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Why does it have anhedral wings and not "normal" wings? Many other similar aircraft with low-wing have dihedral wings.
enter image description here
Source: DassaultFalcon.com

Edit: This is about the Falcon 900, which apparently has a low-wing design and it's not used for cargo like the An-225

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    $\begingroup$ Possible duplicate of Why does An-225 have anhedral wings though it is a cargo aircraft? $\endgroup$ – GHB Mar 12 '16 at 18:29
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    $\begingroup$ Aside from the size difference, the same effects should apply on the Falcon 900. $\endgroup$ – fooot Mar 12 '16 at 18:48
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    $\begingroup$ @fooot but this has not high wings, so there is a fundamental difference. $\endgroup$ – Federico Mar 12 '16 at 19:14
  • $\begingroup$ @Federico right, that too, but it still has the wing sweep, and the fact that it's only very slight anhedral. $\endgroup$ – fooot Mar 12 '16 at 19:17
  • $\begingroup$ I'm not an aerodynamics expert, but the raised horizontal stabiliser is a clue - T-Tails seem to have pretty neutral dihedral as well. $\endgroup$ – Ben Mar 12 '16 at 20:42
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For the same reason why the Lockheed F-104 Starfighter had such a pronounced anhedral: It is the size and location of the vertical tail.

Lockheed F-104 Starfighter

Lockheed F-104 Starfighter (picture source).

In both cases, the vertical tail is large relative to the wing and fully above the roll axis. In a sideslip it produces a high rolling moment, so any more rolling moment from the wing would reduce the handling qualities of the aircraft.

Especially in case of the F-104, the raised position of the horizontal tail shifts the center of pressure on the vertical tail upwards, exacerbating the offset location of the vertical tail.

The rear-mounted engines on the Falcon 900 move the center of gravity backwards, so the wing is more backwards than usual for aircraft with wing-mounted engines. Therefore, the part of the fuselage ahead of the center of gravity is large, requiring a larger vertical tail to overcome the destabilizing yawing moment of the fuselage.

The same is true for the Tupolev 134 and 154, and - surprise! - they also have no dihedral, even though both are low-wing configurations.

Tupolev 154M of the Polish Air Force

Tupolev 154M of the Polish Air Force (picture source)

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  • $\begingroup$ I wonder if the DC-9 and B727 would be good comparison points as well.... $\endgroup$ – UnrecognizedFallingObject Mar 13 '16 at 7:21
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enter image description herePicture source

It may seem so when on ground, but in flight the wings flex up. Judging from the photo, the wings seem to have the tiniest bit of dihedral. They also have wing sweep, which provides sideslip-to-roll stability as well.

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