"James M. Knox" wrote in message
There are a number of different models used in the US. First off, let's
look at sources of income to the airport (excluding landing fees, which
VERY few airports in the US have):

o Fuel, oil sales
o Hangar rental
o Tiedown rental
o Building lease (to FBO's, maintenance facilities, etc.)
o Lease of overrun land (farming)
o Sale of pilot supplies, food, etc. (if direct)

Additionally, if the airport is open to the public, it is eligible for
public tax monies. This is the MAJOR source of support for most
airports, amounting to 90 to 95% or the total capital budget. This
money is basically a recognition of the fact that everyone in the area
benefits by having the airport, not just those who actually have an
airplane. [Similarly, everyone in the community pays school taxes, even
though they may not have children.]

[snip]

In addition to the capital budget typically being subsidized by both
federal and local governments, most small airports have their
operating budget subsidized by the local government (operating
expenses are not eligible for federal funds). Some GA airports are
self-sufficient on the operating side of things, but they are few and
far between. So, part of everyone's local tax dollars are going to the
local airport to support its operations.

This only applies to publicly-owned airports in the US. Private
airports, even if they are open to the public, are not eligible for
federal money and generally can't get state or local money.