I too believe that it was useful. Regarding the issue with people who don´t read, that could be fixed by filling the blank boxes with lighter grey text like this same page does in the search box (Search...). For the Callsign box I don´t have a suggestion text (could be "Enter Callsing..."?) but for the Type code box "Search..." will do fine. Once we click there text goes away, I believe this is very intuitive cause is used in several online forms.