Air Flashcards
(23 cards)
What does the BLEED TRIP OFF (amber) light indicate?
Bleed trip sensors have automatically closed the engine bleed air valve, due to:
Excessively high engine bleed air temp (254C), or
Excessively high pressures (220 PSI)
Conditions permitting, the TRIP RESET switch resets which lights?
BLEED TRIP OFF
ZONE TEMP
PACK
How does the ISOLATION VALVE operate with its switch in AUTO?
Four corners in normal position –> closed
Otherwise –> open
What precautions apply with the APU bleed valve when an engine bleed valve is open?
Thrust must be limited to idle
When does the DUAL BLEED (amber) light illuminate?
APU bleed valve open, and one of the following:
Engine 1 bleed switch on, and/or
Engine 2 bleed switch on AND isolation valve open
What does the WING-BODY OVERHEAT (amber) light indicate?
An overheat has been detected:
Engine strut cavity, or Wing bleed air duct, or Wing leading edge, or Pack, or Keel beam, or Aft cargo compartment, or APU cavity
A single pack in high flow mode is capable of maintaining pressurization and acceptable temperature throughout the aircraft up to what altitude?
Maximum certified ceiling
[41,000ft]
Which valve pneumatically modulates to control airflow into the respective air conditioning pack based on air condition demands?
Pack valve
When does a pack automatically switch to high airflow?
When one pack is not operating
[Inhibited on the ground or airborne with flaps extended]
How do the recirculation fans operate with both RECIRC FAN switches in AUTO, and both PACK switches in AUTO?
Both recirc fans would be on
Where do the air recirculation fans draw air from?
Collector shroud of forward cargo compartment,
Air conditioning distribution compartment (pack compartment), and
Floor grilles on each side of passenger cabin
What does ZONE TEMP (amber) indicate?
A supply duct overheat
[Trim air valve for that zone will close]
How do you position PACK switches when using external conditioned air?
PACK switches OFF
What controls the temperature of condition air from an external air source?
The external air conditioning cart
Packs produce air temperature to satisfy which zone?
The zone requesting the lowest temperature
What happens with the failure of the primary flight deck zone temperature control?
Master Caution Recall indicates failure of the flight deck temperature control and will cause an automatic switch to the backup control
What temperatures are commanded by positioning all zone temperature selectors to OFF?
75F for the flight deck [left pack] and 65F for the cabin [right pack]
What provides an equipment cooling alert if an overtemperature occurs on the ground?
EQUIP COOLING OFF (amber) light, and
MASTER CAUTION, and
Horn in the nose wheel well [ground only]
What is the purpose of the overboard exhaust valve (OEV)?
Controls the quantity of equipment cooling exhaust air flowing overboard and has a smoke removal mode.
It closes when a differential pressure is achieved [~1psid]
When is the outflow valve position indicator operational?
Anytime, regardless of the pressurization mode
When does the OFF SCHED DESCENT (amber) illuminate?
Aircraft begins to descend without reaching the preset cruise altitude
[Within ~0.25 psid]
How is pressurization controlled in MAN?
Manual control of the outflow valve
What two warnings use the same aural tone (intermittent horn) when activated?
Takeoff configuration, and
Cabin altitude
