Northrop Grumman B-21 Raider (LRS-B)

PaulMM (Overscan) said:
There's no chance B-21 is a cranked-delta or supersonic, you are clutching at straws here.

If you want to imagine a supersonic 'flying wing' bomber, aerodynamics makes it hard to do much different to Sukhoi's 1969 T-4MS design:
Click to expand...

I agree it's not likely supersonic. I was more interested in possible obfuscation by the AF releasing the early design concept drawing.

My reasons for suspecting obfuscation...

1. If you're that worried about security. Release nothing.
2. If you have to release something. Release something that is different but with "plausible deniability".
i.e. We released an "actual" concept drawing from the initial RFP response. Yes, it's different but we took pains to say it was a concept drawing.
3. The design concept just doesn't look like the plane in the commercial - to me. Maybe it is. Maybe it isn't

The cranked-arrow looked similar to the cranked-kite to me. I was asking the experts available here to help me understand the differences. Which they so graciously did. That's all there is to it.
 
NeilChapman said:
PaulMM (Overscan) said:
There's no chance B-21 is a cranked-delta or supersonic, you are clutching at straws here.

If you want to imagine a supersonic 'flying wing' bomber, aerodynamics makes it hard to do much different to Sukhoi's 1969 T-4MS design:
Click to expand...

I agree it's not likely supersonic. I was more interested in possible obfuscation by the AF releasing the early design concept drawing.

My reasons for suspecting obfuscation...

1. If you're that worried about security. Release nothing.
2. If you have to release something. Release something that is different but with "plausible deniability".
i.e. We released an "actual" concept drawing from the initial RFP response. Yes, it's different but we took pains to say it was a concept drawing.
3. The design concept just doesn't look like the plane in the commercial - to me. Maybe it is. Maybe it isn't

The cranked-arrow looked similar to the cranked-kite to me. I was asking the experts available here to help me understand the differences. Which they so graciously did. That's all there is to it.
Click to expand...

No, I don't buy it.

Northrop Grumman used a cranked-kite design as promotional material during NGB etc. That actually makes it LESS likely the actual design looked like that to me. I'm pretty sure the Superbowl Ad image was not accurate - Northrop weren't cleared to release anything at that stage.

I don't believe the rendering is a placeholder or an "early design". It you look at the "artist's concept" released for YF-23, B-2, the photo of F-117, they omitted details, but were accurate overall in shape. The F-117 photo was dark, a misleading angle, but not "Have Blue".

The more interesting question is - what was omitted? Exhausts, control surfaces etc.
 
I personally feel the USAF released B-21 concept is bogus. I'm willing to bet the actual aircraft looks different. -SP
 
Steve Pace said:
I personally feel the USAF released B-21 concept is bogus. I'm willing to bet the aircraft looks different. -SP
Click to expand...
I have the same 'gut' feeling. What would be the benefit of having Russia and China figuring out how to defend against this and a totally different aircraft came out. For the stealth radar experts out there would this make a difference?
 
Quellish has already stated this is the second best LO design, from a signature standpoint, right after the diamond shape (X-47A). The X-47A layout doesn't have the aerodynamic efficiency to meet the requirements for LRSB, so I don't have any reason to doubt that the painting is accurate. Which means any other design, including the cranked kite, would have a higher signature, all other things being equal. I don't think NG is going to go with a configuration that has a higher signature or lower aerodynamic efficiency.

As Paul stated above, I think the painting is relatively accurate and it's just the details that are hidden, as they've always done before. The only thing that will be different between this and when we saw the first B-2 renderings is when this rolls out they won't let anyone (Aviation Week) fly overhead.
 
We have a drawing.

We don't know the sweep, we don't know the size, we don't know the cockpit configuration, nor a single other detail.

My betting is that it's the voodoo INSIDE that's really going to get the classified to the rafters treatment.
 
The only things the picture reveals are

1) B-21 is stealthy
2) B-21 is subsonic

which we already know from the LRS-B program requirements.

I've tried looking at evidence traces showing which bits have been removed, but I can't see any traces of areas that have been photoshopped. I'm pretty sure its a low-detail rendering specially created for release.

So really, no, its not helping any adversary.
 
When you look the drawing of the B-21 the proportion are completely false the wing of the left is long , when the wing of the right is short, and not in the perspective. This rendering is " some of" by USAF not a Northrop rendering , somebody put Northrop on the plane. When we Watch the 6th gen fighter video of Northrop at the end of the video the shadow of the bomber nose is the same round shape than the past year Northrop commercial video.
 
dark sidius said:
When you look the drawing of the B-21 the proportion are completely false the wing of the left is long , when the wing of the right is short, and not in the perspective. This rendering is " some of" by USAF not a Northrop rendering , somebody put Northrop on the plane. When we Watch the 6th gen fighter video of Northrop at the end of the video the shadow of the bomber nose is the same round shape than the past year Northrop commercial video.
Click to expand...

