The AirField is needed to build Air Crafts. Once you have built both the Hanger and the Runway you can then construct Aircraft at the weapons Facility once you have researched them. The Build Plot for the AirField is located in the top near to the left of the SkyScrapers. The AirField gives you 650 points. The AirField costs $500,000 to build and has a construction time of 5 hours and 6 seconds
The Hanger is part of the AirField but it is built once the AirField is Constructed. It is needed for the Construction of Air Crafts. Only One Hanger can be built. The Hanger gives you 700 points. The Hanger costs $600,000 and has a construction time of 3 hours 25 minutes and 14 seconds.
The Runway is also part of the AirField and it is also needed before you can begin to construct Air Craft. Only one Runway can be built. The Runway gives you 720 points. The Runway costs $650,000 and has a construction time of 3 hours 25 minutes and 14 seconds.