Glider, sailplane, soaring, please! [Feature Requests]

Thanks Paul,

Not even sure if Gliders are planned in MSFS roadmap either.

Would love to see thermalling and soaring model being present in this platform. The cliders will come very quickly then by 3rd party devsā€¦

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Iā€™m pretty sure that at least rotor is modelled in the simulator to some extent because I was flying on the Lee side of a steep cliff in a Cessna and hit some serious sink. It made me smile at the potential of a simulator modelling the fluid dynamics of wind over terrain and good thermal modelling. In other simulators the thermals always feel fake and artificial at least compared to the thermals Iā€™m used to in the UK and Spain. I wonder if we are ever going to see a Paraglider model as well as I fly both sailplanes and Paragliders?

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PG would be awesome! But difficult to simulate with all the moving parts, i guess :slightly_smiling_face:

Excited for the Grob103, FLTSIM76. I have about 180 hours in those. Keep us updated :+1:

Yeah. Really looking forward for that one.

Definitely - and if the donā€™t want to model winch/aerotow launching (like X-plane manages to do) they could at least give us a decent self-launching type.

Multiplayer Aerotow! I can imagine having fun flying the towplane.

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That is fun in X-Plane.

Putting gliders into a sim is such a pain in the ā– ā– ā–  - IMHO Asobo should start with gliders and work forwards from there. There will be numerous ā€˜gotchasā€™ from early sim build decisions that will take forever to resolve, e.g. for FS2020 these might include:

  • The wind settings seem to require ā€˜gustsā€™ (I hope Iā€™m wrong) with a minimum of 50% of the wind speed. These are wrong and will totally mess up the sensitive instruments used in a glider. The bodge solution will be to only implement a ā€˜747ā€™ style rate-of-climb indicator which will be unaffected (but not work for soaring).

  • There is zero chance that flaps are properly implemented in fs2020, as with FSX. Theyā€™ll work fine in a 747 or maybe a Cessna, but not come even close in a glider. Noobs wonā€™t notice but it will mean something like zero flap = best glide at all speeds, which mostly defeats the reason to have flaps on a glider at all, particularly negative flap.

  • Gliders need a ā€˜compensatedā€™ rate-of-climb indicator which subtracts speed changes. The code in FSX and X-Plane gliders is by me, and some guy must have done this for Condor, but AFAIK no-one else has ever managed to implement this for a sim even though it is essential for soaring. The fallback is to simulate colossal amounts of lift so even a plank would soar, and give the pilot a plain rate-of-climb indicator.

FS2020 has the potential for decent soaring, but there are plenty of ways to mess it up and those are actually more likely than not.

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Best glide at all speeds? Iā€™m not aware of any sim where this occurs and I donā€™t see this problem in FSX either. I donā€™t see any specific FDM design problem with gliders.

Hi all,

I agree they should first improve the weather model and add up and down draft to support thermal and slope soaring.

BR

Ricky

(thereā€™s a chance you misunderstood me - I donā€™t mean zero flaps at 200 knots has a lower sink rate than +10 flaps at 50 knots, I mean at any given speed, the zero flap settings will have a lower sink than the +10 setting, up until the stall. If this was the misunderstanding, ignore the rest of thisā€¦)

Yes Iā€™m afraid so - Iā€™m not sure what tools youā€™ve used to conclude the problem is not there but itā€™s understandable you wouldnā€™t notice simply by flying a 747 or a Cessna. Iā€™ve spent many many years on this in FSX and x-plane. By ā€˜best glideā€™ I mean glide ratio in still air, which needs to be measured between stall and Vne. You need custom instruments to plot that ā€˜polarā€™ out, compensating for speed changes (if youā€™ve written one then let me know and weā€™ll compare notes, but itā€™s a niche hobby). I could give more technical details (like the stall speed decreases with positive flap as it should) but thereā€™s not a lot of point comparing my measured data with someone elseā€™s hunch.

This doesnā€™t materially affect 747s and Cessnas - they only have positive flap, that reduces the stall speed, and pilots with flaps out spend much of their time flying slower than the stall speed of the zero flap setting. But in that area of overlap where you can have the flaps positive but the zero flap setting would not be stalled then the glide ratio is always higher at the zero flap setting in FSX and X-Plane.

A glider might have 5 flap settings with much more overlap and in X-Plane and FSX the consequence of this simplistic design in the sims mean in a high-performance glider you need to program an invisible adjustment to the air brakes so poodling around everywhere in zero flap isnā€™t the optimal strategy above the stall.

Counter-intuitive isnā€™t it? At this point you might I admit I know more about it than you do, but hey if you really have looked at this stuff then that makes two of us and Iā€™d be interested to hear what you found out.

** an addendum - another wierd/counter-intuitive aspect of the flight model in FSX is that in zero flap, as you slow down, your glide ratio (in still air) gets better and better until you enter the stall. Weā€™ll see if this carried over into FS2020. It makes very little difference to power pilots, so Iā€™m not suggesting itā€™s a drama, but it will affect gliders.

