Improving atmospheric flight

[haloterm]

I know Evochron is mostly a space flight sim, but flying on planets is still one of its main features.

I use 'real' flight simulators since > 20 years, and I also have several real-world flight hours as well, so it always itches me to see that the atmospheric flight in EL is only done using thrusters.

I think that at least a basic, lift-based atmospheric flight model should be included (maybe in a successor to EL SE). It can be more on the arcade-side of things, but should at least consider if there are wings and what atmosphere type we have.

On an Earth-like planet like Sapphire, for example, it would be realistic that a small fighter with plane-like wings should be able to glide to the ground when engines are off.

The possibility and effectiveness of gliding (read: the lift generated by the wings and the body of the ship while it is moving fast enough) should be dependent on the shape and size of wings and body, and on the thickness and type of atmosphere. Naturally a very thin atmosphere should make it much harder or next to impossible to glide (at least in the types of ships which can currently be built), whereas thicker atmospheres should allow it.

Again, an arcadey approximation would already be sufficient - but flying with a plane-like ship which can not glide (not even like the "flying brick" Space Shuttle) feels always unimmersive to me.


(Oh and as we are at it: I would also like to land the ship using a landing gear, outside a docking area and without using terrain walker/rover)

[Vice]

You can glide, including all the way to the ground from space if you set your speed, declination rate, and angles correctly. I enjoy occasionally gliding around, including all the way from space to the ground via a fairly steep dive starting at the edge of the atmosphere, 4000-4500 speed, nice burn effect for a bit at high altitude, generally slowing to about 2000-2500 by the time I level out over the ground and eventually 'touch down' as speed continues to decrease.

Without forward thrust to maintain the 'lift' factor, the friction/drag will eventually slow you down enough to stall. And the ships aren't exactly the most aerodynamic by design. Some other elements have come into play over the years (including changes), from shield bubbles being a factor to ease of flight, thrusters rather than control surfaces, and weight vs gravity. The existing flight model is designed more to behave like a craft designed for space, but with some restricted elements of atmospheric flight (held in check by computer-controlled thrusters to minimize chances of impacts and loss of control).

You can land your ship using a landing gear. Just get into ground effect, come to a stop to hover, then use your maneuvering thrusters to drop your ship to the surface. The landing gear will be extended and your ship's engines/thrusters will shut down.

[haloterm]

You can glide, including to the ground if you set your speed, declination rate, and angles correctly.

Oh - okay. I need to try that; I think I mainly though about the moment when I fight in the atmosphere and my fuel is empty, that I immediately stall; but maybe it is because I was too slow; if about 2000 to 2500 is just above stall speed, I will keep that in mind.

does ship design (wings, frame, weight) affect the glide ratio?

Could I design a glide-optimized ship with small frame but large wings and no storage capacity?

You can land your ship using a landing gear. Just get into ground effect, come to a stop to hover, then use your maneuvering thrusters to drop your ship to the surface. The landing gear will be extended and your ship's engines/thrusters will shut down.

Oh, again. Either I forgot that over the years or I never realized it, I will try immediatey.

[haloterm]

Okay I have tried gliding in the basic Pulsar frame and can now phrase better what I meant. I tried on Talison.

First I accelerated to 3000 and climbed to about 6000 (is the altitude in feet?) Then I switched to inertial mode and also set throttle to 0 to make sure no unwanted thrusters would fire.

While it slowed down to minimum 200 FVL it indeed was gliding. At about 200 the stall occured.

And what I found irritating then is that my speed did not increase when I dropped the nose (what one would do in a stall in a real aircraft). It kept slowing down, which for a plane-like frame like the Pulsar feels strange. With the nose pointed down, speed should increase; and if high enough even above stall speed so it can glide a bit further.


Also tried landing - worked fine

[Vice]

Oh - okay. I need to try that; I think I mainly though about the moment when I fight in the atmosphere and my fuel is empty, that I immediately stall; but maybe it is because I was too slow; if about 2000 to 2500 is just above stall speed, I will keep that in mind.

Ah ok, I think I know what might happen there. Stall speed is all the way down near 200, 1/10 the speed of 2K, I just tend to like fast approaches and retaining sufficient speed in case I need to perform a few mild turns on a glide path descent (to avoid mountains, find a more level area to land, etc). What can happen though is making sharp turns rapidly depleting your velocity (much like if you were flying an F-16 with a dead engine and tried to perform a hard banking turn). You can lose most or all of your momentum, depending on the severity of the turn. If you still have fuel, then you can compensate by hitting the afterburner to maintain forward velocity better during such rapid maneuvers. But if not, then very gentle turns while gliding would be critical to retaining forward momentum.

does ship design (wings, frame, weight) affect the glide ratio?

With regard to certain control/feel differences in some limited ways, yes, there are some elements of ships size/weight/agility that can come into play, specifically when trying to perform maneuvers. A ship that can't rotate as well (considering base frame and wing/thruster set) may actually maintain forward glide flight a little better since it's not as prone to performing hard 90-degree banks as quickly as something light and agile (meaning its trajectory remains more forward overall, resulting is less loss of potential speed with the same level of control input because it's not turning as quickly). That will probably be the most noticeable kind of behavioral difference (both for powered flight as well as gliding).

