C-40 AIR SYSTEMS/PRESSURIZATION

  1. Image Upload 1
    What does #1 indicate?
    Illuminated (amber) – APU bleed air valve open and engine No. 1 BLEED air switch ON, or engine No. 2 BLEED air switch ON, APU bleed air valve and isolation valve open.
  2. Image Upload 2
    What does #2 do?
    CLOSE – closes isolation valve.

    AUTO –

    -closes isolation valve if both engine BLEED air switches are ON and both air conditioning PACK switches are AUTO or HIGH

    -opens isolation valve automatically if either engine BLEED air or air conditioning PACK switch positioned OFF.

    OPEN – opens isolation valve.
  3. Image Upload 3
    What does #3 indicate?
    Illuminated (amber) –

    -left light indicates overheat from bleed air duct leak in left engine strut, left inboard wing leading edge, left air conditioning bay, keel beam or APU bleed air duct

    -right light indicates overheat from bleed air duct leak in right engine strut, right inboard wing leading edge or right air conditioning bay.

    Image Upload 4
  4. Can a WING BODY OVERHEAT be reset?
    No.
  5. Image Upload 5
    What does #6 indicate?
    Indicates pressure in L and R (left and right) bleed air ducts.
  6. Image Upload 6
    What does #8 indicate?
    Illuminated (amber) – excessive engine bleed air temperature or pressure

    -related engine bleed air valve closes automatically

    -requires reset.
  7. Image Upload 7
    Can a BLEED TRIP OFF light be reset?
    Yes
  8. Image Upload 8
    What does #9 do?
    Push (if fault condition is corrected) –

    -resets BLEED TRIP OFF, PACK TRIP OFF or DUCT OVERHEAT lights

    -related engine bleed air valve opens, or related pack valve opens, or related air mix valve opens

    Lights remain illuminated until reset.
  9. Image Upload 9
    What does #2 indicate?
    Illuminated (amber) –

    -distribution air temperature in related duct exceeds limit

    -air mix valves drive full cold

    -requires reset.
  10. Image Upload 10
    What does #4 indicate?
    Illuminated (blue) – indicates ram door in full open position.
  11. True or False?  A single pack is capable of maintaining pressurization and acceptable temperatures throughout the airplane up to the maximum certified ceiling.
    True
  12. When should the RAM DOOR FULL OPEN lights extinguish?
    In flight, flaps up
  13. What is ram air used for and when?
    The ram air system provides cooling air for the heat exchangers. Operation of the system is automatically controlled by the packs through operation of ram air inlet doors.

    On the ground, or during slow flight with the flaps not fully retracted, the ram air inlet doors move to the full open position for maximum cooling. In normal cruise, the doors modulate between open and closed. A RAM DOOR FULL OPEN light illuminates whenever a ram door is fully open.

    Deflector doors are installed forward of the ram air inlet doors to prevent slush ingestion prior to liftoff and after touchdown. Deflector doors extend when activated electrically by the air–ground safety sensor.
  14. Image Upload 11
    What does #5 do in OFF, AUTO and HIGH?
    OFF – pack signaled OFF.

    AUTO –

    -with both packs operating, each pack regulates to low flow

    -with one pack operating, operating pack regulates to high flow in flight with flaps up

    -when operating one pack from APU (both engine BLEED air switches

    OFF), regulates to high flow.

    HIGH –

    -pack regulates to high flow

    -provides maximum flow rate on ground with APU BLEED air switch ON.
  15. If both packs are in AUTO, when will you get HIGH flow?
    Both engine bleeds off and APU bleed on


    OR

    With one pack operating, operating pack regulates to high flow in flight with the flaps up
  16. Image Upload 12
    What does #9 indicate?
    Illuminated (amber) –

    -indicates pack temperature has exceeded limits

    -related pack valve automatically closes and mix valves drive full cold

    -requires reset.
  17. Image Upload 13
    What does #10 do?
    Push (if fault condition is corrected) –

    -resets BLEED TRIP OFF, PACK TRIP OFF or DUCT OVERHEAT lights

    -related engine bleed air valve opens, or related pack valve opens, or related air mix valve opens

    Lights remain illuminated until reset.
  18. Image Upload 14
    What does #2/4 indicate?
    Illuminated (amber) – no airflow from selected cooling supply or exhaust  fan.
  19. Image Upload 15
    What does #3 do?
    Push –

    -cuts out intermittent cabin altitude warning horn

    -altitude warning horn sounds when cabin exceeds 10,000 feet altitude.
  20. Image Upload 16
    What does #4 indicate?
    ON (white) – reprograms initiation of cabin altitude warning annunciation from

    10,000 to 14,000 feet.

