Northrop Grumman B-21 Raider (LRS-B)

Scott Kenny said:
Access panels for the big fecking antennas hiding in the leading edges. Whether for EW systems or LPI radars. or both.
Click to expand...
The leading edge is probably a suboptimal location for radar: there is minimal vertical room to shrink the beam vertically, which might result in suboptimal gain… EW antennas are definitely doable on the leading edge though, the F-35 has them.
 
Sundog said:
They may be using the bypass air from the fan as a sheet of cooler air between the main nozzle and the upper surface and the hot core flow to help keep the upper surface somewhat cool, as opposed to completely "wrapping" the bypass air around the core flow. Also, it looks like the rear nozzles may actually be slightly higher than the rear deck of the wing, as far forward as they are, raising them up a bit from the rear surface. I also noticed the upper surface of the nozzle on the B-21 is a pointed facet, as opposed to the V-cut on the B-2 to maybe also help mixing the core and bypass flows to cool it faster? Those are just some guesses as to what they may be doing at the exhaust.
Click to expand...
Boundary air may be farther down the inlet duct possibly?
flateric said:
It has, yes, along forward spar
Click to expand...
Cove panels.
 
JJPET said:
is it really a sensor/ towed decoy or some sort of UAP :)
Click to expand...
It's a trailing cone. Standard for flight tests. It also has a Pitot tube as well as SS+AoA vanes on the forward-facing boom to probe the air in a rather undisturbed part of the flow. These devices are there to provide data for the calibration of the air data system (anemometry)
 
https://aviationweek.com/defense/ai...le-company-owned-b-21-test-asset-us-air-force
"Northrop Grumman says a previously undisclosed company-owned test aircraft has been sold to the U.S. Air Force as part of a production acceleration agreement for the B-21 Raider."
...
" It will not change the total number of B-21s that are part of the low-rate production phase of the program, Greene noted on the company’s first-quarter earnings call."
...
 
I would speculate (groundlessly) that it could be one of the three testbed CRJ-700s or the B-737 owned by the company and used for subsystem (such as radar) testing and integration. The B-2 program used an Air Force supplied NC-135A for that purpose.
 
aim9xray said:
I would speculate (groundlessly) that it could be one of the three testbed CRJ-700s or the B-737 owned by the company and used for subsystem (such as radar) testing and integration. The B-2 program used an Air Force supplied NC-135A for that purpose.
Click to expand...

Could be.
Though the AW-article also states: "An Air Force spokesperson confirmed the B-21 purchase."
 
A ground test B-21 airframe repurposed as a flying article?

“To support the acceleration of aircraft deliveries, we agreed to sell an aircraft to the Air Force that was previously planned to be utilized as a company-owned test asset,” CFO John Greene said April 21.

This sounds like they built another B-21 airframe for Northrop testing and have sold it the Air Force to accelerate delivery.
 

Attachments

  • IMG_2651.jpeg
    IMG_2651.jpeg
    16.7 MB · Views: 152
  • IMG_2650.jpeg
    IMG_2650.jpeg
    16.3 MB · Views: 152
  • IMG_2649.jpeg
    IMG_2649.jpeg
    15.9 MB · Views: 197
  • IMG_2644.jpeg
    IMG_2644.jpeg
    525.7 KB · Views: 218
  • IMG_2657.jpeg
    IMG_2657.jpeg
    2.9 MB · Views: 200
  • IMG_2656.jpeg
    IMG_2656.jpeg
    3.7 MB · Views: 186
  • IMG_2655.jpeg
    IMG_2655.jpeg
    2.3 MB · Views: 221
Last edited:
Of course, the real joke would be if someone tried to pack a bunch of B-21s onto a Ford-class for a repeat of the Doolittle op.
 
Scott Kenny said:
Of course, the real joke would be if someone tried to pack a bunch of B-21s onto a Ford-class for a repeat of the Doolittle op.
Click to expand...

What would be interesting is if the USAF and USN did a repeat of the early 1960s experiment where they had a C-130 Hercules land and take off successfully several times from a CV to see if it was feasible (It was) and do it with a B-21A.
 
JoshuaH said:
It’s really weird… At first flight of the exact same aircraft, the exhaust region was either black or a very dark color.
Click to expand...

Sferrin said:
And something is still required on the bottom.

View attachment 809147
Click to expand...

GreenBullet said:
Maybe there's a combination of heat-tolerant RAM, very efficient bypass mixing to get the plume as cool as possible, and airflow control over the surface to keep the exhaust gases separated and stood-off (even by a pretty minor distance) sufficient to keep surface temps reasonable. Definitely easiest to do on a platform that doesn't operate at high AoAs. Could bleed a little bit of bypass into a French drain type outlet combined with careful surface shaping.

Similar principle to the porous boundary cooling in turbine blades.
Click to expand...

Sundog said:
They may be using the bypass air from the fan as a sheet of cooler air between the main nozzle and the upper surface and the hot core flow to help keep the upper surface somewhat cool, as opposed to completely "wrapping" the bypass air around the core flow. Also, it looks like the rear nozzles may actually be slightly higher than the rear deck of the wing, as far forward as they are, raising them up a bit from the rear surface. I also noticed the upper surface of the nozzle on the B-21 is a pointed facet, as opposed to the V-cut on the B-2 to maybe also help mixing the core and bypass flows to cool it faster? Those are just some guesses as to what they may be doing at the exhaust.
Click to expand...

