Looks like the font the US Air Force uses for their planes' signifiers. Check out modeling sites (you know: plastic scale models) - I have seen it there (and it was free, Truetype).

If you are seeking a ( pretty similar ) 'free' font, you may want to take a closer look at 'DEV Gothic'..
www.dafont.com/en/search.php?nq=1&q=dev+gothic

Please note.: I am, still, not too sure, about how 'free', or legally 'free' ( like, say, ripping, hmm, or at least getting 'inspired' by commercial types ), those 'free' fonts at DaFont, really are..