My local airport (KAXH) conforms to the following, and employs directly about 4 people. There are 3 flight schools and about 3 maintenance setups on the field.
- published nav approaches so people can get home in bad weather, encouraging them to base aircraft there.
- at least one flightschool.
- maintenance.
- crew car to allow transient pilots local transport.
- weather, flight planning terminal
- free coffee
- cheapish fuel, at least locally competitive.
- hangar space for locally based aircraft.