Safety Investigation Report 2018:1 Factual Information/1.6/1.6.8 Aircraft Systems/4
SAFETY INVESTIGATION REPORT MH370 (9M-MRO)
4) Cabin and Cargo Compartments
The aircraft, 9M-MRO was configured to 35 business class and 247 economy class seats. The business class and economy class seats were procured from BE Aerospace. An approved Lay Out of Passenger Accommodation (LOPA) determines the cabin interior configuration. Safety and emergency equipment are fitted and positioned throughout the cabin.
There is one crew rest area in the forward cabin behind the cockpit. There is a cabin crew rest area in the aft cabin lower lobe. Access is through a compartment door adjacent to Door 3R.
The cockpit door provides selective entry to the cockpit and is resistant to ballistic penetration. When closed, the door locks when electrical power is available and unlocks when electrical power is removed. A viewing lens in the door allows observation of the cabin. The door can be manually opened from the cockpit by turning the door handle.
An emergency access code is used to gain access to the cockpit in case of pilot incapacitation. Access is provided by the use of a Keypad Access System which consists of a numeric keypad outside the cockpit area and a chime module and electric strike that is not accessible from outside the cockpit. The chime module provides an audible alert to the pilots that the correct code has been entered into the keypad. There is also an indicator light in the cockpit and a Light Emitting Diode (LED) on the keypad that indicates that the correct code has been entered.
The pilots have a 3-position switch by which they can open the door lock, close the door lock, or permanently lock the door for a specified amount of time to prevent access by anyone regardless if the correct code is entered into the keypad.
The door has blowout panels that will open in the event of a rapid decompression of the passenger compartment. A pressure sensor controls an electric strike and allows the door to open inward in the event of a rapid decompression in the cockpit. These features serve to equalise the pressure between the passenger compartment and the cockpit in case of decompression either side of the door.
The aircraft is also fitted with a Flight Deck Entry Video Surveillance System (FDEVSS) which provides the pilots surveillance capability of the cockpit doorway and the forward galley areas. This allows the pilots to see the person who wants to access the cockpit before they allow entry.
There are four Type A passenger and service doors on each side of the aircraft. Each door has a window. The passenger compartment has windows along both sides of the passenger compartment. Each exit is fitted with a slide raft system for emergency use.
The overhead passenger cabin is fitted with Passenger Service Units (PSU) above each seat row. They are hinged and secured by a magnetic latch that is electrically controlled. In the event of cabin depressurisation, the PSU magnetic latch will be electrically released and allow the oxygen masks to drop for passenger use.
The aircraft cabin lighting system comprises of ceiling lights, sidewall lights, entry lights and emergency lights. The cabin management system (CMS) controls the passenger cabin lighting.
The lower section of the fuselage houses forward, aft and bulk cargo compartments. A cargo handling system is fitted for the forward and aft cargo to command power drive units (PDU) to move cargo containers laterally and longitudinally.
Cargo compartment sidewalls, ceilings and walkways are constructed of fire resistant materials. There is a smoke detection warning system and fire extinguishing system installed to contain any smoke or fire eventualities.