No fatalities

6 May 2009: CESSNA TU206 F (N629SP) — ALASKA SCENIC AIR LLC — Bethel, AK

Bethel, AK, United States

On 6 May 2009, a CESSNA TU206 F (registration N629SP) operated by ALASKA SCENIC AIR LLC was involved in an aviation accident near Bethel, AK. No fatalities were reported. Investigators recorded the probable cause as: The pilot’s failure to remove visible frost from the wings during the preflight inspection, and his failure to maintain adequate airspeed to avoid a stall. Contributing to the accident were conditions conducive to structural icing/frost. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

On May 6, 2009, a Cessna TU206F cargo plane veered left and struck terrain during takeoff at Bethel Airport, Alaska, sustaining substantial damage. The pilot suffered minor injuries. Frost was observed on wing and tail surfaces.

Introduction

On May 6, 2009, at 0903 Alaska daylight time, a single-engine Cessna TU206F airplane, registration N629SP, sustained substantial damage when it collided with terrain during takeoff at Bethel Airport, Bethel, Alaska. The aircraft was operated by Alaska Scenic Air LLC of Eagle River, Alaska, as a visual flight rules (VFR) on-demand cargo flight under Title 14 Code of Federal Regulations (CFR) Part 135. The solo commercial pilot sustained minor injuries. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight was en route to Kasigluk, Alaska.

Accident Details

The airplane was taking off on the first flight of the day and had accelerated normally during the short-field takeoff roll. During entry into the initial climb, the airplane suddenly rolled into an uncommanded left bank and entered an uncontrolled descent. The left wingtip struck terrain to the left of the runway approximately 1,000 feet from the beginning of the takeoff roll. The airplane came to rest upright approximately 200 feet from the initial impact point. During the impact sequence, the unsecured cargo shifted forward and struck the back of the pilot’s seat and the right side of the instrument panel. The pilot exited the airplane unassisted.

Wreckage and Damage

An FAA inspector who responded to the scene noted that the nose gear collapsed and there was structural damage to the firewall, forward empennage, and both wingtips. The left wing had a significant buckle at wing station 100, causing the outboard leading edge skin to open up and the inboard inner spar skin to buckle downward.

Weather and Frost Observations

At 0853, an aviation routine weather report (METAR) at Bethel, Alaska, reported wind from 330 degrees at 8 knots, 10 miles visibility, few clouds at 700 feet, temperature 27 degrees Fahrenheit, dew point 23 degrees Fahrenheit, and an altimeter setting of 29.93 inches of mercury. Photos taken 5 minutes after the accident show the leading edges and tops of the wings, and horizontal tail surfaces were covered in rough frost. The photos also show the frost appears to have been scraped off of most of the windshield.

Contributing factors

Causes

PilotAirspeed — Not attained/maintained

Other contributing factors

Effect on operationIncorrect use/operation