The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure

By Edward Chang
Jun 27 2019
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If you are ready, let us turn back the clock to the mid-to-late-1980s and take a ride aboard the S-3A Viking alongside our intrepid SENSOs during their heyday and discover what it took to make it in this exclusive community.

Though overshadowed by the flashier Tomcats, Corsairs, Hornets, and Intruders it flew alongside, the Lockheed S-3 Viking was arguably the most versatile platform of the carrier air wing of its era. Introduced to the fleet in 1974 as an anti-submarine warfare (ASW) aircraft, it went on to serve as an air-refueling tanker, conducted surface surveillance and attack, and was also modified to gather electronic intelligence. It would be relieved of its ASW duties in 1998 and, ultimately, leave frontline service in 2009.

The Viking was also unique for a fixed-wing carrier-based tactical aircraft in that it carried an enlisted aircrewman as a member of its crew. United States Naval Aviation is largely the refuge of commissioned officers, which made the enlisted crewman’s presence on the crew that much more remarkable. It was in the left aft seat the S-3 Sensor Operator, or SENSO, sat and operated the aircraft’s cutting-edge acoustic analysis systems for underwater threats. An extremely challenging, yet incredibly rewarding, line of work, it defined the careers of Navy sailors like Gregory “Ferris” Bules and Michael “Cheeseburger” Worth, placing them in a class all their own.

So, if you are ready, let us turn back the clock to the mid-to-late-1980s and take a ride aboard the S-3A Viking alongside our intrepid SENSOs during their heyday and discover what it took to make it in this exclusive community.

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure
Greg Bules posing in front of a Lockheed S-3A Viking

Airborne Sub-Hunters

In the U.S. Navy, enlisted personnel are referred to by their respective “rating,” which denotes their occupational specialty within the service. S-3 SENSOs were drawn from the pool of Aviation Anti-Submarine Warfare Operators (AWs), who according official Navy literature of the time:

operate airborne electronic equipment used in detecting, locating, and tracking submarines. They also operate radars to provide information for aircraft and surface ship navigation.

In addition to the S-3, AWs also flew aboard the Lockheed P-3 Orion, a land-based ASW and surface surveillance aircraft, along with helicopters. Those who flew aboard helos cross-trained as rescue swimmers in addition to operating ASW systems.

On the Viking, SENSOs sat directly behind the pilot, a Naval Aviator (NA), and beside the Tactical Coordinator, or TACCO, a Naval Flight Officer (NFO). Rounding out the crew and sitting next to the pilot was the Co-Pilot/Tactical Coordinator (COTAC), who was initially an NA before being replaced by an NFO later in the S-3’s service life. The SENSO monitored the S-3’s vast array of sensors, working closely with the TACCO, who oversaw the tactical picture and made the lion’s share of major decisions related to tracking and, if necessary, attacking hostile contacts.

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure
Michael Worth in the cockpit of an S-3A

The AW rating was later re-named to “Aviation Warfare Systems Operator,” then to its current title of “Naval Aircrewman.” Aboard fixed-wing aircraft, the rating is presently divided into three specialties – Mechanical (AWF), Operator (AWO), and Avionics (AWV). AWFs act as flight engineers and loadmasters, while AWOs fulfill the same role the rating did in its previous iterations, except exclusively aboard land-based P-3 and P-8 Poseidon aircraft. AMVs are in-flight technicians/troubleshooters for the aircraft’s avionics, as the name implies. AWs assigned to helicopters are designated as either “Helicopter” or “Tactical Helicopter.” The former serves as utility crewmembers aboard non-ASW-capable Navy helicopters, while the latter flies aboard ASW-capable helos.


