On January 24, 1998, at 1300 hours Saipan standard time, a Hughes 369D, N521ZZ, operated by Big Eye Helicopters, Inc., Guam, crashed into international South Pacific Ocean waters approximately 300 miles east-northeast of the Solomon Islands. The helicopter sank in deep water, and no recovery attempt is anticipated. The commercial pilot succumbed to impact-related injuries, and the second crewmember was not injured. Visual meteorological conditions prevailed at the time of the aerial observation flight. The flight originated from the vessel Fairwell 707 at 1259. According to the operator's manager, the pilot and observer took off in the helicopter without mishap and climbed to about 400 feet. The helicopter crew spotted fish near the bow of the vessel, and the pilot descended to commence a "herd" operation. During the descent, the pilot made a downwind turn in the prevailing 15-knot wind. As the helicopter continued its descent, it changed its heading 180 degrees and appeared to experience a loss of tail rotor effectiveness (LTE). The descent was not arrested, and the helicopter impacted the water. One float broke off and the other was seriously damaged. Both crewmembers were rescued prior to the helicopter sinking to an estimated depth of 6,000 feet. The operator's manager further reported that before the pilot died he stated that no engine problems had been experienced. The pilot indicated that he had erred in controlling the helicopter. On January 28, 1998, the National Transportation Safety Board mailed the operator the required Aircraft Accident Report Form No. 6120.1/2 to complete. This written request was followed up with additional requests for information about the aircraft and accident. As of July 14, 1998, the operator has not responded.