"I am waiting for an airplane."

Translation: Czekam na samolot.

[AdamMlodoz]

why can't I say "Czekam dla samolotu"? Is 'na' just more commonly used in this case?

[mihxal]

"Dla" would mean that you do it for an airplane so it's not the same. You should use "czekać na" + Accusative.