Possible artificial horizon?
Would it be possible to project, as with holograms (think Laser Floyd), an artificial "green line" horizon as seen from the pilots' chairs? This would go some way toward combating this physical illusion.
Such an instrument could take its cue from a simplified onboard inertial navigation unit ("platform"), which could be aligned by the PF shortly before approach if needed. Thus it need not maintain strict alignment over a long time.
-drl