OSAN AIR BASE, Republic of Korea -- The 51st Mission Support Group hosted a change of command ceremony to officially transfer command from U.S. Air Force Col. Jeffrey Elliott to Col. Yesun Yoon at Osan Air Base, Republic of Korea, July 24, 2026.
Military change of command ceremonies symbolize the transition of responsibility and accountability from one commander to another. They emphasize the continuity of leadership and the unit identity despite changes in authority.
The ceremony was presided over by Col. Ryan Ley, 51st Fighter Wing commander, who recognized Elliott for his leadership and dedication to the mission.
“Over the past few years, Col. Elliott’s leadership has been critical to several major initiatives: tour normalization, infrastructure modernization, installation security and wartime planning,” said Ley. “His ability to see the big picture while driving the details has strengthened our mission and prepared us for the journey ahead.”
During his tenure as the 51st MSG commander, Elliott increased command sponsorship billets from roughly 1,000 to 1,650, led the beddown and sustainment of over 500 augmentees four times during large-scale exercises such as Ulchi Freedom Shield and Freedom Shield, and co-signed an installation security Memorandum of Understanding, unifying Osan under a single security forces procedure and ensuring 100% accountability of all personnel on a joint combined installation.
In his farewell remarks, Elliott reminded Airmen that the strength of the 51st MSG extends beyond its mission and lies in the community its members build together.
"The military community is what sets us apart from our civilian counterparts. Our shared stories, our common struggles and our collective triumphs," said Elliott. "You get to create this community, take full advantage of it."
Ley also highlighted Yoon’s financial management background and regional expertise, making her uniquely qualified to lead the 51st MSG. Prior to taking command, she served as a Foreign Area Officer in Northeast Asia and Air Force Liaison Officer to the ROK Air Force Operations Command at Osan, strengthening bilateral and combined air operations.
Yoon expressed her excitement to build upon the foundation set up by Elliott and thanked the leadership and personnel within the 51st MSG for their dedication to defend the base, generate combat power and strengthen the U.S.-ROK Alliance.
“I promise to be fully invested in our mission, our people and our family as we continue the building of the outstanding population already in place,” said Yoon. “It is the honor of my lifetime to serve as your commander.”
As the group commander, Yoon will lead five squadrons responsible for providing communications, engineering, security, law enforcement, transportation, supply, personnel support, logistics readiness, education, food services, housing and recreation activities to over 2,700 personnel, supporting the Air Force’s most forward, permanently based fighter wing, a Numbered Air Force and 24 tenant units.