Complex sentence: The aircraft were said to have been flown by USAF crews during these operations, and one of the RB-57Fs was reported to have returned to its U.S. base before the outbreak of hostilities with India while the other remained.
Split into simpler sentences: The aircraft were said to have been flown by USAF crews during these operations. One of the RB-57Fs was reported as returning to its U.S. base before the outbreak of hostilities with India, but the other remained.