Extremely unrealistic ground friction/gravity/traction/something.

Question

Hello,

Airline Transport Pilot type rated in E145, CL65, E170 and E190 aircraft with a few years of real flying under my belt.  Most glaring problem I have seen with X-plane 11 (latest version I just purchased and d/l'd last night) has my aircraft (SSG E170, x-crafts 175, default 737) skidding all across the runway with a >5kt wind.  Furthermore, the weight of the aircraft doesn't seem to have any effect with the wind as once the aircraft comes to a halt/complete stop, the 5kt and > wind will "push" the aircraft(s) across the ground and wx-vane into the wind.  Being a real life EMB175 driver, it seems a bit impossible for an 85k lbs aircraft to be pushed by a 5kt wind.  Numerous landings under my belt with 45kt crosswinds that still result in <30kt xwind component and when the airplane touches the ground, the tires stick and the aircraft rolls down the runway.  Once stopped, the aircraft does not slide on the ground (even on ice covered ramps) in the wind.  Furthermore, the "lack of ground friction/traction/etc" will not allow a normal takeoff with proper control input to be made.  Roughly about 80kts, the aircraft will uncontrollably wx-vane into the wind and go off the runway.  No amount of control input corrects the undesired flight condition.  Any fix for this?  Hopefully, soon as I am brand new to xplane (again, just bought it last night) and already seeing issues that I wish I would've known about prior to purchasing.  

Cheers,
Caleb

Comments

I do agree. It is a huge annoyance to see your Light, Medium, or Heavy, aircraft moving or spinning like a paper aircraft in the wind. Some calculation goes wrong or some friction parameter is inaccurate.

It is, sometimes when you are having a flying exam on network, a total mess giving the supervisor the feeling you are a rookie despite many hours as a pilot.

X-Plane or Z-Curling ???

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Hi Caleb, I have found the exact same issue with crosswind landings and is extremely frustrating but I think I found a solution which i'll explain. I find the flight physics very accurate once airborne, but as soon as you touch down that's when i start having issues with control. Like yourself, I'm also a pilot (not commercial but private) so I know what an aeroplane should feel like... and its not that! It's so inaccurate its almost silly. I actually spoke to one of the developers at X-Plane and he insisted that the model was correct and that it must be my hardware. I disagreed at the time as all you have to do is type into Google "crosswind issues x-plane" and loads of people have the same problem. 

I found that editing the control curves has vastly improved the ground handling. I noticed that the controls are way too sensitive to the point when I was applying the brake slightly i could hear the tyres screeching. Im using the Saitek rudder pedals and flight yoke and works really well with that hardware. I'll take a screenshot and send you the profiles i created, but these can be further tweaked. I started by looking at the controls in the aircraft and creating a mental image of what the position should look like vs the input i was inputing on the yoke and rudder pedals and then adjusted the control curves accordingly. I can now fly with crosswinds in excess of 10Kts! that was not possible before i changed the control curves.  

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The Yaw axis works for me but you could refine this curve further. Just like when you're flying a real aircraft, match up visually what the controls should be doing vs your joystick inputs. I've only adjusted the rudder and yaw axis as i was only having control issues on the ground. You have to remember that most of the poverty spec hardware (that's what I'm using anyway) is way too easy to move compared with a real aircraft. For example, before adjusting the curves, i was almost able to do a 180 turn just using a 10th of the runway width when backtracking. It normally takes me at least half the width of the runway to do a 180 in the Piper Arrow i fly! So just try comparing the turn radius with the jet you fly when at full scale rudder deflection and adjust accordingly.... if that makes sense. 

Left toe brake adjustment, also do the same for the right toe brake

Answer 1

Totally agree, I also am an experienced real world pilot.This has always been an issue with XP as far as I know.

In the air its wonderful, but as soon as you hit the ground it all goes to heck.Developers either can't fix it or they don't acknowlege there's a problem.

I remember in an ealier version, I was doing a runup in the stock 172,and with the park brake set and at 2100 rpms the entire aircraft stood straight up on its tail.

Just one example of XP ground physics.

Answer 2

I totally agree too! I have already flown a DA40 with 30 kts headwind and 21 kts crosswind. It was hard, and the instructor was definitely needed, but the behaviour on the ground is not realistic on X-Plane. I do think the main reason is that friction wheels/ground is not realistic, but I have never been able to file a bug report with precise data. Mainly because there in no C172 at my airclub, and Laminar Research wants bug reports with default aircraft.

Answer 3

Hello all, waiting for physics coding of friction in X-Plane i wrote a lua script which fixes a little bit this amazing curling effect
https://forums.x-plane.org/index.php?/files/file/43415-friction_fixzip/

Daniel aka diaboloxpfr