History of Flight
On December 15, 2011, at approximately 1530 Alaska standard time, a Cessna U206G airplane, registration N252AL, sustained substantial damage when it impacted ocean waters shortly after takeoff from Runway 01 at Nanwalek Airport, Nanwalek, Alaska. The airplane was operated by Smokey Bay Air, Homer, Alaska, as a visual flight rules scheduled commuter flight under 14 Code of Federal Regulations Part 135. The pilot and three passengers sustained minor injuries. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight originated from Homer Airport about 1445, with a stop in Port Graham, Alaska.
The pilot stated that the wind was from the east at 12 to 15 knots, and the runway was covered with approximately 3 inches of slush, with up to 6 inches in potholes. Extra power was required to taxi. During takeoff roll, acceleration was degraded due to contamination, but the airplane became airborne near the midpoint of the runway. While making a left turn, the airplane encountered a strong downdraft. With full power and pitch attitude set to best angle of climb, the airplane descended approximately 500 feet per minute. When the pilot realized the airplane would not climb, he reduced power to idle and ditched about 100 feet from shore. After entering the water, the pilot and three passengers evacuated through the pilot's door and swam to shore, assisted by bystanders.
Another pilot at the north end of the airport observed the airplane take off in a nose-high attitude, as expected for a soft-field takeoff, and continue nose-high until it descended below his line of sight. He then radioed another pilot that an airplane was down near Nanwalek.
Personnel Information
The 38-year-old pilot held a commercial pilot certificate with single-engine land, multiengine land, and instrument airplane ratings. His most recent second-class medical certificate was issued October 24, 2011, with a limitation to wear corrective lenses for distant vision.
According to the operator's report, the pilot had 1,987 total flight hours, with 462 hours in the accident airplane make and model. In the preceding 90 and 30 days, he accrued 200 and 53 flight hours, respectively.
Company training records showed the pilot completed initial ground training on April 22, 2011, and initial flight training in Cessna 206 airplanes on April 26, 2011. After completing the training program and a check ride, he was officially hired and assigned to fly Cessna 206s from Homer. His most recent FAA Part 135.293 and 135.299 checks were administered on the morning of the accident flight.
The pilot's scheduled duty day was 0730 to 2130. He was off duty the three days prior. On the accident date, he started at 0730 and flew 2.4 hours before the accident.
Aircraft Information
The six-seat, high-wing airplane was manufactured in 1976. It was equipped with a Continental IO-520-F engine rated at 300 horsepower, driving a Hartzell 3-bladed, all-metal constant-speed propeller (model HC-C3YF-1RF).
At the time of the accident, the airplane had 3,895 total flight hours. Maintenance records indicated the last inspection under the continuous airworthiness inspection program was on November 19, 2011. The engine had 1,245 hours at that inspection.
Meteorological Information
No official weather reporting was available at Nanwalek Airport. The nearest official station was Seldovia Airport (PASO), 9 nautical miles northeast. At 1453, PASO reported wind 170 degrees true at 3 knots, visibility 10 statute miles, scattered clouds at 5,000 feet, broken at 7,500 feet, altimeter 29.19 inHg. At 1540, wind was 170 degrees true at 10 knots gusting to 15, visibility 4 statute miles in light rain, broken at 1,800 and 3,900 feet, altimeter 29.21 inHg.
An unofficial weather station near Nanwalek reported at 1417 wind from 076 degrees true at 8 knots gusting to 16 knots.
Communications
There were no communications with air traffic control. Another pilot on the ground relayed weather and airport conditions to the accident pilot over the Nanwalek UNICOM frequency.
Airport Information
Nanwalek Airport is a public-use airport owned by the State of Alaska. It is tightly constrained by terrain and water. The 1,850-foot runway is not regularly maintained. The FAA Airport/Facility Directory Alaska Supplement notes: "Airport Remarks – Unattended. Runway 01-19 north 1,000 feet CLOSED indefinitely, remaining 850 feet soft."
The Alaska Department of Transportation closed the northern portion due to unsuitability and lack of maintenance. A contract maintenance provider inspected the runway the morning of the accident and determined no maintenance was needed. Conditions were changing rapidly; after the first airplane arrived later that day, the pilot on the ground asked if the runway was adequate and was told it was fine. The airport manager stated it is at the contractor's discretion to determine conditions and issue NOTAMs.
The area surrounding Nanwalek produces significant turbulence and downdrafts, especially with prevailing east wind.
Wreckage and Impact Information
The airplane came to rest in English Bay about 100 feet offshore, northeast of Nanwalek, upright and intact. All major components remained attached except the right main landing gear wheel, which separated. The right aileron and right horizontal stabilizer were wrinkled and creased.
Organizational and Management Information
The operator was a FAR Part 135 Air Carrier with scheduled commuter and on-demand operations specifications. Facilities were in Homer. At the time, the Director of Operations lived in Homer but was no longer involved in day-to-day operations; a new DO was being named. The Chief Pilot resided in Anchorage and regularly commuted. The company's operations specification stated flights shall only be initiated, diverted, or terminated under the authority of the DO, who may delegate but retains responsibility. The company president was out of town.
Initial and recurrent pilot training were accomplished in-house. Initial operating experience flights included Nanwalek Airport. The company maintained an FAA-approved training manual.
Operational control used a two-pilot release method. Information was passed to the pilot-in-command, who along with another pilot, DO, or CP determined if conditions could be met. Under some circumstances, the DO or CP must be notified to release a flight.
A basic risk assessment form evaluated five areas (Pilot, Equipment, Weather, Runway Conditions, Daylight Requirements) with Green, Yellow, or Red values. Pilots completed it at the start of the day and reevaluated if conditions changed. Three yellow items required additional approval; a red item required cancellation.
On the accident morning, the accident pilot and another pilot reviewed weather and decided no flights would be initiated. Around noon, weather cleared, and they exercised operational control under the two-pilot release system, with flights beginning about 1300. They assigned green lights for four of five categories and a yellow light for equipment, with no note explaining the upgrade. A review by the NTSB investigator-in-charge indicated that, for conditions during the accident flight, three categories should have been yellow, requiring additional approval.
Standard operating procedures were contained in the company's General Operations Manual.
Additional Information
In the months after the accident, the operator made numerous changes to operating procedures, including operational control mechanisms, having both DO and CP in house, modifying risk assessments, and revamping safety policies to align with the FAA Safety Management System framework.
The FAA Weather Camera Office initiated installation of a weather camera at Nanwalek to help pilots assess conditions, slated for completion by June 2013.
The State of Alaska plans to permanently close Nanwalek Airport and build a new airport to serve Nanwalek and Port Graham. Land acquisition and right-of-way are ongoing; no definitive construction date is set.