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Northrop Grumman B-21 Long Range Strike Bomber

Grey Havoc

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Very doubtful there is any relationship to RQ-180; that is a direct descendant of Lockheed Martin's Polecat program which was intended to prove that high capability dirt cheap stealth drones were viable. Didn't really work out and the RQ-180 has arguably been even more of a disappointment.
 

Flyaway

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According to AW the RQ-180 is seemingly only just being fielded so perhaps early to declare it a failure?
 

TomcatViP

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Research in BWB aircraft indicate ~25% improvement in L/D over tube-and-wing
=> means ~5,000 * 1.25 = ~6,250 miles range is a better estimate (CONUS to near-peer states)
It's also a high altitude Bomber, where range will be maximized given the optimum choice of engine and inlets.
IMOHO, you can expect U-2 type of cruise altitude.
 

flateric

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It's also a high altitude Bomber, where range will be maximized given the optimum choice of engine and inlets.
IMOHO, you can expect U-2 type of cruise altitude.
Not from PW9000 or whatever will she have
 

flateric

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Two tires per main landing gear = 4x ~50,000 lbs/tire = ~200,000 lbs takeoff weight
According to Raymer, two wheels per MLG strut typical for 50-150K lbs MTOW, but can be used for designs up to 250K lbs MTOW
knowing that B-21 should carry at least one MOP, it gives you some idea of payload/mtow combo.
=> means 737-class airplane (or so) [B-2 with 8x main tires actually uses 767 gear].
actually, it doesn't
767 MLG components were used for AV-1 to save time and money, production AV use dedicated design
 

In_A_Dream

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Very doubtful there is any relationship to RQ-180; that is a direct descendant of Lockheed Martin's Polecat program which was intended to prove that high capability dirt cheap stealth drones were viable. Didn't really work out and the RQ-180 has arguably been even more of a disappointment.
How can something be a failure when it's operational status hasn't been declassified, nor its intended role?
 

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Very doubtful there is any relationship to RQ-180; that is a direct descendant of Lockheed Martin's Polecat program which was intended to prove that high capability dirt cheap stealth drones were viable. Didn't really work out and the RQ-180 has arguably been even more of a disappointment.
How can something be a failure when it's operational status hasn't been declassified, nor its intended role?
Possibly a typo? The RQ-170, being a Lockheed Martin design, could be accurately called a descendent of the Polecat.
 

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Very doubtful there is any relationship to RQ-180; that is a direct descendant of Lockheed Martin's Polecat program which was intended to prove that high capability dirt cheap stealth drones were viable. Didn't really work out and the RQ-180 has arguably been even more of a disappointment.
Pretty sure the RQ-180 is part of the same system of systems that the B-21 is. It's role is to find targets for the B-21s in denied airspace.

I would think that the RQ-180 would at least provide some lessons for the B-21, supposedly it's designed to even higher specifications.
 

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Just an FYI, if you download the Hi-Res images from the Air Force site, you can see the detail better. Such as the nose gear having two piece NLG doors in tandem. It's the rear NLG door, hiding part of the left main gear in the images.
 

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So its basically slightly bigger than an A12 Avenger with bigger engines and more fuel? Wonder if they saved space for a third crew member if ever needed (and room for a sleeping bag).
 

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Avenger II was supposed to be in the 80 thousand pound class, mtow wise. B21 is looking like it might be in the 150 to 200 thousand pounds class if we take the artists impressions as accurate.
 

Grey Havoc

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Possibly a typo? The RQ-170, being a Lockheed Martin design, could be accurately called a descendent of the Polecat.
Thought we'd started discussing that design for some reason.

D'oh!

Now if you will excuse me, my head has another appointment with a wall...

 

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Will it likely be using two F135 cores with a non-afterburner exhaust?
 

NUSNA_Moebius

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F135 would be practical from a supply chain perspective but I read the PW9000 might use some variable cycling tech specifically for superceding the F100 and the GE F110 series in fighters. Not sure how much benefit there is when the max speed will likely be transonic at best but could provide for very specific IR tailoring (by using more bypass to mask exhaust) along with economy. Powering up the fan for high Mach flight could increase exhaust temp more than what could be practically masked by the bypass though. Just not sure.......

Makes me wonder how GE's Affinity could fit into this but it is a higher diameter engine (harder to stealthify) with much less thrust. Medium bypass though so plenty of colder air for mixing.
 

