Thanks, very cool

@Cmdr. Mallard: Yes they can! It's pretty simple - drag a Petrel onto a land unit and it will fly to pick it up. You'll know you've sent the command properly when a Hook symbol appears above the ground vehicle.
When offloading ground vehicles, keep in mind that the default altitude is 400 meters. I like to have my Petrels approach and depart at 150m, give or take 50m depending on the terrain and tree cover so they don't spend forever climbing or descending. Petrels can get caught in trees or even collide with terrain; I've lost more Petrels to airlift-related accidents than I have in combat.

Still, Petrels carrying ground vehicles lets you launch an air assault on an island if you can open a landing zone. I've captured islands 20-30km away by sending a flight of Mantas out to perform OCA (offensive counter-air) and anti-surface missions, then dropping a platoon of Bears to clean up.

Wait wha! Can they lift units?