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View Full Version : Torque effect/Yak's and La's



Pusy_Galore
02-08-2005, 07:46 AM
Hi all,

Been flying the Bf 109 a lot. (CEM on) The enginge produces a heavy torque effect, by judging from the slip/skid indicator ball. This is normally compensated with a moderate right pedal appliance.

However, in the Yak/La series, the ball indicator is firstly smaller and secondly doesn't seem to be offset to the left or right during the same flight conditions as in the Bf 109 case.

My questions:
-Is the torque effect similar to the Bf series?
-Is the effect on the same side (i.e. prop wash hits the tail fin at the same side)
-Is there any benefit in compensating with rudder (like in the Bf)though the gauge doesn't indicate slip/skid?

Thanks in advance,
***** Galore

Pusy_Galore
02-08-2005, 07:46 AM
Hi all,

Been flying the Bf 109 a lot. (CEM on) The enginge produces a heavy torque effect, by judging from the slip/skid indicator ball. This is normally compensated with a moderate right pedal appliance.

However, in the Yak/La series, the ball indicator is firstly smaller and secondly doesn't seem to be offset to the left or right during the same flight conditions as in the Bf 109 case.

My questions:
-Is the torque effect similar to the Bf series?
-Is the effect on the same side (i.e. prop wash hits the tail fin at the same side)
-Is there any benefit in compensating with rudder (like in the Bf)though the gauge doesn't indicate slip/skid?

Thanks in advance,
***** Galore

SlickStick
02-08-2005, 09:32 AM
As the 109 does not have rudder trim, it's normal to have to keep right rudder pressure for straight flying. The Ki series always wants to yaw left as well, not having rudder trim either.

The Yaks and Las have rudder trim. For me, whenever I spool up a plane that has rudder trim, I trim 10-15 clicks in the direction of prop rotation to counter the engine torque. La7 to the right, Yak3 to the left for example.

I'll also give 2-3 clicks of aileron trim for those that have it as well, to level the roll axis.

Kurfurst__
02-08-2005, 09:46 AM
Yakovlev series of fighters were built with assymetrically sized wings, ie. one of the wings were smaller than the other. This offset torque effects, iirc it was based on italian design idea.

VW-IceFire
02-08-2005, 09:56 AM
Really? Never heard of that...

Kurfurst__
02-08-2005, 10:01 AM
Yep, Yakovlev was a smart guy, and made great airframes... try to find some drawings, its visible, just barely. Smart thing, but it may cause some handling problems if not turning to the 'right' direction, ie. upper wing usually stalls first, and if it has less lift, it will stall even sooner. I fly the yak rather rarely, but I recall they have stron snapstall when pushed over the limit

But the Lavochkins, they were normal in this regard, directional stability being no bad, no good iirc.

As for the Bf 109 it lacked rudder trim, but it was built with an assymetrical vertical tail, with an airfoil shape just like a wing, to counter the torque... German specs were not to use rudder trimmer for small planes under 5 tons, so for this reason the 190 didnt have it either. I guess they didnt see it important for interceptors with just 1-2 hours of combat activity, little transition flights. In combat, using the rudder was quicker and would had to retrim constantly anyway.

p1ngu666
02-08-2005, 02:38 PM
yeah he was, was in hero's of russia book, really amusing http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

personaly, i hate lack of all axis trim, im a lazy sob, and like my inflight food or wee's http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif or readin a magazine or book on long missions http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

also i think rudder doesnt have the effect it should, cos if u wind on enuff trim to fly straight, then u crab a fair bit http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

i like yak fighters, look really sleak irl, and have cool loudouts http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

Pusy_Galore
02-09-2005, 01:52 AM
Thanks for the replies guys.

Kurfurst, what you are saying about the Yak asymetrical wings is intresting, if that is modelled then there should be no need for rudder compensation/trim (sorry, SlickStick). It seems like it is the case, by judging from the centered ball during level fligth. Or, as logic dictates, it could be like my assumption that the ball movement isn't modelled correctly.

I guess the only way to figure out is to fire the guns with no rudder trim/correction and watch if the bullet flight paths are aligned with the fuselage axis.

TheGozr
02-09-2005, 02:50 AM
Real life Yak9's didn't have a lot of torque on take off etc.. the real yak 9 just goes very litle to the left. at list the one i know.
the real one feels like they are on rails.but in game they are very smooshy.

WOLFMondo
02-09-2005, 03:20 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by p1ngu666:

personaly, i hate lack of all axis trim, im a lazy sob, and like my inflight food or wee's http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif or readin a magazine or book on long missions http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif <HR></BLOCKQUOTE>

Thats the one thing (apart from lack of mirror) I hate about German planes. If the FW190 had aileron and rudder trim it would be perfect.

SlickStick
02-09-2005, 06:52 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Pusy_Galore:
Thanks for the replies guys.

Kurfurst, what you are saying about the Yak asymetrical wings is intresting, if that is modelled then there should be no need for rudder compensation/trim (sorry, SlickStick). It seems like it is the case, by judging from the centered ball during level fligth. Or, as logic dictates, it could be like my assumption that the ball movement isn't modelled correctly.

I guess the only way to figure out is to fire the guns with no rudder trim/correction and watch if the bullet flight paths are aligned with the fuselage axis. <HR></BLOCKQUOTE>

I really don't believe that the yaw of a Yak is due to one wing being shorter than the other in the game. I'm betting it's not even modeled in the game. Maybe the real-life Yak, but in-game I'm betting the yaw is engine torque-induced.

Just IMO, of course. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

A good way to see how a plane is yawing is by turning off pit in PF merged and use the sight that has the little floating ball. As you trim in any one direction, you can see it move left and right and you can set the nose straight using it.

Of course, pit-off for test purposes only. http://forums.ubi.com/groupee_common/emoticons/icon_cool.gifâ