If you’ve ever spent time near a rural airfield in California during fire season, you’ve probably heard a sound that doesn't belong in the 21st century. It’s a rhythmic, heavy thrumming. It sounds like industrial machinery. That’s the S-2 Tracker, or at least a highly evolved version of it, still working for a living decades after it should have been put out to pasture. Most military aircraft have a shelf life. They fly, they fight, and then they rust in a desert boneyard in Arizona. But the "Stoof"—as its pilots affectionately call it—is different.
It was born in the early 1950s. Back then, the US Navy had a massive problem: Soviet submarines were getting faster, quieter, and more dangerous. The Navy's existing solution was a "hunter-killer" team of two different aircraft working together. One found the sub; the other dropped the torpedo. It was clunky. It was inefficient. Grumman Aircraft Engineering Corporation looked at that mess and decided to cram everything—the radar, the sonobuoys, the MAD boom, and the weapons—into one airframe.
The S-2 Tracker was the result. It looks a bit chunky, honestly. It has a high-wing design and a big, protruding belly for the search radar. But that utilitarian ugliness is exactly why it’s still flying today.
The Engineering Behind the S-2 Tracker
When you look at an S-2, you’re looking at a masterclass in carrier-based compromise. To fit on a carrier deck, the wings have to fold in a specific, overlapping way. It’s a mechanical ballet. The original S-2A was powered by two Wright R-1820 Cyclone radial engines. These are nine-cylinder, air-cooled monsters. They are loud. They leak oil. They smell like high-octane history.
But the real magic wasn't just the engines. It was the "MAD" boom—the Magnetic Anomaly Detector. If you see an S-2 Tracker from behind, you’ll notice a long pole extending from the tail. This thing is designed to detect minute changes in the Earth’s magnetic field caused by a giant hunk of Soviet steel lurking underwater.
It’s incredibly sensitive. To make it work, the pilots had to fly low. We’re talking 100 feet above the waves, sometimes in pitch-black darkness or screaming gales. You can’t just "autopilot" that kind of mission. It required hands-on, sweaty-palm flying. The cockpit is cramped. If you're tall, you’re going to have a bad time.
The interior was a cave of vacuum tubes and green-screen cathode ray tubes. The "Sensors 1" and "Sensors 2" operators sat in the back, staring at flickering lines, trying to distinguish the sound of a whale’s song from the cavitation of a Romeo-class submarine propeller. It was exhausting work.
From Sub-Hunter to Firefighter
By the mid-1970s, the Navy started replacing the Tracker with the S-3 Viking. The Viking had jets. It was faster. It had better computers. But while the Viking is now mostly retired, the S-2 found a second life that no one really saw coming.
CAL FIRE (the California Department of Forestry and Fire Protection) realized that the S-2 Tracker was the perfect platform for an air tanker. Think about it. It’s built to take off from short carrier decks with a massive payload. It’s designed to be maneuverable at low altitudes. It’s rugged as hell.
They took the old airframes, stripped out the heavy sub-hunting gear, and replaced the piston engines with Garrett TPE331 turboprops. This version is known as the S-2T Turbo Tracker. The difference is night and day. The turboprops are lighter, more reliable, and provide instant power. When you’re flying into a canyon filled with thick smoke and rising heat, you want that power.
The internal bomb bay, which used to hold Mk 44 torpedoes, was converted into a 1,200-gallon retardant tank. Now, instead of hunting subs, these planes hunt "spots." They drop that bright red ammonium polyphosphate to create lines of defense for ground crews. It’s a violent kind of flying. The turbulence near a wildfire can shear the wings off lesser planes. The S-2 just eats it up.
Why Collectors and Foreign Militaries Still Want Them
You might think an aircraft this old would be a museum piece. Plenty are. You can find them at the Intrepid Sea, Air & Space Museum in New York or the National Naval Aviation Museum in Pensacola. But for some countries, the S-2 is still a frontline asset.
The Argentine Navy, for example, famously used the S-2E during the Falklands War. They even upgraded some to the S-2T Turbo Tracker standard later on. Brazil flew them for years. Taiwan kept a fleet of S-2Ts active well into the late 2010s. They were the backbone of South China Sea surveillance for decades.
Why? Because it’s cheap to operate compared to a P-8 Poseidon. Not every country needs a billion-dollar Boeing jet to watch its coastline. Sometimes you just need a reliable twin-engine plane that can loiter over the water for six hours without breaking the bank.
