On 14 December 1941, then Lieutenant Wheless was the pilot of a B-17 on a mission to attack Japanese warships and transports in the harbor at Legaspi, Philippine Islands.

Again going overseas in June 1944, Wheless served as director of operations for the 314th Bombardment Wing at North Field, Guam.

He returned to the United States and went to Fort Worth Army Air Field, Texas, where he served as deputy chief of staff, operations, for the 58th Bombardment Wing.

A year later, he was assigned in the same capacity to the Eighth Air Force, and in December 1946 assumed command of the 7th Bombardment Group.

In June 1963, he was assigned to Headquarters U.S. Air Force as the assistant deputy chief of staff, programs and requirements.

He was appointed senior Air Force member, Military Staff Committee, United Nations, in August 1967 in addition to his present duty.

Lieutenant General Hewitt Terrell Wheless was assistant vice chief of staff, U.S. Air Force.

As an additional duty, General Wheless was the senior Air Force member, Military Staff Committee, United Nations.