Airship «ZIP» is a mod that basically adds an NPC-controlled airship. The mod is quite fun, it is only in Los Santos near the big buildings and flies in circles. You can take this airship yourself and control it — you need to come to the San Fierro airport.
Disadvantages: It replaces the Beagle airship. If it is destroyed or stolen from an NPC there is a good chance that the mod will crash. Another thing is that if you die the first time in the game, an airship may appear in the streets. Sometimes the blimp collides with the tallest tower in Los Santos, regardless, the mod is a lot of fun and gives a realistic feel to the game.