RE: 319 Dutch Roll?

Date:         30 Nov 98 03:07:57 
From:         MJones <rmjones@cyberhighway.net>
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>As it is a function of sweep back above a certain angle ,what you observed,
>developing regularly and appearing to be almost permanent, is normal.

Dutch roll is by no means confined to planes with swept wings, although
wing sweep on planes so configured certainly is a contributor.  A high
slip-roll coupling, due to wing sweep, dihedral or interference effects, an
'oversized'  vert. stab. perhaps included to improve roll stability
(decreasing the tendency to go off on a wing) are all possibilities.

So does anybody have a good feel for what design feature(s) of the smaller
3xx variants relative to other similarly-sized craft lead to greater Dutch
roll tendencies?  i.e. is the wing sweep significantly greater?  Is the
vert. stab. significantly taller, maybe to improve roll stability?  Is it
shorter-coupled than a 737, say?  Or is the damper algorithm less (or even
too) aggressive?

Mike J.