Which helicopter was first used extensively by U.S. forces during Vietnam?

The Bell UH-1 Iroquois, commonly known as the "Huey," was the first helicopter to be used extensively by U.S. forces during the Vietnam War. This aircraft played a crucial role in various military operations, showcasing its versatility and reliability in combat scenarios.

The Huey was primarily designed as a utility helicopter and became synonymous with aerial troop transport, medical evacuation, and logistical support during the conflict. Its distinctive design, characterized by a two-blade rotor system and a prominent engine sound, made it easily recognizable and an iconic symbol of the Vietnam War. The helicopter's ability to operate in difficult terrain and carry out a variety of missions made it an essential asset for U.S. forces during this tumultuous period in military history.

While the other helicopters listed did have significant roles in military aviation, the Chinook and Cobra were introduced later and used for different missions, and the Black Hawk came into service well after the Vietnam War had ended. The unique contributions of the Huey during this specific conflict solidified its status as the first extensively utilized helicopter by U.S. forces in Vietnam.