Direct proof of use
The GBU-39/B Small Diameter Bomb I entered documented combat use during the 2003 Iraq War on Oct. 5, 2006. The U.S. Air Force reported that members of the 494th Expeditionary Fighter Squadron flew the bomb into combat for the first time, launching a two-ship formation of F-15E Strike Eagles on a close-air-support mission for ground troops operating in Iraq.
A separate U.S. Central Command Air Forces account described the associated loading event: 379th Expeditionary Maintenance Squadron weapons loaders put the first GBU-39/B Small Diameter Bomb onto an F-15E Strike Eagle headed for a combat mission over Iraq. The article tied the load to troops in contact with enemy forces in Iraq and to the new bomb's fielding from a forward operating location.
Sources: USAFE unit debuts small diameter bomb in combat, New weapon makes job of munitions specialists a snap
Timeline
The Iraq debut came immediately after fielding milestones in late summer and early autumn 2006. The Air Force said the GBU-39/B was delivered to operational users ahead of schedule in early September, Air Combat Command declared initial operational capability on Oct. 2, and the weapon made its combat debut three days later.
On Oct. 5, 2006, the 494th Expeditionary Fighter Squadron's F-15E Strike Eagles carried the new munition while providing close air support for troops in Iraq. Air Combat Command separately summarized the same sequence, reporting that the F-15E was then the only aircraft equipped to carry the SDB and that future platforms were planned.
Sources: Small Diameter Bomb I delivered ahead of schedule, ACC declares small diameter bomb initially operational, USAFE unit debuts small diameter bomb in combat
Operational role
In Iraq, the documented role was air-delivered precision strike and close air support by U.S. F-15E Strike Eagle crews. U.S. Air Force reporting emphasized the bomb's small 250-pound class size, GPS-guided precision, and suitability for urban or close-air-support settings where commanders wanted a lower fragmentation and blast area than larger guided bombs.
Air & Space Forces Magazine later summarized the SDB I as a low-yield, all-weather precision guided munition with standoff range and stated that it was first employed by an F-15E over Iraq in 2006. That secondary summary aligns with the contemporary Air Force accounts of the Oct. 5, 2006 combat debut.
Sources: USAFE unit debuts small diameter bomb in combat, GBU-39 Small Diameter Bomb I