Rust, the survival game where you start by banging a rock against a tree and then progress to crafting automatic weapons, has opened up a new mode of travel that lets you take to the skies: hot air balloons. You'll find them scattered around the map, and once they're fueled you can fly wherever the wind carries you. Balloons should hold about four or five passengers, making them the ideal way to soar above the defenses of a fort you'd like to raid.
But every Sherlock has his Moriarty, and you may find your balloon shot down thanks to the inclusion of surface-to-air missiles, which also arrived in the Rust update. You can purchase a deployable SAM site from scientist outposts for 500 scrap and once stocked with ammo it'll automatically target any nearby balloons.
Note: this includes your own balloon. SAMs aren't psychic. They just love killing balloons, so they'll shoot yours down too. So remember to either unload the SAM site before you launch, or just don't fly anywhere near your own fort.