28th Bombardment Squadron (28th BS)
U.S. Army Air Force (USAAF), 5th Air Force (5th AF), 19th Bombardment Group (19th BG)

Background
On June 22, 1917 organized as the 28th Aero Squadron in the U.S. Army at Camp Kelly, Texas. On June 16, 1919 demobilized. On January 9, 1922 reconstituted and consolidated as the 28th Squadron. On August 30, 1921 reauthorized as a squadron. On September 20, 1921 organized at Mather Field in California. On June 28, 1922 inactivated.

On September 1, 1922 reactivated as part of the Philippine Department at Kindley Field on Corregidor Island in the Philippines. During November 1922 moves to Camp Nichols on Luzon. During December 1922 moves to Clark Field as part of the 4th Composite Group (4th CG). On June 4, 1923 returns to Camp Nichols. On June 16, 1938 returns to Clark Field. On January 25, 1923 redesignated 28th Bombardment Squadron. On July 2, 1926 becomes part of the U.S. Army Air Corps (USAAC). On December 6, 1939 redesignated 28th Bombardment Squadron (Medium). On June 20, 1941 becomes part of the U.S. Army Air Force (USAAF). On November 16, 1941 redesignated 28th Bombardment Squadron (Heavy) assigned to the 19th Bombardment Group (19th BG).

Wartime History
On December 8, 1941 at the start of the Pacific War the squadron was at Clark Field.

On December 24, 1941 the air echelon withdraws to Batchelor Field near Darwin in Australia. Meanwhile, the ground echelon remains in the Philippines attached to the 5th Interceptor Command (Provisional) and will fight as infantry to defend the Bataan Peninsula on Luzon and Mindanao. On December 30, 1941 the air echelon transfer from Batchelor Field to Singosari on Java.

On March 28, 1942 moves to Cloncurry Airfield with a detachment operating from Perth.

On December 30, 1942 without personnel and equipment reestablished at Pocatello, Idaho and re-equipped with B-17s and becomes a replacement training unit.

On March 28, 1944 redesignated 28th Bombardment Squadron (Very Heavy). On April 1, 1944 inactivated.

Postwar
On August 10, 1948 redesignated 28th Bombardment Squadron (Medium). On September 18, 1947 becomes part of the U.S. Air Force (USAF). On June 1, 1953 assigned to the 19th Bombardment Wing (19th BW). On July 1, 1961 redesignated 28th Bombardment Squadron (Heavy).

References
Combat Squadrons of the Air Force World War II (1982) pages 141-143 [PDF pages 153-155]