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Here is a B-2 Spirit:

enter image description here

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enter image description here

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Many different things can get in the way with a design like a B-2. Although it has really good stealth and looks, does it have any disadvantages that come with the good stealth and looks?

  1. What kind of disadvantages would this aircraft have of an airliners design or another bombers design like the B-52 or B-1?

  2. What system does this aircraft use to overcome not having stabilizers?

  3. Why have only 22 ever been built?

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    $\begingroup$ By looks I mean its one cool looking aircraft. $\endgroup$ – Ethan Sep 17 '15 at 21:45
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    $\begingroup$ about number 3; it's a highly specialized military aircraft using classified tech; so selling to other countries is a no-go. It was designed near the end of the cold war so after the iron curtain fell there was less need for a fleet of long range stealth bombers. $\endgroup$ – ratchet freak Sep 17 '15 at 22:29
  • $\begingroup$ For 2, the yaw control: it uses drag created by the deceleron, the outer trailing edge control surfaces (on the image we see a kind of air brake open symmetrically in both directions). Deceleron are the most remote possible to provide a larger moment, and are computer controlled. See wikipedia. $\endgroup$ – mins Sep 17 '15 at 23:43
  • $\begingroup$ Related. (As many other questions about flying wing) $\endgroup$ – Manu H Jun 3 '18 at 22:41
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The main problem with the B-2 Spirit (or any flying wing aircraft, for that matter) is that they are statically unstable.

Flying wing stability

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If the lift vector of the wing acts before the center of gravity (as is the usual case when only wings are considered), any perturbation which results in an increase in angle of attack results in a positive moment about the center of gravity, which further increases the angle of attack an so on.

The only way to control such an aircraft is through computers, which continuously detect any changes in the aircraft attitude and apply corrections as required, as it is near impossible (or incredibly taxing) for human pilots to fly the aircraft.

This is the method used in order to 'fly' the B-2 Spirit in the absence of a horizontal stabilizer. If there is any problem with the flight computer (which is remote) or with the sensors supplying data to it, the aircraft will become unflyable and crash.

Another control issue with the B-2 is that the aircraft has little directional stability with no vertical tail. The swept wing offers some stability, though not in the same level as a vertical tail.

Aircraft Directional stability

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Actually, only 21 of these were built, for the following reasons:

  • The B-2 is costly; by costly I mean probably the most expensive aircraft ever built. With a total program cost of over 45b USD, each aircraft costs a whopping 2.1b USD (which was caused due to reduction in numbers from the initial 132). Also, the (hourly) operating costs of B-2 are twice that of other bombers in the USAF fleet.

  • With the dissolution of the Soviet Union, the B-2 had effectively become an aircraft without a mission, as it was primarily designed to penetrate Soviet air defence systems.

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    $\begingroup$ Its worth noting that the problematic parts of the B-2 design aren't related to it's stealth aspects (e.g. venting the engine exhaust above the fuselage doesn't really make it a "worse" design, though it does substantially reduce the ground heat/noise signature). Some of the stealth features DO benefit from it being a flying wing however (e.g. the pointed nose & "W" trailing edge are effective radar-scattering features, and the degree to which we see them on the B-2 is possible because it's a flying wing). $\endgroup$ – voretaq7 Sep 18 '15 at 4:03
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    $\begingroup$ Just to emphasize: They cost $2,100,000,000.00 each. That's why there were only 21. $\endgroup$ – FreeMan Sep 18 '15 at 13:42
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    $\begingroup$ That's about as expensive as a Shuttle, and more expensive than a Nimitz-class nuclear supercarrier (barring airplanes). That's pretty expensive. $\endgroup$ – Nathan Tuggy Sep 18 '15 at 18:59
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    $\begingroup$ Flying wing is not necessarily statically unstable. There were plenty of prehistoric flying wings without any computers and they flew just fine. It just takes a correct choice of airfoil (and S-curved one with negative camber near the trailing edge), or, with sufficient sweep angle, a significant negative wing twist. $\endgroup$ – Zeus Jun 4 '18 at 3:16
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    $\begingroup$ @Zeus: those prehistoric flying wings had fly-by-wire (well, OK - "sinew") and active stabilization systems which worked together to keep them flying as commanded. Also, in emergency situations mass could be ejected via a port in the rear to improve net lift. $\endgroup$ – Bob Jarvis Sep 13 '18 at 18:31

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