Investigation Summary
Flight 99 was a multi-stop scheduled service from Nome to Savoonga and Gambell. After an uneventful leg to Savoonga, the aircraft departed for Gambell at 13:27 BDT. Gambell lacked a control tower, so a local agent activated the Non-Directional Beacon (NDB) to assist the crew. Upon arrival, the crew encountered heavy sea fog with visibility reported between 1/2 and 1.5 miles, though it was fluctuating. The captain attempted several approaches, at one point descending to within a few feet of the surface, according to Flight Data Recorder (FDR) data. During the final attempt, the crew executed a right turn and maintained a heading of 140 degrees for approximately 28 seconds. While configured for landing with the gear down, the aircraft flew into the fog-shrouded Sevuokuk Mountain. The impact occurred at 424 feet MSL, approximately 1 km east of the airport. The aircraft broke apart and came to rest inverted, followed by a small fire in the left engine area.
Final Conclusions
The National Transportation Safety Board (NTSB) issued its final report (NTSB-AAR-76-01) in 1976. The board concluded the probable cause was the flight crew's failure to adhere to prescribed company instrument approach procedures while attempting to land in adverse weather conditions. Contributing factors included weather below authorized minimums and the fact that the runway rotating light beacon was not operating at the time of the accident.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
William C. Arant, age 39. Fatality.
First Officer
Gerald W. Schaefer, age 28. Fatality.
Systems & Failure Modes
Non-Directional Beacon (NDB)
A ground-based radio transmitter used for navigation; the Gambell NDB was the primary aid used by the crew to locate the airport in the fog.
Cockpit Voice Recorder (CVR)
The CVR captured the crew's discussion regarding the fog and their decision to 'take a shot' at the approach despite the weather.
Flight Data Recorder (FDR)
FDR data revealed the aircraft had descended dangerously low during previous approach attempts before the final impact.
Interesting Facts
- 01The aircraft was a Fairchild F-27B manufactured in 1958.
- 02The Gambell NDB was manually activated by a local agent specifically for the flight's arrival.
- 03The aircraft struck the mountain and slid approximately 132 feet upward before coming to rest inverted.
- 04Visibility at the time of the crash was reported as low as 1/4 to 1/2 mile in patchy sea fog.
- 05The runway rotating light beacon was found to be inoperative during the investigation.
Safety Actions & Advisories
Adherence to Minimums
The investigation emphasized the necessity of strict adherence to published weather minimums and company approach procedures, particularly in remote regions with limited navigational aids.