MD-11 Flight Crew Operations Manual
k
Air -
Description and Operation
Air.10.3
The MFDS sends failure signals to the ESC, which then isolates the affected duct
from its bleed air system.
Manifold failure indications appear on the AIR synoptic.
Air Conditioning System
The air conditioning system uses engine compressor bleed air from the main
engines during flight, and the engines, the APU, or preconditioned air from a
ground source during ground operation.
Hot, pressurized air is supplied to the air conditioning packs, where it is cooled
and routed to a common manifold. The cooled air is mixed with hot air prior to
distribution.
The air conditioning system accomplishes the following:
• Air conditioning packs provide conditioned air in response to a
temperature control system.
• An Air Conditioning Controller (ACC) determines cockpit and cabin
temperature requirements and provides the appropriate signals.
• The distribution system controls conditioned air flow to the cockpit and
cabin
• The compartment ventilation system provides ventilation for the avionics,
center accessory and right hand aft tunnel.
• The lower cargo compartment temperature control and ventilation system
allows temperature sensitive shipments.
Three identical Air Conditioning Controllers (ACC):
• Interface with the Environmental Control System (ESC), the EIS, and the
CFDS.
• Interface with the AIR control panel, the altitude warning system, the
oxygen mask deployment system, the APU controller, and the CPCS.
• Send altitude warning and oxygen mask signals.
With ignition A, B, or OVRD selected and the air system in auto, air conditioning
is unavailable prior to engine start. It remains unavailable for two minutes if there
has not been an engine start.
Individual zone temperature requirements are adjusted by mixing hot trim air from
the pneumatic duct with air from the conditioned air manifold.
Avionics and Instrument Ventilation System
The ESC controls the avionics and instrumentation ventilation system. The ESC
performs a power-up test of all fans, flow sensors, and annunciation circuitry prior
to flight.
October 02, 2006
To Next Page
Loading...