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Never saw this problem with high quality FDEs in FSX. Below ~VIMD the L/D ratio correctly decreases.

I donā€™t think youā€™ve ever measured any of this stuff in FSX or X-Plane, and donā€™t understand why youā€™re posting your confident simple statements like you know the answer.

Back to the thread, for gliders in FS2020 (flapped, and unflapped) this will turn out to be fairly important.

I have no idea why you are becoming impolite.
Of course Iā€™ve measured all this ā€˜stuffā€™. Otherwise it wouldnā€™t be possible to design high quality FDEs.
Have you ever developed a FDE for FSX?

Hm, at this point Iā€™m probably coming to the realisation that the atmospheric model is not quite there (yet?). I can find pictures showing visualised air streaming over mountains, so thatā€™s a promising start and should allow for some slope soaring.
But what about thermal updrafts? Created dependent on the current atmospheric make up, sun intensity, surface properties and angle etc.
Also: The formation of clouds should be linked in with the movement of the air masses. The simplistic weather dialog suggests that clouds so far are just a plausible decoration. Flying under a fresh firm cumulus doesnā€™t really seem to do much. On the other hand you see those time lapses of ā€œboilingā€ cumuli - is that just dead animation?

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Iā€™m being honest - apologies if it sounds impolite.

Iā€™ve spent months if not years tuning the flight models for gliders in FSX and X-Plane using every tool available (although I had to look up the acronym FDE ). To do this effectively you need additional hand-crafted tools that can do things like compensate for speed changes while drawing the speed polar at different flap settings - Iā€™m not aware of anything comparable on the internet or within some of larger commercial sim aircraft suppliers (Iā€™ve collaborated on commercial gliders particularly the flight model). This is something of a niche but it does require really effective tools because modern glider performance is so ā€˜extremeā€™ in efficiency compared to other sim aircraft.

I suppose the key tool is to produce a flight polar e.g. (this was developing a glider on X-Plane) - this is speed vs. compensated sink i.e the numbers from which you would derive L/D (which is by far the dominant parameter glider pilots care about):

So given the tool you do see directly any quirky flap behaviour (not on the chart above, that is during development) and it was worth looking at existing planes to see what the hell their flaps were doing and that showed the behaviour I describe above (that you disagree with, I think).

Iā€™ve worked on X-Plane more recently, but IMHO the glider development for FSX peaked with the ASH25 (Iā€™ve worked on quite a few gliders before and since) which under the hood has fly-by-wire corrections to tweak the flight model so the flaps are modelled correctly.

So I apologise again for seeming impolite - your brief comments donā€™t match my measurements of FSX and X-Plane aircraft and I donā€™t think anyone has looked into the specifics of sim aircraft L/D at the level of detail I have, including Microsoft and Laminar - itā€™s understandable because there are a thousand things more important in a flight sim for most users. Iā€™m being specific here and differentiating between a given aircraft implementation (e.g. the stock glider in FSX) and the capabilities of the flight model in FSX and XPlane (which are very different, that would be a whole other thread).

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I think the ridge lift in FS2020 is going to be ā€œokā€ - the strength might be a bit off and the current ā€˜gustā€™ settings mess it up, but the basics seem to be there and you can detect the lift in a powered aircraft . How high above the ridge it goes, how much sink there is on the back of the ridge, are unknowns.

The ā€˜time lapseā€™ animation for the clouds is genuinely promising and I think Asobo really do mean to have upward air movement beneath the clouds there. Iā€™ve ā€˜glidā€™ a Cessna under those clouds to try and work out if the vertical movement approximates something realistic and thereā€™s definitely something there but itā€™s difficult to work out how far below the cloud the rising air extends. Also the clouds I experimented with all had relatively ill-defined bottoms. Real soaring cumulus have really well defined bottoms and the ones with good thermals actually dish up from underneath, so you have a good idea where the lift it. These arenā€™t a criticism but comments about the difficulty of testing.

I reckon Asobo have got the right ideas for both ridge lift and thermals, and theyā€™re certain to tweak the atmosphere engine when they start developing a glider and it all becomes pretty obvious whatā€™s not good then. The ridge lift is a safe bet so we can survive a less good implementation of thermals at the beginning.

Iā€™m most concerned about the ā€˜gustā€™ model for the wind. Powered planes arenā€™t affected much (even those are being tossed around) but I know from experience how much bad gusts interfere with soaring (a 10 knot gust on the nose of an aircraft is like a very rapid injection of energy (makes sense, no?) and this is exactly what the glider instruments are measuring so the instruments just peg all the time. If someone knows how to turn the gusts to zero that would be a fix (the UI seems to require gusts of at least 50% of the wind speed, but Iā€™m not sure).

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I am a glider instructor CFI-G if any company would like my input ā€¦ I have thousands of hours soaring of all types

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