Certainly not, always go for the correct spelling.
1: Extreme risk of people remembering the correct spelling as the URL, hence giving your traffic away to the person owning the right name.
2: You practically cut away all search engine benefits of owning the term (which you really don't) when its misspelled.
On a sidenote I always get annoyed that our national airport site is on maltairport dot com - to me that just reeks of lack of money, lack of professionalism, and inadequacy. That happens to be a spot on assessment of this airport but don't go down the same path.