Final answer:
Pressing and holding the EMER ENTRY button typically initiates the emergency unlocking of the aircraft cabin door for authorized personnel, not the deployment of emergency equipment such as evacuation slides or oxygen masks, nor does it control in-flight entertainment or cabin lighting.
Step-by-step explanation:
Pressing and holding the cabin EMER ENTRY button for a short time typically initiates the emergency unlocking of the cabin door for use by authorized personnel in situations that require immediate access to the cabin from the outside without normal key or code entry. It does not trigger the following actions:
- The emergency evacuation slide, which is deployed manually by crew members in the event of an emergency landing.
- In-flight entertainment, which is a system used for passenger entertainment and is unrelated to emergency procedures.
- Oxygen masks deployment, which occurs automatically in the event of a loss of cabin pressure.
- Cabin lighting, which includes various lighting options controlled typically by the flight attendants or automatic systems.
Thus, it is important to note that the EMER ENTRY button's function is specifically related to emergency access to the aircraft cabin and not to other emergency or non-emergency systems on the aircraft.