A 19-year-old U.S. Navy airman has been discharged after surviving a severe mental-health crisis aboard the USS Abraham Lincoln, intensifying scrutiny of conditions on the carrier during its extended Iran-war deployment.Nicholas McKelvey went overboard from the Lincoln on August 3 after roughly 255 consecutive days at sea. According to reporting based on his account, he had been working long flight-deck shifts while dealing with family health problems and the emotional strain of missing the birth of his daughter. He was recovered alive after spending about 50 minutes in the water.