CARGO VENTILATION AND HEATINGAs an

CARGO VENTILATION AND HEATINGAs an option on the Airbus single aisle family, the forward and aftcargo compartments can have a ventilation system. A heating systemcan also be installed in these two compartments or only one of them.The heating system will only be installed together with a ventilationsystem.The operation is equivalent for the two compartments, thus we willonly look at the forward cargo compartment as an example. Air fromthe main cabin is supplied into the cargo compartment by the extractfan or by differential pressure in flight (FWD Cargo Compartmentonly). After its circulation through the compartment, the air isdischarged overboard.The operation of the two isolation valves and the extract fan iscontrolled automatically by the cargo Ventilation Controller (VC).One VC can control one cargo compartment or the two of them.For the heating of the cargo compartment, the pilots select the desiredcompartment temp and hot bleed air is mixed with the air comingfrom the main cabin to increase the temperature if necessary. Thesupply of hot air is controlled by the Cargo Heating Controller. Eachheated compartment has a dedicated Cargo Heating Controller. Thereis NO direct air conditioning supply to the cargo compartments. Thepilots cannot add "cold" air to the compartments.