The a-4 skyhawk was designed by douglas in response to a u. S. Navy call for a jet-powered attack aircraft to replace the older a-1 skyraider.  douglas opted for a design that would minimize its size, weight, and complexity. The result was an aircraft that weighed only half of the navy's weight specification. It had a wing so compact that it did not need to be folded for carrier stowage

A-4m: dedicated marine version with improved avionics and more powerful j52-p-408a engine with 11,200 lbf (50 kn) thrust, enlarged cockpit, iff system. Later fitted with hughes an/asb-19 angle rate bombing system (arbs) with tv and laser spot tracker, 158 built.