbofan to Turbojet, Turbofan to Turbojet to Ramjet, Turbojet to Ramjet)


FightingIrish,

I think those are vortex flaps...

 

[hesham]

Hi KJ_Lesnick,

I think turbojet to ramjet.

 

[hesham]

Hi,

here is the California Polytechnic State University SST aircraft.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930008866_1993008866.pdf

 

[blackkite]

Oh! It has flaps.
And no window for passengers!!

 

[kenneth]

hey
found this picture of an SBJ. anyone knows something about it?

 

[flateric]

something says me think late 80s Gulfstream

...or Dassault?

obviously have seen it in Volare ca.88

 

[Michel Van]

ahem
cant it be that this SST
is flying a littel bit to high ?
so 1246719160 ft ;D

or is this a SSTO also used as SST ?

 

[hesham]

Hi,

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19770005054_1977005054.pdf

 

[blackkite]

Oh it's F-108!
JAXA's researcher taught me that,
1.Wave resistance minimum shape is not equal to sonic boom minimum shape.
2.It's effective to stretch the fuselage for sonic boom reduction.
3.Quiet spike or plasma discharge is one method to get stretch fuselage effect.
4.Self weight origin sonic boom is difficult to deaden.
5.The "A" shape tail stabilizer such as SAI's SSBJ is effective to reduce sonic boom from fuselage after
end. Also it has stiffener effect for main wing.
6.Combination of expansion pressure part and compression pressure part along the fuselage is
important for sonic boom reduction. Strong boom from the fuselage tend to catch up the boom
from top of the fuselage.
7.MISORA's concept is interesting, but self weight origin sonic boom is difficult to deaden also for
bi-plane SST.

I can't understand exactly what he means. It's very difficult to understand sonic boom for me.