Trying to figure out what the Project Zomboid helicopter does? When you first start playing Zomboid, every little growl means danger and every thump of an undead hand against a window makes your heart jump. Avoiding imminent death means paying a lot of attention to all the sounds around you, but you might not be sure which ones are worth worrying about. Those wolf howls in the forest, for example, aren't signs of an incoming canine attack.
The sound of helicopter blades is one you should be wary of, though. If you're caught unaware by a rogue helicopter you're about to be swarmed by more zombies than you want to handle. Plus, you'll never actually see a helicopter in Project Zomboid, so you'll be relying entirely on hearing it. When you do, here's what you'll want to know about how the helicopter event works.
What does the Project Zomboid helicopter do?
Essentially, the helicopter in Project Zomboid attracts zombies. So when you hear it, you'll want to be extra cautious. If you're outside and hear the helicopter blades in the distance, you'll likely hear them grow closer until they seem to be on top of your character and begin following you around the map.
The sound will stir up zombies in the area the way other loud noises do, causing them to wander more frequently and drawing them to your location. Even if you run inside, the helicopter will remain overhead, attracting the undead to your hiding spot.
If you've been spotted by a helicopter and are being followed, get yourself far away from any building you're using as a base so you don't draw zombies to your home. Unless you're extremely geared up and looking to fight a horde, that is.
In multiplayer, a helicopter may switch between following different players. The helicopter event will happen randomly between days six and nine of your save, so be particularly careful at the end of your first week.
How to avoid the helicopter
The helicopter is a random event, but you can get a heads up when it's going to happen. The automatic emergency broadcast station (AEBS) on the radio will announce "air activity detected" on a day when a helicopter is going to be out and roaming for players to torture. Of note, the AEBS is not on a fixed frequency across save games, so you'll either need to manually hunt the airwaves for it or find a radio that has it saved as a preset in your world.
To avoid being spotted and followed, you can stay inside or in a forest for the entire day. Once you've been seen, the helicopter will follow you to any attempted hiding spots. If it can't find you for around an hour, it may leave and come back later. Don't get too comfortable though. You aren't totally free from hovering doom until you've survived the entire day of the event.
By default, the helicopter event only occurs once in your world. If you'd like to never be bothered by it (or be challenged by it more often) you can create a custom sandbox world and find the options to change helicopter event frequency in the rightly named "Sadistic AI Director" section.