A bird  was a service member's way of saying  aircraft,  often referring to a helicopter or chopper. This derogatory term referred to someone who service in rear areas away from the fighting and the danger.
It is a two-engine attack helicopter designed for close air support of ground forces against armoured targets, and for transport of personnel. It has a classic design with a five-bladed main rotor and a three-bladed anti-torque tail rotor.