C-5 Galaxy cargo plane carries Chinook helicopters from U.S. to Australia

The delivery, from Dover Air Force Base, Del., to Royal Australian Air Force Base Townsville in northeastern Australia, was the first two of of four Boeing-built heavy lift helicopters and related equipment sold to the Australia's Defense Department in a $259 million deal announced in April.

A U.S. Defense Security Cooperation Agency announcement at the time said the sale "will improve Australia's capability to meet current and future threats, increase operational capabilities, strengthen its homeland defense and promote military cooperation."

The 9th Airlift Squadron at Dover Air Force Base delivered the helicopters in July, a U.S. Air Force statement on Monday said, adding that the helicopters would be used in the Australian Army.

The Chinook CH-47 can fly at speeds of over 175 mph with a payload of more than 21,000 pounds. Typically carrying underslung supplies and equipment, suspended from the aircraft as it travels, the helicopter is used in combat situations as well as in humanitarian deliveries during natural disasters.

When the helicopters arrived at the Australian air base, employees of Boeing Defense Australia worked with the U.S. Air Force's 436th Aerial Port Squadron to unfasten rotors and other components that were folded during the trip.

The Australian Army now has 12 Chinooks, many of which served in Afghanistan from 2006 to 2013 and also participated in wildfire containment during the Australian summer.