my Posky 747-400's won't ground steer

[Allen_Z]

100's and 200's do ok, kinda sluggish

the 400's won't turn even @ 4-7 knots I used to be able to turn 'em at 15-20kts or so at GROSS

I have reduced weight to less that half of gross and it doesn't help

these are all Posky 747's

the default turns fine, as do my DC-10's, MD-11's, 777's etc

has this happened to anyone else?

[Sean_TK]

Downloading the plane now and will look into the problem shortly....

EDIT: Haven't taken it over 10 knots yet but turning performance seems a little too sluggish compared to what I have seen in real life. I'm going to look into the contact points section, there should be a section that can adjust the maximum angle that the nosewheel can turn.

EDIT Again: Hopefully someone can help here, but I'm sure that there is a certain value here that you can increase to increase the "steering angle", I just don't know which one:

[contact_points]

       //0  Class                        <0=none,1=wheel, 2=scrape, 3=float>
       //1  Longitudinal Position        (feet)
       //2  Lateral Position             (feet)
       //3  Vertical Position            (feet)
       //4  Impact Damage Threshold      (Feet Per Minute)
       //5  Brake Map                    (0=None, 1=Left, 2=Right)
       //6  Wheel Radius                 (feet)
       //7  Steer Angle                  (degrees)
       //8  Static Compression           (feet)  (0 if rigid)
       //9  Max/Static Compression Ratio
       //10 Damping Ratio                (0=Undamped, 1=Critically Damped)
       //11 Extension Time               (seconds)
       //12 Retraction Time              (seconds)
       //13 Sound Type
       //14 Airspeed limit for retraction     (KIAS)
       //15 Airspeed that gear gets damage at (KIAS)

point.0 = 1.000,  67.333,   0.000, -13.850, 2181.102, 0.000, 5.812, 78.480, 0.859, 0.500, 0.518, 11.000, 11.000, 0.000, 0.000, 0.000
point.1 = 1.000, -12.583, -18.000, -13.833, 2574.803, 1.000, 5.812,  0.000, 0.602, 0.500, 0.551, 14.900, 14.900, 2.000, 0.000, 0.000
point.2 = 1.000, -12.583,  18.000, -13.833, 2574.803, 2.000, 5.812,  0.000, 0.602, 0.500, 0.551, 17.100, 17.100, 3.000, 0.000, 0.000
point.3 = 2.000, -49.000, -102.900,  7.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 5.000, 0.000, 0.000
point.4 = 2.000, -49.000,  102.900,  7.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 6.000, 0.000, 0.000
point.5 = 2.000, -92.667,   0.000,  -2.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 9.000, 0.000, 0.000
point.6 = 2.000,  88.167,   0.000,  -5.750,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 4.000, 0.000, 0.000
point.7 = 2.000,-132.667,   0.000,  55.500,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 8.000, 0.000, 0.000
point.8 = 2.000, -14.917, -69.500,  -7.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 9.000, 0.000, 0.000
point.9 = 2.000,  14.917, -39.167, -11.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 9.000, 0.000, 0.000
point.10= 2.000,  14.917,  39.167, -11.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 9.000, 0.000, 0.000
point.11= 2.000, -14.917,  69.500,  -7.000,  787.402, 0.000, 0.000,  0.000, 0.000, 0.000, 0.000,  0.000,  0.000, 9.000, 0.000, 0.000
static_pitch= -1.000
static_cg_height= 13.125

// Nose gear
//point.0= 1.000, 67.333, -1.500, -15.333, 1181.102, 0.000, 2.000, 70.000, 1.859, 2.500, 0.518, 9.000, 11.000, 0.000, 240.000, 280.000
//point.1= 1.000, 67.333,  1.500, -15.333, 1181.102, 0.000, 2.000, 70.000, 1.859, 2.500, 0.518, 9.000, 11.000, 0.000, 240.000, 280.000

[Groundbound1]

Auto pilot (wing leveler) on?

[Sean_TK]

He looks to be talking about ground steering, seeing as 747s cant fly between 4-20 knots...

Still researching.....I think adjusting something in that contact points post will solve it, but seeing as how my plane at least turns a little bit, you don't have autorudder on in the realism settings do you? If so, turn it off and see how the plane handles.

[Allen_Z]

747s cant fly between 4-20 knots...

[Sean_TK]

I've been taxiing this 747 for a little bit longer now, and one thing that caught me is the fact that this bird slides around quite a bit on the ground. I have it in spot view, and have noticed that the plane is acting as if it is on ice or something, very, very strange.....

I'll mess with it a bit more, but the "grip" of the tires now seems to be the main problem.....no idea how to fix that though!

Getting ready for a short Tu-154 flight before my college classes this evening!

EDIT: Ok, been taxiing a bit more and now I am back to my nosewheel angle hypothesis. I can handle the plane somewhat ok now, but your right, it is acting like the 10 degree steering mode on the Tupolev.....

EDIT once more: Ok, I know I've been giving constant updates, but as I experiment more, it seems to be a little bit of both problems. A low nosewheel angle, and the fact that the plane for whatever reason slides   around quite a bit......

[Allen_Z]

slides around quite a bit on the ground. I have it in spot view, and have noticed that the plane is acting as if it is on ice or something, very, very strange.....

EXACTLY, it's as if the mains are turning the same direction as the nose wheel

they don't, I've watched, but that is how the plane acts

[Sean_TK]

Just figured out a way around this problem to some extent.
Use differential brakes when turning, it seems to be more controllable that way.
I'm using some Saitek Rudder-Pedals with it, so I can implement differential brake controls easily, but I hope you can. If not on your control, just use the keyboard defaults.

[microlight]

Download the updated FDEs from the Posky website - it cures the problem.

[Sean_TK]

I'm assuming that your are talking about this file?
http://www.projectopensky.com/downloads ... fdepackage

Thanks for the help in solving this mystery!!!!  :)

[Groundbound1]

He looks to be talking about ground steering, seeing as 747s cant fly between 4-20 knots...

Still researching.....I think adjusting something in that contact points post will solve it, but seeing as how my plane at least turns a little bit, you don't have autorudder on in the realism settings do you? If so, turn it off and see how the plane handles.

My fault! I missed it.

[Allen_Z]

Thanks microlight but something else is the problem, they still won't steer even at 4-10 knots,  medium - low weight

I used the new files on 10 models and they are all having the same problems

[Sean_TK]

All I can think of now is what I mentioned previously. Use differential braking. It seems to work well for me, and that is the only workaround to this problem that seems to work so far period.

Good Luck,
-SeanTK

P.S. Won't be able to try to help more until later today.  I have to leave to go to my college classes. See ya around, and good luck with learning the Tupolev as well!  :)

[microlight]

Sorry, Allen - I just checked the aircraft.cfg for my Posky 744v4, and I see that I've put the line

differential_braking_scale=1

in the [brakes] section.

Duh...

[Allen_Z]

hmmmm, ok

since I prefer copters, I use a stick exclusively, and differential braking with a stick is a pain, any plane that REQUIRES differential braking gets deleted

The taildraggers that will quick fix to allow twisty steering I'll keep, a tricycle gear airliner that requires differential braking to steer is a goner