Air cart with auxiliary container coupled to multiple distribution tubes

An air cart apparatus for an agricultural product dispensing system, comprising:

• a) a primary container assembly extending longitudinally along a frame, the primary container assembly including at least a first container and a second container;
• b) an auxiliary container mounted to a side of the primary container assembly;
• c) a plurality of distribution tubes extending longitudinally between the first and second containers and disposed laterally inward of the auxiliary container for pneumatically conveying product from the primary container assembly and the auxiliary container to an agricultural implement, the distribution tubes arranged in a side-by-side arrangement across a tube assembly width;
• d) a first metering assembly comprising a first transfer chamber disposed between a first lower end of the first container and the plurality of distribution tubes, and a plurality of first metering devices in communication with the first transfer chamber;
• e) a second metering assembly comprising a second transfer chamber disposed between a second lower end of the second container and the plurality of distribution tubes, and a plurality of second metering devices in communication with the second transfer chamber;
• f) a third metering assembly comprising a third transfer chamber disposed above the plurality of distribution tubes, and a plurality of third metering devices in communication with the third transfer chamber;
• and
• g) a feed device for conveying product laterally inward from the auxiliary container to the third transfer chamber;
• wherein each of the first, second, and third metering devices is coupled to at least one of the plurality of distribution tubes for delivering product in metered amounts from the first, second, and third transfer chambers to the distribution tubes.