Term
| How are the packs powered? |
|
Definition
Left - DC essential
Right - DC bus 2 |
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Term
| When do the packs operate in LOW/HIGH mode? |
|
Definition
LOW - engine bleed air, both packs operating
HIGH - single pack ops in flight, APU bleed air on the ground |
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|
Term
| What is the output pressure of the packs? |
|
Definition
LOW - 24 psi
HIGH - 39.5 psi |
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Term
| After a pack failure, will the remaining pack operate in HIGH mode? |
|
Definition
Yes, AUTO if overpressure or overtemp
Otherwise, the pack must be turned off manually |
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Term
| Where are the fan sensors located? |
|
Definition
| right hand side in cockpit and cabin |
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|
Term
| How is conditioned pack air distributed in the airplane? |
|
Definition
Left - 40% cabin, 60% cockpit
Right - 100% cabin |
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Term
| On the air conditioning panel, which systems have inputs to the different modes - NORM, STBY, and MAN? |
|
Definition
NORM - fan sensor, duct sensor, temp selector
STBY - duct sensor, temp selector
MAN - temp selector |
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Term
| Where are the pack overtemp and overpressure sensors located? |
|
Definition
Overpressure - primary heat exchanger output
Overtemp - air cycle machine input |
|
|
Term
|
Definition
| Scoop at base of vertical fin draws air over the heat exchangers and discharges it on both sides of the upper fuselage |
|
|
Term
| How is ram air assisted on the ground/in flight? |
|
Definition
| An ejector valve draws air from the aft equipment bay |
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Term
| "L/R PACK HI PRESS" caution |
|
Definition
Pack shuts down
Auto-closes ACU, respective 10th stage and isolation valve |
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|
Term
| "L/R PACK NOT OFF" caution |
|
Definition
ACU valve remains open
thermostatic switch detects bleed air |
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|
Term
| "DISPLAY FAN FAIL" status |
|
Definition
| avionics cooling fan speed below 60%, extinguishes when speed increases or cooling fan is no longer needed |
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Term
| What is the pressurization computer called? |
|
Definition
| CPAM - Cabin Pressure Acquisition Module |
|
|
Term
| How does the CPAM manipulate the cabin signs? |
|
Definition
| Auto-illuminates NO SMKG and SEAT BELT signs when cabin altitude exceeds 10,000' |
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|
Term
| Which static port does the CPC use? |
|
Definition
|
|
Term
| Describe automatic and manual modes of the outflow valves? |
|
Definition
Auto - electropneumatic, CPC controls vacuum pressure, secondary is slaved
Manual - pneumatic, manually controlled vacuum pressure, primary is slaved |
|
|
Term
| When do the outflow valves automatically open? |
|
Definition
Differential pressure of 9.1 ±.1 psi
or -.5 psi negative pressure |
|
|
Term
| What differential pressure does the cabin normally maintain? |
|
Definition
|
|
Term
|
Definition
| differential pressure > 9.0 psi |
|
|
Term
| When do the outflow valves automatically close? |
|
Definition
Cabin altitude limiter 14,500' ±500'
Masks also drop at 14,500' |
|
|
Term
| What safety feature is built into the aircraft for rapid decompressions? |
|
Definition
Pressure differential diaphragms in the cabin floor prevent buckling
Open at 3 psi differential |
|
|
Term
| What are the 7 modes of cabin pressurization operation? |
|
Definition
| Ground, Pre-pressure, Takeoff Abort, Flight, Landing, Touch and Go |
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|
Term
| Describe CPC schedules when departing and arriving at high altitude airfields (8000'). |
|
Definition
Arrive: cabin climbs to 8000', during descent (below 25,000') cabin climbs to field elevation at 700 fpm
Depart: descends at 600 fpm to 8000', then meets auto schedule at normal rate |
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|
Term
| When does the "FAIL" light illuminate on the pack sw/lt? |
|
Definition
Over-temperature
Over-pressure
SOV failed open |
|
|
Term
| What are the limits of the rate selector? Pip position? |
|
Definition
Selector: 0-2500 fpm up, 0-1500 fpm down
Pip: 500 up, 300 down |
|
|
Term
|
Definition
| Cabin altitude > 10,000' or 14,500' (high altitude mode) |
|
|
Term
|
Definition
| Cabin altitude 8500 - 10,000' |
|
|
Term
|
Definition
| High altitude airfield takeoff or landing has been initiated |
|
|
Term
|
Definition
CPC failure
Outflow valves go into isobaric hold mode
Amber fault light on cabin press selector
"FAIL" light on pressure controller sw/lt |
|
|
Term
| How does the cabin transfer switch work? |
|
Definition
COCKPIT: gives cabin ±2°C
CABIN: full range of whatever mode is selected |
|
|
Term
| How does the temperature controller maintain the temperature selected by the control knob? |
|
Definition
| Full hot or full cold until the temperature is within 3 deg |
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|
Term
| At what altitude will the CPAM illuminate the seat belt sign? |
|
Definition
|
|
Term
| What is the function of the PRESS CONT sw/lt? |
|
Definition
| Allows manual control of the CPC |
|
|
Term
| Where is flight compartment air exhausted? |
|
Definition
| Under the floor through the avionics bay |
|
|
Term
| How are the outflow valves opened? Closed? |
|
Definition
Opened - spring-loaded
Closed - CPC controlled vacuum pressure (jet pump on 10th stage manifold) |
|
|
Term
| Which CPAM does the DCU use if both are powered? |
|
Definition
| DCU uses the one with the highest value for it's logic |
|
|
Term
| What are the indications of a CPC failure? |
|
Definition
"AUTO PRESS" caution
amber "FAULT" light on CPC
PRESS CONT "FAIL" sw/lt |
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