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GDB
Posts: 14253
Joined: Wed May 23, 2001 6:25 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jun 11, 2021 7:06 am

btfarrwm wrote:
I was just reading up on the history of SSTs and I was intrigued about the testbed NASA used based on a re-engined Tu-144. They used Russian NK-321 engines that appear to have better performance specs (thrust and fuel consumption) than the Olympus engine that was powering Concorde. No way Boom uses Russian engines, but it would be interesting to understand the differences.

https://www.nasa.gov/centers/armstrong/ ... -DFRC.html


NASA originally asked the Concorde operators but we had no airframes to spare.
Interestingly, the example TU-144LL was as stated, already built as a test aircraft, being the last constructed example in 1981, that's three years after that limited 102 flights in total ended and the program as an airliner was cancelled.
The stats for it likely did not account for carrying a pax load, though it was a great improvement on earlier models.
Really, the TU-144 in it's various forms was sort of the N1 rocket compared to the Saturn V.
 
iamlucky13
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Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jun 11, 2021 10:42 am

GDB wrote:
To the 2707, it was cancelled in 1971 after several attempts by Nixon to save it.
What did for it was not an enhanced business nous, it was that wildly over ambitious spec they drew up, Mach 3, later 2.7, meaning you could not use alloys like Aluminium, it would have to be expensive, hard to work and hard to get Titanium, it was one thing to have the CIA set up front companies to get it from the main supplier, the USSR, for the small number of A-12/SR-71's, quite another for the 2707.


Part of the over-ambition, of course, was the size. Not that it ever got far enough to truly test the market, but it would have relied on a large number of passengers willing to pay a premium for speed to establish each route it would fly.

Boom does have a couple contrasting positive factors. Obviously, it is less technically ambitious: Smaller, lower speeds, 50 years of improvement in materials and design tools to rely on.

The number of viable routes is also defined by an aircraft roughly 1/3 the size of the 2707, and operating in a market that has literally grown to over 10 times the size it was in 1971.

GDB wrote:
If designing and building a new, environmentally acceptable SST, large, medium or small, that was also a commercial prospect, why haven't Boeing, nor Airbus, nor for a potential SSBJ


This is certainly a compelling argument. The only counter I can think of at the moment is risk aversion. Boeing and Airbus both operate in a demonstrated market. They know continual improvement in subsonic aircraft makes them money. Investing in an SST might not make them money, and even if they think it could, it still needs to make them more than further investment in subsonic aircraft to be worth prioritizing their investments in. Their investors are not clamoring for them to try out the supersonic market, either.

In a sense, for Boom, the supersonic market is not about risk, but about opportunity. They've got close to zero hope going head-to-head against Boeing and Airbus in the demonstrated market. So they either need to look at an alternative market, or not bother. Likewise, the investors who want to take a swing at the supersonic market won't get enough traction among the rest of the investors in Boeing and Airbus.

Hence, Boom either tries the supersonic market, or they don't try at all. I fully recognize the best answer may be that Boom should not try at all.

It's not my money though (and it's too risky for me to invest in even if they were publicly traded), so I'm glad they are trying and I get to watch from the sidelines and hope they get a win.
 
GDB
Posts: 14253
Joined: Wed May 23, 2001 6:25 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jun 11, 2021 11:03 am

iamlucky13 wrote:
GDB wrote:
To the 2707, it was cancelled in 1971 after several attempts by Nixon to save it.
What did for it was not an enhanced business nous, it was that wildly over ambitious spec they drew up, Mach 3, later 2.7, meaning you could not use alloys like Aluminium, it would have to be expensive, hard to work and hard to get Titanium, it was one thing to have the CIA set up front companies to get it from the main supplier, the USSR, for the small number of A-12/SR-71's, quite another for the 2707.


Part of the over-ambition, of course, was the size. Not that it ever got far enough to truly test the market, but it would have relied on a large number of passengers willing to pay a premium for speed to establish each route it would fly.

