• An underwater locator beacon is an underwater acoustic locating device designed to survive the impact of an aircraft crash. The device is attached to the cockpit voice recorder and flight data recorders. It is designed to begin emitting a periodic ultrasonic acoustic signal at a frequency of 37.5 kHz when submerged in water.
• The underwater locator beacon is powered by a lithium battery with a lifespan of 6 years. Typical maintenance requires the beacon to be tested every two years and a full battery replacement every 6 years.
• The underwater locator beacon is approved in compliance with Technical Standard Order (TSO) C121, C121a, or C121b. Each recorder with beacon provisions manufactured by L3Harris is compliant with a system level TSO which includes an underwater locating beacon as a subset.

All operators/ aircraft that require a flight data recorder and/or cockpit voice recorder also are required to have an underwater locator beacon attached to those recorders.

• The rules governing underwater locator beacons are the Federal Aviation Administration (FAA) TSO-C121, C121a, and C121b. European Aviation Safety Agency (EASA) is expected to publish ETSO requirements that parallel the FAA standards.
• Most recently the FAA announced that it would no longer be granting TSO-C121 or C121a approvals to beacons manufactured after December 1, 2015. The intent of this approach is to limit the new manufacture of underwater locating beacons to the newest 90-day standard, TSO-C121b.
• L3Harris' interpretation of this change is that the FAA hopes to move the industry towards only the 90-day standard underwater locator beacon through attrition. 30-day beacons that are fielded can continue to be used as long as they are serviceable.
• The European Aviation Safety Agency (EASA) recently published a draft rule change that will require all Commercial Transport Aircraft to be equipped with recorders including the 90-day beacon by 2018. Many people in the industry believe that this will be approved by the EU in 2015 with a mandatory adoption date by the end of 2018. It is L3Harris' belief that with the FAA notice and recent tragedies surrounding Malaysia Flight 370, as well as the availability of the new 90 day beacon, all signs indicate adoption by the European Union.
• L3Harris is in the process of updating the Component Maintenance Manuals (CMMs) associated with products affected by the newest standards. The CMMs provide specific guidance on which 90-day beacon retrofit kits will be available for which product along with the proper maintenance information as it relates to the Recorder and underwater locating beacon.

• L3Harris will offer a 90-day retrofit kit for each serviceable product that carries a beacon today. This approach makes a 90-day beacon immediately available to all of our customers who would like to fit their product with a compliant beacon. L3Harris has updated the corresponding component maintenance manuals with the appropriate retrofit kits to be fielded. A service bulletin is available, as a part of each associated retro-fit kit, detailing the steps for a compliant installation in the field.
• L3Harris offers 30-day battery replacement kits for customers unable to transition to a 90-day beacon retrofit solution. The CMMs have been updated with the part number for these replacements as well.

The L3Harris beacon received TSO approval in late December, 2014 and is now available.

L3Harris is offering a one stop shop for all underwater locator beacon needs. We will offer a 90-day beacon compliant with our recorders (compliant under our recorder TSO), compliant L3Harris 90-day battery replacement kits, and compliant 30-day battery replacement kits. Additionally, we will offer battery testers to perform a return to service test.

Some of our customers have indicated an interest in converting their entire fleet to the 90-day beacon immediately. Reasons to consider an immediate fleet-wide transition:

1. Permits you to complete the maintenance at one time,
2. Enables you to insure complete traceability as to which aircraft and recorders have been upgraded the newly compliant underwater locator beacons, and
3. Allows you to claim that you have become fully compliant with the most advanced safety regulations. L3Harris is willing to provide fleet wide transition assistance service to install the new beacons for customers who do not have their own maintenance capability or who prefer to have factory installation made available.

Although there are many reasons to switch (traceability, public image, safer product), the regulations permit you to continue to operate with a 30-day underwater locator beacon. In order to assist you in this choice, L3Harris will continue to make compliant battery replacement kits available.

L3Harris has designed the retrofit kits in such a manner that the conversion can be done on wing via beacon replacement and recorder nameplate modification marking.

No. The notice currently affects the manufacture of the underwater locating device. The EASA Notice of Proposed Amendment (NPA) indicates that European aircraft will however, be mandated to carry only the 90-day beacon. Simply translated, the 30-day beacons are no longer available for sale with a valid TSO certification, and can only be maintained. When the EASA rule change takes effect, those operators will be forced to change to the 90-day beacon.

L3Harris has started to release service bulletins for each product impacted by the beacon change. The service bulletins include Manufacturing Inspection District Office (MIDO) approved installation instructions. These service bulletins will be available as part of the 90-day retrofit kits.

L3Harris would prefer to begin transitioning these orders as soon as possible because the beacon battery has a shelf life. This means we are unable to stock 30-day beacons to continue production. We will be happy to work with you to transition the orders to the 90-day variant.

L3Harris sells a beacon test set to support the beacons in your fleet. Each of the retrofit kits and beacons will come with all necessary components to complete the replacement. (*a torque wrench is required but will not be included)

The 90-day beacon will carry a 1 year warranty.

The new 90-day beacon has increased the size of the lithium battery to enabling it to operate for three times as long as the current underwater locator beacon. The increased size of this lithium battery will require special shipping and handling requirements. It is considered a class 9 hazmat.