During SINCGARS startup, which COMSEC switch position should be selected?

During SINCGARS startup, which COMSEC switch position should be selected?

• A. CT
• B. ON
• C. OFF
• D. ENABLE

Answer: (A)

The main idea here is that the COMSEC switch must go into the CT position to initialize the cryptographic system as the SINCGARS radio powers up. Selecting CT puts the radio into its crypto initialization mode, which kicks off the crypto engine, allows the crypto material to be loaded, and establishes secure operation before normal use. This ensures keys and crypto state are properly loaded so encryption can operate correctly once you move into standard transmission and reception. If you leave the switch in other positions, the radio either won’t initialize the crypto subsystem or would be attempting normal operation without having completed the required startup cryptographic steps, which can lead to insecure or failed communications. That’s why CT is the best choice during startup.

The main idea here is that the COMSEC switch must go into the CT position to initialize the cryptographic system as the SINCGARS radio powers up. Selecting CT puts the radio into its crypto initialization mode, which kicks off the crypto engine, allows the crypto material to be loaded, and establishes secure operation before normal use. This ensures keys and crypto state are properly loaded so encryption can operate correctly once you move into standard transmission and reception.

If you leave the switch in other positions, the radio either won’t initialize the crypto subsystem or would be attempting normal operation without having completed the required startup cryptographic steps, which can lead to insecure or failed communications. That’s why CT is the best choice during startup.