United Air Lines Douglas DC-8-12 N8004U on the occasion of it's delivery in May 1959. N8004U was just the eighth airframe off the Douglas line in November 1958 as a DC-8-11 with Pratt & Whitney JT3C-6 engines. It was modified after testing, to the delivered version, a DC-8-12 that included leading edge slots. N8004U was later modified to become a DC-8-21 in February 1964 with the addition of Pratt & Whitney JT4A-3 engines. (Image: Douglas Aircraft Company)
