PC-21 Oxygen System Flashcards
What is the purpose of the oxygen system?
- To supply the aircrew with oxygen enriched breathing gas from engine start through all phases of aircraft operation, including ejection
- Protects the aircrew from inhaling noxious and toxics fumes during an emergency.
What is a disadvantage of the system?
Pilot loses the ability to smell invisible fumes that are an early indication of a potential problem.
What does it mean when the oxygen system is self-contained?
No cockpit air is breathed once the mask is fitted and the oxygen system has been turned on.
What are the two sub systems of the oxygen system?
- OBOGS - primary source of breathing gas for the aircrew during normal operations
- Emergency Oxygen (EO) - supplies oxygen to the aircrew during ejection from a cylinder fitted to the ejection seat.
What are the main components of the OBOGS?
- Heat exchanger
- OBOGS Pressure Reducing Shut-Off Valve
- Overpressure and overtemperature switches
- Water separator
- Oxygen Concentrator
- Solid State Oxygen Monitor Controller
- Oxygen hoses
What does the heat exchanger do?
Reduces temperature of incoming bleed air and passes cooled air to the PRSOV
What does the PRSOV do?
Controls the air pressure at a preset level
What does the overpressure switch do? Overtemperature switches?
- If PRSOV fails to control the air pressure, the switch will sent a signal to close the PRSOV and stop the airflow.
- Same thing if air is too hot
What does the water separator do?
Removes water from the air that is passed through
What does the Oxygen concentrator do?
Comprises of 3 oxygen concentrator beds that transform cooled, dried bleed air into oxygen enriched breathing gas.
What is the SSOM-C?
- It constantly monitors and controls the % of oxygen ini the output breathing gas
- Monitors air pressure in the cockpit
What is the primary function of the oxygen regulator?
- Reduces the pressure of the breathing gas to a suitable level for breathing.
- Maintains constant positive pressure differential in order to prevent breathing air contamination if there is a leak in the system
What controls does the oxygen regulator have?
- OXY switch
- Test pushbutton
- Mixture switch
What does the anti-suffocation valve?
Allows the pilot to breathe when the OBOGS is not operating.
What are the main components of the anti-g system?
- Anti-g valves
2. Connector assemblies
What is the function of the anti-g system?
Supply cool air to the pilots anti-g suits.
What are the main components of the EO system?
- EO cylinder
- Emergency Regulator Connector (ERC)
- EO regulator
- EO handle
- EO pressure gauge
What does the ACS shutoff lever do?
- Used to mechanically close the firewall shut-off valve in order to prevent air from flowing into the cockpit air distribution system
- OBOGS PRSOV is closed
- OBOGS and anti-g systems no longer function
What does OBOGS interface with to allow for warnings to be displayed on MFDs? What about DWP
Mission Computer (MC) RIOC 3
What provides power to oxygen regulators?
28V DC from BATT BUS
What does the OXY switch ON/OFF do?
When On:
- Power is supplied to SSOM-C, which in turn supplies power to the OBOGS concentrator
- OBOGS PRSOV is opened to provide engine bleed air
- Internal regulator valve is opened to pass breathing gas to the pilot
What is the TEST pushbutton used to ?
Used to check leakages of breathing gas at the face seal and from the flexible hoses.
What does the MIXTURE switch do?
- AUTO (normal position)
- MAX (generates max oxygen to both pilots)
Where is OBOGS schematic shows?
MFD ECS
