The 10th Air Force began combat operations on April 2 with raids against Rangoon and shipping in the Andaman Islands. Major General Brereton led the first raid on the Andamans where 3 B-17's claimed hits on 1 cruiser and 1 transport. Also during April the 10th began supply operations to Army Air Forces units in China, when 30,000 gallons of gasoline and 500 gallons of lubricants were moved by DC-3 from Calcutta to a staging field at Asanol. The fuel was subsequently moved via Dinjan to bases in China for use by Doolittle's Tokyo raiders, then at sea aboard USS HORNET (CV-8) Combat operations against Rangoon continued throughout the month with additional raids on the 3rd, 16th, and 29th. With the Japanese pushing north along the Burma Road the 10th began to evacuate military and civilian personnel from Burma to India on the 22nd. By the end of the evacuation operation in June they would move 4499 passengers and over 866 tons of freight. Ground echelons of the 9th Bombardment Squadron moved from Karachi to Allahabad on the 27th.

     On April 30 the Japanese captured Lashio, Burma, beginning a move to drive the Chinese back along the Burma Road toward China, and US and British forces back toward India.

During April the 88th Reconnaissance Squadron (H) was redesignated the 436th Bomb Group (H)