Here's What You Need to Know: The S-3 Viking was first conceived in 1960s to serve as a next-generation submarine hunter.

Eight years ago the U.S. Navy retired:

A) Its only dedicated carrier-based tanker;

B) its last dedicated carrier-based antisubmarine airplane;

C) a carrier-based plane with more than twice the range of its current jets;

D) all of the above.

With a maximum speed of only five hundred miles per hour—many airliners fly faster—the S-3 Viking wasn’t about to be the subject of any movies starring Tom Cruise. However, the long-legged jets proved extremely useful in a very wide variety of roles, whether as an electronic spy, submarine hunter, aerial tanker, cargo plane or even an attack jet. And many of those roles have not been satisfactorily replaced since.

The S-3 Viking was first conceived in 1960s to serve as a next-generation submarine hunter. In the event of a war between NATO and the Warsaw Pact, the U.S. Navy’s most important mission would have been combating the Soviet Union’s large submarine fleet. If the war went nuclear, Soviet ballistic-missile submarines could have wreaked terrible devastation on U.S. cities. And if the conflict remained conventional, then attack submarines would have done their best to sink convoys of American troop ships reinforcing NATO forces in Europe.

During World War II, carrier-based aircraft such as the TBF Avenger torpedo bomber played a major role in sinking Axis submarines. However, the diesel-electric submarines of that era needed to surface frequently to recharge their batteries, exposing themselves to air attack. By the late 1950s, the Soviet Union had begun to deploy its first nuclear submarines, which could remain submerged for weeks, and later months, at a time, and the current S-2 submarine hunters were no adequate for chasing them down.

Lockheed partnered with LTV—which had experience developing the carrier-based A-7 and F-8 jets—in producing a new antisubmarine plane with a sophisticated new design. The resulting twin turbofan jet seated a crew of four in a two-by-two configuration, including a pilot and copilot, a sensor operator and tactical coordinator. The long-legged plane had a range of 2,300 miles and came with an aerial refueling probe that could extend that even further—leading on one occasion to an S-3 flying thirteen hours from a carrier in the Mediterranean to Washington, DC, carrying a captured terrorist hijacker.

The plane’s twin TF-34-400 turbofans—an engine related to that on the A-10 attack plane—were infamous for their peculiar vacuum-cleaner-like whine, leading to the plane’s nickname of “Hoover,” which you can hear for yourself in the video below.

The Viking’s crew had access to a diverse array of sensors, starting with a APS-116 sea-search radar that could switch between a high-resolution mode for detecting submarine periscopes and a long-range mode that could extend up to 150 miles. A meters-long Magnetic Anomaly Detector boom could extend from the tail to scan the water for the metal in submarine hulls. The Viking also carried up to sixty sonar buoys to aid in tracking submarines, an infrared sensor and an ALR-47 ESM sensor that could track electromagnetic emitters. Most impressively, the Viking was one of the first U.S. planes to implement a degree of data fusion between the various sensors.

The Viking’s internal weapons bay and external wing pylons could carry a diverse array of weapons including homing torpedoes, CAPTOR antiship mines, Harpoon antiship missiles, unguided bombs, rocket pods and even nuclear gravity bombs.

The S-3A entered operational service in 1974 with VS-41, and soon each carrier had its own squadron of the antisubmarine planes. Though the U.S. Navy fortunately did not engage in any actual antisubmarine warfare in the subsequent decades, the records of S-3 squadrons suggest they might have proved pretty effective at their job. For example, in 1984 a Viking was the first NATO platform to detect a new class of Russian submarines, and in 1986, S-3s of VS-28 flying from the USS Independence detected submarines from eight different countries while on a cruise in the Mediterranean. Around that time the Navy began upgrading over a hundred Vikings to the S-3B model, which came with new APS-137 synthetic aperture radars with high enough resolution to identify ships by class.

Meanwhile, the U.S. Navy began assigning additional roles to the S-3 Viking. For example, taking advantage of the type’s large hull, six Vikings were modified into US-3A cargo planes modified to serve as special high-priority Carrier On-Deck Delivery planes, capable of carrying six passengers and up to four thousand pounds of cargo.

