context: The Douglas A-4 Skyhawk (English: Douglas A-4 Skyhawk; prior to 1962 had the A4D index) is an American lightweight deck attack aircraft developed in the first half of the 1950s by the Douglas Aircraft Company. Serially produced before the 1979 year, was in service with many countries of the world. Widely used in the Vietnam War, Arab-Israeli wars and other armed conflicts.
question: Until what year was the Douglas A-4 Skyhawk mass-produced?
answers.text: 1979