Gunship version of the Huey helicopter
It was nothing but a standard Huey equipped with some extra weapons (heavy machine guns, rockets, etc.). The heavier weight reduced the infantry-carry capabilities of the helicopter, and made him less agile overall.
After the end of the war the Huey was upgraded with two engines instead of one, becoming more reliable in any situation, but during the war it was easily influenced by the weight-load, altitude and bad weather. Only the most skilled pilots could use it to it's full capabilities