It was after midnight on June 19, 1968, when U.S. Navy Lt. Clyde Lassen and his helicopter crew flew into the jungle of North Vietnam to rescue two Navy aviators whose fighter jet had been shot down.

The monument — known as the CDR Clyde E. Lassen, USN (Ret.) Medal of Honor SH-60F Oceanhawk Memorial Display — will be installed at the entrance to Coronado/Naval Air Station North Island.

The X-49A is a Sikorsky SH-60F Seahawk naval helicopter that Piasecki modified with an airplane wing and an aft propeller to give it greater speed and range. During the October demonstration ...