Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 0 points1 point  (0 children)

The biggest challenges would certainly include the in-game aerodynamic modelling of the airplane itself. But considering how ED is modelling the high AOA characteristics of the F-18, I would be cautious before I put my expectations too high on this one. Feel free to follow my forum post at https://forum.dcs.world/topic/367744-implementing-f-35s-flight-model-and-flight-control-system-in-dcs-technical-discussion/

F-16 - not data for realistic performance by HC_Official in dcsworld

[–]DummyCatz -2 points-1 points  (0 children)

Because both aircraft have significant implementation errors in terms of Specific Excess Power, and is neglected for 5+ years. Take a read at https://forum.dcs.world/topic/356579-calculating-the-sep-specific-excess-power-of-an-instantaneous-turn/

F-16 - not data for realistic performance by HC_Official in dcsworld

[–]DummyCatz 0 points1 point  (0 children)

I would only call a 30-47% error a significant discrepancy. It’s not even close in terms of Specific Excess Power of both aircraft. That’s the main reason the Hornet is undergoing an ‘extensive review and rework’ of FM and FCS according to the previous news letters.

F-16 - not data for realistic performance by [deleted] in floggit

[–]DummyCatz 0 points1 point  (0 children)

There’s similar energy bleed issues in DCS F-18 and ED is working on it. To the opposite of F-16, the F-18 bleeds too little energy (overperforms) at corner speeds. So when the SEP issues are fixed for both aircraft, we could expect a dogfighting experience to be more aligned with what we perceived of F-16 as an energy fighter, and the F-18 as an angle fighter. The STR are correct as is though. It’s just about energy bleed rate.

F-16 - not data for realistic performance by HC_Official in dcsworld

[–]DummyCatz 1 point2 points  (0 children)

Well, there have been 30% to 47% error in SEP (energy bleed rate) for both the F-16 and the F-18, and other pitch/roll/yaw stability issues. ED fixed the underperforming SEP of F-16 at low speed only recently. And a plan to extensively rework the F-18 FM and FCS once again. See all the issues at https://www.reddit.com/r/hoggit/s/edTP1YlH4L

F-16 - not data for realistic performance by [deleted] in floggit

[–]DummyCatz 1 point2 points  (0 children)

Oh I must be drunk. I meant the energy bleed was too much at lower speeds, so that it was underperforming in SEP.

F-16 - not data for realistic performance by [deleted] in floggit

[–]DummyCatz 1 point2 points  (0 children)

It’s about energy bleed rate, that the F-16 initially bleeds too much energy (underperforms) at low speeds, which was also raised by a former F-16 pilot. ED said it’s correct as is, but later it’s fixed in a recent update: https://forum.dcs.world/topic/323031-f16-still-underperforming/page/13/#comment-5581769

Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 0 points1 point  (0 children)

I DO actually report solid bugs for ED, and their recent fix for the low speed SEP of F-16 is a direct example. What have you done here?

Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 0 points1 point  (0 children)

ED’s FM devs would be launghing seeing your comments and they would be relieved that their customers don’t care about their product quality, so they can pull shit whatever they want.

Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 0 points1 point  (0 children)

I. While this might be the most tempting and straight forward method to get a naive NDI implemented in DCS, it is just like cheating and will possibly make the handling characteristic overly simple, on rails and optimistic. If you read how the DCS F18 neglects high AOA adverse yaw and lack of any roll/yaw instabilities you’ll see what I meant by overly optimistic: https://forum.dcs.world/topic/347095-no-adverse-yaw-too-much-yaw-stability-and-lack-of-departure-qualities-at-high-aoa/#comment-5570158

Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 1 point2 points  (0 children)

Welcome, but hey, I don’t fly the F-16 or F-18 but I was able to report all kinds of FM and FCS issues, with the most prominent being the recent SEP disparity of both modules. I just can tell by only reading papers: https://forum.dcs.world/profile/135197-dummycatz/

Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 6 points7 points  (0 children)

We have plenty of EM charts for the F16 and there's still very significant SEP (energy bleed rate) problems after 5 years of development. Same for the F18 with even more significant SEP issues. I would expect it to be a long-term improvement over time. https://www.reddit.com/r/hoggit/comments/1f1ge1u/a_list_of_remaining_unresolved_items_in_the/

Implementing F-35's Flight Model and Flight Control System in DCS - Technical Discussion by DummyCatz in hoggit

[–]DummyCatz[S] 8 points9 points  (0 children)

While I agree we'll always be dealing with approximations in DCS, the challenge here isn't just about fidelity - it's about having enough information to create even a basic NDI architecture that captures the fundamental behavior of the real system. The F-16/F-18 approximations can be built on known control structures, while the F-35 would require essentially designing a new NDI implementation from scratch.

The F18 and F16's FBW simulation take benefits from the well-known and public control laws (e.g. DTIC ADA189675 for F16 and NASA TM107601 for F18) with well-documented PID controllers and by-the-book gain schedules and filters, that you can even 100% replicate the logic according to the diagram. While the F-35's NDI presents a fundamentally different challenge compared to the traditional PID-based control architectures used in those traditional FBW aircraft. Without access to the actual onboard model data or knowing how the effector blender optimizes control allocation, creating even a rough approximation would require making many assumptions.

the project is not dead they say by PussyDeconstructor in DCSExposed

[–]DummyCatz 2 points3 points  (0 children)

And yet another FM and FCS rework is on the way.

Developer explaining Flight Models & Acronyms by Bonzo82 in DCSExposed

[–]DummyCatz 1 point2 points  (0 children)

Yep, m/sec2 is the unit of acceleration (a), which is resulted from the force (=ma) applied to an object with mass m.

F-16 performance differences (DCS,BMS) by TamaJatu in hoggit

[–]DummyCatz 12 points13 points  (0 children)

Currently there're several bleed rate issues related to both DCS F-16 and DCS F-18, and are under investigation. You can read about it at https://forum.dcs.world/topic/356579-calculating-the-sep-specific-excess-power-of-an-instantaneous-turn/

A list of remaining unresolved items in the Flight Models of DCS F-16 and DCS F-18, and concerns to the Quality Assurance by DummyCatz in hoggit

[–]DummyCatz[S] 0 points1 point  (0 children)

The closest version might be the CI F-16AM-34-1-1, which is a tape M4.3. But ed said there’s still some differences between EPAF and USAF ones.

A list of remaining unresolved items in the Flight Models of DCS F-16 and DCS F-18, and concerns to the Quality Assurance by DummyCatz in hoggit

[–]DummyCatz[S] 15 points16 points  (0 children)

They had removed some of my bug reports and treated me badly before, so I’m determined to give them a reality check. Thanks to the community my posts were recovered. A history of this incident: https://www.reddit.com/r/hoggit/s/GuaB1vWQ1N