real lion
Hold E to ressuply primary (non-rpg) ammo being near any jeep/apc/heli.
Slowly auto-fill health being inside.
If you're support with m249, you could shot from heli door until you have ammo, then just press ressuply to refill your gun being inside helicopter right on the fly.
If you get one rarely shot - health slowly refilled too. You still allowed to use bandage, but if no - health slowly restores without.
Optionally could be limited and needs resuply in order to repairing.