On April 19, 1999, about 1418 Alaska daylight time, a wheel equipped Britten-Norman BN-2B-21 airplane, N414JA, received substantial damage while landing at the Kongiganak Airport, Kongiganak, Alaska. The airplane was being operated as a visual flight rules (VFR) nonscheduled cargo flight under Title 14, Part 135, when the accident occurred. The airplane was registered to, and operated by, Larry's Flying Service, Inc., Fairbanks, Alaska. The solo airline transport pilot was not injured. Visual meteorological conditions prevailed, and a VFR company flight plan was in effect. The flight was a continuation of a cross-country flight that originated at the Bethel Airport, Bethel, Alaska, about 1242. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on April 20, the pilot reported that the accident flight had made a brief stop at two remote villages before departing for the accident airport. He said that prior to landing at Kongiganak, he did a visual inspection of runway 18. He noted that the runway appeared wet in some areas, but within acceptable limits for landing. He said that during the final stages of the landing roll, while moving at a relatively slow ground speed, the airplane's nose wheel encountered a large, water and mud-filled hole. He said that the impact threw water, mud, and stones over the nose, windscreen, engines, and wings. The pilot added that he was able to taxi the airplane to the parking area, to assess the damage. He said that his inspection revealed that the nose strut had been bent aft, about 20 degrees from its original position. During the pilot's postaccident inspection of runway 18 at Kongiganak, he said he discovered a large hole about 15 inches deep, by 1 foot wide, and 20 feet long in the middle of the runway. After he reported the accident to the flight service station personnel, the runway was closed to all operations until repairs could be accomplished. The pilot noted that there were no preaccident mechanical anomalies with the airplane. An FAA ferry permit was issued for a one-time maintenance ferry flight to the operator's main maintenance facility located in Fairbanks, Alaska. A subsequent inspection revealed that the airplane sustained substantial damage to the nose wheel bulkhead.