Table 3. Airport category USA 2

법적정의	기준
Commercial service	Publicly owned airports with at least 2,500 annual enplanements and scheduled air carrier service (§47102(7)). Primary airports are a commercial service airport with more than 10,000 annual enplanements (§47102(16).
Large hub	Receives 1 percent or more of the annual.U.S. commercial nplanements.
Medium hub	Receives 0.25 to 1.0 percent of the annual.U.S. commercial nplanements.
Small hub	Receives 0.05 to 0.25 percent of the annual.U.S. commercial enplanements.
Non hub	Receives less than 0.05 percent but more than 10,000 of the annual U.S. commercial enplanements.

상기 HUB공항의 정의는 모두 Primary 공항을 기준으로 함.