The E-2 Hawkeye has been on active-duty service for six decades. Built by Northrup Grumman, the E-2 can operate in all-weather and from carrier decks, to provide tactical airborne early warning (AEW). Designed in the 1950s, the Hawkeye took its maiden flight in 1960 and entered service in 1964. And today, remarkably, the E-2 is still in production; the E-2 has remained in production since 1960, making the Hawkeye the longest-produced carrier-based aircraft ever.

Meet the E-2 Hawkeye

The E-2 was designed to replace the E-1 Tracer. And the E-2 was the first aircraft ever built from scratch specifically for airborne early warning. The airborne early warning aircraft that came before the E-2 was modified from existing aircraft, demonstrating that AEW was an afterthought.

The engines of the E-2 make a distinct humming sound, so naturally, the aircraft has earned the nickname “Hummer.” The E-2 and its humming engine are rather distinct on board a carrier, mostly populated with jet-engine-equipped aircraft like the F/A-18 and F-35.

While the E-2 has served steadily as a workhorse success story, the initial design process was troubled. For one, the US Navy demanded that their next AEW aircraft could integrate data with the Naval Tactical Data System found aboard Navy vessels. Then, the Navy demanded that the E-2 be able to land on aircraft carriers, which was especially difficult in the 1950s. In the 1950s, the US Navy operated some World War II-era carriers, like the Essex-class. The Essex was modified to allow for jet operations but was still relatively small. Accordingly, the E-2 had strict height, weight, and length restrictions to allow for landing on a smaller deck. Unfortunately, the sizing requirements resulted in poor handling. In the end, the E-2 never flew from the Essex-class – the hassle was for naught.

The finished product E-2 Hawkeye featured high wings and two Allison T56 turboprop engines. To land on carriers, the Hawkeye used a retractable tricycle landing gear and tail hook. The most distinctive feature of the E-2, however, is the 24-foot diameter rotating radar dome, known as a rotodome. The rotodome contains the E-2’s long-range radar and IFF system – basically, the equipment that allows the E-2 to perform the mission it was designed to perform. The E-2 is the only carrier-based airplane that features a rotodome. Typically, rotodome-equipped aircraft, the E-3 Sentry for example, are based on land.

To save space aboard the tightly confined aircraft carrier, the E-2 features a Sto-Wing, which folds to save space when the Hawkeye is not in use. When in use, the E-2 requires a five-person crew. Up front: a pilot and a co-pilot. In the back, below the rotodome: a combat information center office, air control officer, and radar operator.

Although the E-2 has enjoyed an enduring service history, the plane had problems when it first entered service in 1964. Most pressingly, the E-2 had an inadequate cooling system, which allowed the plane’s tightly packed avionics equipment to overheat. The entire fleet had to be grounded because the problem was so rampant. Several upgrades were made, especially with respect to on-board computer systems. The result was the E-2B variant, which naval aviators found was much more reliable. Gradually, the E-2 proved itself, situating itself as a fundamental piece of modern carrier air wings. Today, six decades after debuting, four E-2s are featured in each carrier air wing.

The US Navy is not the only military using the Hawkeye; the E-2 has been exported worldwide: Mexico, France, Taiwan, Egypt, and Japan all rely upon the E-2 for trustworthy airborne early warning.