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Towed Pinger Locator 25

The TPL-25 System meets the Navy’s requirement for locating emergency relocation pingers on downed Navy and commercial aircraft down to a maximum depth of 20,000 feet anywhere in the world.
The system consists of the tow fish, tow cable, winch, hydraulic power unit, generator, and topside control console, although not all of these components are required on every mission. Navigation is accomplished by using algorithms incorporating the amount of cable in the water, the depth indication from the pressure sensor and other parameters. The generator provides electrical power for the system or power from the support platform can be used if it is compatible. The tow fish carries a passive listening device for detecting pingers that automatically transmit an acoustic pulse. Most pingers transmit every second at 37.5 kHz, although the TPL can detect any pinger transmitting between 3.5 kHz and 50 kHz at any repetition rate. Commercial aircraft pingers are mounted directly on the flight recorder, the recovery of which is critical to an accident investigation. The Pinger Locator is towed behind a vessel at slow speeds, generally from 1 - 5 knots depending on the depth. The received acoustic signal of the pinger is transmitted up the cable and is presented audibly, and can be output to either a Oscilloscope, or Signal Processing Computer. The operator monitors the greatest signal strength and records the navigation coordinates. This procedure is repeated on multiple track lines until the final position is triangulated. The current TPL-25 replaces all previous systems; TPL-20, 30, & 40.

Tow Body
Length - 30 inches
Diameter - 35 inches
Weight - 70 lbs

Depth - 20,000 feet of seawater
Speed - 1-5 knots
Point Of Contact
Naval Sea Systems Command
Office of Corporate Communications (SEA 00D)
Washington, D.C. 20376
(202) 781- 4123
Last Update: 27 February 2017