ANC97LA150

The pilot stated that after placing the landing gear handle in the down position, he observed 3 green, down and locked, indicator lights. He indicated that the touchdown on the gravel runway was normal, and that as he slowed the airplane, the airplane settled onto its nose. Metallurgical inspection revealed overstress fractures of the nose gear actuator upper attachment lug, and overstress fractures of the supporting sheet metal structure. No preexisting defects were noted. No reports were received of previous hard landings. An inspection of the drag link assembly was conducted 45 hours prior to the accident, and no discrepancies regarding the nose landing gear were noted at that time.

On September 14, 1997, at 1955 Alaska daylight time, a Cessna 402C airplane, N2649Z, sustained substantial damage when the nose gear collapsed during landing at the Kivalina Airport, Kivalina, Alaska. The airline transport certificated pilot was uninjured, and no passengers were on board. The airplane was operated by Hageland Aviation Services, Inc., of St. Mary's, Alaska. The flight was conducted under 14 CFR Part 135, as scheduled commuter flight number 916, and had departed Point Hope, Alaska, at 1925. Visual meteorological conditions prevailed at the time of the accident, and a company VFR flight plan was filed.

The airplane was landing on runway 12, which was gravel. Winds were reported by the pilot as 080 degrees at 15 knots. The pilot reported that he observed three green, down and locked, landing gear indications after selecting the gear handle to the down position. He stated that as the nose wheel touched down, the nose continued to settle, coming to rest on the nose cone.

Postaccident inspection of the nose landing gear assembly revealed that the nose gear actuator upper attachment lug was fractured, and the nose gear sheet metal mounting structure was fractured in several locations. Microscopic inspection conducted at the NTSB metallurgical laboratory revealed features typical of overstress separations, with no indications of preexisting cracks or corrosion.

A review of maintenance records showed that the nose gear actuator was replaced on July 16, 1996, at a tachometer time of 637 hours. The accident occurred at 1,466 hours. The last 100 hour inspection conducted on August 28, 1997, 45 hours prior to the accident, included a dye penetrant inspection (#L-28) of the nose gear drag brace. No discrepancies were noted during this inspection.