For its time, the S-3A possessed a cutting-edge avionics suite for detecting surface and sub-surface contacts. Its primary means of underwater detection were 60 sonobuoys coming in four varieties, including one search-and-rescue sonobuoy, whose signals were run through a sophisticated processing system. The S-3 also had a 20-foot Magnetic Anomaly Detector (MAD) boom which extended from the tail of the aircraft like a “stinger.” Large, metallic objects, like submarines, create disturbances in Earth’s magnetic field; the disturbance was what the MAD looked for and was employed for final confirmation of a submarine’s presence underwater.

For surface detection, Vikings utilized a radar specially designed to detect contacts at sea up to 150 miles and a Forward-Looking Infrared (FLIR), the latter which was housed in a pod that was extended from underneath the cabin. The FLIR imagery pod allowed for close-up observation of contacts at all times during the day, including low-light conditions, and during inclement weather. Finally, the S-3A was geared with the most sophisticated Electronic Support Measures (ESM) system available among carrier-based aircraft upon its debut. Primarily a defensive system, it also allowed the Viking to act as a quasi-Electronic Intelligence (ELINT) platform, a concept later expanded upon and implemented in the dedicated ES-3A Shadow ELINT variant. The S-3A had no active defenses, however, such as chaff and flare for defeating inbound missiles.

The SENSO’s console consisted of two screens; one for displaying radar data and FLIR imagery, while the other displayed acoustic detection data. These displays and associated systems were operated using a fold-down keyboard-like control console known as the Integrated Control System (INCOS). The INCOS sat higher than the McDonnell Douglas Escapac 1E zero-zero ejection seats the crewmembers sat in, so that it would be pushed away by the tops of the seats as they rocketed skyward and through the opaque canopy above the SENSO and TACCO.

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure
SENSO station aboard S-3, positioned behind the Pilot. Credit: LCDR Tom Twomey, USN

The S-3A carried a surprisingly diverse array of ordnance for such a specialized platform on its two underwing hardpoints and bomb bays. In addition to the Mk. 46 air-dropped torpedo, depth charges, and mines for ASW, the Viking also carried Mk. 80-series General Purpose Bombs, cluster munitions, unguided rockets, and even nuclear bombs. Its arsenal would expand in the proceeding variant to come.

Being specifically designed to fit onto and operate within the confines of a crowded carrier flight deck did not diminish its performance, either. The SENSO alone was a highly-skilled and trained specialist; together with the other three crewmembers, the Viking could equal the performance of its larger land-based counterpart, the Lockheed P-3 Orion, despite possessing less than half the crew complement – the S-3’s lone AW did the work of three AWs aboard an Orion.

Like most military aircraft, Vikings were not designed for comfort. “That ejection seat might be designed to save your life but sit on it long enough and it felt like it was ‘cutting’ into you,” as bluntly characterized by Bules. “Fortunately, the S-3 was spacious enough we could get up to stretch our legs and relieve ourselves in-flight using a ‘piddle pack.’ But you never wanted to stay out of your ejection seat for too long, in case of an emergency, lest it blast off without you in it!”

The upgraded variant, the S-3B, entered frontline service in 1988 and gradually phased the S-3A out of service. The B-variant featured improved avionics and detection systems and carried a wider-range of weaponry, including the air-to-ground AGM-65 Maverick missile and the AGM-84 Harpoon anti-ship missile. As surface attack gained greater emphasis, ASW lost emphasis with the end of the Cold War and the fall of the Soviet Union. Sensing a diminished underwater threat, the Navy elected to cut costs in part by stripping the S-3 of its ASW mission, removing equipment designed for that mission and de-necessitated the need for a SENSO and TACCO in the back. The final ASW-geared and SENSO-manned S-3 flew in 1998; all subsequent flights were crewed by a pilot and co-pilot only.

The Making of a SENSO

Greg Bules went through a “Rambo” phase during his late-teen years. Inspired by the Sylvester Stallone-starring 1982 action movie, the Ohio-native decided he wanted to become a U.S. Army Ranger. That was, until, he met “Jack,” a family friend and Navy Blue Angels flight demonstration team crew chief, and his life was changed forever.

