OVERVIEW: The VTT‑1 Strizh (projected AT‑1M variant) is a Soviet 450 mm helicopter-launched, wire-guided, lightweight anti-submarine torpedo introduced in 1976.

DETAILS: VTT‑1 (“Vertoletnaia Teleupravliaemaia Torpeda” meaning helicopter remotely controlled torpedo) is a wire-guided adaptation of the AT‑1M torpedo for airborne platforms . It weighs approximately 540 kg and employs a silver‑zinc battery driving an electric motor. The torpedo features active/passive acoustic homing with wire guidance controlling the torpedo mid-course, effective against submarines at depths up to 200 m and homing ranges between 500–1 000 m. It has an overall range near 5 000 m at speeds around 28 kn and carries a 70 kg high-explosive warhead.

TYPE: Lightweight helicopter-launched wire-guided ASW torpedo

FUNCTION: Launched from ASW helicopters (e.g., Ka‑25, Mi‑14), the VTT‑1 enters the water via parachute, then uses wire guidance and acoustic homing to locate and engage submarines in its search and terminal phases.

NOTE:
IOC: circa 1976 
Manufacturer: Gidropribor and Dagdizel (Soviet Union)
Operators: Soviet Navy 
Platforms: Ka‑25 variants and ASW helicopters like Mi‑14PL and Ka‑27PL 

SOURCE:
Warships.com.cn – VTT‑1 Strizh technical data; WeaponsSystems.net – AT‑1/AT‑1M lineage and variants; Helicopter Handbook (Shephard) – VTT‑1 specifications