A330 Dutch Roll ?

[TopperHarley]

Hi Folks,

I was paxing for the first time on an A330-200 the other day and noticed something odd for the first hour or so of the flight.

The aircraft appeared to be consistantly rolling (and yawing slightly) rythmicly.

I was sitting a few rows aft of the leading edge (close to the C of G i would imagine) and the rolling seemed to be well balanced as the sensation could harly be felt. The only evidence was to look out the window.

I havent noticed this on any other aircraft - IS THIS DUTCH ROLL ??

Is it a problem ?

SHouldnt the yaw damper correct for this ???

.... or was i just imagineing it ?!? (Id had a few drinks the night before !)

Thanks !

[aviate1138]

TopperHarley said in part....

"I was sitting a few rows aft of the leading edge (close to the C of G i would imagine) and the rolling seemed to be well balanced as the sensation could harly be felt. The only evidence was to look out the window.

I havent noticed this on any other aircraft - IS THIS DUTCH ROLL ??"

Aviate 1138 adds...

I was on a BMI flight in an AirBus 320 and noticed the same almost imperceptible rythmic roll.

I have also noticed it on 757's especially on finals.

Aviate 1138

[Milt]

Descriptions are typical Dutch Rolls

Yaw dampers/flight control computers are supposed to take it out.
Perhaps the Yaw damper/s were off or their sensitivity is too low.

[lineboy_nz]

I'd say that TopperHarley's Airbus case, there is more weight outboard laterally (longer weight moment arm).
due: full wing tanks in the first hour of flight. This would increase dutch roll inertia.

In aviate1138's 757 case on approach there'd be more drag outboard laterally (longer drag moment arm) due: greater drag on approach configuration.

Does "the software" automatically change y-d sensitivity to suit changing tank levels and/or a/c configuration?



"I know anuff to learn"

[Bre901]

Milt & lineboy_nz

I asked a similar question some time ago, alas to no avail.
As you seem to be helpful people, would you mind taking a look here (http://www.pprune.org/forums/showthread.php?threadid=108769)

Thanks in advance.

[bankrupt]

The yaw damper on the busses can not be switched off witout affecting autopilot function and flight control laws.

[the egg man]

i too have been very sick in the back of a a330 during desent and finals,same yaw and roll cycling sensation in the back of the aircraft.
i have ben told that on the a330 fuel is pumped from the tail tanks to the wings during desent to alter the c of g ,making the tail very light so making the yaw and roll more noticeable during low speed.

[Lump Jockey]

Doesn't "Dutch-roll" incorporate a little pitch too? A name derived from Dutch sailors back in the day, when there were Dutch sailors! coming ashore after months at sea.