Complex sentence: In January 1953, Hagerstrom was transferred to Osan Air Base to help with the transition from propeller P-38s to jet F-86s, and by mid-February the wing's 125 pilots were trained in the F-86.
Split into simpler sentences: In January 1953, Hagerstrom was transferred to Osan Air Base to help train pilots on the transition from propeller P-38s to jet F-86s. By mid-February the wing's 125 pilots were trained in the F-86.