#772 YASim aircraft takeoff/landing drifting with winds more than 3 kts

[Anonymous]

Originally created by: houriehs... (code.google.com)@gmail.com
Originally owned by: andy.ros... (code.google.com)@gmail.com

*What steps will reproduce the problem?*
1.  Starting Flightgear with the Boeing 777-200er at any airport with winds just 3 kts or more.
2.  Start the plane and start to takeoff.
3.  Once it reaches about 80+ kts, the plane drifts to one side.
4.  Even on landings, the plane drifts once it touches down.

*What is the expected output? What do you see instead?*
I expect the plane to not drift as much on takeoff and landing.  3 kts winds should not cause a plane to drift like this.  I know I need to control the plane a little, but even with these three knot winds once it reaches 80+ kts I can NO longer control the plane.

*Any output in the console (black window)?*
NO

*What FlightGear version are you using (when using GIT version, please
mention date)?*
Latest Version
*What operating system and graphics card?*
Windows 7 ATI graphics card

*Please provide any additional information below or as attachment (Avoid
expiring external links, such as to imageshack/pastebin/...).*

I know other planes have been having this same issue.  I guess it is all YASIM planes. 

[Anonymous]

Originally posted by: aeitsch...@yahoo.de

I noticed the same today- it applies to all YASim aircraft.
Even full aileron doesn't help all too much. And as said above- it occurs at speeds above 60-80 ktns, and it drifts to the direction where the wind comes from.

Bad if you want to practice cross wind landings- that's why set to Priority: High

Summary: YASim aircraft takeoff/landing drifting with winds more than 3 kts
Labels: YASIM Priority-High
Status: Accepted

[Anonymous]

Originally posted by: aeitsch...@yahoo.de

Issue 625 has been merged into this issue.

[Anonymous]

Originally posted by: h... (code.google.com)@hyde-tech.com

I assume no one can fix this issue, right?
Then I just want to disable this "wind effect on ground" until it will have been fixed.
No effect is better than wrong feature.
Can someone advice where should I investigate to disable/enable?

[Anonymous]

Originally posted by: Wrench11... (code.google.com)@gmail.com

I concur with the above comment. I have win7 64 with git64 win version of flightgear installed. Going thru the same problems the 777-300er does not land as it use to.
Being a Licensed FAA Airframe and Powerplant Mechanic, I'am doin as much diagnosis
as I can, I am about to go to Flightgear 2.60 on a different user on my system to see if I return to regular landings.
So much has been changed and modified in Git, which on the whole is GREAT!!!, but this
issue is either a side effect or a loose unknown. One of the things that allowed me to save lives was... I    saw things, that others don't................ Its been true to me, and all the others that I see alive around me. :)

[Anonymous]

Originally posted by: h... (code.google.com)@hyde-tech.com

I submit the patch to disable wind effect on ground.
Once this would be fixed, the patch should be removed.

[Anonymous]

Originally posted by: philippe... (code.google.com)@gmail.com

hello,

where can we find this patch ? thank

OOZVY

[Anonymous]

Originally posted by: h... (code.google.com)@hyde-tech.com

I submit the merge request.
You can see https://gitorious.org/fg/flightgear/merge_requests/1572.

[Anonymous]

Originally posted by: vivian.m...@lineone.net

This one seems to have gone away. It was never reliably repeatable on all Yasim aircraft, but is now apparently "fixed" on the 777.

Owner: andy.ros...@gmail.com
Status: WontFix

[Anonymous]

Originally posted by: aeitsch...@yahoo.de

It may be that the problem appearently has dissapeared on the 777. (I need to test again.) But on a lot of other aircraft it still visible.

I tried yesterday buckaroos MD 81. No problems with wind speeds up to 15ktn. But everything above, and wind from left makes the problem appear again.
What I could notice again, that as soon the wheels touches the ground, the aircraft will drift. So I'm sure there is a problem, and the cause should be found and fixed.

Status: Testing

[Anonymous]

Originally posted by: aeitsch...@yahoo.de

Did some testings with the 777 now- unless I'm doing something really wrong I can still see the behavior with crosswinds from left > 20-25ktn  (The real thing is certified up to 40ktn !)

777-200ER:
Location: Edwards base KEDW, RWY 15
Weather: 08025KT 12SM  20/08 Q1013 NOSIG
gross weight: 574595 lb

I don't think this is a problem with the aircraft itself....

FGdata and fgfs.exe from yesterday

[Anonymous]

Originally posted by: h... (code.google.com)@hyde-tech.com

This issue is weaker than before but still exists.
If you run around 80knots and get strong left wind, ship is pulled to left.
My feeling is that the nose gear friction for left wind is match weaker than right side.
If I push the control column to have friction with nose gear then ship is controllable.

Could someone check that friction calculation area?

[Anonymous]

Originally posted by: h... (code.google.com)@hyde-tech.com

Finally I've found the cause of 777 veer to left when strong left x-wind.
Because the nose gear friction is too weak to control. Almost as same as controlling steering on the ice when speed is greater than 80knots.
I've changed the friction to be able to control for x-wind.
Autoland with 40knot x-wind from 10:00 is quite well now.

Status: Fixed