Airlines' theme is exactly as suggested by the title. The game is similar to the Sid Sackson classic, Acquire, in that players are competing to become majority stockholders in several highly-abstracted companies' with the player owning the most valuable portfolio at the end being the winner.
Each turn, a player chooses from one of two actions: expand an airline and put stock into his hand, or play stock from his hand. Expanding an airline adds to its route(s) on the board and increases it's value but the trick is that when a scoring card shows up (randomly), only played stock counts as a player's holdings.
This is a further editing & organizing of the English Airlines rules based on the rewrite by BGG user oudknoei. I have also added back in an edited version of the game summary from the original rules, which can also be used as a player aid.
Airlines is a good game, but it's original English rules translation is a little awkward. This is my attempt to re-write the rules to make them easier to read and use.
Ref thread: http://www.boardgamegeek.com/thread/389411
x2fer improved on my work. Get the improved version here: http://boardgamegeek.com/filepage/118981/airlines-re-edited-english-rules-summary