Accident Details
On November 11, 2012, about 1700 Alaska standard time, a Piper PA-18-150 airplane, registration N8466Y, sustained substantial damage during a forced landing following a loss of engine power. The accident occurred near Akiachak, Alaska. The airplane was operated by the certificated private pilot as a visual flight rules (VFR) cross-country flight under Title 14, CFR Part 91. The pilot, the sole occupant, sustained minor injuries. Marginal visual meteorological conditions prevailed, and no flight plan had been filed. The flight had departed Aniak, Alaska, about 1600, en route to Bethel, Alaska.
Pilot Account
During a telephone conversation with the NTSB investigator-in-charge (IIC) on November 11, the pilot stated that he ran out of fuel. He explained he had attempted to fly from Bethel to Willow, Alaska earlier that day but turned around due to deteriorating weather. At the time of the accident, he was attempting to return to Bethel. He stopped briefly in Aniak and departed with approximately 9 gallons of fuel for the 82-nautical-mile flight to Bethel. En route, he became concerned about fuel duration and diverted to Tuluksak, Alaska, which he overflew after determining he had sufficient fuel to reach Bethel, 32.1 nautical miles southwest. The pilot said he exhausted fuel from the right tank, and when the engine lost power, he switched to the left tank; the engine continued running. While maneuvering to land at Akiachak Airport, all engine power was lost, and he selected an off-airport, snow- and tree-covered area for a forced landing. During the approach, the airplane stalled and collided with terrain. The airplane sustained substantial damage to the wings, lift struts, and fuselage.
Carbon Monoxide Detector and Symptoms
The pilot also reported that near Tuluksak, approximately 58 miles southwest of Aniak, he noticed the airplane's carbon monoxide detector had turned black. On December 3, 2012, the pilot and the Akiachak Village Police Officer (VPO) who located the detector at the accident site on November 16 recalled that the detector had turned black. On December 11, about one month after the accident, the pilot reported experiencing an elevated heart rate and severe headache after the accident, and prior to the accident he reported impaired judgment and confusion. In the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1), the pilot indicated no preaccident mechanical anomalies and stated that 24 hours after the accident he had a carboxyhemoglobin (COHb) level of 1.3%, attributing it to possible carbon monoxide poisoning. The US Department of Health and Human Services notes typical COHb levels in non-smokers are 0.5–1.5%.
Witness Observations
During a telephone conversation with the NTSB IIC on November 12, an Alaskan State Trooper reported he observed the accident airplane land in Aniak and noted ice on the airframe. He discussed de-icing and fueling with the pilot, then returned to his office. Shortly thereafter, he was surprised to hear the airplane depart, stating the pilot would not have had sufficient time to de-ice or fuel the airplane before departure.
Muffler Inspection and Carbon Monoxide Detector Details
On December 28, 2012, an FAA aviation safety inspector from the Anchorage Flight Standards District Office disassembled and inspected the muffler assembly from the accident airplane; no leaks or anomalies were found. The airplane was equipped with an AERO Phoenix Aviation Distributors 18-month carbon monoxide detector manufactured by Quantum Eye, which provides visual indication of carbon monoxide contamination (yellow = normal, green = caution, dark blue = danger). The instruction manual states that excessive dosages, multiple exposures, or use after expiration may cause the sensor to turn permanently dark, and that the sensor should be kept away from contaminants. No replacement date was recorded on the accident airplane's detector.
Weather Conditions
The closest weather reporting facility is Bethel Airport, about 17 miles southwest of the accident site. About 7 minutes before the accident, at 1653, a METAR reported wind from 020 degrees at 6 knots, visibility 9 statute miles, mist, overcast clouds at 600 feet, temperature 22°F, dew point 21°F, altimeter 29.93 inHg.