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Simicro

Is adverse yaw well modeled in P3D?

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Hi,

After years of carelessness, I decided to re-learn the basics of flying and yesterday I read the chapter "rudder" in Stick and Rudder by Wolfgang Langewiesche.

Now I better understand what is adverse yaw and the necessity to use rudder in turns.

At this time I'm flying the A2A C172: in a 30 degrees turn, the ball is perfectly centered while I apply NO rudder at all?!?! Normally the ball should be more on the right side indicating that action on rudders is required?

I confess that I did not pay too much attention to adverse yaw when I was on FSX or other simulators but I don't recall noticeable adverse yaw whereas in real life I read that instructors insist a lot on the use of rudders to make coordinated turns.

Hence my question: is adverse yaw is well modeled in P3D (and other simulators)?

Maybe in recent/modern GA aircrafts, the design is better and adverse yaw limited?

adverse_yaw.png

Edited by Simicro

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Ensure your autorudder option is disabled.

The basics of adverse yaw depend as much on the flight model as the simulator platform.  If you want realism get ahold of the quality stuff from A2A.  They have very good flight dynamics for a PC simulator.

Nothing replaces the seat of the pants that you get in the real thing.


Dan Downs KCRP

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Don't forget that 172's etc have differential ailerons that offset any adverse yaw. Most modern aircraft aren't affected significantly compared to older types such as Austers etc.

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David Porrett

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11 minutes ago, downscc said:

Ensure your autorudder option is disabled.

.  If you want realism get ahold of the quality stuff from A2A.  They have very good flight dynamics for a PC simulator.

 

That’s exactly what he’s flying. So maybe the auto rudder is on as you say. 

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1 minute ago, DavidP said:

Don't forget that 172's etc have differential ailerons that offset any adverse yaw. Most modern aircraft aren't affected significantly compared to older types such as Austers etc.

 

True. I did some learning to fly many years ago. I never used the rudder because I was never told to use them. 

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Very little rudder is used in the real 172 on level flight. 


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1 hour ago, Simicro said:

At this time I'm flying the A2A C172: in a 30 degrees turn, the ball is perfectly centered while I apply NO rudder at all?!?!

I haven't flown the A2A 172 since I moved over to P3D from FSX but my recollection of it was that rudder was absolutely needed when appropriate.  In fact, my early criticism (before some of the first patches) was that it required too much.

As others have suggested, make sure autorudder is turned off.

5 minutes ago, Raging Bull said:

True. I did some learning to fly many years ago. I never used the rudder because I was never told to use them.

Wow.  I'm going to guess that you never went much past a simple introductory flight lesson.  Especially in the pattern, my primary instructor would all but reach over and slap me if I didn't keep the ball centered.  Almost all maneuvers to be mastered for a PP certification require rudder attention, as do normal takeoffs and landings - especially in crosswind situations. 

Sure in normal level flight you can keep your feet on floor for minor turns and course corrections without making your passengers barf, but for other phases of flight and for practice work on basic skils (turns around a point, steep turns, stalls...), you need to learn good rudder work.  Fly a tail-dragger and you REALLY need to learn those pedals.

There are a few planes which feature rudder-aileron interconnects which help keep the ball centered (A2A models one of these with their new Bonanza) but even with these you need to use the rudder for all but normal turns.

Scott

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1 minute ago, Bobsk8 said:

Very little rudder is used in the real 172 on level flight.

The OP referenced a 30 degree turn.

Scott

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10 minutes ago, tttocs said:

Sure in normal level flight you can keep your feet on floor for minor turns and course corrections without making your passengers barf, but for other phases of flight and for practice work on basic skils (turns around a point, steep turns, stalls...), you need to learn good rudder work.

I think you'll find in types such as the 172 that most of the rudder is to do with engine torque. Demonstrating adverse yaw in these types, while not difficult, meant aggressively rolling the aircraft left and right and eventually you could see some sort of effect. The amount of rudder input needed on these types is often overstated by simmers.

 

Tail draggers, of course, are different beasts.

Edited by DavidP

David Porrett

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17 minutes ago, tttocs said:

I haven't flown the A2A 172 since I moved over to P3D from FSX but my recollection of it was that rudder was absolutely needed when appropriate.  In fact, my early criticism (before some of the first patches) was that it required too much.

As others have suggested, make sure autorudder is turned off.

