While cost, access, engineering, and construction concerns are important, the most critical evaluation factors for siting an airport include airspace and aviation requirements, and especially environmental impacts related to aircraft operations.

The single most important factor in siting an airport is Obstacle-Free Airspace and Terrain, which falls under the broader category of "Aeronautical Suitability." While economic impact, land cost, and proximity to city centers are critical, they are secondary to the physical safety and operational requirements of aircraft. An airport must have a vast, flat area that allows for long runways and, more importantly, clear "approach and departure paths" that are free from mountains, tall buildings, or radio towers. Wind patterns are also a vital subset of this; runways must be oriented to align with prevailing winds to facilitate safe takeoffs and landings. Additionally, the soil composition must be stable enough to support the massive weight of concrete runways and heavy aircraft. If a site doesn't meet the strict FAA or ICAO standards for "safe climb-out" or "approach slope," it cannot function as a commercial airport regardless of how convenient the location is. Environmental factors, such as bird strike risks and noise pollution impact on nearby residential areas, are the next major hurdles after basic aeronautical safety is confirmed.