question

Well spotted Alexis !

Let's see what they say...

Hey,

I don't know if that helps, but in the Flight Model Physics page, there is a mention about the axes and referentials used by MSFS.

Here is a screenshot that might answer your question:

It's a bit confusing since, from the original MS FS SDK documentation one can get the following:

Axis

Longitudinal X Positive Forward

Lateral Y Positive to the Right

Vertical Z Positive Down i9n FS9/X

which agrees with the8old conventional Ixx, Iyy, Izz notation and moments...

Here's an interesting (old) post by Tom Goodrick on MOI estimates for MFS aicraft:

Calculating MOI's | BGA Forums (proboards.com)

where Tom advocates that in general and for most aircraft designs roll moi < pitch moi < yaw moi

The above example shows that the relation is not valid for that model, but I really don't know if it can be justified. Anyway the yaw moi is lower...

Thank you all for the very good insights on the subject!

This page on the SDK saying MSFS doesn't follow the usual convention might explain why there are all swapped. I wonder if that was the case also in previous FSs, or something that was implemented in Asobo's Hands.

Very good Link Jose! For sure, Yaw is always bigger on all planes I have seen so far. Disregard my first example, as that 60.000 in Pitch MOI is just me trying to break the system :D