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-4E, including new Pratt & Whitney J52-P-6A engine with 8,400 lbf (37 kN)) of thrust, strengthened airframe with two more weapon pylons (for a total of five), improved avionics, with TACAN, Doppler navigation radar, radar altimeter, toss-bombing computer, and AJB-3A low-altitude bombing system. Many later upgraded with J52-P-8 engine with 9,300 lbf (41 kN) thrust;499 built.