ATA 47 – INERT GAS SYSTEM
- Reduces the amount of oxygen in the air within the center tank.
- Fuel Tank Inerting System (FTIS)
- Conditioned Service Air System (CSAS) – ATA 21
- Inert Gas Generation System (IGGS)
CSAS
Hot Bleed Air > CSAS Isolation Valve > Ozone Converter > CSAS Heat Exchanger (TCM) > Conditioned Air
- CSAS Controller Unit (CCU)
- Controls CSAS Isolation Valve
- Interface with IGGS Controller Unit (ICU)
- Has BITE function of CCU
- Also has BITE functions of ICU
IGGS
Conditioned Air > IGGS Isolation Valve > D-ULPA (Double ultra low particle) filter > Air Separation Module > NEA + OEA
- NEA > Dual Flow Shut Off Valve > Dual Flapper Check Valve > Center Tank
- OEA discards overboard.
- Dual Flow Shut Off Valve, two function –
- Open/Shut for NEA
- Controls NEA Flows
- Low – Climb and Cruise
- Mid – Approach
- High – Descent
- IGGS Controller Unit (ICU) – Controls IGGS Isolation Valve
- Oxygen sensor – measures the oxygen concentration of the NEA.
KEY POINTS
- The ozone converter catalytically decreases the ozone concentration of the bleed air. The decreased ozone concentration prevents damage to the air separation module fibers of the inert gas generation system.
- The CSAS Temperature Control Module (TCM) has:
- a CSAS heat exchanger,
- a hot air bypass valve,
- a temperature sensor,
- a pressure sensor.
- TCM is installed on the ram air inlet side of the air conditioning pack 1 heat exchanger.
- IGGS Pallet – a structural support made of aluminum, contains the isolation valve, D-ULPA filter, ASM, oxygen sensor, and Dual Flow Shut-Off Valve.
- The fuel tank is inert when the average oxygen concentration is below 12% at sea level.
- The aircraft crew does not operate the FTIS, because it has automatic control.
- When the aircraft is on ground the FTIS does not operate.
- During aircraft flight, the FTIS operates automatically.
- CSAS is required to cool down hot bleed air at a level compatible with IGGS.
COMPUTERS
- CSAS Controller – 1
- IGGS Controller – 1
