MD-11 Flight Crew Operations Manual
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Air -
Description and Operation
Air.10.9
• Preflight - During normal preflight control actions and engine start
operations proper operation of the eight ESC-controlled pneumatic/air
conditioning valves is verified. A preflight ESC test verifies trim air
shutoff function, and proper operation of the avionics and CAC fans, and
the respective flow sensors.
• APU ground operation - The flight crew starts the APU and opens the
APU load bleed valve. When in auto mode, the ESC pressurizes all 3
pneumatic systems, thus allowing air conditioning.
• Ground conditioned air operation - Conditioned air flows directly into the
distribution ducts downstream of the packs. There are no automatic
controller functions.
• Ground engine start with APU pneumatic supply - Selection of engine
ignition causes the ESC to:
1. Turn packs off.
2. Verify adequate pneumatic pressure for engine start. Display START AIR
PRES LO alert, if pneumatic pressure is not adequate.
3. Close 1-3 ISOL valve and turn on pack 3, after engine 3 start.
4. Close 1-2 ISOL valve and turn on pack 1, after engine 1 start.
5. Turn on pack 2 when flight crew closes APU load bleed valve, following
engine 2 start.
NOTE: Engine 3 pneumatic supply is inhibited by the PSC when using
ground carts until the pressure in all 3 systems has been low for 20
seconds.
• After engine start - Normal air conditioning allowed.
• Takeoff - The three takeoff configurations are:
1. BLEEDS OFF - (Default) Pneumatics and air conditioning turned off when
throttles are advanced for takeoff.
2. BLEEDS ON PACKS OFF - Airfoil anti-ice manually selected on and packs
selected off by flight crew after throttles advanced for takeoff.
3. PACKS ON - Packs selected on from FMS TAKEOFF page. Airfoil anti-ice
manually selected on or off by flight crew.
NOTE: The avionics exhaust fan turns on and the OVRD light
illuminates for a packs off takeoff.
• Climb through landing roll - Climb phase begins when thrust is reduced to
climb power, after passing through 1,000 feet above airport elevation. At
4,500 feet above airport elevation, if climb thrust is not set, the ESC
automatically configures the aircraft for the climb. Pneumatics and air
conditioning are restored. Recirculation fan available with ECON
selected.
October 02, 2006
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