Guest FSWMD Posted November 2, 2008 Share Posted November 2, 2008 i have confirmed that this issue lies in the air file,as it follows from plane to plane when i used this air file for testing purposes on another aircraft. yess i know "dont use the rudders in f16" but this is still wrong and because of fsx limitations this should be fixed. besides on of the uses for the rudders is in some cases to help line up with the runway, as it is now if you try it will throw you out of control when trying to land. Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/ Share on other sites More sharing options...
SUB750 0 Posted November 2, 2008 Share Posted November 2, 2008 The rudder/roll issue.For what its worth, I'm not so sure there is an issue.My reasoning for this is based on some basic aerodynamic theory. Now the F16 is basicaly a Delta wing with a tail, the wing has a swept leading edge.Ignoring rudder input for now and lets say we are flying along straight and level. The F16 is happily flying along then a gust of wind comes in say about 40' from the right towards the aircraft. What happens now is that the angle of the right hand wings leading edge to the airflow is reduced by 40'. Its become a straight leading edge into the relative airflow. On the other hand the left hand wings leading edge angle has increased by 40'.At this point if we were looking at the F16 from the winds point of view it would appear that the right hand wing has a greater span than the left hand wing.Still with me?Therefore this causes an inbalance in lift generated by the wings. The right hand wing will generate more lift than the left hand wing. This causes the right hand wing to rise and the aircraft starts to roll left. Eventually the situation will reverse as the left hand wing drops and the angle at which the left hand wings leading edge relative to the airflow reduces and the right hand wings leading edge increases.The aircraft not only rolls but will pitch up and down as well. This is called "Dutch roll" and is something that only effects aircraft with swept wings. True the F16 has leading edge strakes and the fuselage is blended with the wings and there are other amazing aerodynamic features to it, but the fact remains that it still has a swept leading edge wing. Greater the sweep greater the effects of dutch roll.Most Swept wing aircraft have a yaw damper to give a bit of automatic input to counter the tendancy to Dutch roll, but I've not seen this in the F16's cockpit.Bearing all that in mind, I would hazzard a guess that as you give the F16 a boot full of rudder the aircraft will and should roll.Maybe the real F16 doesn't need a yaw damper because some bright spark worked this all out and wrote it into the flight control software. I have no idea how FSX models this behaviour either, it is just performing how I would expect, thats all.There are some very good books about out there about theory of flight etc. I would recommend "Mechanics of flight" by A.C Kermode, Its a bit heavy going in places but it will explain this better than I can. As for FSX I have no interest in how it works or doesn't, I just have to accept its doing the best it can even if it is flawed. Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-129339 Share on other sites More sharing options...
saprintz 82 Posted November 2, 2008 Share Posted November 2, 2008 i have confirmed that this issue lies in the air file,as it follows from plane to plane when i used this air file for testing purposes on another aircraft. yess i know "dont use the rudders in f16" but this is still wrong and because of fsx limitations this should be fixed. besides on of the uses for the rudders is in some cases to help line up with the runway, as it is now if you try it will throw you out of control when trying to land.Not that this wouldn't be obvious to many, but...What happens if you cross the controls, as in the "other" crosswind landing technique? What I'm saying is, when you come in crabbed on the approach, the instant you stomp on the rudder to try to straighten the nose out, what happens if you apply opposite aileron? Maybe people could try opposite aileron at varying degrees, to see if there's any amount or any combination that can allow you to reduce the [heading - track] difference without continuing to roll.I can't test this where I'm at this weekend, but can later. I just haven't done a lot iof windy flying since I need a centered HUD for other testing purposes. But I would agree that if there's no amount of opposite aileron which allows us to both straighten out the crab and stop the rolling, then the rolling tendancy should perhaps be toned down a bit. I have no doubt that it's done "by the books" as it is currently, but perhaps something within FSX prevents whatever it is in the real world that would counter this from happening. I can imagine that it is "stealing" some of the fun away for some people. But let's make sure it's not our flying technique, first. ;-) Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-129401 Share on other sites More sharing options...
Guest FSWMD Posted November 2, 2008 Share Posted November 2, 2008 Not that this wouldn't be obvious to many, but...What happens if you cross the controls, as in the "other" crosswind landing technique? What I'm saying is, when you come in crabbed on the approach, the instant you stomp on the rudder to try to straighten the nose out, what happens if you apply opposite aileron? Maybe people could try opposite aileron at varying degrees, to see if there's any amount or any combination that can allow you to reduce the [heading - track] difference without continuing to roll.I can't test this where I'm at this weekend, but can later. I just haven't done a lot iof windy flying since I need a centered HUD for other testing purposes. But I would agree that if there's no amount of opposite aileron which allows us to both straighten out the crab and stop the rolling, then the rolling tendancy should perhaps be toned down a bit. I have no doubt that it's done "by the books" as it is currently, but perhaps something within FSX prevents whatever it is in the real world that would counter this from happening. I can imagine that it is "stealing" some of the fun away for some people. But let's make sure it's not our flying technique, first. ;-)you cant "crab"there is no rudder effect if you apply you do a rather nice barrel roll. Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-129403 Share on other sites More sharing options...
saprintz 82 Posted November 2, 2008 Share Posted November 2, 2008 you cant "crab"there is no rudder effect if you apply you do a rather nice barrel roll.No, you're crabbed by default in the wind, when you're track differs from your heading. UNDOING the crab is what you're speaking of, and I'm asking what happens if you apply opposite aileron with rudder.Scott Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-129409 Share on other sites More sharing options...
JamesChams 108 Posted November 2, 2008 Share Posted November 2, 2008 ...UNDOING the crab is what you're speaking of, and I'm asking what happens if you apply opposite aileron with rudder.ScottMr. Scott,I tried that on the TOF roll in my first posting; But that was v1.0; I'll try again but, could you let you know - Were there any changes in the FLT model from version 1.0 to 1.01?Thanks! PS: The first time I did this it was unsuccessful, in that the bank roll did NOT balance out with the opposite rudder. The Rudder induced bank over came the Aileron pressures causing a tumble: see post Here. Please standby, I'll try again with v1.01. Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-129422 Share on other sites More sharing options...
Guest FSWMD Posted November 2, 2008 Share Posted November 2, 2008 i will try that as well. Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-129425 Share on other sites More sharing options...
Qapmax 0 Posted November 13, 2008 Share Posted November 13, 2008 hello everybody. Do we gona have some solution too that problem Link to comment https://forum.aerosoft.com/index.php?/topic/21003-roll-instead-of-yaw-with-rudder/#findComment-130767 Share on other sites More sharing options...
Recommended Posts