Boom does have a couple contrasting positive factors. Obviously, it is less technically ambitious: Smaller, lower speeds, 50 years of improvement in materials and design tools to rely on.

The number of viable routes is also defined by an aircraft roughly 1/3 the size of the 2707, and operating in a market that has literally grown to over 10 times the size it was in 1971.

GDB wrote:
If designing and building a new, environmentally acceptable SST, large, medium or small, that was also a commercial prospect, why haven't Boeing, nor Airbus, nor for a potential SSBJ


This is certainly a compelling argument. The only counter I can think of at the moment is risk aversion. Boeing and Airbus both operate in a demonstrated market. They know continual improvement in subsonic aircraft makes them money. Investing in an SST might not make them money, and even if they think it could, it still needs to make them more than further investment in subsonic aircraft to be worth prioritizing their investments in. Their investors are not clamoring for them to try out the supersonic market, either.

In a sense, for Boom, the supersonic market is not about risk, but about opportunity. They've got close to zero hope going head-to-head against Boeing and Airbus in the demonstrated market. So they either need to look at an alternative market, or not bother. Likewise, the investors who want to take a swing at the supersonic market won't get enough traction among the rest of the investors in Boeing and Airbus.

Hence, Boom either tries the supersonic market, or they don't try at all. I fully recognize the best answer may be that Boom should not try at all.

It's not my money though (and it's too risky for me to invest in even if they were publicly traded), so I'm glad they are trying and I get to watch from the sidelines and hope they get a win.


The old adage comes to mind, about having to get not only the technology and market right but also the politics, the 'optics' of a high altitude emissions producing transport for the wealthy is as bad as it gets when like it or not, the direction of travel (pardon the pun), is very much in the other direction.
And the airlines mostly and the vendors know this, hence where they are headed as regards future technology.
 
btfarrwm
Posts: 147
Joined: Fri May 06, 2011 5:50 am

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jun 11, 2021 12:25 pm

GDB wrote:
Really, the TU-144 in it's various forms was sort of the N1 rocket compared to the Saturn V.


How about the NK-321 engine? What were it's advantages and drawbacks compared to the Olympus?
 
GDB
Posts: 14253
Joined: Wed May 23, 2001 6:25 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jun 11, 2021 3:49 pm

btfarrwm wrote:
GDB wrote:
Really, the TU-144 in it's various forms was sort of the N1 rocket compared to the Saturn V.


How about the NK-321 engine? What were it's advantages and drawbacks compared to the Olympus?


Interesting question, the fact this engine was for the TU-160 Bomber already makes it a much newer engine, if you consider the original Olympus for the Vulcan (itself from a spec. drawn up in 1947!), dates from the 1950's, the greatly enhanced 593 mk610 as fitted to production Concorde aircraft dates from the early 70's, the NK-321 is really of a different generation, as well as being a low bypass turbofan. It's nearest western version being the power-plant of the US B-1 Bomber.

Now if Concorde B had become real, we would have I think a better comparison, albeit with another enhancement to the Olympus rather than an all new engine.

Since the history of the TU-144 is even more complex, convoluted and at times plain bizarre compared to Concorde, though an obvious source, what I see here checks out and with more info I was not aware of, it's worth reminding ourselves of the aircraft;
https://en.wikipedia.org/wiki/Tupolev_Tu-144

The very limited TU-144 internal services effectively ended as shown, in 1978, so we can say no TU-144 carried pax with the NK-321.
This makes a comparison with the Oly 593 as at least a service engine impossible.
Another factor, operational maturity, despite the tiny fleets with two operators, Concorde's performance improved over time, early mods like the thinning of some airframe and control surfaces, updates including ones to maintain compliance with ATC - more of an avionic issue - as a result 20 years in service it could do this;
 
GDB
Posts: 14253
Joined: Wed May 23, 2001 6:25 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jun 11, 2021 4:47 pm

