In early 1944 AAF Material Command commenced a program to convert a number of Liberators as fuel transports under the designation C-109. The XC-109 was derived from a B-24E stripped of all armament and bombing equipment and fitted with six new fuselage fuel tanks, one in the nose, two in the bomb bay, and three aft of the wings, totaling 2,400-gallons. After testing, a further 218 B-24Js and Ls underwent similar conversions with fuel capacity
upped to 2,900-gallons. Initially, all C-109s served with 10th AF in India flying fuel over the Himalayas into China to support early B-29 operations, however, after acquisition of the Mariana Island bases for the B-29s, many C-109s were transferred to ATC control where they were used to as fuel transports in other theaters of the war. Like C-87s, they were withdrawn as soon as the war ended.
E.R. Johnson, Lloyd S: American Military Transport Aircraft Since 1925