ECS Flashcards
2 packs
Engine 1 controls pack 1
Engine 2 controls pack 2
Recirc fans
Help reduce load on packs by recycling air
Provides 52% fresh 48% recirculated air
Will not work when
- Dump is pressed
- Smoke is detected in recirc bay
- Respective pack is off
Gaspar ventilation
Provides personal air to PAX and Crew
Supplied by right recirc fans
Electronic compartment bays
Forward central and aft electronic bays are vented with conditioned air and vented overboard
Cargo bays
Forward bay receives air from cabin and then is vented overboard
Aft cargo bay is not vented
Emergency ram air ventilation
In case of failure
Enters left side of system through a valve if
- In flight
- Both packs are off or failed
- Below 25,000
Emergency ram air enters right side through a check valve if outside pressure is greater than inside pressure
Pre cooler
Uses fan and/or ram air to cool engine bleed going to the ECS
Pressurization
Cabin pressurization system (CPCS)
Outflow valve (OFV)
Negative pressure relief valve (NPRV)
Positive pressure relief valve (safety valve)
Static port
CPC
Controls OFV
2 channels
Alternate each flight
OFV
Regulates amount of air leaving vessel to maintain cabin pressure
Auto
Manual
LFE
PPRV
Opens when cabin pressure reaches 8.8 PSI (OFV FAIL)
Dump function
Only works in auto
Shuts off packs and recirc fans
Allows cabin to climb to max ALT. Of 12400 feet @ 200 fpm climb rate
APU bleed air
ECS on ground
Engine start on ground
Engine start inflight up to FL 210
Electrical source up to FL330
Bleed air for pressurization, heating, and cooling (below 15000 MSL)
Valve prevents blowback to APU
Where is bleed air trapped from engines
6 and 10th stage of compressers
What cools the pre cooler
Ground N1 fan
Flight N1 fan or ram air
When does APU have bleed air priority
On ground less than 50 knots wheel speed
Opposite engine bleed isnt enough to support engine start