Continued (due to the very limited editing time if you have any computer issues)
So, 20 years in Concorde could do this;
https://simpleflying.com/concorde-faste ... -crossing/

Same with BGI, initially a route with a stop at usually the Azores or Lisbon, our technical and flight crews took advantage of the fact that although BGI was beyond the aircraft's range, at 58-60,000ft, the air at the tropics is cooler than on the North Atlantic, enhancing engine efficiency.
You also more often got to 60,000, as I and 74 other BA Concorde did on G-BOAE's final flight and the last international Concorde one, to retirement in BGI.

So could a refined TU-144 with NK-321 engines be a sort of Concorde B for the type?
It seems that by then Aeroflot had given up on the type, so fitment to the TU-144 was a testing project, quasi military considering it was developed for the TU-160.
The fact that the USSR never tried to exploit the PR coup of say Moscow to Havana via say Shannon, no US and only two Western airlines operating SST's speaks volumes about their confidence in the aircraft.

An improved TU-144, with the refinements needed as seen from the experiences on board it on the wiki link above, with NK-321's, maybe. But as mentioned, Aeroflot had given up on it by then.
Most of all to make any assessment of this impossible at least as an airliner, it did not fly with these engines until 1996!

To put the issue of operational maturity in context, 20 years into Concorde's career in BA, (when I happened to join the team), in around two months we would fly more scheduled JFK round trips than the whole of the TU-144's pax service.
More like a month if you count in charters.

The fact that the TU-144 was in low rate production some years after Aeroflot stopped flying pax on them points to them being for testing or maybe just the absurdities of stagnation era Soviet economics.
 
KlimaBXsst
Posts: 938
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Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Fri Jul 23, 2021 8:28 pm

Did Boom just add reheat to the #2 to assist in transonic acceleration during the high drag zone prior to reaching MACH 1.7? In an article I read momentarily it does seem to? I believe this was the article one but I can no longer seem to have access to it.

United Airlines talks about Boom being so much more efficient than Concorde which had 4 engines running with afterburners while Boom has "two" and NOT using afterburners. Was this an info "Slip of the tongue?" REHEAT makes sense in some ways!

https://www.flightglobal.com/fleets/ove ... 35.article

NOTE to editors... somehow this post went to the Alaska thread. Please delete on the Alaska thread ....
Aesthetically the A 340 got it right!
 
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LAX772LR
Posts: 13976
Joined: Sun Nov 09, 2014 11:06 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Sat Jul 24, 2021 8:23 am

KlimaBXsst wrote:
Did Boom just add reheat to the #2 to assist in transonic acceleration during the high drag zone prior to reaching MACH 1.7? In an article I read momentarily it does seem to? I believe this was the article one but I can no longer seem to have access to it.

United Airlines talks about Boom being so much more efficient than Concorde which had 4 engines running with afterburners while Boom has "two" and NOT using afterburners. Was this an info "Slip of the tongue?" REHEAT makes sense in some ways!

https://www.flightglobal.com/fleets/ove ... 35.article

NOTE to editors... somehow this post went to the Alaska thread. Please delete on the Alaska thread ....

Hard to believe that it was anything more than an oversight, as reheat/afterburn = insane noise, and there's so few places they could ever expect to get it into to, if it's going to be used on takeoff.

Even if they're just going to use it for the transonic acceleration, I still find it dubious... though would be cool as hell if the case.
I myself, suspect a more prosaic motive... ~Thranduil
 
KlimaBXsst
Posts: 938
Joined: Wed Jan 23, 2019 4:14 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Sat Jul 24, 2021 2:41 pm

LAX772LR wrote:
KlimaBXsst wrote:
Did Boom just add reheat to the #2 to assist in transonic acceleration during the high drag zone prior to reaching MACH 1.7? In an article I read momentarily it does seem to? I believe this was the article one but I can no longer seem to have access to it.

