What is Airside and landside utilities?
Airside and landside utilities are the power, water, cooling, heating, wastewater and fuel networks serving an airport, divided by the security boundary between the aircraft side and the public side.
What sits on each side
Airside covers aprons, stands, airfield lighting, hangars, fuel farms and the post-security half of the terminal. Landside covers ticketing halls, curbs, parking structures, rental car facilities and offices. A single feeder or water main often crosses the boundary, so a fault on the apron may have to be traced back to a substation or pump house landside, and the repair crew still needs airside access.
How federal security rules define the boundary
At US airports the line comes from TSA rules. Under 49 CFR 1540.5, the air operations area includes aircraft movement areas, aircraft parking areas, loading ramps and safety areas. The sterile area is the part of the airport where passengers reach their aircraft after screening, and the secured area is where airlines enplane and deplane passengers and sort and load baggage. Each airport's security program maps these zones, and maintenance inside them follows that program's access rules.
Both sides in one Aqueduct model
aQ Core places every meter in a site, zone and device hierarchy, so an apron feeder and the landside substation that supplies it sit in the same model. aQ WaterGuard compares main supply with metered branches on both sides of the line, and Billing Management splits shared meters among concessions, airlines and rental car operators by measured share.