Piper PA 22-160 N2805Z accident near Tyler, Minnesota

Probable cause

The student pilot's failure to adequately ensure the carburetor was clear of ice before takeoff, which resulted in a partial loss of engine power during takeoff due to carburetor icing.

NTSB analysis

The student pilot reported that the airplane was topped off with fuel before the flight and that he completed a functional check of the carburetor heat during his pretakeoff engine run-up. Shortly after liftoff, he observed a significant decrease in engine speed, and the airplane began to descend. He reduced the pitch to increase airspeed, but the airplane descended into a cornfield about 50 ft past the end of the runway.

Postaccident engine examination did not reveal any evidence of preimpact anomalies that would have precluded normal operation. Fuel samples from each wing tank, the fuel lines, the fuel strainer, and the carburetor bowl were consistent with 100 low-lead aviation fuel and did not contain any water or debris. The weather conditions were conducive to the formation of serious carburetor icing at all power settings. Additionally, the pilot reported that the grass runway was wet with dew, which likely increased the air humidity over the runway and the possibility of carburetor ice formation during taxi and takeoff. Although the pilot reported that he conducted a functional check of the carburetor heat before departure, it is likely he did not adequately ensure that the carburetor was clear of ice before beginning the takeoff. Based on the available information, the partial loss of engine power during takeoff was likely due to carburetor ice accumulation.

The pilot did not have a valid pilot certificate, and his most recent student certificate had been expired for 5.5 years. Additionally, federal regulations prohibit student pilots from acting as pilot-in-command of an aircraft carrying passengers.

Text from the NTSB. Open the NTSB docket for CEN15LA382 for the full record.