This May 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Cessna 150. Injuries: 1 Serious. Location: Palestine, Ill. Aircraft damage: Substantial.
What reportedly happened: The pilot reported that at about 2,000 feet MSL he was unable to maintain altitude. He turned toward the 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 applied full power, but the airplane continued to stall. He attempted to land in a clearing on the other side of a stand of trees but did not have sufficient altitude and hit the trees and the ground during the forced landing. GPS data retrieved from a unit on board the airplane indicated that it began a left-hand spiraling descent about five minutes prior to impact. The spiraling descent began at about 1,600 feet MSL and consisted of six 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. Analysis of the weather conditions indicated that they were favorable for moderate icing at cruise power settings or serious icing during descent power settings.
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.
For more information: NTSB.gov