DK120-90 - Dukane Seacom 90-Day Underwater Acoustic Beacon

DK120-90 – Dukane Seacom 90-Day Underwater Acoustic Beacon (TSO-C121b)

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The Dukane Seacom DK120-90 is a flight-critical, life-limited underwater acoustic beacon (UAB), commonly referred to as a "pinger." This device is the global standard for the location of submerged aircraft flight recorders. Its sole, vital purpose is to be attached to the chassis of a Cockpit Voice Recorder (CVR) or Flight Data Recorder (FDR) and to automatically activate upon immersion in water. Once activated, it emits a powerful, locating acoustic pulse once per second for a minimum of 90 days, leading search and rescue teams directly to the site of the submerged wreckage.

The DK120-90 is engineered to meet the latest and more stringent FAA and international standards, which mandate a 90-day operational transmission life. It is a completely self-contained unit, powered by a long-life lithium battery and activated by an integrated water-sensitive switch. Housed in a robust, corrosion-resistant case, it is designed to withstand the immense pressures of the deep ocean. The ability to recover flight recorders is absolutely essential for accident investigation, and the proven reliability of the Dukane Seacom beacon is a cornerstone of this capability.

Key Features

• FAA TSO-C121b & EUROCAE ED-112A Certified: Meets the latest international standards requiring a minimum 90-day operational life after activation.

• 90-Day Operational Transmission: A significant improvement over the older 30-day standard, greatly increasing the window for search and recovery operations.

• 37.5 kHz Acoustic Pulse Frequency: Transmits on the internationally recognized standard frequency for underwater locator beacons.

• Water-Activated Switch: A corrosion-resistant, galvanic switch automatically activates the beacon upon immersion in either fresh or salt water.

• Long-Life Lithium Battery: Powered by a high-energy density, hermetically sealed lithium battery pack with a 6-year replacement life.

• Deep Ocean Survival: Engineered and tested to operate at depths down to 20,000 feet (6,000 meters).

Technical Specifications

• Part Number: DK120-90

• Component Type: Underwater Acoustic Beacon (UAB) / Pinger

• OEM Manufacturer: Dukane Seacom (a brand of Orolia/Safran)

• Operating Frequency: 37.5 kHz ± 1 kHz

• Acoustic Output: 160 dB re 1 µPa at 1 meter

• Operational Life (after activation): Minimum 90 days

• Battery Replacement Life: 6 years from date of manufacture (unit is replaced)

• Activation Method: Water immersion (fresh or salt water)

• Depth Rating: 20,000 feet (6,000 meters)

• Governing Specifications: FAA TSO-C121b, EUROCAE ED-112A

Aircraft Compatibility

The DK120-90 is a standard component installed on the flight recorders of virtually all modern commercial, corporate, and many general aviation aircraft that are required by regulation to carry a CVR or FDR. It is not specific to an airframe, but to the flight recorder it is mounted on (e.g., recorders from Honeywell, L3Harris, Collins Aerospace).

Crucial Note: Verification of the correct beacon part number must be made against the Illustrated Parts Catalog for the specific flight recorder unit.

Applications

• Attached directly to the chassis of Cockpit Voice Recorders (CVRs) and Flight Data Recorders (FDRs), often referred to as "black boxes."

• Mandatory replacement based on the battery expiration date marked on the unit.

Why Choose DK120-90?

Choosing the genuine Dukane Seacom DK120-90 is a non-negotiable requirement for regulatory compliance and flight safety. In the aftermath of an accident over water, this beacon is the single most important tool for locating the vital flight recorders. Using an expired unit, a non-certified part, or a beacon that does not meet the current 90-day standard violates FAA and international regulations and critically hampers accident investigation efforts. Dukane Seacom is the world's leading manufacturer of these life-saving devices, and installing their TSO-C121b certified beacon is the only way to ensure compliance and guaranteed performance when it is needed most.

The acoustic pulse of the DK120-90 is generated by a piezoelectric transducer. The beacon's electronic circuitry, powered by a high-energy density Lithium-Sulfuryl Chloride (Li−SO2​Cl2​) battery, delivers a precise, high-voltage electrical pulse to a piezoelectric ceramic element (typically a lead zirconate titanate - PZT composite). In accordance with the piezoelectric effect, the application of this electric field causes the ceramic material to rapidly deform or change shape. This high-speed mechanical deformation creates a powerful pressure wave—a sound pulse—in the surrounding water at the specified 37.5 kHz frequency. The beacon's rugged, corrosion-resistant housing is not just for protection; it is also an integral part of the acoustic system, designed to efficiently couple this acoustic energy into the water with minimal attenuation, thereby maximizing the transmission range and probability of detection from the surface. The entire system is engineered for a single purpose: converting the battery's stored chemical energy into acoustic energy with the highest possible efficiency for 90 days.

Note: This is a flight-critical, life-limited safety component. The entire unit must be replaced on or before the battery expiration date marked on the housing. Federal and international aviation regulations (e.g., 14 CFR § 91.207) mandate the operational status and timely replacement of these beacons. Installation must be performed by a certified A&P or avionics technician. After installation, a functional test of the beacon is required and must be logged in the aircraft's records.

Documentation

The definitive part number applicability, installation, and testing procedures are detailed in the Component Maintenance Manual (CMM) for the specific flight recorder and the Dukane Seacom DK120-90 beacon.