OVERVIEW: The AT-1M is a Soviet lightweight, ship- and aircraft-launched passive acoustic-homing torpedo introduced in 1973. Known by NATO as E45-75A, it was designed for anti-submarine warfare in both open-ocean and coastal environments.

DETAILS: The designation “AT” stands for Aviasionnaya Torpeda (Airborne Torpedo), and the AT-1M was a modernized version of the earlier AT-1. It retained a 450 mm diameter and featured passive acoustic homing, an electric propulsion system powered by silver-zinc batteries, and a contact fuze. Improvements over the base AT-1 included increased range, deeper operational depth, and improved seeker logic for better performance against quiet submarines. The torpedo was cleared for deployment from maritime patrol aircraft, helicopters, and surface ships using compatible launch gear.

TYPE: Lightweight passive acoustic-homing torpedo

FUNCTION: Upon launch, the AT-1M descends into the water and begins searching for submerged targets using passive sonar. Once a target is detected, it homes in on the acoustic signature and detonates on contact with a high-explosive warhead.

NOTE:
IOC: 1969 (AT-1), 1973 (AT-1M)
Operators: Soviet Union
Platforms: Tu-142, Il-38 aircraft; Ka-25PL helicopter; Krivak-class frigates (RBU-tube adapted)
Conflict used in: No confirmed combat use
Manufacturer: Soviet Union (design attributed to GNPP Region, Russia)

SOURCE:
Jane’s Underwater Warfare Systems ; Federation of American Scientists (FAS): https://fas.org/man/dod-101/sys/ship/weaps/index.html ; Naval Institute Guide to World Naval Weapon Systems ; SIPRI Arms Transfers Database: https://armstrade.sipri.org