Airports are the main structures that your planes fly from. Each airport is tied to a particular city and can be advertised and upgraded to enhance business in that city.
The size of a city impacts the airport build cost, the number of jobs that will be available when the jobs list refreshes, and the number of people or cargo units that can be in layover at any time at an airport. City sizes range from 0.0M to 10.0M people.
The general formula for build cost is , where the population is in millions.
Airport Size & Upgrades
Airports are divided into three sizes based on the population of the underlying city. In the "Airport Info" screen these are referred to as "Class 1", "Class 2", and "Class 3". The Class of an airport indictates what planes can fly into it. A Class 1 airport () will only allow Class 1 airplanes to land. A Class 2 () airport allows Class 1 and Class 2 planes to land, and Class 3 () airports allow all planes to land. You cannot change an airport's Class.
|Class 1 Airport||Class 2 Airport||Class 3 Airport|
|Class 1 Plane||✓||✓||✓|
|Class 2 Plane||✗||✓||✓|
|Class 3 Plane||✗||✗||✓|
Airports can be upgraded to add more jobs & layover slots for a certain cost. All airports start at "Upgrade 1" and can be upgraded further using coins. Upgrading an airport will not change the airport's Class.
Airports can be advertised for a certian cost to increase demand in that city for 8 hours. This will, of course, bring more people to that airport.
Airport Lists by Region
There are 3 main formulae for airports: Opening Cost, Upgrade Cost, and Closing Value. (NB: In game, populations are given in millions to 2 decimal places, whereas the formula requires the 3 decimal places)
Opening cost = (population x 5,000) + 1,000
For example: San Diego (pop = 3.095 million) opening cost = 16,475
Upgrade cost = (opening cost x next airport level)
For example: to upgrade San Diego to level 2 = 16,475 x 2 = 32,950
Closing value = (opening cost / 2) x (airport level x (airport level + 1) / 2)
For example: San Diego level 3 = (16,475 / 2) x (3 x (3 + 1) / 2) = 8,237.5 x (3 x 4 / 2) = 8,237.5 x 6 = 49,425
NB: The (airport level x (airport level + 1) / 2) part is the formula for working out the triangular numbers. Multiply that by half of the opening cost, and you have the closing value
The closing value calculation comes out to half of the total you've spent on the airport: (Opening cost + Upgrades) / 2.
Example costs for San Diego:
Initial or Upgrade Cost