A big focus for flight sims and combat flight sims in particular is the flight model and so the latest IL2 Korea “Brief Room” episode is focused on the flight model. There’s also a tiny bit of a tidbit about what the next project is at the end. Here’s a summary.

A Q&A summary

The first part of the video covers a bit of background information how they make the flight models for aircraft.

In short, they take some basic data like mass inertia characteristics. Then they begin to break the aircraft down into smaller pieces such as the wing profile. After all of that is done, they begin to refine the aircraft performance based on real world data and their simulated values.

One of the questions they answered was concerns about flap effectiveness in Great Battles. Sometimes dropping flaps appears to provide too much extra lift. Here’s the response:

What do we think about this? Yes, I agree there is such a concern. How do we approach this? First of all, we have the aerodynamic atlases that show how much lift and drag the flaps are supposed to add. I have run into situations where it feels like an aircraft is flying too well with the flaps extended, but then you look at the atlas again and it turns out that the drag in the simulation is already more than it should be, according to this data.

Because real world data for aircraft in all situations is not always available they sometimes have to fall back on what they call “general aerodynamic approaches” and “general correlations.” I think that’s to say that they make an educated guess using physics calculations and data that they do have to infer the scenarios that they don’t have hard data for. I suspect this is the case for most or all aircraft developers in flight sims.

The discussion turned to older sims including IL-2 1946 which had a far more limited series of calculations which they say could be written down on the back of a napkin. Data points were limited to just a few points (one on each wing for example). They also reference DCS’ predecessor, Lock On: Modern Air Combat which had a similar system in place. They say its actually a pretty good way to do flight models if you have a lot of real world data but it doesn’t do so well with damage effects where things become a little more complicated. They share this interesting anecdote.

By the way, I’ve managed to find some studies that evaluate the effect of holes in the wing on aerodynamics. Well, obviously it gets worse overall, but there were also some funny moments. For example, in very rare cases, a through-hole in the wing resulted in an increase in the critical angle of attack. The hole started to act like a leading edge slat due to the airflow mix.

They go through some other discussions about flight models and multiplayer calculations. They also answer a question about G force modeling on pilots which they say they have no plans to change right now as the current model in Great Battles is the result of quite a bit of research into human responses to G-forces. Fair enough!

They are busy improving their engine simulation as well. Especially so for jets which are around half of the aircraft in Korea and just a handful in Great Battles. One of the questions asked was would compressor stalls be modeled which they answer is already in the sim. And I know that for a fact because I had quite a bit of fun causing compressor stalls in the Me262 when it came out. Great Battles is already doing quite a bit!

They say that the future modeling will enable different parts of the aircraft to know more about each other. Right now the fuselage isn’t affected by the wing and so situations where a stall might make an elevator less effective (because its in the disturbed air) have to be modeled in other ways.

They also report that their next project is “99% decided” to be a Pacific theatre simulation at the 38 minute mark.

Those are the things that stood out to me. If you watched the full Q&A, what stood out for you? Let me know in the comments!