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Guest jcomm

Fly!2 and slipstream effects....

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I am back to Fly!2 after a loooong while away from this great sim.I recall that one of the issues that made me leave about 2 years ago was the poor PC I then had. Things have changed, and Fly!2 flies... in my new (not top-notch) machine.There has allways been a very special sensation, when I use this sim, of really being there, and one that no other sim replicates as well (with the possible exception of Fligh Unlimited it it wasn't for the rather arcadish panels it comes with...).Well, back to Fly!2, there were allways some aspects of the FM which I found remarkable (still find!), and also a few that disappointed me. One of the major limitations, IMHO comes to torque & slipstream effects modelling. Fly!2 prop aircraft can have their props reved and re-reved without the slightest hint of slipstream effect on the tail surfaces. When using the ATR though, I noticed that sudden power changes induced abrupt pitch variations, which I believe might well be something programmed to simulate the effect of propwash on the horizontal stabilizer. I feel the effects is a little bit overdone, but something similar could probably be programmed and directly tied to power variations in terms of Yaw.Since I know nothing about Fly!2's internals I wonder if it would be possible to include some sort of invisible rudder that comes to play just when power changes are operated. On clockwise (as seen from the cockpit) rotating props, and increase in power would usualy cause the tail to slide to the right due to propwash, and thus the nose to point left taking action from the pilot to counteract (using necessary amount of right rudder). Maybe one could program some "invisible rudder" that could induce that yaw moment when power increases, an the way around when throttle is retarded.A friend of mine who flies the ATP for real tells me that the aircraft requires a good deal of rudder trim both when power is increased (during climb) and when the throttles get retarded for descents. The "invisible rudder" could be used to model such effects?Other than that Fly!2 is remarkable in modelling assymetric thrust, and probably the only sim that models such details as the drag caused by assymetric use of cowl flaps on twin props!!!I think I am starting to love this sim again :-)

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Welcome home! :-)If you would like to try and modify torque values for any particular aircraft it is not really hard.Use Podview(tools folder) to extract the *.prp file and open it in notepad. Then try adjusting a few of the variables and resave to the world folder. Ensure that you have SearchPodFilesFirst=0 set in Fly.ini and your changes will be reflected in the aircraft performance. The original *.pod file is unaffected so don't worry. If you don't like the changes you've made simply delete the *.prp from the world folder and your aircraft will revert back to the default.I've listed the *.prp file below and you can readilly see the appropriate variables.Fly! II is a great sim. Big developments are in progress to make it it even better. Hope you enjoy Fly! II second time around.Cheers,Roger /////////////////////////////////////////////////// // // Propellor // /////////////////////////////////////////////////// -- Interference Mode -- - blade count 3 -- blade mean width 0.46 -- prop diameter 10.85 -- min blade angle (degree) 13 -- max blade angle (degree) 70.5 -- .42 Thrust Factor -- 0.70 -- 0.4395 Torque Factor -- 0.4395 -- Ice Accumulation Rate (hz) -- 0.005 -- Ice Drag Coeficent -- 0.10 -- Prop Effect factor -- 0.8 -- Prop Torque Effect -- 0.0 -- blade lift Table f(AOA) -- -- AOA, CL -- 1.57 -0.3508 5.1 -- end data -- -- blade drag Table f(AOA) -- 1.57 0.06 -0.4 1.1 -- AOA, CL(AOA) -- 1.57 0.02 -0.2 1.6 -- end format -- -- Interference Ratio Table f(Advance Angle Ratio) -- -- AAR, IR(AAR) -- 1.0 0.0 2.429814 -1.469319 -- end format -- -- Rotational Interference Factor Table f(Advance Angle Ratio) -- -- AAR, RIF(AAR) -- 1.0 0.028411 -0.029471 -- end data -- -- Repair Cycle (hours) -- 100 ========== END CPropeller OBJECT ==========

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Thank you for your answer!I didn't recall such parameters, but a few years ago I did spend a LOT of time trying to study/figure out the internals of Fly!2...I will try the parameters you showed in your post.

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