The purpose of monitoring 121.5 prior to engine shutdown is to determine:

• A. If the ELT has not been activated
• B. If the ELT is currently signaling on 406 MHz
• C. If the ELT needs replacement
• D. If the ELT antenna is aligned

Answer: (A)

Listening on 121.5 before shutting down checks for an active distress beacon in the area. 121.5 MHz is the emergency frequency used for ELT homing, so hearing a signal there means an ELT has been activated and rescue coordination may be underway. If you don’t hear anything, you can be reasonably confident that an ELT in range isn’t broadcasting, allowing you to power down normally. This frequency isn’t used to verify 406 MHz satellite transmissions or to assess ELT replacement or antenna alignment.