Could I design a glide-optimized ship with small frame but large wings and no storage capacity?

It wouldn't make much of a difference in a relatively straight line (this game is definitely not a gliding simulator I'd suggest designing your ship for more general purposes you'd want to use it for, bias for either combat or cargo transport. Then manage glide performance more with how you fly rather than ship parameters (especially when gliding... powered flight is a different story though). How you fly while gliding will have the most impact on ratio/distance and longevity. It's generally most important to design a ship to be purpose built for the gameplay objectives you'll be most interested in... usually involving powered flight.

[Vice]

And what I found irritating then is that my speed did not increase when I dropped the nose (what one would do in a stall in a real aircraft). It kept slowing down, which for a plane-like frame like the Pulsar feels strange. With the nose pointed down, speed should increase; and if high enough even above stall speed so it can glide a bit further.

Only with modern era aircraft limited to control surfaces with only one mechanism of thrust in only one direction. The 'future' spacecraft and their projected/theoretical design elements in the game use a very different control system (entirely thruster based in virtually any direction, including reverse thrust during a stall). The ship's control system attempts to keep your velocity below levels that would cause damage/collisions (previous discussions on the forum may be of interest as to some of the reasons such behavior was developed over time based on feedback/requests). To quote an excerpt:

Your ship's (spherical) shield system and anti-collision protection systems will generally help protect you from smacking into terrain and blowing up. However, you can override those systems by flying too fast and at too sharp of a nose down angle to cause your ship to either take damage (if speed is low enough), or destroy it entirely.

What happens is your ship's thrusters attempt to keep you airborne at all costs, not allowing your ship to 'fall' dangerously toward the ground. And once you reach ground effect, the limited thruster output is capable of levelling your ship out and holding it above the terrain. If you slow down to very low speeds, then sufficient lift is lost to maintain forward flight and you can still stall. But the effects of that stall are tapered/limited by the thruster system on your ship to prevent said crash/damage potential.

[haloterm]

Only with modern era aircraft limited to control surfaces with only one mechanism of thrust in only one direction. The 'future' spacecraft and their projected/theoretical design elements in the game use a very different control system (entirely thruster based in virtually any direction, including reverse thrust during a stall).

I understand that reasoning ... but what happens if these thruster systems fail completely? If there would be elevator, rudder and aileron on planes with wings, a controlled emergency landing would still be possible.

I think that if we ever build spacecraft capable of atmospheric flight, we would still add these classic control surfaces, at least as a backup

But I understand if it is too much effor for just little overall gains to implement such a feature in the game.

[Vice]

I'd venture to guess system redundancy, alternate power resources, and other mechanisms will likely make great strides in many hundreds of years. But even today, some airplanes still have parachutes on them just in case their control surfaces and engines fail So it can always be a balancing act of risk mitigation.

The problem with fixed control surfaces on spacecraft is that they assume Earth-like atmospheric pressures everywhere. And that's just not the case. Control surfaces would often be mostly or entirely ineffective in thin atmospheres and also risk damage in extremely high-pressure conditions whereas a standardized thruster system can still rotate a craft with a level of adjustable consistency whether it's in the thin atmosphere of Mars or wild wind and density conditions of a gas giant (and you can fly inside gas giants in this game... with the theoretical/fictional flight systems mentioned earlier). For flight control consistency, functional effectiveness, and reliability/durability, it would likely be far better and more practical to have thruster systems rather than any kind of flight control surfaces that would not behave consistently across the widely variable range of atmospheric environments on different planets. Space/components/resources saved by not using control surfaces could then be devoted to more robust thruster systems that are more flexible/adjustable, effective, and durable for such variable conditions.

[haloterm]

But even today, some airplanes still have parachutes on them just in case their control surfaces and engines fail

Yes - used to take flight hours in one of these until summer last year, but had to stop due to funding.
No, not the Cirrus SR2x but a smaller C42 ultralight (https://en.wikipedia.org/wiki/Ikarus_C42). My colleagues and me at vFlyteAir even developed a X-Plane 11 simulator version of that plane, based on my real-world flying.

It would be better and likely more practical to have redundant thruster systems, rather than any kind of flight control surfaces that would not behave consistently across the variable range of environments on different planets.

You are probably right.

Still I think the behavior in Evochron should be based on the actual shape, size and profile of the wing and the specific atmospheric conditions - on an Earth-like planet with all engines and thrusters cut off a plane-like shape should still continue to glide more smoothly until it stalls. On a Mars-like planet it should of course behave differently. Anyway, it is not REALLY important

[Vice]

The C42 looks fun. Not sure I'd heard of that aircraft before. Most of the time I'd spent flying was in Cessna 172-210's, with an occasional Stinson or Bonanza trip once in a while. Always thought it'd be fun to fly in an ultralight sometime though.