[no bug] rudder control rolls plane

[Fionn]

Im not sure if this is correct and its just me... i think it is a new thing since 1.5 but i would need to go back to 1.2 and check.

 

basically now full rudder will bank and then continually roll the plane rather than yaw the plane. is this correct behavior for the f15c? i have no idea lol

[speedbird5]

Im not sure if this is correct and its just me... i think it is a new thing since 1.5 but i would need to go back to 1.2 and check.

 

basically now full rudder will bank and then continually roll the plane rather than yaw the plane. is this correct behavior for the f15c? i have no idea lol

 

Ensure that the CAS is on for yaw, pitch and roll. Also the ARI should compensate for this. Check the Belsimtek manual.

 

In real world aircraft, the secondary effect of rudder is roll. The first thing one is taught in training is "Effects of Controls".

 

When one applies rudder, the advancing wing moves at a faster rate than the receding wing thereby creating more lift on the advancing wing and hence a rolling moment. Hence the roll you are observing with yaw.

 

As an aside. The secondary effect of roll is adverse aileron yaw. The downward deflected aileron causes more drag (because it is creating more lift) than the upward deflected aileron and causes a slight yaw in the opposite direction to the roll. Not all aircraft exhibit this.

 

As far as the simulation is concerned, I am not sure how realistic this is. I haven't had a chance to try it myself.

Edited December 17, 2015 by speedbird5

[GGTharos]

The f15 is close to spot on, with the exception of 0aoa handling. That should give you all yaw and no roll.

[Fionn]

def got CAS on for all, just seems to roll really quick rather than yaw a bit. If its accurate thats cool, it just felt different to how it was on 1.2. Thanks for the answers :)

[SkieRider]

But if you try full rudder at a high speed(e.g. Mach 2), f15 will roll into spin in a few seconds. The rudder effect shouldn't be such high at supersonic.

[JINX_1391]

This is normal/typical flight dynamics. I will say that I do not know how or to what degree this effects an F-15C (IRL or sim) but it is a basic flight principle.

 

Yaw is a side effect of roll, and roll is a side effect of yaw.

 

For example, if you hold your arms out like wings ( :pilotfly: ) and yaw left. Your right arm (wing) is now forward and your left is aft. That forward wing now has increased airflow, an conversely less airflow on the left wing. Increased airflow creates lift; the forward wing will always want to roll upwards.

 

Increased speed will increase airflow making the roll seem like an automatic response to yaw.

 

Hope that helps.

[SinusoidDelta]

Rudder deflection should be limited at Mach 1.5+ to +/-5 deg to reduce the possibility af potentially deadly yaw/roll coupling. I'm not if such an inhibitor exists is the current FM.

 

The f15 is close to spot on, with the exception of 0aoa handling. That should give you all yaw and no roll.

 

I'll have to practice more but the Knife-Edge pass is pretty difficult to replicate, using the F-15C Flight Demonstration manual as a reference.

Edited February 11, 2016 by SinusoidDelta

[GGTharos]

I can do knife-edge edge no problem, though there's a question as to what is the minimum airspeed at which the rudder should be able to prevent the nose from dropping.

 

But in any case, the procedure from the manual is:

 

Enter at 400 (min 350), MAX power, nose up 5 degrees, then roll onto the side and perform the knife-edge.

[SinusoidDelta]

Actually, nose up 5-10 degrees ;)

 

...Guess I need to practice.