Arrival and Weather Information
During arrival, the crew of NP flight 1802 contacted the company weather observer at Soldotna, who reported wind calm, ceiling 600–800 feet, visibility 8–10 miles, and no precipitation. The crew conducted an NDB approach but missed and requested another approach. Approximately one minute later, they reported heavy ice accumulation on the aircraft.
Diversion and Second Approach
Although they could have diverted to nearby Kenai for an ILS approach, the crew elected to perform a VOR approach back to Soldotna. While being vectored, they checked twice more with the weather observer, who reported conditions had deteriorated to below minimums and recommended diverting. The crew did not acknowledge.
Collision
The aircraft subsequently collided with trees on high terrain about 1.5 miles southeast of the airport. Evidence indicated the aircraft was circling at the time; circling was not authorized south of runway 07/25.
Aircraft and Maintenance Issues
Investigation revealed recurring problems with the anti-ice system; its single mode was inoperative. Furthermore, two de-ice boots were missing from propeller blades.
Weather Station Deficiencies
The weather station used only one lighted marker (1/4 mile away) for visibility reference, while minimum landing visibility was one mile. The ceilometer was inoperative. The FAA had not inspected the weather station in two years.
Occupants
All nine occupants were killed.