I've opened up routes to both Frankfurt (EDDF) and Schipol (EHAM) at the moment I am using DC-8-55 aircraft.
Are these particularly suited to this sort of work or should I look at something else? I'm getting around 40% load factor after running the routes for about two weeks, with the flights overall making a loss.
DC-8 aren't good anymore, they consume way too much fuel for less pax.
You could go for DC-10 or, maybe better for your airport, Boeing 767 as longhaul aircraft.
A330, 777 etc. are too big for your airport.