Edfilho,
While I love Brasil dearly (there is no other place quite like it), I know she doen't have much of a Navy to speak of (I used to live in Barbacena, where they have an Airforce trainging facility, so I got an idea for what kind of jobs were available there... not too plentiful). So, jobs fixing Navy planes are a little rare in the old patria amada. However, in the U.S. armed forces there are a lot of foreign-born people fulfilling various roles. You would have to come to the U.S.A. and sign an allegiance to them over any other nation. I'm not trying to encourage you to leave Brasil. In fact, I'd encourage you to think twice before leaving it (there are jobs there that you could work on planes, you'd just need the right training). But, not being American born doesn't rule you out for working in the American armed services. Just wanted to let you know that this is an option that is still open.
Sphynx
By the way...
Vive Brasil!
Minha terra tem palmeiras...