I haven't studied in Germany but been living here for 3 years. German is a very difficult language and each state has a very strong accent (compared to high German), which makes things complicated.So try to get an English-only course, otherwise you will need several years to properly understand them.Unsure if Freiburg has an aerospace course, but it is a very nice city for foreign students who don't speak much German.
I'm going to have to disagree (conditionally) with the poster above. From their location, I guess they're Portuguese? Learning German from a Latin language can be tricky, I'd guess, but if you're already speaking English, or another Germanic language, it's not that tricky. True, you won't pass for a native for years (if ever), especially with the aforementioned regional accents, but you should be fine. I'd be surprised though if they don't offer English language programs. (Poster is fluent in English, Dutch and German)