Navy officials said the MH-60S Seahawk was conducting routine flight operations from the USS Abraham Lincoln last Tuesday when it crashed down into the sea roughly 60 miles of the San Diego coast.
[Ads /]
RELATED: 29-year-old U.S. Navy pilot from Oakhurst among 5 sailors killed in helicopter crash
The helicopter reportedly touched down on the flight deck and "experienced side-to-side vibrations." It caused the main rotor to strike the deck and the helicopter fell over the side of the aircraft carrier.
The crash summary in a Naval Safety Center document, first reported by the Navy Times, did not include any information on what might have caused the vibrations.
Michael Canders, a retired military helicopter pilot who is the director of the Aviation Center at Farmingdale State College in New York, told the Navy Times that side-to-side vibrations can occur if rotor blades are out of balance.
Several sailors were injured, and five others were declared missing.
RELATED: 'An absolute hero': Oakhurst community mourns Navy sailor killed in helicopter crash
[Ads /]
After several days of searching for the missing crew, they were presumed dead on Saturday.
The Navy identified all five service members on Sunday, including Lt. Bradley A. Foster, a pilot from Oakhurst.
The Associated Press contributed to this report.