A sailor aboard the aircraft carrier USS Yorktown (CV-10) poses beside the ship's Sikorsky HO4S-1 plane guard helicopter in 1953. Helicopters like this one flew alongside carrier flight operations, standing ready to rescue aviators in the event of a water landing. Shipmates in the background, one in swim trunks, illustrate the informal moments sailors enjoyed between flight operations during the Korean War era. Project: 218507