United Airlines talks about Boom being so much more efficient than Concorde which had 4 engines running with afterburners while Boom has "two" and NOT using afterburners. Was this an info "Slip of the tongue?" REHEAT makes sense in some ways!

https://www.flightglobal.com/fleets/ove ... 35.article


...reheat/afterburn = insane noise.

Even if they're just going to use it for the transonic acceleration, I still find it dubious... though would be cool as hell if the case.


In the article it also stated “the engines would be placed further outboard upon the wings” of the Overture. This gave me a Lockheed hmmm!!! By utilizing transonic afterburner / reheat “reserve power”

ONLY DURING ***engine out emergencies***

at takeoff and landing...the asymmetric thrust issues of losing the number 1 or 3 when low and slow, have just been minimized significantly. Fortunately if the #2 is lost, powerplant / engine asymmetry really does not factor into aircraft controllability as much as maintaining altitude and building speed. At this time it’s all about dropping the nose, hoping the two remaining continue operating to clear obstacles, and keeping it level as checklists are completed for a big loop return to the airport.
Aesthetically the A 340 got it right!
 
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LAX772LR
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Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Sun Jul 25, 2021 6:10 am

KlimaBXsst wrote:
LAX772LR wrote:
...reheat/afterburn = insane noise.

Even if they're just going to use it for the transonic acceleration, I still find it dubious... though would be cool as hell if the case.


In the article it also stated “the engines would be placed further outboard upon the wings” of the Overture. This gave me a Lockheed hmmm!!! By utilizing transonic afterburner / reheat “reserve power”

ONLY DURING ***engine out emergencies***

at takeoff and landing...the asymmetric thrust issues of losing the number 1 or 3 when low and slow, have just been minimized significantly. Fortunately if the #2 is lost, powerplant / engine asymmetry really does not factor into aircraft controllability as much as maintaining altitude and building speed. At this time it’s all about dropping the nose, hoping the two remaining continue operating to clear obstacles, and keeping it level as checklists are completed for a big loop return to the airport.

All fair and good, but what the heck does that have to do with what you quoted me as saying? :confused:
I myself, suspect a more prosaic motive... ~Thranduil
 
KlimaBXsst
Posts: 938
Joined: Wed Jan 23, 2019 4:14 pm

Re: United orders supersonic planes from Boom (was: Big United Announcement Coming Up?)

Sun Jul 25, 2021 3:45 pm

LAX772LR wrote:
KlimaBXsst wrote:
LAX772LR wrote:
...reheat/afterburn = insane noise.

Even if they're just going to use it for the transonic acceleration, I still find it dubious... though would be cool as hell if the case.


In the article it also stated “the engines would be placed further outboard upon the wings” of the Overture. This gave me a Lockheed hmmm!!! By utilizing transonic afterburner / reheat “reserve power”

ONLY DURING ***engine out emergencies***

at takeoff and landing...the asymmetric thrust issues of losing the number 1 or 3 when low and slow, have just been minimized significantly. Fortunately if the #2 is lost, powerplant / engine asymmetry really does not factor into aircraft controllability as much as maintaining altitude and building speed. At this time it’s all about dropping the nose, hoping the two remaining continue operating to clear obstacles, and keeping it level as checklists are completed for a big loop return to the airport.



....what the heck does that have to do with what you quoted me as saying? :confused:


Just did not want to have people or yourself confused, with an assumption that afterburner-reheat was to be used normally during every takeoff.

I am pretty sure this innovation would never be used unless during a safety of flight concern arises for example during engine-powerplant failure at takeoff, which is actually quite rare.

Let us see if a staggered seating arrangement can make it on to a three abreast higher capacity version of this aircraft, DC2 to DC3 style down the road! It’s all cool stuff! Thanks for sharing in my enthusiasm for this HSCT second generation SST project by BOOM!
Aesthetically the A 340 got it right!
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