Rotation and CoM

[Darnok]

Put two parts one as root and second radially (for example tank), rotate tank by 90deg and attach engine on bottom node.

Look at CoM it is going up and if you remove fuel from rotated tank CoM is going even further up.

[Darnok]

I turns out that it is not rotation gizmo issue just jet engines and rapier have broken CoM :/ It is far to high.

[sal_vager]

Actually the offset CoM for jets is intended, as the part you see is only the nozzle.

If the CoM was on the part it'd be at the back of this, which makes no sense.

[Darnok]

But that doesn't makes sense if we have both jet engines and intakes as separate parts. It would be ok if intake and jet engine would be single large part with CoM like you said.