On 8 December 1965, while serving as copilot aboard the second aircraft of a flight of three UH-34Ds, I witnessed an act of heroism performed by Sergeant Gordon J. Barnes.  While on a mission over the South China Sea, the third aircraft in our flight experienced a complete engine failure, and crashed landed in the sea.  Our aircraft immediately descended to the scene of the crash and started rescue operations.  On the way to the scene Sergeant Barnes emptied our entire 1,700 pounds of internal cargo and readied the sling for rescue operations.  Sergeant Barnes demonstrated exceptional skill in verbally guiding the maneuvering of the aircraft, despite extremely rough sea and high wind conditions.  Two of the downed crew members were picked up with the rescue sling and Sergeant Barnes then seeing the futile attempt of the other aircraft, which had an inoperative hoist to pick up the crew chief of the downed aircraft, directed the pilot to a position where he could immediately begin another rescue attempt.  During this rescue attempt, the sling parted from the hoist and seeing that the crew chief could not be hoisted into the aircraft, Sergeant Barnes requested permission to jump in the water and attempt to hold the crew chief above water until the hoist could be repaired.  The pilot denied permission as the man had a good hold on the hoist cable itself, which Sergeant Barnes had immediately lowered, and he could be towed to shore,  Sergeant Barnes then continued to direct the pilot as the downed crew chief was towed to the beach where he was picked up by the crew of the other aircraft.  At this time Sergeant Barnes requested the pilot to position his aircraft in an advantageous manner to deliver suppressive fire upon the enemy in the tree line adjacent to the beach.  During the entire rescue operation the aircraft was subjected to intense enemy small arms fire.  Sergeant Barnes showed professional skill, good judgment and extreme courage during the entire rescue operation.