HMX-1 performed its first vertical envelopment from the deck of an aircraft carrier in an exercise in 1949. American forces later used helicopters for support and transport to great effect during the Korean War showing that the helicopter could be a versatile and powerful military tool. First helicopter air assaults The first helicopter airlift and helicopter sling load mission was conducted on September 13, 1951, during the Korean War. "Operation Windmill I" was conducted by the United States Marine Corps in support of a battalion clearing the enemy from a series of ridges around an extinct volcano called "The Punchbowl." In total seven HRS-1 Marine helicopters made 28 flights that delivered 8,550 kg (18,848 pounds) of supplies and evacuated 74 seriously wounded men. On November 5, 1956, the Royal Marines' 45 Commando performed the world's first combat helicopter insertion with air assault during an amphibious landing as part of Operation Musketeer, in Suez, Egypt. 650 marines and 23 tons of equipment were flown in ten Westland Whirlwind Mark 2s of 845 Naval Air Squadron from the deck of HMS Theseus, and six each Whirlwinds and Bristol Sycamore HC.12s and HC.14s off s embarked Joint Experimental Helicopter Unit (JEHU) (Royal Air Force). The plan was to use the helicopters to drop No. 45 Commando at Raswa, to the south of Port Said, in order to secure two vital bridges. Last-minute concerns about their vulnerability to ground fire meant that they were replaced in this role by French paratroops who conducted a daring low-level drop on 5 November, securing one of the two bridges intact. Instead No. 45 Commando was landed the following day, disembarking close to the seafront in the aftermath of the seaborne landing that had secured the area. This first-ever operational use of helicopters to land troops during an amphibious assault proved successful. With their carriers lying nine miles offshore, the marines were landed far more quickly than could have been achieved using landing craft, and without the need to get their boots wet. However ... they landed the marines in much the same place that old style landing craft would have put them. In 1956, the United States Marine Corps executed the first Division-strength exercise of vertical envelopment when the 1st Marine Division was helicopter-lifted from converted WWII jeep carriers to landing sites at Camp Pendleton, CA, U.S. Marine Corps Base. One of the ships utilized for this