The first batch of Arleigh Burke class DDGs had a helipad but no hangar; they were intended to refuel and re arm other ship's helos within the battle group, and building a ship that size with no helipad made no sense. The first 21 ships (Flight I) and the next 7 (Flight II) have no hangar but all following ships (34 Flight IIA) have a double hangar for two SeaHawk helicopters. The Flight III ships will also have the double hangar.