Excerpts from the FAA Airport Compliance Manual

Here is the entire Compliance Manual from which the excerpts below were taken.  The manual is the "mother-lode" of the FAA regulations at public airports for ultralights their relationship with general aviation aircraft.

8.8. Exclusive Rights Violations.

a. Restrictions Based on Safety and Efficiency. An airport sponsor can deny an individual or
prospective aeronautical service provider the right to engage in an on-airport aeronautical
activity for reasons of safety and efficiency if the kind of activity (e.g., skydiving, sailplanes,
ultralights) would adversely impact the safety and efficiency of another aeronautical activity at
the airport, typically fixed-wing operations. An aeronautical operator holding an FAA certificate
is presumed to be a safe operator, and the airport sponsor may not deny access to an individual
certificated operator on the basis of safety of its aeronautical operations. Any safety concerns
with an operator would need to be brought to the attention of the FAA. However, the airport
sponsor may find that an aeronautical activity as a whole is inconsistent with the safety and
efficiency of the airport and may, therefore, not permit that activity at all, subject to concurrence
by the FAA. The airport sponsor may also prohibit access by an individual or individual service
provider that has not complied with the airport’s minimum standards or operations rules for safe
use of airport property.

Any denial based on safety must be based on reasonable evidence demonstrating that airport
safety will be compromised if the applicant or individual is allowed to engage in the proposed
aeronautical activity. Airport sponsors should carefully consider the safety reasons for denying
an aeronautical service provider or individual the opportunity to engage in an aeronautical
activity if the denial has the possible effect of limiting competition or access.
The FAA is the final authority in determining what, in fact, constitutes a compromise of safety.
As such, an airport sponsor that is contemplating the denial of a proposed on-airport aeronautical
activity or access is encouraged to contact the local ADO or regional airports division. Those
offices will then seek assistance from FAA Flight Standards (FS) and Air Traffic (AT) to assess
the reasonableness of the proposed action because of safety and efficiency, and to determine
whether unjust discrimination or an exclusive rights violation results from the proposed
restrictions.

Safety concerns are not limited to aeronautical activities but may include Occupational Safety
and Health Administration (OSHA) standards, fire safety standards, building codes, or sanitation
considerations. Restrictions on aeronautical operators by airport sponsors for safety must be
reasonable. Examples of reasonable restrictions include, but are not limited to: (1) restrictions
placed on the handling of aviation fuel and other flammable products, including aircraft paint
and thinners; (2) requirements to keep fire lanes open; and (3) weight limitations placed on
vehicles and aircraft to protect pavement from damage.22 (See Chapter 14 of this Order,
Restrictions Based on Safety and Efficiency Procedures and Organization.)