 Variants of the original CH-53A Sea Stallion include the RH-53A/D, HH-53B/C, CH-53D, CH-53G, and MH-53H/J/M.The RH-53A and RH-53D were used by the United States Navy for minesweeping.The CH-53D included a more powerful version of the General Electric T64 engine, used in all H-53 variants, and external fuel tanks.