Continental
Rev. 12/01/00 #29 Flight Manual
Flight and Passenger Compartment Temperature Control
Flight compartment and passenger compartment temperature is controlled from the flight compartment. Movement of the CKPT TEMP and CABIN TEMP selectors in the AUTO mode (right or left of the center index) selects and automatically maintains temperature in the flight and passenger compartments through a temperature range of 65.F to 80.F (18.C to 27.C). Operation of the AUTO mode requires normal electrical power.
When operating in the MANUAL mode, the CKPT TEMP and CABIN TEMP selectors are spring loaded to the STOP position and must be momentarily held in HOT or COLD positions until the desired temperature is obtained. The MANUAL mode operates when the Emergency AC Bus is powered.
Movement of the left pack temperature control valve in the hot direction is inhibited by a thermal switch if pack discharge temperature exceeds 130.F (54.C). The switch will reset if pack discharge temperature is less than 130.F in either the MANUAL or AUTO mode, or if pack is shut off.
A CABIN TEMP indicator displays temperature in the passenger compartment or cabin supply ducting only as selected. Temperature in the flight compartment may be adjusted according to flight crew comfort requirements.
Radio Rack Cooling and Airplane Air Exhaust
Radio rack equipment cooling is provided by conditioned air from the flight compartment. When the RADIO RACK switch is in the FAN position, the conditioned air is drawn by fans from the radio rack and then exhausted under the forward cargo compartment floor for heating. When the RADIO RACK switch is in the VENTURI position, forward cargo compartment heating is not provided, and the air from the radio rack is exhausted overboard through the venturi.
A standby radio rack fan, located in the radio rack cooling ducting, will turn on automatically if the primary fan fails in flight. In ground mode, the primary and standby fans are both on when the RADIO RACK switch is in either FAN or VENTURI position. An annunciation, RADIO FAN OFF, will come on only when both fans have failed in flight or if the primary fan has failed on the ground.
APU On Ground Air Conditioning
The APU can be used to supply air conditioning to the flight compartment and passenger compartment while the aircraft is on the ground. The bleed AIR switch, in the ON position, supplies electrical power to the APU bleed air control valve, thereby providing air to the pneumatic system. The AIR COND COLDER position provides increased differential pressure for additional cooling air capacity. The OFF position discontinues electrical power to the APU bleed air control valve and the pneumatic shutoff valve circuits.
When the airplane is on the ground and the throttles are in idle, placing the APU bleed air switch to ON or AIR COND COLDER also activates an electrical solenoid which causes the air conditioning pressure regulator to move full open. In this mode, full APU bleed air pressure is provided to increase the cooling capabilities during ground operation. Advancing the throttles or when in flight mode, will revert the system to normal regulation by deactiviating the solenoid.
Airplane Pressurization
Pressurization is provided by a controlled flow of bleed air from the pneumatic supply, which passes through the air conditioning systems and is then ducted to the pressurized areas. Desired pressurization levels are maintained by regulating escape of the compressed air through the cabin air outflow valve. Normally, the outflow valve is automatically positioned by a dual automatic pressurization system to control cabin pressure rates from takeoff to landing.
For automatic operation of the outflow valve, the CABIN ALT control lever must be in the up position. The CABIN ALT control wheel will rotate as it automatically adjusts to maintain pressurization. A position indicator, next to the wheel, will move to indicate outflow valve position.
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本文链接地址：MD-80 Flight Manual 麦道80飞行手册 2(122)