I don't think there are any "main nozzles" on the upper surface. It seems likely that the dark areas on the trailing edge are the nozzles, possibly a fixed SERN type. This may be one of the innovations that will be used in the F-47 and F/A-XX also, though likely incorporating fluidic TVC there.
 
what_is_that said:
I don't think there are any "main nozzles" on the upper surface. It seems likely that the dark areas on the trailing edge are the nozzles, possibly a fixed SERN type.
Click to expand...
I’m afraid this hypothesis has already been disproven:
 

Attachments

  • 1762319047307.png
    1762319047307.png
    811.2 KB · Views: 571
Last edited by a moderator:
JoshuaH said:
My guess would be there is something on the surface of the expansion ramp that they want to keep as secret… Or it might just be bureaucracy…
Click to expand...
They blurry the Square on the Tail fuselage too.
 

Attachments

  • B-21-refueling-official-photo-2.jpeg
    B-21-refueling-official-photo-2.jpeg
    337.1 KB · Views: 501
Last edited by a moderator:
dark sidius said:
Or this picture could be modified.....Are we sure this is the real exhaust ?
Click to expand...
Well this is not an official image, but an image taken by an outsider… So I believe there is no motive in modifying the image to show a fake exhaust setup.
FighterJock said:
Best to wait until Northrop releases the real exaust image I think.
Click to expand...
On that note I think a picture of the real aircraft taken by an outsider is more reliable than any official image… Official images can be modified with all kinds of purposes.
 
Above was the original post containing this image. The same setup can also be seen in other pictures taken by other people:
 

Attachments

  • b-21-raider-first-flight-3.jpg.jpeg
    b-21-raider-first-flight-3.jpg.jpeg
    571.4 KB · Views: 403
  • new-higher-res-images-of-the-b-21s-back-end-v0-zz4akfkh3dxb1.jpg.jpeg
    new-higher-res-images-of-the-b-21s-back-end-v0-zz4akfkh3dxb1.jpg.jpeg
    976.7 KB · Views: 438
Last edited by a moderator:
Back in 2013 there was a Northrop Grumman demonstration of a completely novel AESA EHF array: Looking at the sides of the B-21 in all of your images, it appears to me that this same array is positioned either side of the B-21 just behind the cockpit.
 

Attachments

  • flat.jpg
    flat.jpg
    133.9 KB · Views: 308
Josh_TN said:
IIRC the B-21 program had a requirement of all elements of the aircraft being at TRL6 or higher. I think that pretty easily would exclude any active control. In any case, we can *see* the control surfaces, so that seems to imply conventional flaps are used exclusively.
Click to expand...

I had been thinking the same thing and wondered if the RQ-180 program hadn’t derisked certain technologies. Given the planform similarities - albeit at different scales - i couldn’t rule out the possibility that some “novel” (quoted bc most are decades old) effectors might be employed by B-21 subsequent to sufficient tech readiness being demonstrated by RQ-180.

I also agree that it’s quite likely the case that from a purely aerodynamic perspective the B-21 may get along quite well without exotic control effectors, but at the same time from an RCS perspective it might be quite advantageous to utilize adjunctive or substitute control systems that minimize or eliminate traditional TE surface deflections.
 
Training_Dummy said:
I also agree that it’s quite likely the case that from a purely aerodynamic perspective the B-21 may get along quite well without exotic control effectors, but at the same time from an RCS perspective it might be quite advantageous to utilize adjunctive or substitute control systems that minimize or eliminate traditional TE surface deflections.
Click to expand...
Agree here. IF the air-bleed effector systems were of a high enough TRL I would absolutely expect the B-21 to use them because they'd allow for not deflecting the control surfaces.

Or there's space saved in the airframe for it and NG intends to do a B-21B with the effectors in addition to the physical surfaces, and maybe to be followed by a B-21C without mechanical surfaces at all and effectors only.
 
You just don't understand what [useless] weight, volume and energy penalties this means for high-altitude bomber.
 
flateric said:
You just don't understand what [useless] weight, volume and energy penalties this means for high-altitude bomber.
Click to expand...
Certainly possible, but it depends on how much of the wing is taken up by fuel tankage or if there's a gap just forwards of the last spar that could hold a bleed air duct and the effector nozzles. Use carbon-fiber tubes glued together to minimize the weight of the wing air manifold.
 
https://www.airandspaceforces.com/hegseth-us-military-a-lot-more-b-21-bombers/

While Hegseth did not say precisely how many B-21s the Pentagon should purchase, he said the B-21 and the Air Force’s F-47 sixth-generation fighter jet are “critical” for the U.S.’s future warfighting capabilities and that the Pentagon would increase its planned procurement “where necessary.”

“We have to invest in more capabilities to include the B-21, which is ahead of schedule,” Hegseth told the Senate Armed Services Committee. “We believe we will require a lot more—over 100—in the future.”
Click to expand...
 

Similar threads

Back
Top Bottom