JP 3-50 National Search and Rescue Manual Vol I - US Navy

vessels) will be required to carry Category I 406 MHz
Satellite EPIRBs. These EPIRBs transmit for at least 48
hours.
6. Category II 406 MHz EPIRBs are similar to the Category I
devices except the Category II EPIRBs are manually activated.
Similar to the Class B EPIRBs in usage, vessels are encouraged
to replace aging 121.5 MHz EPIRBs with the 406 MHz Satellite
EPIRBs. These EPIRBs transmit for at least 48 hours.
B. ELTs, also referred to as Crash Position Indicators (CPIs) and
as Emergency Location Beacons-Aircraft (ELBAs), emit a distress signal
on 121.5 MHz and/or 243.0 MHz either when turned on manually or when
subjected to G-forces, such as an aircraft crash. They are required on
most noncommercial aircraft registered in the United States. Certain
classes of aircraft, such as agricultural and aerobatic, are not
required to carry an ELT. Commercial aircraft with extended overwater
operation carry an ELT for use in one liferaft. 406 MHz satellite ELTs
are coming into international use; these devices will provide accurate
positions worldwide.
C. COSPAS-SARSAT
1. A national glossary of terms and abbreviations for COSPAS-
SARSAT was developed to help standardize and clarify terms,
and reduce national use of multiple terms with the same or
similar meaning. Since COSPAS-SARSAT is part of the GMDSS and
serves the SAR system, account was taken of terminology
already used internationally for SAR. Terms selected are
those likely to be encountered and used by SAR personnel and
have been incorporated into the Abbreviations/Acronyms and
Glossary of this manual.
2. COSPAS-SARSAT alerts not determined to result from signals
emanating from beacons are
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