Minutemen vs Vertibird

So, in anticipation of defending the Castle from a significant Institute attack, the Minutemen called in almost all of their recruits as backup with myself included. A group of them had garrisoned themselves on top of one of the walls and I decided to join them. During the calm before the storm, I noticed a Vertibird attacking something on the ground though I did not see what exactly. As I’m no fan of the Brotherhood, I decided to do some target practice on it.