Flight Controls question AV8B

[Dangerman]

Probably a silly question and might be a simple answer concerning DCS AV8B flight controls.

 

when moving the stick laterally, I get small amounts of rudder movement. (the stick is mapped ONLY to X&Y axis so no rudder input coming from it)

 

I haven't flown the Harrier so can't definitively say it shouldn't happen, but I get rudder input when the stick is moved laterally. This is extremely unusual for a fast jet to have a rudder/aileron cross-tie at all speeds. (or any speed TBH).... Ive never flown a FJ with this feature and if there ever was a need for any yaw damping, this was done in the background by FBW or equivalent system. (The heavy metal I fly now has rudder aileron cross tie at slow speeds that is taken care of in the background by the FBW= no pedal movement. Pre FBW types had yaw damping in the background with no pedal movement.

 

On a FJ, rudder pedals are footrests unless you need to cover the extremely slight asymmetric in case of Eng Fail case, ....or use NWS, .....or slice the nose down to retain visual in arrow formation at low level.. or get a degree or 2 extra turn rate in combat, or eliminate roll reversal at max AoA due downgoing aileron exceeding stall AoA. (obviously not a problem if you don't have ailerons and use spoilers and diff tailplane for roll)

 

And rudder isn't used in jets to "balance" turns

So why is the rudder moving on their own?

Is it a setting I am missing.. but haven't found?

Is it what the harrier does?

Help....tell me its a setting that I have missed.......it's really bugging me now!

[mvsgas]

Is this what you are talking about?

A1-AV8BB-NFM-000, page 2-52, para 2.16.1

- The yaw SAS also provides a lateral stick to rudder interconnect for improved turn coordination.

-An interlock between the yaw SAS switch and the weight--on--wheels switch on the main gear inhibits the yaw stability augmentation when the aircraft

is on the ground.

 

para 2.16.1.1

Above 4° AOA, lateral stick commands increasing rudder in the direction of the roll and decreasing aileron in order

to reduce adverse sideslip and improve high AOA roll performance. Lateral stick also commands nose--down

stabilator to reduce AOA build--up from inertial and kinematic coupling. The maximum rudder commanded by the

SAS is equivalent to 1/2 pedal and occurs at 8° AOA and above with lateral stick at the high speed stop. The departure

resistance incorporates a roll rate feedback and increased gain to the ailerons at low airspeed that improve Dutch roll

damping at high AOA and lessen wing rock. Wing rock is greatly reduced or eliminated above 120 KCAS above the

maneuvering tone.

Above 3° AOA and 10° AOA respectively, rudder and ailerons are commanded in a direction to reduce sideslip

excursions. To improve Dutch roll damping and lessen wing rock, rudder and ailerons are also commanded in the

direction to oppose the rate--of--change of sideslip. The ability of DEP RES to control sideslip is degraded to varying

degrees by overriding the lateral high speed stop, by large rudder pedal deflections, by large lateral weight

asymmetries, and by installation of the inflight refueling probe. These effects are cumulative and in combination can

overwhelm the ability of DEP RES to prevent departures. The departure resistance in the absence of the air refueling

probe, eliminates rudder induced departures at all AOA.

[Dangerman]

That will be it as it is designed for damping and departure prevention.

......although I would venture it is extremely unusual to have the system actually move the pedals... these things normally happen in the background with the PFCUs commanded to move but no rudder pedal movement as is the case on previous types I have flown I suppose maybe the harrier is just different

 

Thanks for the info.--- case closed

Edited January 17, 2018 by Dangerman
edited for spolling errors