AMS Flashcards
What does the AMS use bleed air for?
- ECS
- Engine Start
- Pressurization
- Engine and Wing A/I
- Water Pressure
- Hot Air Leak Detection
How many AMS controllers are installed?
One controller with 2 channels which control the respective onside pack
What happens if a single pack fails?
The remaining pack is able to control the entire AMS through the X-BLD valve
What provides air for the AMS?
- Engine Bleeds
- APU Bleed
- External Pneumatic Source
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 are some of the uses of APU bleed air?
- ECS on the ground
- Engine starting on the ground
- Assist with Engine Start up to FL210
- Bleed source up to 15000
Can engine bleed air flow back to the APU?
No, there is a check valve in place that prevents flow-back
Where is bleed air tapped from the engines?
Located at the 6th and 10th Stage Compressors with the system alternating between valves to regulate pressure and temperature
What is the normal bleed pressure for any engine operation?
roughly 45 psi
What is the purpose of the pre-cooler?
Cools the bleed air coming from the engine to the AMS (204C˚)
What cools the pre-cooler?
NACA air inlets that provide ram air to cool pre-coolers along with the Fan Air Motor Valve FAMV
What does the Overheat Detection System (ODS) observe?
- Engine bleeds and packs
- APU Bleed
- Plumbing for the wing and engine A/I
How many ECS packs are on the airplane and what provides air for these packs?
2 independent packs run by their respective onside engine bleeds
Can a single pack provide adequate temp control and pressurization?
Yes, up to FL310
What is the ratio of fresh air to recirc. air?
52% new 48% recirc.
When are the recirc. fans commanded off?
- On ground, when APU is Bleed Source
- Smoke is detected in Recirc. Bay
- Dump button pressed
- Both packs are commanded OFF
- Cargo Bay Fire Signal Present
What keeps the 3 avionics bays cool?
FWD & CTR E-Bay = 3 fans pull air from cabin to bay
AFT E-Bay = Natural air flow from cabin to bay
When is the emergency Ram Air Ventilation activated?
Left RAV (AMS controlled) = < FL250 and both packs are off
Right RAV (check valve) = Ram air pressure (outside) > cabin pressure (inside)
How many channels are on the Cabin Pressure Control?
2 Channels, one active and one standby
Where does the CPC get LFE?
FMS or manually selected
What happens when the DUMP button is pressed?
- Both packs commanded off
- OFV opens (2,000 fpm up to 12,400 then natural leak)
- Recirc fans off
- RAID Doors Open
Can the cabin altitude be higher than 12,400?
Yes
1. it can be done manually
2. Due to natural leak
In manual mode, will the cabin depressurize automatically?
No
What is the bleed priority in flight?
- Onside
- Opposite engine
- APU (if avail)
If engine and apu bleed is avail, when does APU have priority?
- A/C on ground
- Wheel speed < 50 kts, and 30 secs have passed after touchdown
- ECS off AND A/I NOT ALL or single engine taxi
When does the PPRV open?
∆ psi of 8.6
What is the cabin diff pressure normally at under 37,000?
7.8 ∆ psi
Can the cabin be returned back to normal operation after pressing the dump button?
Yes, after pressing the dump button for the 2nd time, the CPCS will return to normal operation
Where is the AMS Controller located and how many channels does it have?
It is located on SPDA 2 and has 2 channels
Which valve does the Bleed 1 (2) buttons control?
EBV or Engine Bleed Valve
What type of valves are the HSV and EBV?
Pressure Regulating Valves as controlled per the AMS, which receive info from Pressure and Temp Sensors downstream of the EBV
What type of valve is the 6th stage valve?
Check Valve
When does the X-Bleed Valve open?
Whenever there is no manifold pressure on one side and there is pressure on the other side
In flight:
1. #2 start in the air
2. #1 start in the air, APU unavail.
On-ground:
Main engine start, APU unavail.
When are the packs auto recovered?
- 500’ both engines operating
- 9,700’ OEI, takeoff elev. below 8,000’
- 15,000’ OEI takeoff elev. above 8,000’
- thrust levers at or below TOGA
How many fans are a part of the ECS system?
9 total
6 fans for avionics cooling (3 fwd/3 aft)
2 recirc. fans
1 fwd cargo fan
When scenarios do the FADEC send an ECS off signal to the AMS controller?
takeoff:
1. OEI, APU bleed unavail.
2. Thrust levers max, APU unaval
3. Ref ECS off in TDS, APU unavail
4. REF ECS off in TDS, A/I ALL
G/A
1. OEI, APU bleed unavail
2. Thrust max, APU unavail
3. Thrust max, Wing A/I requested ON
When are both Ram Air Inlet Doors (RAID) commanded OPEN?
- In climb up to FL17.5
- In descent below FL17
- RAT Deployed
- A/I system is activated
- Dump button
When is a single RAID door commanded OPEN?
Onside Pack fail or commanded off
When are both RAID doors commanded to CLOSE?
- A/C on ground
- GS less than 50 kts
- ECS 1/2 packs detected OFF
- Packs 1/2 Selected OFF on OVHD Panel
- Dump Button NOT Activated
- Above 17.5 in climb and above 17 in descent
At what temp does the Gasper SOV open?
at 35˚ C the Gasper SOV Opens directing Recirc Fan #2 Air directly into Gasper Manifold
Which valve does the Pack 1 (2) buttons control?
FCV or flow control valve
How long does it take for the OFV to fully actuate to 90˚ OPEN?
50 seconds
What is the approximate temp of air leaving the pre-cooler?
Roughly 204˚ C
What is Abort Mode and when does it activate?
Sets Takeoff Field Elevation, assuming returning to the field
1. A/C stops climbing
2. CRZ never activated
3. Pres. ALT below 10,000’
or
4. less than 5,000’ above Takeoff Elev.
When does Cabin Alt Caution come on?
8,000’ Cabin Alt (turns yellow)
Cabin Alt Hi Warning altitude?
9,700’ Cabin Alt (turns red); Aural Warning: CABIN
When does the AMS ignore the FADEC ECS OFF Signal?
Above 15,000’
What is the primary purpose for opening the Emer. Ram Air Ventilation Valve?
Smoke Evacuation of Flight Deck/Cabin
What altitude must the Cabin ALT reach to auto deploy PAX Oxy and what is the ALT range?
Above 14,000 and between 14 and 14,750
When does bleed manifold pressure disappear off of the Status Page?
When both engines are started
5 Components of the CPCS?
- CPC (dual channel)
- OFV
- PPRV (spring-loaded check valve)
- NPRV (spring-loaded check valve)
- Static Port vented to PPRV
