Undeterred by either the constant rain during April and May or by heavy enemy artillery shelling and repeated day and night aerial bombing of the air strips, the unit succeeded in carrying out highly effective aerial operations against the enemy from Kyushu to the southernmost island of the Ryukyu Group, flying reconnaissance and search missions, escort missions, day and night bomber strikes.

It was not until after it moved to the Muroc Bombing and Gunnery Range, California, four days after the attack on Pearl Harbor, that the Group received a full complement of personnel and equipment.

In addition to training its pilots and ground crews, the Group also assisted in patrolling the coastal waters for enemy submarines.

A projected offensive against the Japanese in the Central Pacific required that the Seventh Air Force be augmented by one heavy and one medium bombardment group.

On 20 November, the Marines charged ashore on the beaches of Tarawa, the most strategic of the enemy held islands in the Gilberts.

The uncomfortable climate, the temporary delay, and an outbreak of dengue fever and dysentery combined to make life miserable for the men of the 41st.

On 28 December, the 820th Squadron launched the Group's combat mission with an attack on the new enemy air facilities at Mili Atoll in the Marshall Islands.

Those islands contained air facilities from which the Japanese might interfere with the scheduled invasions of Kwajalein and Eniwetok set for February 1944.

The change of tactics, plus the fact that the Japanese air forces were greatly diminishing, resulted in a significant decline the number of losses incurred by the 41st.

Upon completion of the Marshall invasions, United States forces had pushed to a point about midway between Pearl Harbor and Japan.

Within another week, the Seventh Air Force moved the 48th Bombardment Squadron to Saipan to assist in softening up enemy defenses preparatory to the next invasions in the Marianas.

By the Fall of 1944, the medium bombers of the 41st were no longer needed in the Central Pacific, so the Seventh Air Force withdrew the Group to Wheeler Field, Hawaii in October 1944.

New gunnery techniques were also employed during practice on tow targets, and gun cameras were used during maneuvers with local fighters.

The United States launched the bitter battle at Iwo Jima in February 1945 and attacked Okinawa in April.

The B-25s hit Japanese air facilities nearby in an attempt to neutralize enemy islands and troop concentrations.

During July, the Group flew 36 missions, dropping fragmentation and general-purpose bombs on enemy airfields, bridges, railroads, and shipping facilities.

New tactics against Japanese shipping included an experiment with glide bombs against targets in Sasebo, Makurasaki, and Nagasaki harbors.

Two weeks later another move was made to Machinato Airfield on Okinawa, where the unit's activity consisted of routine training flights and maintenance checks.