Complex sentence: The 1944 AAF handbook notes that on May 15,1940 the Air Corps Specialized Flying School at Eglin Field was redesignated6the Air Corps Proving Ground and that it was redesignated Proving Ground Command on 1 April 1942.
Split into simpler sentences: The 1944 AAF handbook notes that on May 15,1940 the Air Corps Specialized Flying School at Eglin Field was redesignated6the Air Corps Proving Ground. It was redesignated Proving Ground Command on 1 April 1942.