TRB's Airport Cooperative Research Program (ACRP) Synthesis 74: Combining Mixed-Use Flight Operations Safely at Airports documents practices in safely accommodating mixed-use aeronautical activity at airports. Mixed-use aeronautical activity refers to the different categories of aircraft a public-use airport is intended to accommodate in compliance with FAA sponsor assurances. These categories include gliders, helicopters, ultralight vehicles, balloons, airships, blimps, skydiving, aerial applications for agriculture and firefighting, banner towing, aerobatic practice, and similar flight operations. Also discussed are unmanned aircraft systems and radio-controlled model aircraft activity that take place on an airport and can become part of the mix of an airport’s operation. Not discussed are seaplane operations; ACRP Synthesis 61: Practices in Preserving and Developing Public-Use Seaplane Bases covers this topic.