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3rd stream is also a battery to power the most demanding systems aboard an aircraft this class.
 

coanda

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The new pictutes look quite like the Northrop ATA in the A12 thread in Postwar.
 

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If the B21 is a smaller aircraft than the B2, does that mean it will be used as an F111 rather than a strategic heavy bomber?
 

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The smaller footprint comes from a lighter structure and benefits mainly cost and range (equal or better than the B-2 with all the other gizmo added).

At best we could say that B-21 is strategic bomber with a tactical footprint. It's a noticeable difference that won't be missed by pear opponents.
 

totoro

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If the B21 is a smaller aircraft than the B2, does that mean it will be used as an F111 rather than a strategic heavy bomber?
Doubtful. F111 had ferry range of over 5000 km. And combat radius of roughly 2000 km on a simple bombing mission with internal bomb load.
B-2 allegedly has ferry range of 11 000 km. (though of course that may be a fake figure) Combat radius is unknown but I wouldn't be surprised it can do 4000+ km with a decent bomb load.

With the landing gear depicted, IF we take it for granted, we're looking at 100-120 tons MTOW. Almost 2.5 to 3 times the F111 figure. And roughly 40 to 30% less than B-2.

But would that mean similar range drawback? likely not.
B-2 is a 4 engine plane, while B-21's two engines should be somewhat more fuel efficient solution. Airliners of similar generation usually benefit from 5-10% lower fuel consumption per seat per mile when using 2 engines compared to 4. B-2's engines are basically 80s tech. B-21's engines have 30+ years of tech development. New variants of F135 engine have projected 6% better fuel efficiency compared to engines from 10 years ago.

B-21 may enjoy fairly low construction weight compared to B-2. And enjoy lighter RAM materials. F-35 to F-22 comparison is a pretty good sign there.

So, even if B-21 ends up 35% lighter, MTOW wise, than B-2, I don't think the range and payload will also be 35% less. It might be as little as 10 or 20% less. I think USAF would be willing to sacrifice a bit of payload compared to B-2 to get B-1B range. (9400 km ferry) Which is perfectly doable for this "little" package. Which isn't that little anyway.
 

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I also think they went with a smaller aircraft for the following reasons;
(1) A smaller aircraft has a smaller signature. Given the signature performance the USAF was looking for, that might not have been possible with a B-2 sized aircraft.
(2) The big thing in the military now is networking. Having a greater quantity of smaller aircraft, versus a lower quantity of big aircraft means more nodes in the network that can have a greater distribution, which most likely shortens the time delta in the kill chain.
 
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TomcatViP

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Probably that they went smaller because they had enough range first with the B-2 and secondly, new tech gave them a similar range in a more nimble design.
There is no way that they would have relinquished range to rely today on non-stealthy tanker support.
 

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I also think they went with a smaller aircraft for the following reasons;
(1) A smaller aircraft has a smaller signature. Given the signature performance the USAF was looking for, that might not have been possible with a B-2 sized aircraft.
(2) The big think in the military now is networking. Having a greater quantity of smaller aircraft, versus a lower quantity of big aircraft means more nodes in the network that can have a greater distribution, which most likely shortens the time delta in the kill chain.
Think it has more to do with the SDB II or another similar smaller munitions being dropped out of it. You also don't need a 40k lbs payload to launch a couple of AARGM-ERs.
 

bring_it_on

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I also think they went with a smaller aircraft for the following reasons;
(1) A smaller aircraft has a smaller signature. Given the signature performance the USAF was looking for, that might not have been possible with a B-2 sized aircraft.
(2) The big thing in the military now is networking. Having a greater quantity of smaller aircraft, versus a lower quantity of big aircraft means more nodes in the network that can have a greater distribution, which most likely shortens the time delta in the kill chain.
Having a Unit cost as a KPP probably also played a role in this. Being able to field it in the 100-200 range probably also played a role. If I were to guess, I'd guess the bomber program that was terminated prior to restructuring as the LRS-B probably created designs that were unaffordable to acquire in such high numbers.
 

