rudder movement with roll controls

[combatace]

Rudder is mixed with roll controls so when ever the A/c rolls it vobbles because the rudder moves too.

[159th_Viper]

Cannot replicate.

 

Kindly post a track.

[combatace]

Look at the rudder, I was just applying roll input but still rudders were moving.

 

Also, the landing light animation stays on even after gears are up.

rudder.trk

[flying.toaster]

Rudder is mixed with roll controls so when ever the A/c rolls it vobbles because the rudder moves too.

Observed too, I guess it is a replication of an aileron rudder interconnect to counteract adverse yaw at low speed.

Problem is it seemed to trigger dutch roll but I guess last updates fixed it.

Has anything been done about that or am I dreaming it ?

[combatace]

Observed too, I guess it is a replication of an aileron rudder interconnect to counteract adverse yaw at low speed.

Problem is it seemed to trigger dutch roll but I guess last updates fixed it.

Has anything been done about that or am I dreaming it ?

 

My track in above message is from latest version.

[SNAFU]

I guess the times, in which control surfaces just moved according to the position the pilot put his stick to, are long gone. Nowadays the FCS interprets the pilots wish and moves the control surfaces to the optimum position methinks.

[flying.toaster]

I guess the times, in which control surfaces just moved according to the position the pilot put his stick to, are long gone. Nowadays the FCS interprets the pilots wish and moves the control surfaces to the optimum position methinks.

Well it actually dates waaaaayyyy back. The X-15 for instance (first flight 1959) already had an aileron rudder interconnection (named YAR) and a 3-axes stability augmentation system.

 

Stability augmentation has become a must with aircraft for which speed ranged from 100 knots to mach 3 (if only in the form of artificial feel).

 

So yes a form of ARI is expected on the Su-27, and mentionned in the flight manual too (so, yes combatace, I guess it is normal to see the interconnection even in the latest update :smilewink:).

 

What I *really* find annoying is the way the ARI will induce dutch roll, if anything because roll is not kept in check by the FCS even in the latest update. Once again, my bets are on insufficient controller gain at low speed for roll control law (generally in roll rate vs. stick deflection). A simple proportional controller for deflection vs. roll rate (and gain adjusted to IAS), helped by a Ny law for rudder deflection can do a fair business, but it is all the better if eagle dynamics has access to a more accurate description of the FCS

 

As it is, low speed handling is just a pain, and that really feels weird to me because

 

a/ Airliners are actually better behaved with much larger inertia (and that's first hand experience on full flight simulator)

 

b/ I would not like to go on an airshow demo with such a behavior. The wing drop after a stall is just appalling and darn hard to control. Don't even think about hornet walk in that bird... Oh wait .. Low speed low altitude pass is part of any airshow routine :)

 

But then again it's all a matter of taste. A lot of people seem to enjoy the extra challenge. It sure has become an interesting thing to throw around, but I hardly believe the soviet air force flight test center would accept such poor low speed handling in a fighter that reaches operational squadrons.

 

If somebody could find us a MiG-29/Su-27 pilot to give first hand feed back, and I will be more than happy to accept his/her word !

Edited November 18, 2014 by flying.toaster

[efeballi]

I second this. Especially under autopilot control, the plane does Dutch rolls, and at low speeds any roll correction quickly leads to oscillation.