Cessna 150M N66381 accident near Palestine, Illinois

Probable cause

The loss of engine power due to carburetor icing. Contributing to the accident were the pilot's decision to conduct a low-power spiraling descent operation during conditions conducive to carburetor icing, and the weather that was conducive to carburetor icing.

NTSB analysis

The pilot reported that during flight, at about 2,000 feet mean se level (msl), he was unable to maintain altitude and decided to divert to his home airport. He said that he made a gradual left turn and had descended to 1,000 feet msl when the stall warning horn activated. He stated that he applied full power, but the airplane continued to stall and he attempted to land in a clearing on the other side of a stand of trees. The airplane subsequently hit the trees and the ground during the forced landing. Global positioning system data retrieved from a unit on board the airplane indicated that the airplane began a left-hand spiraling descent about 5 minutes prior to impact. The spiraling descent began at about 1,600 feet msl and consisted of 6 complete left-hand turns that ended at a recorded altitude of about 650 feet msl. The average speed during the descent was about 60 knots and the average descent rate was about 250 feet per minute, indicating a reduced power descent. Further evidence indicated that the nearest residence to the accident site was the home of a relative of the pilot. Analysis of the weather conditions indicated that they were favorable for moderate icing at cruise power settings or serious icing during descent power settings.

Text from the NTSB. Open the NTSB docket for CHI08LA134 for the full record.