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View Full Version : Noob Q: Twin engine Yaw?



LameDuck.
01-27-2006, 10:52 AM
I first noticed this after losing an engine in the me-262. If I lost an engine in my old Air Warrior sim the plane would yaw, and the amount of yaw was proportional to throttle. It could get quite nasty at 100% throttle and landing a one-engined beasty became a real trick.
Here's what I'm experiencing now (100% throttle):
http://home.earthlink.net/~touring23/IL2/P38Yaw_1.JPG
But here's what I would expect (simulated with rudder input):
http://home.earthlink.net/~touring23/IL2/P38Yaw_2.JPG

Seems it's not a prop pitch issue because the me-262 behaves similarly.
All of my realism settings are on. Am I missing a setting, or does one of the later patches cover it?

LameDuck.
01-27-2006, 10:52 AM
I first noticed this after losing an engine in the me-262. If I lost an engine in my old Air Warrior sim the plane would yaw, and the amount of yaw was proportional to throttle. It could get quite nasty at 100% throttle and landing a one-engined beasty became a real trick.
Here's what I'm experiencing now (100% throttle):
http://home.earthlink.net/~touring23/IL2/P38Yaw_1.JPG
But here's what I would expect (simulated with rudder input):
http://home.earthlink.net/~touring23/IL2/P38Yaw_2.JPG

Seems it's not a prop pitch issue because the me-262 behaves similarly.
All of my realism settings are on. Am I missing a setting, or does one of the later patches cover it?

dbillo
01-27-2006, 11:20 AM
What are your realism settings?

I recently landed a P-38J in FB+AEP 2.04 and then one engine conked out. Trying to takeoff again with just the one engine was impossible. Even with full opposite rudder, the plane veered off to the side of the dead engine.

I haven't tried what your are doing in flight, but maybe I will and see what happens.

LameDuck.
01-27-2006, 11:47 AM
http://home.earthlink.net/~touring23/IL2/RSettings_1.JPG (http://home.earthlink.net/%7Etouring23/IL2/RSettings_1.JPG)

Complex Engine Mgmt is off, could that be it? I'll try it.

dbillo
01-27-2006, 01:05 PM
LD, I just repeated your test scenario. There is a slight roll effect induced towards the dead engine, which is probably caused by a very tiny yaw, otherwise not discernible. Nothing at all like full rudder input.

My view like your top pic has the smoke trails converging slightly to one side of centre.

The roll could be counteracted by a small amount of opposite rudder. I think at flying speed, the asymmetric force is almost completely countered by the stability offered by the tail surfaces.

The effect of a dead engine is more pronounced at slower speeds, like on landing approach and, as I found, on takeoff. I think if I had persisted at taking off, once some speed built up, the yaw could have been corrected.

The question is, which sim models this more accurately, FB or AW?

RocketDog
01-27-2006, 01:45 PM
AFAIK, IL-2 was never designed to handle multi-engined aircraft and so the engine-out modelling is hopeless. For quite a while Oleg wouldn't add them to the flyables because of this and when we evenbtually got them it was with a health warning that the model breaks down when you lose an engine.

If you read Eric Brown's comments about multi-engined LW aircraft (including the Me-262), it's quite clear that they consequences of losing an engine were far more severe than modelled in-game.

Cheers,

RocketDog.

VW-IceFire
01-27-2006, 02:47 PM
You do have to retrim a P-38 or any other twin when one engine is shut down. With the prop feathered there isn't too much extra drag so you can carry on fairly normally. Not sure how realistic it all is but there is some flight changes when you've got just one engine on.

LameDuck.
01-27-2006, 06:45 PM
Hhhmmm, OK, thanks guys....

Max.Power
01-28-2006, 02:58 AM
In actual twin engined flight, if an engine fails, you're supposed to counter the asymmetrical thrust forces by banking into the engine that is still running. The reason for this is that it could be dangerous to yaw and present an increased frontal area perpendicular to your vector and increasing drag while your half of your available power is gone.

In il2 this might work similarly. You might be able to fly around faster/ preserve more energy by banking instead of yawing.

Max.Power
01-28-2006, 02:59 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Max.Power:
In actual twin engined flight, if an engine fails, you're supposed to counter the asymmetrical thrust forces by banking into the engine that is still running. The reason for this is that it could be dangerous to yaw and present an increased frontal area perpendicular to your vector, increasing drag while your half of your available power is gone.

In il2 this might work similarly. You might be able to fly around faster/ preserve more energy by banking instead of yawing. </div></BLOCKQUOTE>

LameDuck.
01-28-2006, 09:16 AM
While that may be true, Max, I would think one Jumo at full thrust would be sufficient to spin a 262 like a child's top. http://forums.ubi.com/images/smilies/53.gif Said with due respect to the games designers. Perhaps this is an accurate simulation and my expectations need to be adjusted?

I had a few minutes more to tinker with it, so I tried some landings in one-engined P-38 and He-111 and it seems to me that it was goofy. Left engine out needed left rudder on approach, and vice versa...?! Dbillo's right, it's more significant near the ground.