Storm Eagle
The Storm Eagle Assault Gunship is the "middle brother" of Space Marine aerial transports, carrying twenty Marines as opposed to the Stormraven's twelve-plus-Dreadnought or the Thunderhawk's thirty. The Space Marines used loads of them during the Great Crusade, but the forge worlds that made them were destroyed during the Horus Heresy. This meant that the only Storm Eagles in use were those left over at the end of the Heresy, so you had to be from the First or Second Foundings to even have them and they were only seldom deployed, but those chapters who are friends of the Adeptus Mechanicus seem to be using theirs a lot more frequently, almost as if they're being made again...
It's a Forge World product, created to beef up the Space Marines' section of Imperial Armour Aeronautica (as if the Marines didn't have enough toys already), and to give some non-Apocalypse aerial transport to those Chapters that aren't Blood Angels or Grey Knights (including Chaos Space Marines). It also spots a twin-linked Heavy Bolter, an array of Missile Launchers and four Lascannons.