A Bonanza F33A is the only airplane with a YD I have flown. The YD was integrated in the KFC 150 A/P but worked independently. I never noticed any difference, but rear seat passengers preferred having it on, despite the F33 being short-bodied and with a straigt tail.
In most of the twins I fly, the ball is 1/3 to 1/2 out of center with a bank towards the good engine of approximately 3 degrees. With the ball in the center, the twin loses almost all climb performance.
Of course I should have written "helps you push the ball towards the center". Pilots of (piston!) twins know that, I'm sure. The usual yaw damper servos are not strong enough to fully center the ball anyway. The things I fly at work now are also twins and like to continue to fly straight and level (no bank, now yaw) in case of an engine failure, therefore it is SOP to turn the yaw damper on as soon as the gear comes up.
Peter,
The Stec Yaw Damper can be added to an existing autopilot of a different manufacturer. It has a trim knob that the pilot uses to center the ball. I use it during climbs with my feet on the floor. There is a single wire interface to the existing autopilot to turn the YD off when the AP is off. The YD has a three position switch, up for auto, center for off, down for on. In the auto position, the YD on/off is controlled by the primary autopilot. It is also less expensive than the HBK unit.
Other than for passenger comfort the yaw damper becomes really useful in twins as it helps you keeping the ball centered in case of an engine failure.
Not a good idea, the ball is not supposed to be in the center when an engine fails in a twin or the aircraft will be in a sideslip. In most of the twins I fly, the ball is 1/3 to 1/2 out of center with a bank towards the good engine of approximately 3 degrees. With the ball in the center, the twin loses almost all climb performance.
Turning the A/P on automatically engages the YD in the Cirrus SR22T. There is no manual rudder trim that I know of.
From the POH: Yaw Trim System Yaw trim is provided by spring cartridge attached to the rudder pedal torque tube and console structure. The spring cartridge provides a centering force regardless of the direction of rudder deflection. The yaw trim is ground adjustable only. A ground adjustable trim tab is installed on the rudder to provide small adjustments in neutral trim. This tab is factory set and does not normally require adjustment.
Usually you won't notice as the plane is flown most of the time with the autopilot which in turn engages the yaw damper anyway
A/P doesn't engage yaw damper in mine.
But when sitting on the rear seats I get sick quite fast if the plane is flown without yaw damper.
An old issue with Piper singles... When I fly with students in the Pa28 and they bring friends or relatives (which may be legal or not, but I never cared) I always make sure they carry sickbags... What greatly helps in most aircraft is just to keep your feet on the rudder pedals all the time. Just having your feet there and not doing anything already eliminates 80 percent of the unpleasant oscillations in yaw!
Other than for passenger comfort the yaw damper becomes really useful in twins as it helps you keeping the ball centered in case of an engine failure. That's why on Boeings and Airbusses it is always on (so I am told). Back when I was flying the Metroliner, forgetting to turn on the yaw damper right after takeoff meant having to dispose of nineteen sickbacks after the flight. If you were lucky and everybody found his bag in time. In this aircraft, even slightest oscillations in yaw that were hardly felt in the cockpit produced 50 centimeter sideways movement in the last row of seats...
In the PA46 as pilot I barely notice if the yaw damper is on or off. But when sitting on the rear seats I get sick quite fast if the plane is flown without yaw damper. Usually you won't notice as the plane is flown most of the time with the autopilot which in turn engages the yaw damper anyway. But when you fly by hand for some reason the YD is very important to keep the passengers happy.
There is no rudder trim in the SR22?
If I climb to e.g. FL150 in my TR182 at full power, I couldn't manage to hold the rudder all the way up so rudder trim is vital. I can trim it completely and don't need my feet on the rudder during climb.
I activate the AP after departure at e.g. 400 feet. Then the Yaw Damper basically takes over in the climb. Actually, without the YD on, it is quite some legwork to keep flying coordinated, so I consider it a great help. So on the takeoff run and initial climb I have to do the work myself :-)
