Ron Hardin wrote:

Do modern jet airliners still have a noticeable dutch roll? I haven't
flown in anything for a couple decades, and was wondering if it's been
damped out to zero by modern control theory, or still exists.

I first noticed it trying to take solar sights with an elaborate
protractor and bubble level setup on trans-Pacific flights, in
DC-6's and later 707's (something to do). It was a few degrees
in roll magnitude, quite noticeable. You'd think today it would
be gone completely, though, but I don't know.

It came to mind because my bicycle seems to do the same thing under
heavy baggage load. No doubt from a different cause.


Hmmmm, Dutch Roll in a DC-6? My understanding has always been that
Dutch Roll is a by-product of a swept-back wing. While the leading edge
of the big Dougs does angle back from the lateral plane, the wing as a
whole, is straight. Any lateral occilations you observed were probably
due to the crudeness of the autopilot.

As for the 707, I would guess that the Dutch roll characteristics you
observed where properties of a first generation jetliner yaw damper, ie:
less than perfect dampening.

In regards to transport category aircraft, anything of a newer
generation has, in my observation, perfectly eliminated any Dutch roll
tendencies.

Happy Flying!
Scott Skylane