Ground handling/friction/physics for sure… thankfully it’s also been identified as an area for improvement and rework by Asobo, starting in SU10. Multi-monitor support already coming in SU10, at least a first iteration of.
From a recent Q&A: Live Dev Q&A - May 25th, 2022 - #2 by N316TS
Chat question – What are some improvements that are coming for ground friction and handling? - Timestamp 3
Seb – Four new parameters are coming in Sim Update 10. Two of them are going to give the possibility to eliminate or at least tune, but we decided to cancel it out on our plane where we tested it. Basically, an old feature that we kept from FSX. FSX was canceling out all crosswind below a certain speed. At 50 knots, you had 100% crosswind, and then it was fading out to 10 knots and then it was 0. The problem is, while you take off or land, the crosswind keeps changing. And it’s very unnatural. So this is something where, in the parameters for the plane you can say at what speeds you want this to happen. So on the Cessna 172, we’re testing this, so we basically canceled the effect completely. So you have a 100% crosswind even if you are parked, or if you go very slow. If there is a lot of wind, it can actually spin your plane around, at first. So that’s one of the new parameters.
Seb – And the other one, two parameters are there to allow you to control how sticky your wheels are when they are rolling fast. So when you are already going pretty fast in the takeoff, the sim was considering the wheels to be pretty much on rails as if there were slick tires from a Formula 1 car. Very sticky. And only the weight…so if you pull on the yoke, your plane gets a bit lighter. And the weight goes down, which reduces friction a little bit. But it’s still static. So it means that as long as you don’t push to the side strong enough, you’re still on rails. And so, there’s two parameters that allow you to make it so that the plane drifts off. The wheels are spinning so if you push to the side, it’s going to drift off a little bit, especially with plane tires that are not anything but racing tires. So we tested that with taildraggers. Taildraggers will always be hard to land and takeoff. But it’s a lot more natural and easy with that. So this is something we implemented on the Extra 330 for Sim Update 10. Also, plane makers have examples of how this works, so they can use it, too. We will deploy on more based on feedback. These four parameters are a first step on improving the ground handling. So more stuff will come afterwards. But Sim Update 10 is going to be these four.
From a previous Q&A: Live Dev Q&A - March 2nd, 2022
Forum Community Question - Any update on the revamped ground physics handling/friction? In a past Q&A, we mentioned it had been done. Can you go into more detail and what’s coming up in the future?
Seb - last year in Sim Update 7, there have been a few improvements on ground physics. I think one was related to an assistance. When you turn on assistance of ground rudder – basically it’s the thing when there’s a crosswind and propeller effects and the plane goes all over the place, and you have a hard time using the rudder to just stay straight – that is very tough. And then when you rotate, it changes a little bit because you don’t have the wheels that hold you a little bit in place anymore, and you have to do some rudder work again to stay more coordinated. On ground, you’re basically changing from one system, which is staying straight on the runway to staying coordinated in flight. You have to make the switch. The assistance takeoff rudder does that for you. And previously it was just switched off whenever you rotated. It made this hard transition when you take off. That’s something that has been fixed so that this assistance, instead of switching off instantly when you rotate, it gradually fades out over the first 200-300 feet once you take off. It doesn’t have this brutal thing where the rudder turns off instantly. And there’s other little tweaks and improvements on ground friction that we’ve been improving. Mostly for specific bug fixes on specific planes.
But still, there is a deeper rework we need to do. Basically, it all comes from heavy simplifications that were in the sim 10-15 years ago, which were always assuming that the ground was flat. That’s why you couldn’t have sloped runways or undulated runways. The ground friction model…basically when something’s on the ground and when the brakes are fully engaged, you don’t move at all: The plane sticks to the ground. There’s what one could call infinite friction: There’s no movement at all. This is something we added that didn’t exist at all. And it wasn’t really needed 10 years ago because there were no slopes. When you put a plane on a flat terrain without wind, it’s not going to roll anywhere. But if you put that same system on a slope, it’s going to roll away and not stay there.
There’s also wind. Historically, in the sim, there was a system so that at low speeds, any crosswind was cancelled out. The plane ignores any form of wind, when you’re below, maybe 5-10 feet/second, which is why when you’re stopped on the ground, you go full propeller power and then there’s some propeller effects, so the plane starts going left. And then, all of a sudden, the wind kicks in, and then if you have a strong crosswind, it does this sort of thing which is not realistic. In reality, if I have a plane on the ground, and there’s a strong wind, and I release all brakes, it’s going to start moving: The wind is going to push it. And that currently does not happen. There are changes like that that we want to do. We want to do the ground friction model to make it 100% realistic. Which means that we don’t have to do anything: We don’t have to cancel it out anymore. Everything is going to be realistically simulated from when you stop to when you take off. There’s no such thing as crosswind that comes in over a few knots. I think it’s going to make the rudder a little easier. You’re just fighting one crosswind. It doesn’t change over time unless there’s gusts. Also, it’s going to work better on slopes. This rework is planned for somewhere this year, whenever we have time to go into that. It’s going to be compatible because the parameters are the same. It doesn’t change anything in the way you define or create or make airplanes. It just changes the way all the constraints and forces are sold so that the plane does what it’s supposed to do. All the constraints are the friction, the ground friction, the prop wash, the wind, even the engine, which is slightly shaking the plane. All these things come together. Currently, it’s a little bit better because we worked more in a bug fix development system, where we said, “The plane is sliding on the slope? Let’s fix that.” “The plane is sliding when there’s wind? Let’s fix that” Now we’re in a situation where we need to implement a real system instead of having a block of patches. That’s basically the next step, and that will give us much more realism the precise moment when you rotate.
For example, a wheel is currently simulated as a single point. So, a wheel can resist movement or rolling or sliding when you brake. It does not resist rotation. A wheel can rotate [with a rudder or tiller] without resistance. If you’re in your car and you’re parked, and you turn the steering wheel, if you don’t have power steering, it’s not easy to turn the tire because it’s not a point: It’s a flat surface. It’s a patch on the ground of rubber that you’re moving. The new simulation is going to allow this. This helps with stability when you’re taking off. Currently, the plane is just a tripod of points, and as soon as the nose is up, you feel that it’s already twisting because the wheels are not simulated as patches of rubber. They do not resist rotation enough. These kinds of changes are going to make the moments of takeoff a lot more precise and realistic. Later this year.