Infantrymen nicknamed the Corsair "The Sweetheart of the Marianas" and "The Angel of Okinawa" for its roles in these campaigns. Among Navy and Marine aviators, the aircraft was nicknamed "Ensign Eliminator" and "Bent-Wing Eliminator" because it required many more hours of flight training to master than other Navy carrier-borne aircraft. It was also called simply "U-bird" or "Bent Wing Bird". Although Allied World War II sources frequently make the claim that the Japanese called the Corsair the "Whistling Death", Japanese sources do not support this, and it was mainly known as the Sikorsky.