DB's SY 737 Air Systems Flashcards
ISOLATION VALVE switch:
- CLOSE
- AUTO
- OPEN
- Closes isolation valve
- A. Closes isolation valve if both engine BLEED air switches are ON and both air conditioning PACK switches are AUTO or HIGH
B. Opens isolation valve automatically if either engine BLEED air or air conditioning PACK switches are positioned OFF - Opens isolation valve
DUAL BLEED light illuminated
- APU bleed air valve open and engine 1 BLEED switch ON
2. Engine 2 BLEED air switch ON, APU bleed air valve and isolation valve open.
WING-BODY OVERHEAT light illuminated
- left light
- Right light
- Overheat from bleed air duct in
a. left engine strut
b. left inboard wing leading edge
c. left air conditioning bay
d. keel beam or
e. APU bleed air duct - Overheat from bleed air duct in
a. right engine strut
b. right inboard wing leading edge or
c. right air conditioning bay.
Engine BLEED Air switches
- OFF
- ON
- Closes engine bleed air valve
2. Opens engine bleed air valve when engines are operating
APU BLEED Air Switch
- OFF
- ON
- Closes APU bleed air valve
2. Opens APU bleed air valve when APU is operating
Wing-Body Overheat TEST switch - push
- Tests wing-body overheat detector circuits
2. Illuminates both WING-BODY OVERHEAT lights
BLEED TRIP OFF Light - illuminated (Amber)
Excessive engine bleed air temp or pressure
• related engine bleed air valve closes automatically
• requires reset
TRIP RESET Switch- Push (if fault condition is corrected)
- Resets BLEED TRIP OFF, PACK and ZONE TEMP lights
- Related engine bleed valve, PACK valve, or trim air modulating valve opens
- Lights remain illuminated until reset
CONT CAB ZONE TEMP light
- illuminated
- During master recall
- Duct temp overheat or failure of the flight deck primary and standby temp controller
- Failure of the flight deck primary or standby temp controller
FWD CAB or AFT CAB ZONE TEMP light
- illuminated
- During master recall
- Duct temp overheat
2. Failure of associated zone temp control
Temperature Selector
- Auto
- OFF
- Provides automatic temp control for associated zones ranging from 65°F (C) to 85°F (W)
- Closes the associated trim air modulating position
RAM DOOR FULL OPEN light
- Illuminated
- When would it normally be illuminated?
- Ram door in full open position
2. On the ground or during slow flight with the flaps not fully retracted
Air Conditioning PACK Switch - OFF
PACK signaled OFF
Air Conditioning PACK Switch - AUTO
PACKs regulate to low or high flow, depending on conditions.
When do PACKs operate in low flow mode?
With PACK Switches in AUTO and both PACKs are operating.
When do PACKs operate in high flow mode automatically?
Both air conditioning PACK Switches AUTO and
- One PACK not operating
- Inflight
- Flaps up
When do PACKs operate in high flow mode manually?
- When operating at least one PACK from APU and both engine BLEED air switches OFF, either Inflight or on the ground
- When either PACK switch is positioned to HIGH
Air Conditioning PACK Switch - HIGH
- Regulates to high flow
2. Provides maximum flow rate on ground with APU BLEED air switch ON
PACK light - Illuminated (amber)
- During recall
- On its own
- Failure of either primary or standby PACK control
2. Indicates PACK trip off (due to excessive heat) or failure of both primary and standby PACK controls
TRIM AIR Switch
- ON
- OFF
- Trim air pressure regulating and SOV signaled open
2. Trim air pressure regulating and SOV signaled closed
RECIRC FAN Switches - OFF
Fan signaled off
RECIRC FAN Switches - AUTO
In-flight
1. Left RECIRC fan
2. Right RECIRC fan
- Operates if both PACKs are operating unless either PACK switch is in HIGH
- Operates if both PACKs are operating unless both PACK Switches are in HIGH
RECIRC FAN Switches - AUTO - on the ground
- Left RECIRC fan
- Right RECIRC fan
- Operates unless both PACK switch is in HIGH
2. Operates even if both PACK Switches are in HIGH
AUTO FAIL light - Illuminated (amber)
- Single controller failure (with ALTN light on)
- Dual controller failure (with ALTN light off)
- Loss of DC power
- Outflow valve control fault
- Excessive differential pressure (>8.75 PSI)
- Excessive rate of cabin pressure change (+/- 2000 ft/min)
- High cabin altitude (> 15,800ft)
OFF SCHED DESCENT light - illuminated (Amber)
Airplane descended before reaching the planned cruise altitude set in the FLT ALT indicator
FLT ALT or LAND ALT Indicator displays “88888” or all dashes?
A panel failure was detected after a DC power interruption
MANUAL light - illuminated (green)
Pressurization system operating in manual mode
ALTN light - illuminated (green)
- With AUTO FAIL light
- Without AUTO FAIL light
Pressurization system operating in alternate automatic mode:
- Indicates a single controller failure and automatic transfer to ALTN mode
- Pressurization mode selector in ALTN position
In which pressurization modes (auto, alternate, or manual) will the outflow valve operate?
All modes
Pressurization Mode Selector - AUTO
Pressurization system controlled automatically
Pressurization Mode Selector - ALTN
Pressurization system controlled automatically using ALTN controller
Pressurization Mode Selector - MAN
Pressurization system controlled manually by outflow valve switch (both auto controllers bypassed)
What is the Cabin/Flight Altitude placard used for?
Determining the setting for cabin altitude when operating in manual mode
What systems rely on the bleed air system for operation?
- Air conditioning/pressurization
- Wing and engine thermal anti-icing
- Engine starting
- Hydraulic reservoir pressurization
- Water tank pressurization (817SY and 818SY)
- Aspirated TAT
Where is engine bleed air obtained from?
The 5th and 9th stages of the compressor
The L and R duct pressure indicates a 30 PSI split, but everything else remains normal. Is this a write up?
No. Indications are considered normal as long as there is sufficient air for cabin pressurization.
When and why do the deflector doors of the ram air inlet extend?
When on the ground to prevent slush ingestion.
If a passenger cabin zone trim air, or all trim air is lost, what temperature will be produced by;
- The left PACK
- The right PACK
- Whatever is selected by the CONT Cabin temp controller
2. The average of the forward and aft zone temp demands
If all zone controls are positioned to OFF, what is this called and what temp will each PACK produce?
Fixed Cabin Temperature produces 75° from the left PACK and 65° from the right PACK.
Where does the forward cargo compartment receive its warm air supply from when;
- Outboard exhaust is open (normally on ground)
- Outboard exhaust is closed (normally in flight)
- The passenger cabin exhaust
2. Electric equipment cooling exhaust
At what PSI does the positive pressure relief valves provide safety pressure relief?
They open at 8.95 PSI limiting the differential pressure to a max of 9.1 PSI.
When would you expect the overboard exhaust valve (located just after of the E&E compartment) to open?
- On the ground
- In flight with low differential pressure
- For smoke removal (either PACK switch OFF and right RECIRC OFF)
How is the take off airport altitude set on pressurization auto controllers?
Automatically using cabin altitude when on the ground.
