The U.S. Navy is developing a new kind of anti-submarine weapon — one that glides through the air before hitting the water. The program, called Silent Anvil Air-Launched Torpedo (SAA-LT), represents a significant shift in how the Navy plans to hunt submarines from aircraft and drones.
The U.S. Navy is developing a new kind of anti-submarine weapon — one that glides through the air before hitting the water. The program, called Silent Anvil Air-Launched Torpedo (SAA-LT), represents a significant shift in how the Navy plans to hunt submarines from aircraft and drones.
Details of the program emerged in a Navy Request for Information published in late August 2026. The Navy is exploring two approaches: a brand-new torpedo designed from the ground up to glide, or a glide kit that can be attached to existing torpedoes like the Mark 54.
How It Works
The concept borrows from an existing system: the High Altitude Anti-Submarine Warfare Weapon Capability, which added a glide kit to standard Mark 54 torpedoes, allowing them to be launched from P-8 Poseidon patrol aircraft flying at altitudes up to 30,000 feet. Silent Anvil extends this concept significantly further.
According to the RFI, SAA-LT must work across a wide envelope of speeds (Mach 0.25 to Mach 0.85) and altitudes (10 feet to 60,000 feet) — far beyond the P-8's normal operating ceiling, and closer to what high-altitude drones like the MQ-4C Triton can reach.
The weapon is being designed around a compact form factor similar to the GBU-39 Small Diameter Bomb (SDB), meaning it will weigh no more than 268 pounds, measure no more than 70 inches long, and have a diameter of up to 7.5 inches. It will be compatible with the standard BRU-61/A bomb rack and can be carried internally or externally on a wide range of manned and unmanned aircraft.
Why It Matters
The strategic driver is clear: China is rapidly expanding both the size and sophistication of its submarine fleet, including the development of large, long-range autonomous underwater vehicles. The Navy's existing anti-submarine arsenal — including the aging RUM-139C Vertical Launched ASROC, with a publicly stated range of just over 10 miles — is increasingly outpaced by the threat environment.
SAA-LT also complements the Navy's separate Long Range ASW Weapon (LRAW) program, which is focused on extending the reach of surface-ship-launched anti-submarine torpedoes.
Timeline
The SAA-LT timeline calls for a prototype within 18 months of contract award, followed by 180 all-up-round prototypes within three years after a successful demonstration. The Navy's request for industry input has a deadline of September 29, 2026.
