NTSB Factual Report

On September 7, 2004, about 1700 Alaska daylight time, a tundra tire-equipped Cessna 170 airplane, N3492C, sustained substantial damage when it collided with a sand/gravel bar during takeoff initial climb from a remote creek area, about 19 miles northeast of Teller, Alaska. The airplane was being operated as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the pilot. The airline transport certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. No flight plan was filed, nor was one required.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September 20, the pilot reported that he was departing from a gravel area that was oriented north/south, and was about 800 feet long, and about 100 feet wide. The pilot indicated that he departed toward the north, and the wind was variable, about 7 knots. He said about 25 feet from liftoff, the right main landing gear tire struck about a 2 foot high embankment. The airplane settled onto the gravel bar and came to a stop. The pilot said that an observer on the ground reported to him that the wind appeared to switch to a tailwind during the takeoff run. The pilot reported that the airplane was resting on the right wingtip, and the right main landing gear was bent up and aft about 6 inches. The pilot was picked up from the accident site by an Alaska State Trooper aircraft. Aerial photographs of the accident scene provided by the State Troopers revealed the airplane was in a small creek, with the airplane resting on the right wingtip. The right main landing gear was not visible. A scuff, or soil disruption, was visible along the surface of the gravel area, adjacent to the airplane.

The airplane was retrieved from the scene by helicopter. In a telephone conversation with the NTSB IIC on September 23, the pilot of the helicopter reported that when he arrived at the scene, he observed the right main landing gear strut and tire lying in a small creek, separated from the fuselage, between what appeared to be the takeoff point, and the airplane's point of rest. The airplane was lifted by helicopter from the scene to the Teller Airport. It was disassembled and packaged for shipment to Anchorage, Alaska, via Nome, Alaska.

A Federal Aviation Administration (FAA) aviation safety inspector, Fairbanks Flight Standards District Office (FSDO), examined and photographed the airplane as it was sitting on shipping pallets in Nome, prior to it being sent to Anchorage. The photographs revealed damage to the right wingtip, the right main landing gear attach point, and the fuselage. The propeller tips had slight curling.

The airplane was examined by the NTSB IIC on September 22 in Anchorage. The examination revealed that about 12 inches of the outboard end of the right wing aileron was missing from the inboard end of the aileron. The point of separation displayed tearing and upward curling. The outboard end of the right wing was missing its plastic wingtip. The outboard rib and trailing edge of the wing structure was crushed and bent, with tearing of the wing structure evident along the bottom of the wing. The left wing lift strut fuselage attach point was intact and undamaged. The left main landing gear attach point within the fuselage structure was undamaged. The right wing lift strut fuselage attach point was bent aft and fractured. The entire right main landing gear attach point, normally located within the fuselage structure, was missing. The attaching structure for the right gear strut was torn and fractured. The underside of the fuselage area, just aft of the right cabin door post, had upward crushing and bending, with vertical separation of the first rivet line aft of the door post.

NTSB Probable Cause

The pilot's selection of unsuitable terrain for takeoff, and his inadequate evaluation of the wind conditions, which resulted in a collision with an embankment during takeoff-initial climb. Factors contributing to the accident was the presence of a sand embankment, and a tailwind.