Final answer:
Cabin checks for CM 4 are usually done before takeoff as part of the pre-flight safety procedures to ensure the cabin is secure.
Step-by-step explanation:
Securing the cabin checks for CM 4 are typically performed before takeoff. This is a crucial part of pre-flight procedures ensuring that the cabin is safe and secure for takeoff. Such measures include checking that all carry-on luggage is properly stowed, seat belts are fastened, seats are in the upright position, tray tables are locked, and all electronics are turned off or set to airplane mode. This protocol aims to minimize the risk of injury and ensure passenger safety throughout the flight.