This Sub-class includes the provision of other supporting services for air transportation that are not elsewhere classified.
•air traffic control services •aircraft inspection services •aircraft testing services
•wholesaling fuel at airports, see 4661 •branches of foreign airlines, see 51003, 51004 •representative offices of foreign airlines, see 52231 •airline agencies (freight), see 52232 •airport operation services, see 52233 •airport terminal services (e.g. ground service activities), see 52234 •cargo handling, see 52243 •airline food catering services, see 56200 •cleaning of airports, see 81211 •operation of flying schools, see 85406