Translation:In front of the big airport a red bus is waiting.
The course is still in beta and many fine, upstanding alternative translations are not in the system yet. You can help by reporting missing translations as you come across them and the program tells you that you are "wrong" because it didn't know your version yet. So please report such missing sentences from the exercise (not here in the discussion threads).
Fair point and thanks for the reminder. Great the Magyar Csapat (Hungarian Team) got this program off the ground. I usually do just that - point out what I think are acceptable alternate responses. I had a feeling I shouldn't be Duolingo-ing at 1:30 in the morning. Too easy for frustrations to creep in! Cheers, Max
I just failed with "a red bus is waiting in front of a big airplane"
Normally, though, it's not correct in English to say "by the airport waits a man" (for instance). I can't explain why, unfortunately, but compare with a sentence like "By the airport eats a man" <- it sort of sounds like "eats" belongs more to "the airport" than to "a man".
Are you saying that you tried your translation and it was not accepted? Then maybe you should use the ⛿Report function. Posting alternative solutions here in the learner discussion is not likely to change anything.
Your word order is also possible in Hungarian: Egy piros busz a nagy repülőtér előtt vár. I cannot say whether DL's sentence is clumsy in Hungarian, and I have to take your word that it's clumsy in English (though I think it would make a good introductory line for a novel).
Because egy piros busz előtt means "in front of a red bus".
A postposition such as előtt refers to the thing that stands in front of it.
A bit like how a preposition in English such as "by" or "in front of" refers to the thing that stands after it. You can't change "In front of the big airport a red bus is waiting" to "The big airport in front of a red bus is waiting" and keep the same meaning -- "in front of" has to be in front of (heh) the thing that it modifies and can't just stand anywhere in the sentence.
While I appreciate your frustration with what often seems like arbitrary word order (I myself often report suggestions for alternate translations) -- in this case, I don't believe that your translation is entirely correct. Just rearrange two words, and you get a perfectly fine sentence: " In front of the big airport, a red bus is waiting". [Instead of "... is waiting a red bus."]