FSX-MS Inherent flaw of FSX to give too much ground friction?

[Bob Scott 7,721]

Many thanks.

 

Do you know if it works also with saved and resumed flight?

 

Yes, it works with a saved flight.

[tttocs 301]

I'd like to join the legions saying THANK YOU! to all involved in discovering this and working towards a fix. I'm actually a bit surprised (and very pleased) at how much of a difference it seems to make in taxi control.

 

I still haven't tried it landing yet, as I haven't made a landing in over a week - a combination of not much contiguous time to fly and a recent OOM problem that's suddenly reared its ugly head, but that's another story for another place. But so far, so good using the LUA script in ground ops and takeoffs.

 

Thanks again to all who contributed their time, skills and creative problem solving abilities.

 

Scott

[riccardo74 36]

Yes, it works with a saved flight.

 

Yesterday, as said, I completed I flight to Mumbai (VABB). This flight was started before this addon. I resumed the flight, landed, but taxing and parking I noticed no difference with default NGX behaviour. As no change was made. So I asked if it works with saved flights. Maybe because this flight was started before the change in INI file doesn't work properly. I will recheck with another flight.

[rspaans 0]

This thread makes mention of a sliding coefficient and a spreadsheet, but with no specifics. How do I actually implement the changes to ground friction discussed above?

 

RDS

[kevinh 409]

This thread makes mention of a sliding coefficient and a spreadsheet, but with no specifics. How do I actually implement the changes to ground friction discussed above?

 

RDS

No need to worry about spreadsheets, just download the updated version of FSUIPC from Pete Dowson's forum link here. The version you need is 4.859m. All you need to do is replace your existing FSUIPC module with the one included in the zip file and edit the INI file as described in the documentation.

[kevinh 409]

Since first trying out this new friction model out on the PMDG NGX I've made some flights on a few other addon aircraft with varying success.

 

As with the NGX, the new friction values seemed to work well with the SimCheck A300B4.

 

However with Level D 767 and Wilco Airbus Vol 1 (A318/A319/A320/A321) the aircraft accelerates from static at idle thrust too rapidly even at high gross weight and you need to apply brakes too much and too often. The LDS767 will easily exceed 30 kt ground speed with idle thrust. In both cases takeoff and landing seems reasonable, it's just the friction at low speeds which is the issue. It's possible these addons have modified idle thrust to achieve more realistic taxi acceleration.

[mjrhealth 820]

Acceleration isnt a patch its an addon and needs to be purchased.

[Bob Scott 7,721]

Since first trying out this new friction model out on the PMDG NGX I've made some flights on a few other addon aircraft with varying success.

 

As with the NGX, the new friction values seemed to work well with the SimCheck A300B4.

 

However with Level D 767 and Wilco Airbus Vol 1 (A318/A319/A320/A321) the aircraft accelerates from static at idle thrust too rapidly even at high gross weight and you need to apply brakes too much and too often. The LDS767 will easily exceed 30 kt ground speed with idle thrust. In both cases takeoff and landing seems reasonable, it's just the friction at low speeds which is the issue. It's possible these addons have modified idle thrust to achieve more realistic taxi acceleration.

 

There are some FDE design techniques which augment the thrust during very low speed (i.e. taxi) ops to overcome the MSFS ground friction problem. If the thrust curves in the FDE already compensate for the excessive default ground friction, reducing the rolling friction to realistic values would be a problem. If you know which acft those are, the Lua script could be modded to leave rolling friction alone when those specific aircraft are loaded.

 

Regards

[TechguyMaxC 516]

I propose that we start listing which AC have FDEs which already account for FSX's default ground friction so we can start adjusting the LUA script as needed. New thread time?

[mas618 17]

 

Indeed it would be handy to exclude certain AC from the lua script! I find using the NGX with the script to be pure joy however. On another note:

I'm using the lua script, and if I understand correctly, this only affects the rolling friction, when GS is below 30 kts - so far so good. Is there a way to add/modify the values for sliding/skidding friction, that handles the way the AC behaves when landing in crabbed condition? I'm thinking this would mean that the LUA scriot would be active above 30 kts, but maybe so that rolling friction was modified on departure, and only sliding values were modified on arrival phase. Don't even know if this is possible? We talked about it ealier in this thread, and if I remember correctly, these values were improved for the .dll patch (the global and overall solution)...

 

Any ideas?

 

Mas

[Johan_Dees 84]

http://www.aero.sors.fr/

 

Download Aired, and the cfg/ini file for it.

Load the airfile with Aired, goto table 1506, and adjust the values.

 

Top row is the N1, just below are the values you are looking for.

If your plane for example has idle N1 of 25%, then you need to change the value to a lower one, works with some trail and error.

If your N1 is 28% for example, you have to interploate a bit at 30% and 25% to get it tamed.

Save and try out in the sim.

 

EDIT: I have no idea how to do this for props.. will investigate, because I need it for myself :-)

Turboprops are even more worse.. but they always were in FS

[Andydigital 93]

Why not just increase the rolling friction a little above 10 knots in the LUA on an aircraft specific basis and that should allow for fudged air files which try to overcome this ground friction problem on their own.

 

The greatly increased side friction on landing is a good idea too and this should probably be made aircraft specific too as some aircraft are more realistic than others in this regard anyway.

[mas618 17]

http://www.aero.sors.fr/

 

Download Aired, and the cfg/ini file for it.

Load the airfile with Aired, goto table 1506, and adjust the values.

 

Top row is the N1, just below are the values you are looking for.

If your plane for example has idle N1 of 25%, then you need to change the value to a lower one, works with some trail and error.

If your N1 is 28% for example, you have to interploate a bit at 30% and 25% to get it tamed.

Save and try out in the sim.

 

EDIT: I have no idea how to do this for props.. will investigate, because I need it for myself :-)

 

Turboprops are even more worse.. but they always were in FS

 

Thx Johan...

 

But are you reffering to the rolling friction or the sliding friction? If the latter, how are n1 values related to sliding friction? I'm very satisfied with the rolling friction on the NGX now, and I really love what the the lua script accomplishes. Just wish landing in crabbed condition would be more realistic...

 

Thx again

[Johan_Dees 84]

Rolling friction is what I ment.

[mas618 17]

Ah ok, thx. I like the values for those, so I'll leave them intouched.

 

Mas