It took me years to accept/understand why a Prop Aircaft, single or multi (provided not counter-rotating), should start banking/yawing to the right (on a clockwise rotating prop as seen from the cockpit) when the throttle was retarded/idled...

 

I could understand the Torque, P-factor, Slipstream and even Gyroscopic effect contributing to a left bank/left yaw when power is applied , i.e.: during climb/go around, etc... (something we have debated here several times regarding FLIGHT), but I just couldn't understand why there should be a bank to the right when the throttle was retarded, say, during descent.

 

The only exception, of course, is when the aircraft are built with canted engines, or different incidences in the wings, or incidence in the vertical stabilizer to account for cruise compensation, but what if the aircraft has none of these compensations built in? What if the trims are set to their neutral position and controls centered? Why?

 

MSFS previous versions (including the best add-ons) never modeled this, and I, not being a prop aircraft pilot, could only try to observe and/or ask my fellow engine-rated pilots, who looked at me as ... well as you sometimes think of me here at the forum :-)

 

Well, guess what?, ELITE models this effect, X-Plane 9 and now 10 models it too, and I have argued with Austin about it, but, BUT!!!! MS FLIGHT in it's NEW/redesigned flight dynamics model, also models this effect.

 

Pick the Maule, clear skies for zero winds / turbulence, go up to say, 6000', then stabilize the aicraft, full prop RPM, and retard the throttle... Observe the AH and the magnetic compass or HSI and see it starting to bank and yaw right....

 

Well, of course there is a mathematical/mechanical justification for this to happen, but I will leave it for another thread :-)

It is a continuing amazement to me how far the "common knowledge" of what flight was diverged from the great things we keep finding out were really going on beneath the hood.

 

Things that could have been expanded and built on even further.

 

A nice write-up, Jcomm.

Pick the Maule, clear skies for zero winds / turbulence, go up to say, 6000', then stabilize the aicraft, full prop RPM, and retard the throttle...

 

Did you just say retard? lol

Did you just say retard? lol

 

Pretty funny. At last nights "back to Hawaii" multiplayer gathering, someone was explaining certain aspects of landing procedures, and that word got tossed around a lot, too, with pretty much the same reaction.

 

Flying humor, I guess. :P

IMO...............the right bank in X-Plane is too much. Also, most single engine aircraft ( including R/C models) are built with engines canted to the right, for props that turn clockwise as viewed from the cockpit. Vertical stabs may have an offset, or rudders just use tabs, or a combination of both.

 

L.Adamson

IMO...............the right bank in X-Plane is too much. Also, most single engine aircraft ( including R/C models) are built with engines canted to the right, for props that turn clockwise as viewed from the cockpit. Vertical stabs may have an offset, or rudders just use tabs, or a combination of both.

 

L.Adamson

 

I kinda of agree, though I don't have the "Real pilot" credentials to support it. My most recent X-plane10 experiences a few days ago were full of wondering what was up about the sharp tendency to the right.

I also agree that in x-plane, both the left bank and the right bank, due to prop effects, are excessive, but, there is a possible explanation laying on the fact that the slipstream model in x-plane is either not present at all or not completely modeled.

 

Should prop slipstream and the way it asymmetrically hits the vertical stab/rudder be fully modeled and the yawing moment it creates would sum to and contribute to make not so excessive/prevalent the torque effect on x-planes... Just my way of trying to explain, of course....

Hi,

 

Enough with the incessant x-plane references!

thank you.

 

Jim F.

You guys notice things I would never even think to look for, and that would make little to no difference to me. But that is the thing about us flight sim enthusiasts, different strokes...

 

 

Now I could go into a dissertation on what is really impressing me with another very nice, very complex sim I am getting into, but not here.

In XP I finally ended up (gratefully!) turning on some assists so I did not have to constantly fight with the plane.

 

I only got 15 minutes of testing, dontcha' know, and I don't want to waste it struggling with the controls...... :P

ended up (gratefully!) turning on some assists so I did not have to constantly fight with the plane.

 

The one thing that annoyed me, was I would take off full throttle and full rpm ( in the Maule ), then during climb out I would reduce engine rpm to 2300, and the dang plane would climb drastically and increase speed.

I think it was RoboRay who suggested this, now I engage the brake, full throttle, then ease the rpm back to 2400, release brake and take off. Now, I don't have that during climb out, and I achieve actually faster climb when I go wheels up. Then when I get close to my intended cruising altitude, I reduce rpm to 2300 and lean the mixture out, with no drastic effects on the plane.

I think all these sims have their idiosyncrasy's, even a ten-jillion dollar professional one. I guess the clincher is if they are a deal breaker for whatever your purposes are.

Now I could go into a dissertation on what is really impressing me with another very nice, very complex sim I am getting into, but not here.

 

C'mon, give us just an hint! Puleeeeeze :-) I've been there too - look for "jcomm" at the forum, if we're talking DCS :-)

I also agree that in x-plane, both the left bank and the right bank, due to prop effects, are excessive, but, there is a possible explanation laying on the fact that the slipstream model in x-plane is either not present at all or not completely modeled.

 

Should prop slipstream and the way it asymmetrically hits the vertical stab/rudder be fully modeled and the yawing moment it creates would sum to and contribute to make not so excessive/prevalent the torque effect on x-planes... Just my way of trying to explain, of course....

 

Since I've tried various X-Plane models over the years.........default, payware, & freeware, I've seen flight dynamics range from being very poor to rather good. It's my belief, that the program isn't as powerful as some would like you to believe. For instance, the included RV's in X-Plane, have always balooned up like a Cessna when the flaps are extended. Thats opposite of what the real RV's do...........as the nose pitches down. Some X-Plane developers will tell you, that it's the programmers fault for mistakes such as this. While other developers will plainly tell you that X-Plane has it's many faults, and requires work-a-arounds, just like other sims we know of.

Some X-Plane developers will tell you, that it's the programmers fault for mistakes such as this. While other developers will plainly tell you that X-Plane has it's many faults, and requires work-a-arounds, just like other sims we know of.

 

I know Larry.... ;-)