SENSO ejection seat. Notice the porthole left of the seat. Credit: Willy Peeters

“My parents were understandably leery about me joining the Army and becoming a grunt, so they split the difference and drove me towards a different destination in the military,” remembers Bules. “Luckily, I had a mentor, ‘Jack,’ to vector me by getting the recruiter to introduce me to the AW rating.” Initially, the recruiter suggested Bules become a rescue swimmer, which sounded like an exciting, adrenaline-rush of a job. In June 1986, the day after graduating high school, Bules left for recruit training after spending most of his senior year in the Delayed Entry Program with a guaranteed AW ‘A’ school slot, with hopes and dreams of flying on a Navy helicopter as a rescue swimmer.

Meanwhile, in Florida, Michael Worth dreamt of flying in the Navy since high school. But flying requires an officer’s commission, which, in turn, requires a college degree, which his family found difficult to afford. As fate would have it, a friend who enlisted in the Navy at around the same time introduced him to the AW rate which, Worth was pleasantly surprised to discover, would allow him to fly without becoming an officer!

But the Navy recruiter, according to Worth, “pursued his own agenda,” attempting to force young Michael down a different career path. Determined to fly, Worth did what most recruiters and recruits would consider unthinkable – ship to recruit training without a guaranteed job. Doing so created a high likelihood the Navy would pick a job, any job, for him and he would be stuck with it for the duration of his enlistment contract, whether he liked it or not.

“I would never recommend that to anyone,” says Worth in retrospect, “It was a risky gamble.” But, ultimately, his Armed Services Vocational Aptitude Battery (ASVAB) test scores, knowledge of the AW rate, and sheer determination all converged at a single point, allowing him to take his pick of rates and choose what he always knew he wanted. Worth reported to recruit training a full year ahead of Bules, in June 1985.

SENSO station and the TACCO station

Regardless of rating, all Navy enlistees begin their career at Recruit Training Command, or RTC. Today, RTC is located exclusively at Naval Station Great Lakes, north of Chicago, but prior to the mid-1990s, Navy recruit training was also offered at Naval Training Centers Orlando and San Diego – Bules attended San Diego, while Worth went through RTC in Orlando.

After graduation, prospective AWs headed for Naval Air Station Pensacola, Florida, and the Naval Aircrewman Candidate School, or NACCS. NAS Pensacola, referred to as the “Cradle of Naval Aviation,” is best known as the starting point for NAs and NFOs. Though there were once multiple enlisted aircrew schools, Pensacola has served as the single starting point for all AWs since 1983. During the S-3 era, NACCS was a five-week course that taught basic safety and survival skills and instills the physical conditioning necessary to survive and thrive as AWs, regardless of which platform they ultimately flew.

During the approximately one-month-long course, the aircrew candidates were put through a grueling physical training regimen, among the toughest in the Navy. The running was endless; daily three and five miles were the norm, coupled with other conditioning workouts. In the end, male candidates were expected to run one-and-a-half miles in no less than 11 minutes, 39 seconds to pass NACCS, with women expected to do it in 14 even, plus an obstacle course where each station was to be completed successfully.

Then there was the swimming, which put the “naval” in “Naval Aircrewman.” Candidates swam almost exclusively in flight gear, beginning with a one-mile swim in a flight suit, then adding the helmet, harness, gloves, boots, and other apparel. Drown-proofing was taught in the swimming pools of NACCS and in the waters off the Pensacola coast, attempting to instill confidence in one’s ability to survive, in addition to teaching hard survival skills, parachute training (no actual jumps were involved), and being hoisted up a rescue helicopter.

