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[Boufogre]

To be honest, comparing professional simulators and MSFS makes absolutely no sense at all.

However, one does not need to dig very deep to find problems with the MSFS flight model in its current state:

• Incorrect simulation of wing sweep: changing the wing sweep will change MAC position as follows: a positive sweep will move the MAC forward and conversely, completely changing the balance of the aircraft. There is no way to set a distinct and fixed MAC position and dimension for weight and balance purposes.

• Incorrect simulation of leading edge flaps: they currently act as trailing edge flaps.

• Absence of propeller drag when engine is failed, absence of propeller feathering simulation.

And the list goes on…:

Summary of missing items in MSFS, important to realistically simulate flight

The simulator looks fantastic but it is still lacks functionality and has some flaws which prevents it from being a realistic flight simulator. Although somewhat more true for the IFR pilots compared to the VFR pilots amongst us. Just as many others I’m also addicted to the nice visuals MSFS has to offer which makes it difficult to move back to other platforms. I just wished the rest of the sim was as big of a leap forward as the graphics. Apart from the many positive effects of having such a b…

It would be unreasonable to expect a 100% exact flight model for all the various planes that MSFS has to offer. But it doesn’t mean that there are not problems to be solved.

I’m currently investigating the default 747-8 and here is what I’ve discovered so far:

• the drag problem associated with flaps beyond 5 is due to a wrong animation of the LE flaps. If you want to remember, when MSFS was released, the LE flaps were deployed incorrectly, following this sequence: UP, 1°, 5°, 10°, 20°, 25°, 30° when IRL they fully extend when flaps 1 are selected. In order to fix this problem, the devs have changed the values in the flight_model config file to 21° for all LE flaps settings. Unfortunately, this “fix” for the animation of the 3D model introduced the drag bug which sees full lift and drag applied from flaps 5 and beyond. At the moment, there is no difference in the flight model between flaps 5 and flaps 30 in the default 747-8. To fix the drag problem, just return the values back to 0, 1, 5, 10, 20, 25, 30 in the config file, with the animation returning to wrong as a drawback.

• the fuselage length of the 3D model is the one of the 747-400, not of a 747-8. It is missing 6 meters in length. I discovered that while trying to solve the mass and balance problems. I went to change the Datum reference to the one of the TCDS, trying to position the MAC correctly when I noticed that the fuselage orange box was longer than the 3D model. In the config file, the length was correct, 250 ft. By intuition, I changed it to the 747-400 fuselage length of 232 ft, and it now matches the 3D model.

• to be continued?

I understand if the devs want to keep the control over the flight model. But they need to improve it and fix it so that developers don’t feel the need to use an external one.