Cessna 170B N2814C accident near Skwentna, Alaska

Probable cause

The pilot’s failure to maintain airspeed during a departure turn, resulting in an aerodynamic stall and collision with terrain.

NTSB analysis

The wheel/ski-equipped airplane was departing to the northwest from a remote, frozen and snow-covered lake toward rising terrain. A gusty northwesterly wind was blowing, and the frozen lake was covered with soft snow. Witnesses said that just after takeoff, the airplane began to climb slowly with a nose-high attitude. As the airplane approached the area of rising terrain, it began a left turn, and the airplane subsequently descended to the ground in a nose-down attitude, colliding with snow-covered terrain nearly vertically.

The pilot reported that just after takeoff, the airplane encounter a downdraft and that it was not climbing sufficiently to avoid rising terrain ahead. As he started a left turn, he lowered the nose, applied full engine power, but the downdraft pushed the airplane into the snow-covered terrain.

The pilot reported that there were no preaccident mechanical problems, and a subsequent postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. An estimated weight and balance calculation indicated that the airplane was at or near its maximum gross weight and within the center-of-gravity envelope at the time of the accident.

Given the lack of mechanical deficiencies with the airplane and engine, along with the witness statements and the nature of the damage to the airplane, it is likely that the pilot did not maintain sufficient airspeed and inadvertently stalled the airplane when it reached the critical angle of attack during the turn, and the pilot was unable to recover because of the low altitude.

Text from the NTSB. Open the NTSB docket for ANC13FA024 for the full record.