There was an explosion and a good number of those heads were cut off, a silver Quinjet arcing through the air, with Captain America at the helm, shooting down one of the HYDRA helicopters. He circled round, firing off another set of rounds before passing off control to his co-pilot, parachuting from the jet to the deck of the helicarrier.
A red-white-and blue shield soared through the air, taking out HYDRA agents before arcing back to its owner in time for Cap to snatch it and smash it into someone's face.