Wow.  I'm going to guess that you never went much past a simple introductory flight lesson.  Especially in the pattern, my primary instructor would all but reach over and slap me if I didn't keep the ball centered.  Almost all maneuvers to be mastered for a PP certification require rudder attention, as do normal takeoffs and landings - especially in crosswind situations. 

Sure in normal level flight you can keep your feet on floor for minor turns and course corrections without making your passengers barf, but for other phases of flight and for practice work on basic skils (turns around a point, steep turns, stalls...), you need to learn good rudder work.  Fly a tail-dragger and you REALLY need to learn those pedals.

There are a few planes which feature rudder-aileron interconnects which help keep the ball centered (A2A models one of these with their new Bonanza) but even with these you need to use the rudder for all but normal turns.

Scott

 

I flew many more flights then an ‘introductory’ flight including solo many times. And using rudder was never really taught as a requirement except landing in a crosswind. 

 

As some have mentioned, it’s not really as necessary as many think. 

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20 minutes ago, Raging Bull said:

 

I flew many more flights then an ‘introductory’ flight including solo many times. And using rudder was never really taught as a requirement except landing in a crosswind. 

 

As some have mentioned, it’s not really as necessary as many think. 

Trust me, it's very necessary.

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32 minutes ago, DavidP said:

I think you'll find in types such as the 172 that most of the rudder is to do with engine torque. Demonstrating adverse yaw in these types, while not difficult, meant aggressively rolling the aircraft left and right and eventually you could see some sort of effect.

I have a few hundred hours grinding through the sky in a variety of 172s.  If you're suggesting that the ball will stay centered in a 30 degree banked turn without rudder input, I guess we'll have to agree to disagree.

That said, as I noted, one of my initial complaints about the A2A 172 as it was originally released was that the need for rudder use was greatly exaggerated.

23 minutes ago, Raging Bull said:

I flew many more flights then an ‘introductory’ flight including solo many times. And using rudder was never really taught as a requirement except landing in a crosswind.

My apologies if my comment came off as overly dismissive - not my intent - but I was certainly drilled from hour one on rudder use in everyday stuff like takeoffs and pattern work, without even getting into stuff like stalls (which I'm sure you worked before soloing), slips and all of the other PP maneuvers.

Scott

Edited by tttocs

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I find that in the A2A 172 is well modeled. Not only will you need right ruder (right turn) to maintain coordinated flight at a 30 bank, but you also need to hold some back pressure to maintain altitude, and sometimes you might need opposite aileron to prevent the over banking tendency as a result of the outer wing traveling faster and creating more lift than the inner wing.

Edited by DJJose

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8 minutes ago, DJJose said:

Trust me, it's very necessary.

 

Well, having flown some real aircraft around the skies never using or ‘needing’ rudder, it’s wasn’t necessary. (C152 i recall and a Piper warrior on occasions). 

Perhaps it wasn’t totally ‘coordinated’ in the turn, but barely (or not) noticeable anyway. I never looked to be honest at the turn and slip indicator. Most light aircraft turns are not that sharp so never really need it.  

I’m guessing if multiple intructors never taught me to use it wasn’t necessary. 

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At a very basic level:

My early flying was gliders (got to Silver 'C' standard, probably preferred gliding to powered tbh). The use of rudder in a turn is way more in gliders than it is in powered. There is also a lot of 'jockeying' of the rudder in a turn to keep the reference point balanced on the horizon / fight against a thermal pushing you out etc. so when I moved over to powered I found initially I was over-controlling the rudder.

Adverse aileron yaw is caused in the main by deflection of the ailerons (no surprises there!) and the effect that has on the shape of the wing / airflow over said wing. If you are in a balanced turn of any angle, once you have centred the stick you are just flying through the air so will also pretty much centre the rudder because the removal of the aileron deflection removes the requirement for rudder. There are still aerodynamic reasons for the use of rudder whilst in a banked turn, but the actual adverse aileron yaw is removed the instant the stick is returned to centre in a lateral sense. All this is based on a straight wing, of course. It was a bugbear of mine before I got into development as most FS aircraft required a progressive application of rudder purely dependant on angle of bank, whereas I have never flown anything in real life which requires such excessive use.

To answer specifically the question asked, in all FSX versions and P3D up to and including v3 the aerodynamics of this are dealt with in table 1101 (primary aerodynamics). P3Dv4, there are new tables in the .air file which address the bulk of what used to be in 1101. Both methods have the ability to create yaw moment due to aileron deflection and yaw moment due to roll rate. It is entirely dependant upon how the fde modeller chooses to interpret the subject and create it within those tables.

Paul.

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