Cessna U206G N252AL

Summary

On 15 December 2011 at about 19:30 local time, a Cessna U206G registered N252AL, operated by Smokey Bay Air Inc, was involved in an accident near Nanwalek, Alaska, United States. 4 people were on board and 4 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

15 December 2011 at 19:30

Classification

Accident

Location

Nanwalek, Alaska, United States

Nearest airport

Nanwalek (KEB)

Coordinates

59.3522, -151.9253

Aircraft

Cessna U206G

Registration

N252AL

Category

Airplane

Engines

1

Operator

Smokey Bay Air Inc

Operating rule

Part 135: Air Taxi & Commuter

Phase of flight

Not recorded

Route

Nanwalek → Homer

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC12FA014

4 people had minor injuries.

The pilot’s decision to takeoff from a contaminated runway with unfavorable wind conditions, and his failure to maintain airspeed during the initial climb, which resulted in an aerodynamic stall. Contributing to the accident was the operator’s inadequate procedures for operational control and dispatch.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The commercial pilot was taking off on the third leg of a scheduled flight returning to the airplane’s base of operation. Earlier in the day, the weather in the area was not suitable for flight operations, but the pilot, along with another company pilot, performed the company risk assessment and decided that, under the current conditions, flights could depart. The pilot reported that the first two legs were uneventful. However, he noted that, upon landing at the end of the second leg, about 3 inches of slush covered the runway, with as much as 6 inches in some areas, and that the wind was from the east at 12 to 15 knots. After loading passengers, the pilot decided to taxi from the north parking ramp to the opposite end of the runway for a northerly departure. The pilot and witnesses stated that the airplane’s takeoff performance was degraded due to the runway contamination, but the airplane was still able to lift off just past the midfield point. The pilot stated that after the airplane lifted off in a nose-high attitude, he immediately started a shallow left turn to avoid the rising terrain at the north end of the runway. He said that after the airplane cleared a retaining wall on the west side of the runway, it encountered a downdraft, and the pilot was unable to maintain a climb. The airplane impacted the ocean about 100 yards offshore. There is no official weather reporting at the airport. About 35 minutes before the accident, the nearest official weather reporting station, located 9 nautical miles northeast of the airport, reported wind from 170 degrees at 3 knots. About 10 minutes after the accident, it reported wind from 170 degrees at 10 knots, gusting to 15 knots. The airport is tightly constrained on both sides by terrain and water, and the runway condition is difficult to maintain due to sea erosion and lack of suitable maintenance equipment. According to the airport manager, there is a contract maintenance provider in the village, and, on the morning of the accident, it was determined that runway conditions did not require maintenance. The contractor stated that the weather was very dynamic that day; he asked the pilot of the first airplane that landed if any maintenance was required on the runway and was told that the runway was fine. However, given the contamination on the runway, the accident pilot likely lifted off farther down the runway than normal. The airplane’s attitude and slow airspeed, combined with the unfavorable wind conditions he encountered after he executed the shallow turn, likely resulted in an aerodynamic stall. A review of the operator’s flight risk assessment form showed that, for the conditions during the accident flight, the pilot and another company pilot should have assigned three of the five risk areas a value that requires additional management approval before flights could be released. Instead, they agreed that conditions were appropriate for flight and were allowed to exercise operational control to release the flights for departure, which placed the flight at risk for an accident.

Quoted verbatim from the NTSB record.