helicopter, project zomboid, dynamic event, random timing, survival game, zombie apocalypse, player character, intense moment, seeking shelter, noise attraction, undead horde, in-game days, unpredictable schedule, gameplay mechanic, tension increase, emergency broadcast, player strategy, rooftop landing, aerial vehicle, detailed model, realistic sound effects, immersive atmosphere, 3/4 view, overcast sky, post-apocalyptic environment, action sequence, high-stakes gameplay, survival challenge, resource management.