You are completely right, Northrop cleverly revealed elements of the *actual* B-21 shape in a commercial more than a year ago. Before any declassification of this highly secret program, and before they'd won, because of course that's how they roll in California. Helps make the government confident they can handle the program security, right?

I can't quite understand why everyone wants to disbelieve this picture so badly.
 
Sure, the drawing USAF release is the start of the LRS-B program not what the shape it have in 2016 .
 
PaulMM (Overscan) said:
I can't quite understand why everyone wants to disbelieve this picture so badly.
Click to expand...

Because they want a Mach 5, uber stealthy fanboy dream plane. Hell, I want one of those as well, but then there's reality in the way.
 
Sundog said:
PaulMM (Overscan) said:
I can't quite understand why everyone wants to disbelieve this picture so badly.
Click to expand...

Because they want a Mach 5, uber stealthy fanboy dream plane. Hell, I want one of those as well, but then there's reality in the way.
Click to expand...

I felt a similar disappointment when that first B-2A image was released back in '88. I was hoping for some uber, stealthy cross between a B-1B and an XB-70 and I get a flying wing? :'(
 
I've been trying to figure out the inlet shape. You can see the kink in the lip on the far side, if you zoom into it. At first I thought it was an inverted "V" lip, but now I think it may be more like the three lobe design shown in this image, due to the angle of the second "kink".

Also, the reason one wing looks bigger than the other is forced perspective. It's a simple option in most 3D modeling software. I'm sure they did it to make it as difficult as possible to figure out the exact dimensions.
 

Attachments

  • LRS-B-Concept-sml.jpg
    LRS-B-Concept-sml.jpg
    44.9 KB · Views: 469
It'll be a flying W (B-21) rather than a flying double W (B-2). Or will it? -SP
 
I feel like the intakes are closer to this other NGB/LRSB concept, set slightly further back.
 

Attachments

  • B-21Intakes.jpg
    B-21Intakes.jpg
    47.5 KB · Views: 453
Steve Pace said:
I personally feel the USAF released B-21 concept is bogus. I'm willing to bet the actual aircraft looks different. -SP
Click to expand...

If it's only subsonic then it's accurate. The same mathematical solutions to making something LO and making something fly that existed at the time of the ATB are the same solutions as today. If its purely subsonic there is no reason for a cranked kite planform. If it's supersonic capable, then it's not accurate.
 
PaulMM (Overscan) said:
I can't quite understand why everyone wants to disbelieve this picture so badly.
Click to expand...

Honestly, I don't know if I believe the picture. I'd put it at 75% that you are right, though.

It pretty much looks like the ATA proposals before the saw-teeth, which makes sense if they want a high-altitude VLO platform with loiter (and they probably do). The photo certainly appears to be optimized for that.

There are other performance desires beyond purely signature ones that might necessitate a different configuration, with various compromises (as any design). I would not be completely shocked to see it looking different than the released image if they've decided the combination of EW elements and signature reduction made it plausible to deviate from the ATA-style design for other goals, and that the image was disinformation or just a placeholder image.

Having said that -- if you base some disbelief on the fact it doesn't look like the shadow cast on a cloud in an advertisement, or look like what some thing looked like under a shroud in a different advertisement, you are probably crackers.
 
PaulMM (Overscan) said:
NeilChapman said:
PaulMM (Overscan) said:
There's no chance B-21 is a cranked-delta or supersonic, you are clutching at straws here.

If you want to imagine a supersonic 'flying wing' bomber, aerodynamics makes it hard to do much different to Sukhoi's 1969 T-4MS design:
Click to expand...

I agree it's not likely supersonic. I was more interested in possible obfuscation by the AF releasing the early design concept drawing.

My reasons for suspecting obfuscation...

1. If you're that worried about security. Release nothing.
2. If you have to release something. Release something that is different but with "plausible deniability".
i.e. We released an "actual" concept drawing from the initial RFP response. Yes, it's different but we took pains to say it was a concept drawing.
3. The design concept just doesn't look like the plane in the commercial - to me. Maybe it is. Maybe it isn't

The cranked-arrow looked similar to the cranked-kite to me. I was asking the experts available here to help me understand the differences. Which they so graciously did. That's all there is to it.
Click to expand...

No, I don't buy it.

Northrop Grumman used a cranked-kite design as promotional material during NGB etc. That actually makes it LESS likely the actual design looked like that to me. I'm pretty sure the Superbowl Ad image was not accurate - Northrop weren't cleared to release anything at that stage.

I don't believe the rendering is a placeholder or an "early design". It you look at the "artist's concept" released for YF-23, B-2, the photo of F-117, they omitted details, but were accurate overall in shape. The F-117 photo was dark, a misleading angle, but not "Have Blue".

