N455A
2010-AUG-09 · Muklung Hills, near Aleknagik, Alaska

GCI Communication Corp. — Flight N455A

A turbine-powered de Havilland DHC-3T Otter impacted steep, wooded terrain in the Muklung Hills during a private executive flight, killing five of the nine people on board, including former U.S. Senator Ted Stevens. The flight was operating under visual flight rules in an area of marginal weather and variable terrain. Investigators determined the aircraft struck the mountain in a level or slightly climbing attitude, suggesting the pilot may have been temporarily unresponsive or incapacitated. The lack of an onboard cockpit recorder and the pilot's decision to disable the Terrain Awareness and Warning System (TAWS) were cited as significant factors in the accident and the subsequent investigation.

Aircraft
de Havilland Canada DHC-3T Texas Turbine Otter
Registration
N455A
Phase
Cause
Souls on Board
9
Fatalities
5
Origin → Dest
Lake Nerka-GCI Lodge, AK → Nushagak River-sport fishing camp, AK
Report

Investigation Summary

The accident occurred during a short 52-mile flight intended to transport guests from a private lodge to a fishing camp. Earlier that morning, the pilot had reported 'very bad' weather with low ceilings and visibility, but he decided to proceed after lunch when conditions appeared to improve locally. During the flight, the aircraft traveled at low altitude to remain clear of clouds. One surviving passenger reported seeing 'white-out' conditions, while another noted the pilot was maneuvering to avoid terrain just before the impact. The aircraft struck a 40-degree slope at an elevation of approximately 950 feet MSL. The rescue was significantly delayed because the Emergency Locator Transmitter (ELT) antenna snapped off during the impact, preventing a distress signal from being broadcast. Additionally, although a satellite phone was available in the cabin, the surviving passengers were unaware of its presence and could not summon help for several hours. The NTSB highlighted that the pilot, who had a history of a previous stroke, had been medically cleared under FAA guidelines that the board later found to be 'conflicting and unclear' regarding the risk of recurrence or subtle cognitive impairment.

Final Conclusions

The NTSB determined the probable cause was the pilot's temporary unresponsiveness for reasons that could not be established. The investigation was hampered by the lack of a cockpit recorder. The board also criticized the FAA's medical certification process for pilots who have suffered strokes, noting it failed to require formal neuropsychological evaluations to detect subtle impairments that could affect flight safety.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Airframe Hours
9,372
Engines
Honeywell TPE331-10R-511C

Crew Experience

Captain

Total hours
28,768
On type
35

The pilot was an Airline Transport Pilot (ATP) and a recovered stroke victim.

Systems & Failure Modes

i

Terrain Awareness and Warning System (TAWS)

A system designed to prevent CFIT by providing alerts; it was manually deactivated by the pilot, a common practice among bush pilots to avoid nuisance alerts in variable terrain.

i

Emergency Locator Transmitter (ELT)

The unit failed to broadcast a signal because the impact forces caused the antenna cable to separate from the housing.

i

Sky Connect Tracking System

A satellite-based tracking system that provided investigators with GPS data points from the earlier flights that day.

Interesting Facts

  • 01Former U.S. Senator Ted Stevens was among the five fatalities.
  • 02Former NASA Administrator Sean O'Keefe survived the crash with serious injuries.
  • 03The aircraft was equipped with TAWS, but the pilot had elected to fly with the system turned off.
  • 04The ELT antenna separated upon impact, rendering the emergency beacon useless.
  • 05The pilot had previously suffered a stroke but had been recertified to fly by the FAA.
  • 06The aircraft was a 1957 airframe converted to a 'Texas Turbine' Otter with a Honeywell TPE331 engine.
  • 07The pilot's son-in-law had died in the Elmendorf AFB C-17 crash only 12 days prior to this accident.

Safety Actions & Advisories

FAA Medical Certification Reform

The NTSB recommended that the FAA clarify and strengthen medical certification guidance for pilots following a stroke, specifically requiring neuropsychological evaluations.

Cockpit Recorder Requirements

The NTSB reiterated the need for cockpit image and data recorders on turbine-powered aircraft not currently required to carry them to aid in accident investigation.

Location

Muklung Hills, near Aleknagik, Alaska · 59.3294, -158.3810

Case File History

  1. New evidenceUpdated findings.

Related Cases

Case ID · gci-dhc3-2010Last updated · Filed

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