Development of the Northrop Grumman B-2 Spirit began as far back as 1979; however, this was nearly thirty years after the last flight of Northrop's earlier flying wing the YB-49.

There aren't many apparent similarities: engine position, wing-sweep, shape and control surfaces are all different. Yet they have identical wingspans of 172 feet or 52.4 m.

Is there something special about this particular size? Did Northrop mutate their earlier design (through wind-tunnel testing etc.) from one to the other, or is it purely coincidence?

B-2 in flight B-2 source

YB-49 YB-49 source


1 Answer 1


A random guess without any supporting information. (please edit or delete if this turns out to be inaccurate)

I would guess the logistics of manufacturing. It could the space needed for handling the aircraft in and/or out of manufacturing buildings. The B-2 program was wildly expensive due to the large number of new technologies involved.

So I guess it was a prudent, maybe even progam-saving decision, to use existing manufacturing facilities are far as possible.

  • $\begingroup$ No. You design the aircraft first, then you build or modify the production & assembly facilities to manufacture it. For something as unimaginably expensive as the B-2, designing it so that it could be built on a decades-old production line, with entirely new technologies for literally everything, would be thoroughly pointless. (Besides, the YB-49 wasn't exactly mass-produced.) For a vastly different scenario, this might happen, but in the case of the B-2, no. $\endgroup$
    – Ralph J
    Commented Nov 28, 2019 at 18:30
  • $\begingroup$ Northrop Grumman has buildings only that big. While you need to design a new production line for a new plane, why don't use existing buildings? I do not claim that this is the true reason, it's speculation on my part. There are many constraints one new designs, be it airplanes, rockets or ships, and some of these constraints derive from the surrouding, supporting infrastructure. E.g. US warships are designed to fit the Panama canal locks, while the Bismark or the Yamato were free of such constraints. $\endgroup$
    – Dohn Joe
    Commented Nov 29, 2019 at 8:54

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