Grumman AF-3S Guardian

The Grummian AF‑3S Guardian was the United States Navy’s first carrier‑based anti‑submarine warfare jet, entering service in 1955. Developed from the piston‑engine AF‑2, the AF‑3S replaced the twin radial engines with two Allison J33‑3 turbojets, giving a top speed of 395 knots and a range of 1,200 nm, crucial for tracking Soviet submarines during the Cold War. Its airframe retained the high‑wing, twin‑tail layout but incorporated a larger, bubble‑canopy cockpit and a strengthened deck‑landing gear for carrier operations. Key sensors included a retractable AN/APS‑20 radar nose radome, a magnetic‑anomaly detector housed in the tail boom, and sonobuoy dispensers beneath the wings. Armament consisted of depth‑charge racks, torpedoes and the Mk 32 Hedgehog, allowing rapid engagement of submerged targets. The Guardian’s integration of jet speed with dedicated ASW equipment set a new standard for maritime patrol aircraft, demonstrating that carrier‑borne jets could fulfil specialised roles beyond strike missions. Though it served only a decade before being superseded by the Grumman S‑2 Tracker, the AF‑3S proved pivotal in shaping naval aviation doctrine and underscored the importance of airborne anti‑submarine capabilities in modern naval strategy. Only 25 were built, and the type left service in 1965, but its concepts influenced later carrier ASW aircraft.