On September 10, 1999, about 1630 Alaska daylight time, a Eurocopter AS-350B-2 helicopter, N6099Y, sustained substantial damage when it impacted the surface of the Juneau ice field, about 18 miles north of Juneau, Alaska, at 58.37.809 north latitude, 134.32.310 west longitude. The helicopter was being operated as a visual flight rules (VFR) search and rescue flight under Title 14, CFR Part 91, when the accident occurred. The helicopter was operated by Temsco Helicopters, Inc., Ketchikan, Alaska. The certificated commercial pilot and the three passengers aboard were not injured. Visual meteorological conditions prevailed at the time of departure, and company flight following procedures were in effect. The flight originated about 1530 from the Juneau Airport. During an interview with the National Transportation Safety Board investigator-in-charge on September 11, the pilot reported that he and his sole passenger were en route from Petersburg to Juneau, when he was requested to join a search for an overdue company helicopter (N6007S). He said that just after entering the search area, about 1530, he received a radio transmission from the pilot of another company helicopter (N6052C), who was also involved in the search. The pilot of N6052C informed him that he had crashed on the ice field, and required assistance. The pilot of N6099Y stated that poor weather conditions in the vicinity N6052C would not allow the him to land, so he elected to return to the Juneau Airport for fuel, and wait for better weather conditions. After refueling, about 1600, he departed Juneau, and returned to the accident site of N6052C, where weather conditions had now improved. After landing, the uninjured pilot and passenger boarded N6099Y. He said that after being assured that both occupants of N6052C were uninjured, all aboard agreed to continue the search for N6007S. (See ANC99FA139, and ANC99LA140) The pilot reported that during their resumed search, other search helicopters reported the position of the original missing helicopter, and N6099Y proceeded to the reported accident location of N6099Y. The pilot of N6099Y stated to the National Transportation Safety Board investigator-in-charge, that he was able to locate the downed helicopter about two miles directly in front of his location. He said that he slowed the helicopter to about 30 knots in an attempt to gain reference using a mountain range on the left side of the helicopter, and the accident site of N6007S. He said: "The ceiling at my location was at least 1,000 feet agl, and visibility towards 07S was more than six miles. Just before the impact, I was sure I was at least 500 feet agl." The pilot added that "flat light conditions" hampered his ability to see the topographical features of the ice field below. The helicopter struck the snow-covered ice field, slid about 50 feet, nosed over, and rolled to the left. The helicopter sustained substantial damage to the fuselage, tail boom, and rotor system. The accident pilot did possess an instrument rating for rotorcraft, but had not obtained any instrument competency checks or training since 1995, while being employed by the operator. The accident helicopter was not equipped with a radar altimeter.