This close-up view highlights the powerful radial engines and four-bladed propellers of a Boeing C-97/KC-97 Stratofreighter, a mainstay of U.S. Air Force heavy transport and aerial refueling operations in the 1950s. The distinctive black-and-white striped propeller tips improved visibility for ground crews and reduced the risk of accidental contact, a standard safety feature across piston-engine military aircraft of the era. Project: 218468