The more interesting question is - what was omitted? Exhausts, control surfaces etc.
Click to expand...

I'm sure there is a lot to what you say.

"While there are no existing prototypes of the aircraft, the artist rendering is based on the initial design concept" were the words used by the AF when the image was released. With that, once you start talking with your customer, invariably something comes up. Perhaps there is a change to add 7 hr loiter. Or expected forward deploy from Australia instead of Guam so more fuel. Maybe the C2ISR solution has some specific antenna or altitude requirement that necessitates a modified design. Perhaps AF decides that 40k payload instead of some original lower number. There's a host of potential issues that could change the original airframe design.

http://www.af.mil/News/ArticleDispl...ce-reveals-b-21-long-range-strike-bomber.aspx
I completely agree that B-21 is to be subsonic. Frankly, there doesn't seem to be engines that will provide the performance required - speed & endurance. Perhaps the performance desired will come with the $2 Billion AETP program that will run the next 5 years.

AF had said they they wanted speed in the future and had also suggested that maybe they'd get it with Block upgrades to LRS-B. This had me wondering what could have been built today that with upgrades will get them what they want later.
Today
All frequency stealth - highly survivable
Persistance - loiter
Range - combat radius > couple k nm
Manned
Later
Unmanned and Supersonic variants
Based on what the AE's have said, upgrades to supersonic are not possible. Too many "baked-in" parts of the subsonic design. So maybe this is the optimum shape for LO/persistance/range, and all the other stuff will work with this design. All I was saying is that with weighted decision making it's tough to tell. We don't know the final criteria.

So it looks like will get at least 80 B-21's. They'll increase the # of combat coded bombers to the ~175 range, from the current ~95, until 2040. As the B-21's are being built they'll be looking at what kind of techmat has been achieved in materials, hypersonic missiles etc.. AF will then decide what to do about the next "bomber" in 2025 or 2030 - whether they need a new supersonic platform.

Hopefully, by then, we have a supercruise F-X program in production!
 
PaulMM (Overscan) said:
I feel like the intakes are closer to this other NGB/LRSB concept, set slightly further back.
Click to expand...

If you zoom in on the inlet shown on the right side (of the aircraft, which would be to the upper left in the image) of the B-21 image, you will see the inlet lip changes direction, unlike the second image you show on the bottom.
 

Attachments

  • B-21-Inlet.jpg
    B-21-Inlet.jpg
    52 KB · Views: 367
I can see what you are saying, but you are talking very small single pixel details and the edge of the intake looks rough as hell at that zoom level, so its not clear to me if its a real angle change or not. Regardless, I guess the intake to not be fully separate like the B-2 but to join to the "fuselage" bump, whether there is a kink in the intake edge or not.
 
It makes sense from the 'family of systems' approach. A subsonic platform gives endurance and efficiency to carry a larger payload at longer range. Low observability prevents it from being easily spotted - especially if you have to search a lot of airspace because if its use as a stand-off non-penetrating platform. The payload itself could be a supersonic or hypersonic weapon. If it has large unitary weapon bays it could even be a hypersonic reusable UCAV (getting rid of the pilot weight). Composites are the future.

That said, I'd pick this approach if I were planning on using the platform for five decades and had limited faith in the ability of VLO design to evade future radars. I personally don't have much confidence in RCS reduction as a reliable silver bullet by mid-century - but the USAF brass may disagree.
 
My gut feeling is the B-21 will be optionally manned during flight test, bordering on operationally unmanned.
I have to stop myself with all my speculations and just wait to see. It's boggling what little mind I have left. Damn the USAF anyway. They could have gave us a LITTLE more info....
-SP
 
We've had "good" indication that the PW9000 engine may be used in B-21. Any thoughts on whether the F135 on-going issues would cause delay in B21? Sure wish we had some more info on the engines to be used.
 
Sundog said:
If you zoom in on the inlet shown on the right side (of the aircraft, which would be to the upper left in the image) of the B-21 image, you will see the inlet lip changes direction, unlike the second image you show on the bottom.
Click to expand...
yeah
 

Attachments

  • B-21 other render-.jpg
    B-21 other render-.jpg
    63.7 KB · Views: 1,042
It isn't going to be reviewed. Whatever they may have underbid it by, Northrop has to eat the costs if they don't meet them, just like Boeing has done with the KC-46A. I'm sure they take this into account when they make these bids. They'll still make a profit in the long run and definitely more than they would have made if they lost the contract.
 
Sundog said:
It isn't going to be reviewed. Whatever they may have underbid it by, Northrop has to eat the costs if they don't meet them, just like Boeing has done with the KC-46A
Click to expand...

