 However, the Chief of Naval Operations excluded the system from use on helicopter assets in March 2012, and only one destroyer has been outfitted with the specific mission package as of April 2009.The AN/AQS-20 naval mine hunting sonar systems will be employed for deeper mine threats.The "Q-20", as it is commonly called, is an underwater towed bodycontaining a high resolution, side-looking, multi-beam sonar system used for minehunting along the ocean bottom.