Complex sentence: The Pullman B-29 was flown to Wendover Army Air Field in Utah and assigned to further drop testing in September 1944 with the 216th Army Air Force Base Unit until it was damaged in a landing accident in December.
Split into simpler sentences: The Pullman B-29 was flown to Wendover Army Air Field in Utah in September 1944. It carried out further drop testing with the 216th Army Air Force Base Unit until it was damaged in a landing accident in December.