The B-21 EMD contract is Cost-Plus Incentive Fee vs. the Fixed-Price Incentive Fee for the KC-46A EMD contract.
Unless the B-21 EMD contract has provisions for a negative minimium award fee then the government eats all of the costs above the target.
 
USAF basing revised bomber count on 'minimum' of 100 B-21s

The major command’s chief Gen Robin Rand said at the Air Warfare Symposium in February that America’s needs somewhere between “175 and 200” combined strategic and conventional bombers.

The command counts 159 bombers in its inventory today including the B-1B, B-52H and B-2A.

“AFGSC continues to analyse the required future bomber force structure which includes successfully fielding a minimum of 100 B-21s,” an AFGSC spokeswoman says in an email. “AFGSC is very focused on ensuring we are ready with properly trained operators and maintainers for the B-21. The minimum of 100 B-21s that we intend to field will fly with a mix of legacy bombers and the total number of bombers required is still being evaluated.”
Click to expand...

https://www.flightglobal.com/news/a...evised-bomber-count-on-minimum-of-100-424433/
 
Flyaway said:
USAF basing revised bomber count on 'minimum' of 100 B-21s

The major command’s chief Gen Robin Rand said at the Air Warfare Symposium in February that America’s needs somewhere between “175 and 200” combined strategic and conventional bombers.

The command counts 159 bombers in its inventory today including the B-1B, B-52H and B-2A.

“AFGSC continues to analyse the required future bomber force structure which includes successfully fielding a minimum of 100 B-21s,” an AFGSC spokeswoman says in an email. “AFGSC is very focused on ensuring we are ready with properly trained operators and maintainers for the B-21. The minimum of 100 B-21s that we intend to field will fly with a mix of legacy bombers and the total number of bombers required is still being evaluated.”
Click to expand...

https://www.flightglobal.com/news/articles/usaf-basing-revised-bomber-count-on-minimum-of-100-424433/
Click to expand...

Last I heard was that we need 175-200 bombers. The "plan" is to build 100 B-21's and then evaluate where we are. There was an "implication" that there may be additional B-21's or a follow-on airframe to B-21 depending on the state of the legacy bombers.
 
The Air Force won’t make public the contract value of Northrop Grumman Corp.’s winning bid for the B-21 bomber, saying that would make it “decisively easier” for U.S. adversaries to determine the stealth aircraft’s range and weapons payload.
There is a “strong correlation between the cost of an air vehicle and its total weight,” Randall Walden, director of the Air Force’s secretive Rapid Capabilities Office, which is overseeing the B-21 program, wrote in a letter to Senator John McCain, chairman of Senate Armed Services Committee.
“This correlation makes calculating aircraft range and payload decisively easier for our adversaries looking to develop countermeasures,” Waldon wrote in the letter dated April 11 and obtained by Bloomberg News. He said the information has been provided to congressional staff “in the appropriate classified channels.”
Click to expand...

http://www.bloomberg.com/news/articles/2016-04-19/air-force-says-disclosing-bomber-s-secret-cost-would-aid-enemies
 
Flyaway said:
The Air Force won’t make public the contract value of Northrop Grumman Corp.’s winning bid for the B-21 bomber, saying that would make it “decisively easier” for U.S. adversaries to determine the stealth aircraft’s range and weapons payload.
There is a “strong correlation between the cost of an air vehicle and its total weight,” Randall Walden, director of the Air Force’s secretive Rapid Capabilities Office, which is overseeing the B-21 program, wrote in a letter to Senator John McCain, chairman of Senate Armed Services Committee.
“This correlation makes calculating aircraft range and payload decisively easier for our adversaries looking to develop countermeasures,” Waldon wrote in the letter dated April 11 and obtained by Bloomberg News. He said the information has been provided to congressional staff “in the appropriate classified channels.”
Click to expand...

http://www.bloomberg.com/news/artic...losing-bomber-s-secret-cost-would-aid-enemies
Click to expand...
I call BS on this one. The so-called price has been given - just not the exact production number. -SP
 
NeilChapman said:
Updated CRS report.

https://cdn.arstechnica.net/wp-content/uploads/2016/04/R44463.pdf

Interesting notes....

States there will be 2 or 3 test aircraft. This quantity hadn't been specified before that I recall.

FY17 budget has 100 planes requested - not 80-100.
Click to expand...
Already posted #877
 
bobbymike said:
NeilChapman said:
Updated CRS report.

https://cdn.arstechnica.net/wp-content/uploads/2016/04/R44463.pdf

Interesting notes....

States there will be 2 or 3 test aircraft. This quantity hadn't been specified before that I recall.

FY17 budget has 100 planes requested - not 80-100.
Click to expand...
Already posted #877
Click to expand...

Yep.

I thought I was pointing out two items that I hadn't seen before - the test article count and that 100 was in the budget - and where it was to be found.
 

Similar threads

Back
Top Bottom