Helicopter Sikorsky MH-60S Seahawk Serial Register 166309 used by US Navy USN. Aircraft history and location Aircraft History 166309 US Navy 2011-02US Navy Feb11 HSC-3./SA-18 HSC-3 2014-04Apr14 HSC-21 /VR-61 27jun15 asg USNS Mercy (T-AH 19) in Papua New Guinea for Pacific Partnership 2015 HSC-21 Hospital Ship USNS Mercy in Papua New Guinea Send Updates Use APP to upload photo @ (optional) When Now? / / Send