Section 398.3 - Specific airports(a) At an eligible place, essential air service may be specified as service to a particular airport. In the case of hyphenated places, essential air service will be specified as service to more than one airport only if clearly necessary and if the multi-airport service is economically feasible and justified on the basis of traffic levels at those airports.(b) At a hub, essential air service is not usually specified as service to a particular airport.