INSTALLATION MANUAL OPERATION MANUAL
KANNAD 406 AP-H
PAGE 101
JUL 24/2013
SYSTEM FUNCTIONAL DESCRIPTION AND OPERATION
1. Transmitter
The KANNAD 406 AP-H can be activated either automatically when the crash
occurs (thanks to a shock sensor) or manually (thanks to a switch on the
transmitter itself or on a Remote Control Panel).
The KANNAD 406 AP-H is designed to transmit on three frequencies (121.5,
243 and 406 MHz). The two basic emergency frequencies (121.5 and 243
MHz) are mainly used for homing in the final stages of the rescue operations.
The 406 MHz frequency is used by the COSPAS-SARSAT satellites for precise
pinpointing and identification of the aircraft in distress.
Once activated, the transmitter operates continuously on 121.5 and 243.0 MHz
with an output power of 100 mW on each frequency. The modulation is an audio
frequency sweeping downwards from 1420 Hz to 490 Hz with a repetition rate
of 3 Hz.
During the first 24 hours of operation, a digital message is transmitted on
406.025 MHz every 50 seconds. The output power on 406 MHz is 5 W.
The KANNAD 406 AP-H can transmit two types of messages on 406 MHz:
• 112 bits for a short message (identification only);
• 144 bits for a long message (identifi aircraft position).
The long messages are generated by a separate interface module (called
CS144) connected to the ELT and either NAV equipment of the aircraft by
RS232, RS422 or RS485 link or to an ARINC429 bus.
