As always it’s all about how the aircraft implementation takes advantage of and fully utilizes the sim’s core aerodynamics/physics engine. That’s why we had to wait until recently with all the great add-on aircraft to see what MSFS is really capable of in terms of flight dynamics. With all the coming improvements in SU10 and beyond, i.e. Seb spoke about using their CFD techniques to a larger 20 mile radius around the aircraft on enhancing atmospheric airflow simulation, going to be very interesting.
Useful insights on filght dynamics and flight models of aircraft w.r.t MSFS and XP from Matt Nischan of Working Title here: More Physics, More Real Winds - #256 by Bishop398
He also chimed in on this avsim thread with good info: MSFS has the most advanced flight model? - Page 12 - Microsoft Flight Simulator (2020) - The AVSIM Community
"Additionally, MSFS categorically does not use Blade Element Theory. Blade element theory is the idea that you can slice an airfoil up into cross sections, evaluate those cross sections, and then come up with a single lift and drag component for each cross section. XP does this slicing across the defined lifting surfaces to generate a limited number of lift points. It is relatively coarse and doesn’t generate different values across each individual surface cross-section, but nonetheless it is used to great effect and the work done with it is quite good, as I’ve said before.
MSFS also starts with a base geometrically defined lifting surface, but then goes a completely different direction and discretizes the lifting surface into a large number (comparatively) of grid samples. Each individual grid sample receives its own airflow simulation that gets input from the airflow model in true 3d space: i.e. the atmospheric model is also 3d and thus the air itself is not a just a single scalar contribution but instead a varying 3d contribution across each grid sample where the atmospheric model and grid intersect. This means that each grid sample on any lifting surface contributes its forces individually and is also affected by a 3d atmospheric model individually.
Whether or not one believes the current aircraft flight model configurations use this well or whether enough parameters are exposed, the base grid sampling of the MSFS flight model is of a much higher resolution and the atmospheric contribution in 3d is a consumer sim first (to my knowledge, anyway). It also has the benefit of generating different lift values across the surface from front to back, which can be critical value differences at the flight envelope edges.
Finally, the TBM was chosen because Daher (and the former SOCATA) is a French company and Asobo was able to develop an excellent working relationship with them. As well, this allowed great access to the real plane. I’m not sure anyone on the Asobo team is really super aware of the HotStart TBM for XP, if I’m being perfectly honest.
-Matt | Working Title"
And further insights from Matt, keep in mind this was last year so before Asobo introduced CFD, etc: MSFS has the most advanced flight model? - Page 13 - Microsoft Flight Simulator (2020) - The AVSIM Community
"Right now it uses a basic average airfoil for the base lift/drag contribution. The virtual wind tunnel process then uses the user supplied Cl/Cd to apply normalization scalars across each grid sample to get you to your desired target if the geometry alone is not getting you there. Often times you just don’t have the actual airfoil shape on hand anyway for a given aircraft (these can be closely guarded bits of info, especially for modern aircraft), so this gives a way to get one in the very close ballpark of those supplied values a bit more quickly rather than through a ton of airfoil and geometry trial and error.
The fuselage is currently a very coarse shape and as such contributes somewhat more coarsely than desired; however, it is also subject to the same normalization process and so needing super specific geometry is somewhat less necessary. That being said, Seb has talked about wanting to increase the resolution and potential shapes of the fuselage anyway to take away some of the guessing. However, the science of what exactly a fuselage contributes to lift and drag is dramatically less well defined (outside of CFD, in generalized formulae) than that of airfoil based lifting surfaces, so this is where any simulator using a geometry based technique will invariably require some degree of fudging the actual shape to get the desired effect. The virtual wind tunnel normalization is intended to reduce the number of iterations one requires during that tweaking process, since every single change to any of the geometry has follow on effects."