Factual Information 2015:Appendix 1.6E/1.6E.15
This page contains an extract from MH370/01/15 Factual Information which accompanied the (first) Interim Statement released by The Malaysian ICAO Annex 13 Safety Investigation Team for MH370 on 8th March 2015.
1.6E.15 Oxygen Systems
1.6E.15.1 Crew Oxygen System
The crew oxygen system provides oxygen to the flight crew for emergencies and other procedures which make its use necessary. The oxygen is supplied by two cylinders located in the left side of the main equipment centre. Each cylinder is made of composite material and holds 115 cubic feet (3150 litres) of oxygen at 1850 psi. The oxygen is supplied, through regulators, to four oxygen masks in the cockpit, one each for the Captain, the First Officer, the First Observer and the Second Observer. The mask has a dilution control which is normally set at ‘Normal’ position. In this position the oxygen is diluted with ambient air according to the pressure altitude in the flight deck. It can also be selected to ‘100%’, in which case 100% oxygen will be supplied. Table 1.6A below shows the expected duration of oxygen supply from the two cylinders with the dilution control in ‘Normal’ position. Aircraft altitude is assumed to be 36,000 ft. A cabin altitude of 8,000 ft. would indicate a normally pressurised cabin and a cabin altitude of 36,000 ft. would indicate an unpressurised cabin. At this cabin altitude of 36,000 ft. 100% oxygen will be supplied even with the dilution control in the ‘Normal’ position.
Cabin Altitude: 8,000 ft. |
Cabin Altitude: 36,000 ft. |
||
Crew Members |
Duration (hour) |
Crew Members |
Duration (hour) |
| 1 | 42 | 1 | 27 |
| 2 | 21 | 2 | 13 |
| 3 | 14 | 3 | 9 |
| 4 | 10.5 | 4 | 6.5 |
1.6E.15.2 Passenger Oxygen System
The passenger oxygen system is supplied by individual chemical oxygen generators. The oxygen system provides oxygen to:
- passenger seats
- attendant stations
- lower crew rest compartment
- lavatory service units.
The passenger oxygen masks and chemical oxygen generators are located in passenger service units (PSUs). Oxygen flows from a PSU generator when any mask hanging from that PSU is pulled. Oxygen is available for approximately 22 minutes. The masks automatically drop from the PSUs if cabin altitude exceeds approximately 13,500 feet. The passenger masks can be manually deployed from the flight deck by pushing the overhead panel PASSENGER OXYGEN switch to the ON position.
1.6E.15.3 Portable Oxygen
Portable oxygen cylinder lets the flight attendants move in the aircraft when oxygen is in use. It is also a gaseous oxygen supply for medical emergencies. The bottle is fitted with disposable mask. 15 cylinders are located throughout the passenger cabin. Each cylinder is of 11 cubic feet (301 litres) capacity. The flow of oxygen can be controlled by an ‘Off-On’knob from 0 to 20 litres per minute.
Source: Malaysian ICAO Annex 13 Safety Investigation Team for MH370, 8 March 2015, Factual Information MH370/01/15
The Factual Information was updated in 2018 by the Safety Investigation Report MH370/01/2018 which added new content but did not include all of the previous data.