Anatoli-Kagari9

Yo-Yo, thank you for the confirmation !

Professional Flight Model appears to be the highest in the rank of detail and accuracy when it comes to flight modeling in DCS World. I wonder if ground effect is modelled at a single reference point for the whole aircraft or if destinction is made between, for instance, wings and the tail surfaces ? When during landing, right above the runway and bellow one wingspan of height the ground effect starts increasing, does DCS PFM take into consideration the peculiarities due to it's effects over the main wings and the stabilizers / elevators, expressing itself also as a pitching moment ?

If we set the weather in the weather menu in the Mission Planner and then select a Weather Preset they can be perfectly out of sync. Would be great if it was possible to enable weather themes but let the sim choose the most adequate one when weather parameters like rain and storminess are also set. Of course additional weather themes, with ruin and thunders, fog, etc... would have to become available.

In my test flights and on most youtubes we can observe that he inclinometer needles appears to move out of sync with the true conditions, as if it was in a rather dense medium... It's slow responding to turns and it actually looks like not correctly synced with the "physics" of those turns... Apparently the turn coordinator needle works acceptably though... Very evident on this video, if you monitor the inclinometer:

Just out of curiosity, I tried the Nimbus UH-1H, version 1.5, in XP11, and I noticed correct right anti-torque pedal being required in cruise.

BTW, both DCS and IL2 have the Channel maps, so, sooner or later they'll probably add to their assets the V1 an V2 rocket bombs, which would certainly benefit from a proper implementation of a curved Earth...

Some of the major advantages of modelling a geoid have already been mentioned in this thread. I would just like to add that I do believe it is not rocket science. Microsoft Flight Simulator ( since version 5 ), X-Plane, Flight Gear, Aerowinx PSX, ELITE IFT, etc... are all using geoid representations of the Earth, with the associated benefits regarding for instance navigation, wave propagation for detailled non-satellite communications and instruments like those used these days, etc... It's also important physics-wise in the flight dynamics. Check for instance how it is done in the latest encarnation of MFS: https://docs.flightsimulator.com/html/index.htm#t=Additional_Information%2FFlight_Model_Physics.htm under "Aircraft Attitude And Euler Angles" and "Referential Frames And Conventions"...

My two preferred air combat sims share a limitation: they use a flat representation of the Earth ! While this can be of somehow less importance to ww2 and other slow flying aircraft, modern fighter jets and their weapons are certainly impacted but the curvature, including, but not only, Coriolis effect. Wonder if ED has plans for a new generation of maps tha could use some sort of geoid model ?

Yes, for sure !

Yeh, I'm aware of that since many Moons :-) I just expect that basic stuff get's plausible as much as possible...

I wonder how "true to live" DCS's Mi-8 FDM really is :-( https://www.youtube.com/watch?v=ZhtVvHfS1Lg

Thx for your comments Ironhand, and, it makes sense for jet's regarding that weird effect that appears to "plague" only the props, where the aircraft initially goes opposite what it should, as you apply takeoff power. Say, you're on the P51D or the P47, you have a 30 kts wind from your left ( port side ) and you apply takeoff power... As your takeoff roll starts, these aircraft will actually want to head downwind ( to the right / downwind ) requiring even into wind rudder and away from wind aileron ! Only as you gain more speed and approach rotation will the expected weathervane effect come to play and the nose start pointing to the left.

Thx for the suggestion sLYFa ! Rotary wing are probably modelled differently ( ? )

Indeed a complex one, and I remember having discussed it with Yo-Yo along a big thread I started, maybe around 2017, on this very same subject. One day I found a nice article that looked like it described the effect ( the aircraft wanting to veer downwind side at initial takeoff power application under strong x-wind ) but that was about the only reference to it I ever found. OTOH, I do think that DCS ground physics are designed to soften the wind effects on ground at taxi speeds...

Also checked an old effect I once brought to discussion about the way the P51D reacted to x-wind during takeoff. Just noticed it's even worst in the P 47 D... Pick the takeoff quick mission and edit in the Mission Editor. Set a 90º x-wind at, say, 39 kts from either port or startboard. Save your mission "As" to give it a different name and not ovewrite the original one... Go flying... First you will start fro the Ramp because the aerodrome will be closed due to wind out of operational limits, yet you will be able to taxi to the runway, and not a big deal provided you don't taxi too fast. You don't have to worry about the x-wind during taxi at all ! Then as you lock your tailwheel for takeoff, and start the takeoff run, your aircraft will drift, and actually the nose will turn downwind instead of upwind due to weathervane ! This stops as you reach takeoff / rotation speed and then the aircraft starts to properly weathervane, as it should have right from the beginning I believe ( ? ) The justification given by the Devs is the deflected propwash hitting the downwind wing and tail surfaces creating a higher lift and associated induced drag, plus other effects over the tail, thus causing this initial "reverse weathervane" when takeoff power is applied and propwash is at it's maximal values... Very strange

zhukov032186, thx for your comments, and yes apart from the reduction due to drag effect near ground, I guess they further reduce the axial wind components for low speed taxi operations, maybe to simplify ( ? ) Would rather prefer to have it as an option, as well as more intense weather effects such as wind shear and turbulence. Maybe this will arrive after the new weather visuals.

I know that some time ago ground wind started being reported to a reference 30ft AGL ( ~10m AGL ) according to RL METAR data, but irrespective from this, and although I am aware the physics model applies a reduction due to friction as the aircraft approaches the surface, I find that even setting extreme winds and turbulence, that have as result the mission starting at the ramp due to excessive values, thruth is I am still able to taxi at low to moderate speeds without "feeling" any x-wind effects. It all comes to play during takeoff roll,, as speed crosses a given threshold, and then, all of a sudden, if there's an x-wind component it really kicks in. I get the idea that just as MFS / FS2020 now does, DCS nill any axial wind component up to a certain speed ( on ground ) to make taxinng only as difficult as the prp effects ( if using sucjh modules ) can make it ? Any one shares this thought ?

You're welcome! After all, I myself enjoy your youtube tutorials quite a LOT!

SPITFIRE SPEAKS: Spitfire Longitudinal Stability - YouTube

Came late to the thread, but regarding the original post I would just like to remind that when the aircraft loads in a quick takeoff mission it usually comes with elevator trim set to neutral, when it should actually be set to nose heavy for takeoff, the pointer around 3 o'clock ( neutral in that scale is above from there ).

Gunnar and SirJ, thx for your posts, All the Best ! ( from Portugal ... )

The videos and shots look astounding, but I wonder if: .) Multiple cloud layers will be possible; .) There will also be updates to the weather engine itself, allowing for more varieties of weather regimes, maybe even real world METAR / Model based weather ? Any news about these ?

@Lurker, I made sure I was bellow 30 kts, close to 0 kts... It did fall into int, but took some work Then you really can't get out unless you apply the proper procedure.

It had been a year since I last played with the UH-1H... so I rushed comparing how easily I could get it into and out of VRS using the wrong techniques... It surprised me that I need more than 3000fpm descending to get VRS ? Is it really that permissive IRL too ?

T16000 stick + hotas from an old broken x52 pro + Saitek rudder pro + ed tracker pro.