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If I were to guess, I'd guess the bomber program that was terminated prior to restructuring as the LRS-B probably created designs that were unaffordable to acquire in such high numbers.
You don't need to guess, that is exactly why it was cancelled. At least that was what was noted in Aviation Week at the time.
 

trose213

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If I were to guess, I'd guess the bomber program that was terminated prior to restructuring as the LRS-B probably created designs that were unaffordable to acquire in such high numbers.
You don't need to guess, that is exactly why it was cancelled. At least that was what was noted in Aviation Week at the time.
And industrial automation supposedly played a large role in NG winning the contract, while Boeing focused on digital design tools with Black Diamond. I'm surprised Black Diamond hasn't come up more with the 737 Max problems.
 

bring_it_on

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slight mods to production budget requests.


This is interesting. I'm assuming that the $10.28 Billion represents 3 out of the 5 initial lots that collectively would result in an order for the 21 LRIP aircraft. The other 2 would be outside the FYDP. I just hope they can get production rate close to 10 at Full-Rate Production and hold that for at least a decade. At some point we need to transition all these RDT&E efforts into scaled production and this includes buying 80-100 F-35A's and close to 10 B-21's a year. Otherwise the size of the AF will continue to shrink, and the average fleet age will continue to rise.
 
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In_A_Dream

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This is interesting. I'm assuming that the $10.28 Billion represents 3 out of the 5 initial lots that collectively would result in an order for the 21 LRIP aircraft. The other 2 would be outside the FYDP. I just hope they can get production rate close to 10 at Full-Rate Production and hold that for at least a decade. At some point we need to transition all these RDT&E efforts into scaled production and this includes buying 80-100 F-35A's and close to 10 B-21's a year. Otherwise the size of the AF will continue to shrink, and the average fleet age will continue to rise.
Do you feel 10/yr is hard to attain? Why not more? The US has no choice at this point, bombers are aging and China is rising.
 

bring_it_on

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This is interesting. I'm assuming that the $10.28 Billion represents 3 out of the 5 initial lots that collectively would result in an order for the 21 LRIP aircraft. The other 2 would be outside the FYDP. I just hope they can get production rate close to 10 at Full-Rate Production and hold that for at least a decade. At some point we need to transition all these RDT&E efforts into scaled production and this includes buying 80-100 F-35A's and close to 10 B-21's a year. Otherwise the size of the AF will continue to shrink, and the average fleet age will continue to rise.
Do you feel 10/yr is hard to attain? Why not more? The US has no choice at this point, bombers are aging and China is rising.
It would be a substantial investment and allocation of annual procurement dollars. The best the USAF will likely spend (with congressional additions) on the F-35A per year between now and 2025 is likely to be in the $6-6.5 Billion range. 10 B-21's a year would definitely require an ever higher annual spend. Also, since the USAF is requesting 48 F-35A's through 2025 (though they may receive anywhere from 55-62 given Congress adds them back based on Air Force unfunded priorities) these two buy rate increases may coincide.

From a USAF leadership and political perspective the temptation is always there to add to the program (say increase the requirement from "at least 100" to "at least 140") but not really alter the production rates. Both the Obama and the Trump administration have been doing that under the Budget Control Act with most of the higher "increases" in production rates being pushed to the right leading to a point where all these major ramp ups in investment are going to run into each other (F-35 ramp rate, B-21 FRP, and GBSD investments) and cause a lot of friction.
 
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In_A_Dream

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It would be a substantial investment and allocation of annual procurement dollars. The best the USAF will likely spend (with congressional additions) on the F-35A per year between now and 2025 is likely to be in the $6-6.5 Billion range. 10 B-21's a year would definitely require an ever higher annual spend. Also, since the USAF is requesting 48 F-35A's through 2025 (though they may receive anywhere from 55-62 given Congress adds them back based on Air Force unfunded priorities) these two buy rate increases may coincide.

From a USAF leadership and political perspective the temptation is always there to add to the program (say increase the requirement from "at least 100" to "at least 140") but not really alter the production rates. Both the Obama and the Trump administration have been doing that under the Budget Control Act with most of the higher "increases" in production rates being pushed to the right leading to a point where all these major ramp ups in investment are going to run into each other (F-35 ramp rate, B-21 FRP, and GBSD investments) and cause a lot of friction.
We have to see if Congress is willing to push military spending back to Cold War % of GDP levels, especially with the world in an economic slump.
 

Jemiba

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Please keep in mind the title of this thread !
It's the B-21 and NOT the defence spending of the US ...
PLEASE REGARD THIS AS A WARNING !
 
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