Complex sentence: A general problem for Greenland is that only two airports, Kangerlussuaq and Narsarsuaq, can handle large passenger aircraft but very few passengers live within road connection from those airports and most must transfer to local flights.
Split into simpler sentences: A general problem for Greenland is that only two airports, Kangerlussuaq and Narsarsuaq, can handle typical airplanes. But very few passengers live within road connection from those airports and most must transfer to local flights.