A question regarding best practices: How is the boundary of an airport defined? Is it only the parcels legally owned by the airport or does it include other associated features?
For reference, this question came about more or less because of an observation regarding the security fence surrounding an airport. This fence divides the public and restricted access (“airside”) areas of an airport. The latter can easily be defined as part of the airport, but the former is unclear:
For example, the parking lot for visitors may be on airport land, but outside of the fenced-in area.
In other cases, adjacent parcels may have aviation-related businesses (e.g. maintenance) not technically on airport property and/or outside of the fenced in area.
In still other situations, there are areas that are not officially part of the airport, but are maintained in such a way that they might be generally considered part of it. For instance, approach paths at the end of runways that must be kept clear of obstructions, but are on land physically separated by roads or other barriers.
I suggest ignoring ownership and focusing on what is directly related to airport-related activities. Car parking for customers for example isn’t really airport-specific business, but aircraft maintenance is.
Besides that I’d look at well-mapped airports in and near major cities for guidance, because consistency in our ways of mapping sometimes matters more than perceived correctness.
Taking land administration into consideration is fine, while it doesn’t have to be the only decisive factor. It is desirable to enclose carparks, ground transport connections, and other related facilities inside the =aerodrome to show they are related, possibly for routing. Being adjacent isn’t enough, as there can be untagged or other access=yes=parking outside. Airports can be very big, as far as long term carparks not being in walking distance.
The airside could have eg landuse=aeroway invented, similar to =railway and =highway . Otherwise, you can’t define and guarantee how all the =aerodrome in the world are drawn by others anyway. It will be to difficult to enforce and clean-up. Using something specific is better. This could be used on other aviation related facilities eg navigation and communication, as there is no landuse= equivalent of building=transportation .
For major airports, I map it as everything inside the security fence, plus strongly-associated features such as close-in parking. Mapping ownership can be problematic: Spokane International-owned land, for example, sprawls far beyond the airport proper, and includes a business park and some industrial areas.