Chapter 1: Air Conditioning/Pressurization Flashcards
The ram-air doors are fully open in flight under which conditions?
Slow-flight with the flaps not fully retracted.
When are the ram-air doors fully open?
On the ground or during slow flight with flaps not fully retracted.
What is the source of barometric pressure used by the pressurization system auto contollers?
The ADIRUs.
If the controller is not responding, the AUTO FAIL warning light on the Cabin Pressurization panel will illuminate if the cabin rate of descent or climb exceeds…?
± 2000 FPM
The OVHT TEST push button switch on the Bleed Air Panel tests which circuits?
The wing body overheat circuits.
The recirculation fan is powered by an AC or a DC motor?
AC motor.
How much time is required to drive the pressurization outflow valve through its full range using manual control?
20 seconds
Duct overheat detection for the left pack is located…
In the duct leading from the left pack to the Flight Deck.
What is the maximum altitude that may be set in the FLT ALT windows on the Cabin Pressurization panel?
42,000’
A BLEED TRIP OFF is caused by…
…either an over-temperature or an over-pressure condition.
If the automatic temperature controller fails, what happens to the mix valves, and can they be controlled?
The mix valves stay at the last setting and can be controlled in manual.
If the pressurization controller is not responding, the AUTO FAIL warning light on the Cabin Pressurization panel will illuminate when the cabin differential pressure exceeds…
…8.75 psi.
In normal cruise the air conditioning ram air doors…
… modulate between open and closed according to cooling requirements.
Will the APU bleed valve open when the APU bleed switch is positioned to ON?
Yes, but only if the APU is operating.
The 9th-stage bleed air valve acts as a temperature and pressure regulator or as a modulation and shut-off valve?
A modulation and shut-off valve.
If a pack valve closes, what is the effect on the respective mix valve?
The mix valve drives full cold.
What is the primary source of conditioned air for the Flight Deck?
The left pack.
The ram air system deflector doors are electrically extended…
… when activated by the ground safety sensor.
What is the normal position of the isolation valve when the Isolation Valve switch is in AUTO?
Closed
Why is throttle position used by the automatic pressurization contollers?
To de-pressurize the cabin at lower power settings on the ground.
The source of bleed air is provided by…
The 5th-stage of the compressor section augmented by the 9th-stage.
What is the source of the heated airflow to the mix-manifold coming from the forward cargo compartment?
Air routed through the Flight Deck electronics and the E & E compartment.
The engine bleed valve is operated by…
A DC motor and bleed air pressure.
The mix valve position indicators indicate…
the actual position of the mix valve in both manual and automatic mode.
The 5th-stage bleed air valve acts as a…
pressure regulator and shutoff valve.
If both the AUTO FAIL and MANUAL warning lights on the Cabin Pressurization panel are illuminated, what is indicated with respect to the automatic controllers?
A single controller has failed and pressurization has automatically switched to the operating controller.
What is the maximum negative cabin pressure differential?
0.125 psi
What is indicated if the AUTO FAIL warning light is illuminated on the Cabin Pressure panel with regard to the automatic controllers?
Both controllers have failed.
When the recirc fan switch is in AUTO the fan will operate…
continuously, except with both Packs on and one or both in HIGH.
What cabin altitude is the cabin regulated to at FL410?
8000’
The PACK TRIP OFF warning light indicates which condition?
The pack temperature has exceeded limits.
What is the maximum altitude that may be set in the LAND ALT windows on the Cabin Pressurization panel?
14,000’
Using the engine bleed air, when will a pack automatically switch to HIGH?
In flight with one pack not operating with flaps up and the pack switches in AUTO.
What is the maximum allowable differential pressure?
9.10 psi
An overheat in the APU bleed air duct will illuminate which warning light on the Bleed Air Panel?
The left WING-BODY OVERHEAT warning light.
With the Isolation Valve switch in AUTO, what will cause the isolation valve to open?
Positioning either engine bleed or either pack switch to OFF.
If the controller is not responding, the AUTO FAIL warning light on the Cabin Pressurization panel will illuminate if the cabin altitude exceeds…
15,800’
The duct overheat will…
cause both mix valves to drive full cold and illuminate the DUCT OVERHEAT light.
What is indicated by the OFF SCHED DESCENT warning on the Cabin Pressurization panel?
The aircraft has descended before reaching the planned cruise altitude as set in the FLT ALT indicator.
What will cause illumination of the DUAL BLEED warning?
The APU bleed air valve is open, and the number 1 engine bleed switch is ON, or the number 2 engine bleed switch is ON, and the isolation valve is open.
How is the bleed air from the engine initially cooled for the cabin temperature control?
A heat exchanger in the ram air system.
If the aircraft must do an emergency RTB, what is the landing altitude as programmed by the automatic controller?
The cabin altitude as sensed by the controller before take-off.
The TRIP RESET on the Bleed Air Panel will reset which condition(s)?
PACK TRIP OFF and BLEED TRIP OFF.
The BLEED TRIP OFF light illuminated indicates what condition(s)?
Excessive engine bleed air temperature or pressure.
If only one pack is operating, the operating pack will regulate to high flow with the pack switch in AUTO under what conditions?
When operating the pack with the APU as the only bleed source or in-flight with the flaps up.
Duct overheat detection for the right pack is located…
in the duct leading from the mix manifold to the sidewall riser.
