I just noticed something in a recent Brotherhood playthrough.
When you first arrive on the Prydwen, after touring it you can have a conversation with Captain Kells. In it, if you ask if the Brotherhood has ever build airships before, he mentions that the West Coast Brotherhood had built some years ago but the records were sketchy and they were probably destroyed.
Now the only other reference to the Brotherhood building airships comes from the start of Fallout Tactics. In it, the BoS has a schism over their policy of isolationism vs expansion and recruiting from outside. The recruiting/expansionist faction builds some airships and leaves California in order to hunt down the fleeing remains of the Master's Super Mutant army. While passing over the Rocky Mountains, they hit a storm and the Airships crashed. So in that game you play as the survivors of the crash.
So is Kells mentioning that failed expedition off-hand? It's interesting as that brings up the question: is Vault Zero now canon as a result.
Personally, I hope so.