    Off – (ON not visible)

    -reprograms cabin pressurization from high altitude to normal operation

    -extinguishes INOP light
  21. Image Upload 17
    If #4 is engaged, when does the system switch back to normal pressurization?
    Upon departure from a high altitude airport, the system returns to normal operation as the cabin altitude descends through 8,500 feet.
  22. Image Upload 18
    What does #5 indicate?
    Illuminated (amber) – indicates high altitude landing system fault.
  23. Image Upload 19
    What does #1 indicate?
    Illuminated (amber) – automatic pressurization system failure detected:

    -indicates a single controller failure when ALTN light is also illuminated

    -indicates a dual controller failure when illuminated alone.
  24. Image Upload 20
    What would cause #1 to illuminate?
    An amber AUTO FAIL light illuminates if any of the following conditions occurs:

    -Loss of DC power

    -Controller fault

    -Outflow valve control fault

    -Excessive differential pressure (> 8.75 psi)*

    -Excessive rate of cabin pressure change (±2000 sea level feet/minute)*

    -High cabin altitude (above 15,800 feet).*

    *If controller is not responding properly

    With illumination of the AUTO FAIL light, the pressure control automatically transfers to the other auto controller (ALTN mode).
  25. Image Upload 21
    What does #2 indicate?
    Illuminated (amber) – airplane descended before reaching the planned cruise altitude set in the FLT ALT indicator.
  26. Image Upload 22
    What does #8 indicate?
    Illuminated (green) – pressurization system operating in the alternate automatic mode:

    -Illumination of both ALTN and AUTO FAIL lights indicates a single controller failure and automatic transfer to ALTN mode

    -pressurization mode selector in ALTN position.
  27. What happens if you change the FLT ALT setting after takeoff?
    If the FLT ALT indicator is changed, the automatic abort capability to the original takeoff field elevation is lost.
  28. Image Upload 23
    What are the functions of #11 in AUTO, ALTN, MAN?
    AUTO – pressurization system controlled automatically.

    ALTN – pressurization system controlled automatically using ALTN controller.

    MAN –

    -pressurization system controlled manually by outflow valve switch

    -both auto controllers bypassed.
  29. How does the operation of the outflow valve differ in AUTO/ALTN versus Manual?
    In the MAN mode, the outflow valve position switch is used to modulate the outflow valve by monitoring the cabin altitude panel and valve position on the outflow valve position indicator. A separate DC motor, powered by the DC standby system, drives the outflow valve at a slower rate than the automatic modes. Outflow valve full range of motion takes up to 20 seconds.
  30. What are the sources of bleed air?
    Engines, APU, or external air
  31. Which engine stages provide bleed air?
    5th and 9th
  32. Is a single PACK capable of supplying all of the air conditioning and pressurization requirements of the airplane?
    A single pack in high flow is capable of maintaining pressurization and acceptable temperatures throughout the airplane up to the maximum certified ceiling.
  33. Is the APU capable of supplying bleed air for both packs on the ground and in the air?
    The APU is capable of supplying bleed air for two packs on the ground, or one pack in flight.
  34. When does the air conditioning switch to “high flow” automatically?
    Automatic switching to “high air flow” occurs if both engine bleed air switches are OFF and the APU bleed air switch is ON, regardless of flap position, air/ground status or number of packs operating.  This automatic switching is inhibited when the airplane is on the ground, or inflight with the flaps extended, to ensure adequate engine power for single engine operation.
  35. Both pack switches are in AUTO.  What would cause the left pack to automatically transition to the HIGH flow mode in flight with the flaps up?
    The right pack valve closes
  36. In flight, flaps up, in the event of a bleed trip, what will occur automatically?
    -the bleed valve closes

    -the pack valve will close

    -the air mix valve will drive full cold

    -the remaining pack will automatically go into high flow
  37. What is the maximum pressure differential?
    9.1 psi
  38. When does the cabin warning activate, and what does it sound like?
    Cabin altitude warning activates when cabin altitude exceeds 10,000 feet. An intermittent warning horn sounds. The warning horn may be silenced by momentarily pressing the ALT HORN CUTOUT switch on the Cabin Altitude Panel.

    If the High Altitude Landing Switch is selected ON, cabin altitude warning activates when the cabin altitude exceeds 14,000 feet. On some airplanes, cabin altitude warning activates when the cabin altitude exceeds 14,650 feet. All other characteristics of cabin altitude warning remain the same.
  39. Image Upload 24

    Upon departure from a high altitude airport, the system returns to normal operation as the cabin descends through ___ feet.
    8500 feet
  40. What is the purpose of the recirculation fan?
    The recirculation fan system reduces the air conditioning system pack load and the engine bleed air demand. Air from the passenger cabin and electrical equipment bay is drawn to the forward cargo bay where it is filtered and recirculated to the mix manifold. The fan is driven by an AC motor. The fan operates with the recirc fan switch in AUTO except with both packs on and one or both in HIGH.
Author
CForty
ID
350093
Card Set
C-40 AIR SYSTEMS/PRESSURIZATION
Description
C-40 AIR SYSTEMS/PRESSURIZATION
Updated