History
Development of the A4D-5, later redesignated the A-4E, began in February 1959 as a major follow-up improvement over the earlier A4D-2N (A-4C). The variant introduced a lighter and more efficient Pratt & Whitney J52-P-6A engine generating up to 8,500 pounds of thrust, along with a redesigned fuselage center section and revised air intake ducting. Airframe strength was increased, and two additional pylons were added, expanding the aircraft from three to five external hardpoints and significantly improving its ordnance-carrying capability.
The avionics suite was also modernized with upgraded navigation and bombing systems. To accommodate the AN/ASN-19A navigation computer, the nose section was lengthened by approximately fourteen inches compared to earlier Skyhawk variants.
On July 30, 1959, the US Navy ordered the conversion of two A4D-2N aircraft into the new A4D-5 configuration. Eventually, 498 aircraft would be produced. The first flight of the A4D-5 took place on July 12, 1961, and the aircraft officially became redesignated as the A-4E in September 1962 under the tri-service designation system.
The A-4E entered operational service with VA-23 at NAS Lemoore, California, in November 1962. In total, twenty-two squadrons would eventually operate the variant. Early-production A-4Es visually resembled the A-4C aside from the revised air intakes and extended nose. However, later operational modifications significantly changed the aircraft’s appearance and capability.
Many A-4Es were retrofitted with the distinctive dorsal avionics hump mounted between the rear of the canopy and the base of the vertical stabilizer. This compartment was introduced to provide additional space for defensive electronic warfare systems that could not fit within the compact original airframe. The hump commonly housed systems such as the ALQ-127 Defensive Electronic Countermeasures suite and the ALR-50 SAM alert and missile launch warning system.
During later service, many A-4Es also received the more powerful J52-P-8 engine, producing up to 9,300 pounds of thrust, improving overall performance. The original straight refueling probe was additionally replaced by the angled “cranked” probe as seen on the Skyhawk A-4M.
One A-4E, Bureau Number 152101, was converted into the prototype for the future Douglas A-4 Skyhawk A-4F variant, which standardized the avionics hump and incorporated many improvements that had gradually appeared during late A-4E production.
Following the Vietnam War, the A-4E gradually became surplus to US Navy requirements as newer A-4F and A-4M aircraft entered service. Surviving A-4Es were exported abroad to nations such as Israel and Indonesia, where they continued serving for many years afterward.
