Would "Ich brauche ein Taxi in den Flughafen" be correct?
English is very general...."I need a taxi to the airport." and "I need a taxi to get to the airport" mean the same thing! Don't mark us off for you lack of knowledge!
They just try to make you stick as close to the original sentence as possible.
I need a taxi to get to the airport would translate to "Ich brauche ein Taxi um zum Flughafen zu kommen."