Galvatron’s ship is rather stupid. Observe:
 |
 |
Galvatron is currently speaking to Cyclonus on the Bridge in the pictures above. Note that the air lock opens directly to space. Not really much of an airlock then, is it? Further, why do robotic beings that do not breathe need air at all, let alone an air lock?
If I were Unicron, I would have labeled this "air lock" as "EXIT" or simply "DOOR".