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure
AW rating information sheet, circa 1985. Credit: Greg Bules

There was also the helo-dunker, a.k.a. “Panic in a Drum,” where trainees were tested in their ability to escape from an overturned helicopter in water. A mental, as well as a physical test, the dunker separated those who possessed the calmness and the ability to fall back on their training versus those who resorted to panic and could not apply what they had been taught. Candidates went through the dunker four times, switching crew positions each turn, and the last two “dunks” with opaque goggles on to simulate a nighttime ditch.

Continuing the theme of preparing for helicopter work, NACCS trainees even engaged in boxing matches. Indirectly serving as a form of stress relief, boxing also prepared trainees to take the literal hit in the form of a controlled helicopter crash. As Worth discovered, no punches were pulled during these matches.

“The Navy likes to know you can think while you’re getting your bell rung,” he explained. “My final match was against a Marine that was maybe five-foot even; I was five-foot-nine. Everyone thought I had the advantage and I certainly did have the longer reach. But Marines being Marines, he cleaned my clock good! He says I rang his bell plenty, too, when we went to dinner afterwards. We were friends before the match and better friends after.”

Like much of the NACCS curriculum, boxing helped build the confidence necessary to perform dangerous tasks with no room for error. Other situations with no room for error included dealing with hypoxia, the training for which took place in the pressure chamber. The goal was to recognize the signs and symptoms of hypoxia and retain the awareness and presence of mind to take steps necessary to address the situation before the lack of oxygen overwhelmed the flyer. The pressure chamber was part of an overall aviation physiology curriculum, which also included learning about vertigo and how to perform the Valsalva maneuver to clear one’s ears due to changes in air pressure.

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure
Initial enlistment contract signed by Greg Bules. Credit: Greg Bules

NACCS classes were typically comprised of anywhere from 10 – 20 candidates. Some, like Greg Bules and Michael Worth, were brand-new recruits, a portion of whom dreamt of becoming pilots or NFOs, but either were not college graduates and, thus, lacked a commission, or were not medically qualified to become pilots. Others were “salty dogs,” as Bules described them, who had cross-rated as AWs after spending years performing other specialties in the Navy. At the time, all were male.

Across the way was the now-defunct Aviation Officer Candidate School (AOCS), made famous in the 1982 classic film An Officer and a Gentlemen. Graduates of each candidate schools who went through each program at the same time would eventually fly together as well.

“They played us off each other,” says Bules. “Our instructors reminded us [the pilots and NFOs] would be relying on us to successfully execute the mission and their instructors would remind them we’d be depending on them to accomplish the mission and make it back home.”

The five weeks eventually came to an end with a brief graduation ceremony, but with no other fanfare. Shortly before the end of NACCS, the question on every trainee’s mind was addressed for the first time – which aircraft would they fly? Each candidate filled out a “dream sheet,” with Worth picking S-3s first, helicopters second, and P-3s last. Bules had counted on helicopters but found his uncorrected eyesight did not meet the stricter standard demanded of rescue swimmers, which was 20/50 uncorrected – Bules was 20/70. Narrow margins, indeed, but the standards were not flexible. He picked the next-best option as his top choice, which sounded exciting. “It was the summer Top Gun came out,” Bules pointed out. “Who didn’t want to fly off an aircraft carrier after seeing that?”

The story continues next week in Part Two, as the training continues and the challenges mount. Will Greg Bules and Michael Worth successfully complete their training and make it into the fleet? How was life in an S-3 squadron on deployment and what was it like hunting submarines? Find out by reading the next installment!

The Life and Times of an S-3A Viking Sensor Operator, Part One: It Wasn’t Just a Job, but an Adventure
This print is available in multiple sizes from – CLICK HERE TO GET YOURS. S-3B Viking VS-41 Shamrocks, NJ741 / 160136 / 2006

Technical information regarding the S-3 was taken from S-3 Viking In Action by Brad Elward.

Photo credit: PH1 Ronald Beno and LCDR Tom Twomey / U.S. Navy and Willy Peeters

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Edward Chang

Edward Chang

Edward Chang is a defense, military, and foreign policy writer.
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