Definition
An onboard system that provides a means of voice communication between flight crew stations, and in some installations between the flight crew and cabin crew or passengers, when normal communication systems have failed or during emergency conditions. On larger transport aircraft it is typically a self-contained, independently powered intercom that remains available when primary electrical systems are lost.
Plain English
A backup talking system that lets the people on the flight deck keep speaking to each other, and sometimes to the cabin, when the regular intercom or radios are not working.
Context Anchor
You may see EVCS in airport information, facility notices, emergency planning material, or a notice reporting that the system is working or out of service.
Why Pilots Care
Maintains the ability to declare an emergency, request assistance, or coordinate with ATC when standard VHF or other radios fail, directly supporting safety and decision-making.
Intuition Check
Do not read EVCS as a radio frequency or a distress call. It means the communication system used by people coordinating an emergency response.
Example Sentence 1
After the audio panel failure, the captain switched to the EVCS to keep talking to the first officer and the lead flight attendant.
Example Sentence 2
Training emphasized that the EVCS serves as the final voice link in total electrical or radio failure scenarios.