Complex sentence: Operational squadrons of the wing were the 305th, 364th, 365th and 366th Bombardment Squadrons, while the the 306th Bombardment Squadron was intended to act as a training unit to prepare future B-47 crews.
Split into simpler sentences: Operational squadrons of the wing were the 305th, 364th, 365th and 366th Bombardment Squadrons. The 306th was intended to act as a training unit to prepare future B-47 crews.