Hagel was concerned that the LCS would make up one-sixth of the Navy's 300-ship force. The 2013 DOT&E report on the two LCS ships questioned their survivability as their requirements did not include features for sustained combat operations unlike other Navy surface combatants. A new ship class would need built-in anti-submarine and surface warfare mission features, as opposed to swappable mission modules. On 27 March 2014, Chief of Naval Operations Admiral Jonathan W. Greenert and Secretary of the Navy Ray Mabus defended the LCS' survivability and the need for 52 small surface combatants before the Senate Armed Services Committee. Greenert explained that the LCS meets or exceeds survivability and recoverability standards, was as survivable as a frigate, and was more survivable than mine countermeasures and patrol craft; susceptibility has to be improved upon, and he would consider modifications to increase survivability and flexibility.