What happens if the MCD is not closed properly on the ERJ 175?

If the MCD (Main Cabin Door) is not closed properly on the ERJ 175, it will alert the crew with an indicator. This is a crucial safety feature designed to ensure that all doors are secure and properly closed before the aircraft can proceed with taxiing or takeoff. The indicator acts as a warning system, helping the flight crew to verify door status and address any potential issues quickly, thereby enhancing safety during operations.

This mechanism is vital because it ensures that the crew is immediately informed of any discrepancies regarding the door status, allowing them to take appropriate action before any further steps can be taken in the flight process, such as taxiing or takeoff.