De or het aeronautica?

The correct Dutch article is:

de aeronautica

Rule Words ending in -ica: usually de. See the rule
Meaning (Dutch) (luchtvaart) theorie van de luchtvaart

How to use aeronautica

the aeronauticade aeronautica
this aeronauticadeze aeronautica
that aeronauticadie aeronautica
our aeronauticaonze aeronautica
your aeronauticajouw aeronautica
every aeronauticaelke aeronautica
which aeronautica?welke aeronautica?
a big aeronautica / the big aeronauticaeen grote aeronautica, de grote aeronautica

Meaning, plural, diminutive, pronunciation and translations: WikiWoordenboek (Dutch Wiktionary) (CC BY-SA 4.0). Example sentences: Tatoeba (CC BY 2.0 FR).