The Viking also took on a new role as an electronic spy, particularly with the sixteen modified ES-3 Sea Shadow aircraft that entered service in 1993. These signals-intelligence aircraft were capable of spying on enemy communications and determining the position of hostile transmitters so that friendly forces could target them. The Sea Shadows had a brief but eventful operational career, helping identify targets during the air wars over former Yugoslavia and enforcing the no-fly zone over Iraq before being retired from service in 1998 in favor of a replacement program that never materialized. There were also a half-dozen unique variants of the Viking, including “Aladdin” and “Beartrap” aircraft, engaged in intelligence missions that remain classified to this day.

Meanwhile, one of the Viking’s most important roles was serving as an aerial refueling tanker. After the Navy retired its KA-6 Intruder refueling planes in the mid-nineties, the S-3 remained the only carrier-based tanker plane available until the Navy began introducing air-refueling-capable Super Hornet fighters in 2002. Particularly during the U.S. intervention against the Taliban in Afghanistan in 2001, the Viking flew countless refueling sorties to give short-ranged fighters aboard U.S. carriers the reach to participate in the conflict.

The poky S-3 even saw action in the antiship and air-to-ground role, starting with the destruction of an Iraqi Silkworm antiship missile during the 1991 Gulf War using AGM-84 SLAM missiles. Vikings also sank several Iraqi patrol boats and destroyed antiaircraft guns and coastal radars during the conflict. More than a decade later, an S-3 crippled Saddam Hussein’s 350-foot personal yacht Al Mansur in its harbor at Basra using an infrared guided Maverick missile. The boat was, however, subsequently hit by Tomcat fighters.

In fact, the airplane would soon play a pivotal role in the infamous “Mission Accomplished” speech, when an S-3A was filmed to great fanfare landing President George W. Bush aboard the aircraft carrier Abraham Lincoln on May 1, 2003. Though the carrier was only thirty miles away from shore, well within range of a helicopter delivery, the Viking was chosen for its dramatic appeal.

However, the Navy was intent on phasing the Viking out, skeptical that it was worth the effort to continually upgrade the aircraft’s systems. The last operational Vikings were actually flying out of Al Asad Air Base in Iraq’s Anbar Province in 2008, where they were using LANTIRN infrared targeting and navigation pods to identify ambushes and roadside mines in advance of friendly convoys, proving the type’s versatility until the very end.

The Navy finally retired its last S-3 squadron in January 2009, though three aircraft continued to serve on in the experimental VX-30 unit until 2016. Pilots in the unit remarked the onboard sensors remained so effective that they were detecting “schools of dolphins and patches of seaweed.” The retired airframes now lie in storage in the “Boneyard” facility in Arizona. An inspection revealed the airframes had only flown around ten thousand hours out of a potential twenty-three-thousand-hour service life. The last remaining S-3 in service is an experimental research plane flown by NASA.

This led Lockheed to propose refitting the S-3s to serve as replacements for the reliable C-2 Greyhound cargo plane the Navy was retiring from the Carrier Onboard Delivery role. However, in 2015 the Navy chose to instead purchase the tilt-rotor CMV-22B Osprey instead. The Osprey has much shorter range than either the Greyhound or the proposed S-3 variant, is slower and more expensive to operate per flight hour, and cannot fly high or in adverse weather conditions due to its unpressurized crew compartment. But using the Osprey does allow the Navy to directly resupply non-carrier-based ships directly, rather than having to land cargo on the carrier by plane and then redistribute to other ships via helicopter.

For several years, it also appeared likely that South Korea might purchase up to thirty-six refurbished S-3s to assist in its efforts to hunt down North Korea’s large submarine force, which includes numerous minisubmarines that have on more than one occasion caused considerable havoc. However, in March 2017 Aviation Weekly reported that Seoul had passed over the Viking and is now interested in the much larger P-8 Poseidon maritime-patrol plane.

The Navy is unlikely to return to the Viking, despite its demonstrated flexibility. This is out of a defensible preference for operating fewer different types of aircraft to maximize efficiency in training, maintenance and spare parts. However, the Viking’s retirements reinforces the Navy’s continued reliance on short-range carrier-based aircraft, which is becoming an increasing liability as more capable shore-based missiles threaten carriers at or beyond the maximum combat radius of their onboard aircraft.