Numerous military versions were operated by the United States Navy and United States Air Force as transports and AWACS platforms. The WV-1 Navy version was used during the Cold War with picket ships on the DEW (Distant Early Warning) lines, one east and one west. These lines were to give early warning of an attack by the USSR. The east line was from Halifax, NS to the Canary Islands and back. The west line was from Hawaii to Midway Island then up to the Aleutians and back. The flights would last up to 14 hours or more. These aircraft served in the Vietnam War in several roles, including transmitting television programs from the United States for the troops on the ground, and observing the Ho Chi Minh Trail. One of them was shot down by North Korean aircraft in 1969.