cnn has been reporting from north korea for more than 25 years. the aircraft we're boarding today has been flying for 50. this an 24 is part of an aging fleet of soviet planes, operated by air corio, north korea's only airline. still flying despite sanctions with regular international flights to china and russia. our flight takes us 400 miles north of pyongyang to a place cnn has never been alowed before. as a western journalist, even setting foot here is extraordinary.