I just found a new font for flightgear.
My there is a licenses[1] problem the site say only about the "Eclipse Public License"
but the projcet page say about this 3 license:
Eclipse Distribution License 1.0 (BSD)
Eclipse Public License 1.0
SIL Open Font License 1.1
[1] http://b612-font.com/
[2] https://www.polarsys.org/projects/polarsys.b612
edit: i have contact polarsys project about the license issue
edit2: i contact one of the contribute of this project.