ECS Questions Flashcards
What does the AMS use bleed air for?
- ECS (heating & Cooling)
- Engine start
- Pressurization
- Engine and wing anti-ice
- Water pressure
- Hot air leak detect
How many AMS controllers are installed?
- One controller with 2 channels which control the respective onside system
What happens if a channel fails?
- The remaining channel is able to control the entire AMS
What provides air for the AMS?
- Engine bleeds
- APU bleed
- External pneumatic source
What is bleed air used for?
- ECS (heating & cooling)
- Engine start
- Engine and wing anti-icing
- Water pressurization
What is external pneumatic air used for?
- ECS on the ground
- Engine start on the ground
Where is the external ground source panel located?
- Lower fairing between the wings
What is the primary use for APU bleed air?
- ECS on the ground
- Engine starting on the ground
- Electrical source
Can engine bleed air flow-back to the APU?
- No. A check valve prevents flow back
Where is bleed air tapped from the engine?
- 6th and 10th stage compressors (EBV and HSV respectively)
- System alternates between valves to regulates and adequate and safe pressure.
What is normal pressure for engine operation?
45 psi
What is the purpose of the pre-cooler?
Cools the bleed air coming from the engine to the AMS
What cools the pre-cooler?
- Ground N1 fan
- Flight N1 fan or ram air
What does the overheat detection system (ODS) observe?
- Engine bleeds and packs
- APU bleed
- Plumbing for the wing and engine anti-icing system
Do both loops have to function in order to detect on overheat condition?
- Yes, but if one fails the other will work alone to detect the overheat
How many ECS packs are on the airplane? What provides air for the packs?
- 2 independent packs (left & right)
- Each engine provides bleed air to its respective pack
Can a single pack provide adequate temperature control and pressurization?
- Yes, up to FL310
Can a single bleed source power both packs?
Yes, up to FL310
What is the ratio of fresh air to recirculation air?
- 52% fresh air to 48% recirculated
When are the recirculation fans commanded off?
- Cockpit switch
- Smoke detected in the record bay
- DUMP button is pressed
- Respective pack is commanded off
What keeps the 3 avionic E-BAY’s cool?
- FWD & CTR E-BAY 3 fans each pull air from cabin to bay
- AFT E-BAY natural air-flow from cabin to bay
When is the Emergency Ram Air Ventilation activated?
- Both packs commanded or failed OFF below 25,000 ft (via left side and electronically controlled)
- Ram air pressure greater than cabin pressure (via right side)
How many channels on the cabin pressure control (CPC)?
2 Channels, one active and one in standby mode
Where dose the CPC get Landing Field Elevation (LFE)?
- FMS or can be manually selected