For private collectors, owning an S-2 is the ultimate "flex," but it’s a logistical nightmare. You aren't just buying a plane; you’re buying a full-time relationship with a mechanic who knows how to fix 70-year-old hydraulic systems. Parts are scarce. You’re often scavenging from boneyards. Yet, the community of "Stoof" enthusiasts is surprisingly tight-knit. They share manuals, lead-based paint tips, and stories about that one time a radial engine decided to catch fire at 500 feet.
The Misconceptions: It’s Not Just a "Puddle Jumper"
A lot of people think the S-2 was a safe, easy plane to fly because it looks stable. Honestly, that’s a myth. Ask any pilot who had to trap an S-2 on a wooden-decked Essex-class carrier in a North Atlantic storm.
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The S-2 had a nasty habit of "single-engine minimum control speed" (Vmc) issues. If you lost an engine on takeoff—especially with a full load of depth charges—the plane wanted to roll over and dive into the drink. You had to be fast on the rudder. You had to be precise.
Also, the "Trader" (C-1) and "Tracer" (E-1) variants are often confused with the S-2 Tracker.
- The C-1 Trader was the delivery guy. It hauled mail and people.
- The E-1 Tracer had a massive "pancake" radome on top for early warning.
- The S-2 Tracker was the actual assassin.
Each one used the same basic wing and tail, but they were entirely different animals inside. The Tracer, with that huge dome, handled like a brick in a wind tunnel. The Tracker was the athlete of the family.
Operating the S-2: A Glimpse Inside the Cockpit
If you climbed into an original S-2 cockpit today, you’d be overwhelmed by the smell of old sweat, hydraulic fluid, and ozone. There are no glass displays. There are hundreds of toggle switches. Many of them are safety-wired so you don't accidentally jettison your fuel or drop a torpedo on a friendly whale.
The cockpit visibility is actually pretty decent because of the wrap-around windows. This was vital for "eyeball" navigation during low-level ASW (Anti-Submarine Warfare) sweeps. Pilots would look for oil slicks, periscope wakes, or even just changes in water color.
The noise is the thing most people don't realize. Even with headsets, the roar of the Cyclones is bone-shaking. Your whole body vibrates. After a six-hour mission, pilots would climb out feeling like they’d been inside a washing machine full of gravel.
The Future of the Tracker
Is the S-2 Tracker finally dying out? Technically, yes. CAL FIRE is slowly transitioning to the much larger C-130 Hercules for its heavy lifting. Modern militaries are moving toward drones for maritime surveillance. A drone doesn't get tired. A drone doesn't need a pension.
But there is something the S-2 has that a drone never will: adaptability. The fact that an airframe designed in the Truman era is still dropping fire retardant in the 2020s is a testament to Grumman’s "Iron Works" philosophy. They built things heavy. They built things to last.
The S-2 isn't a sleek stealth fighter. It’s a tractor with wings. And as long as there are fires to fight or coastal waters to watch on a budget, someone, somewhere, will probably keep a Stoof in the air.
Actionable Insights for Aviation Enthusiasts
If you’re interested in seeing the S-2 Tracker in action or learning more, don't just look at static displays.
- Visit the California Wildfire Bases: During the summer months, airports like Grass Valley or Chico often host S-2Ts. You can see them landing and reloading from the public viewing areas. Just stay out of the way; they are working.
- Check the Commemorative Air Force (CAF): Some branches of the CAF still maintain airworthy radial-engine aircraft. Look for regional airshows where a "Stoof" might be performing. Hearing those R-1820s in person is a mandatory experience for any "avgeek."
- Study the Grumman "Iron Works" History: If you're a student of engineering, look into the S-2's wing-fold mechanism. It’s one of the most complex and robust designs ever put on a carrier. It influenced everything from the A-6 Intruder to the F-14 Tomcat.
- Volunteer at a Restoration Hangar: Many museums have S-2s in their "back lot" waiting for love. They need people to scrape corrosion and polish aluminum. It’s the best way to understand the sheer density of equipment packed into that fuselage.
The S-2 Tracker reminds us that technology doesn't always have to be new to be effective. Sometimes, the best tool for the job is the one that was built to never break in the first place. This plane wasn't meant to be pretty; it was meant to endure. And it has.