Accident Overview
On April 25, 2018, at 1714 central daylight time, a Cessna 152 airplane, registration N89904, was substantially damaged during a forced landing after departing from Cullman Regional Airport (CMD), Cullman, Alabama. The pilot sustained minor injuries. The airplane was registered to and operated by Guest Aviation LLC under Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed. The flight departed CMD about 1709 and was destined for Northeast Alabama Regional Airport (GAD), Gadsden, Alabama.
Pilot's Account
According to the pilot, after departure he climbed to about 2,500 ft above ground level. As he pulled the mixture control toward a lean position for cruise flight, the engine lost power. He then pushed the mixture control to full rich and attempted unsuccessfully to restart the engine. The propeller continued to rotate after the power loss. Without an easily accessible engine restart checklist, the pilot relied on memory. He stated he went through the emergency check including avionics, master switch, fuel selector valve, mixture, and primer, noting that although the engine attempted to restart, it never regained full power.
The pilot did not activate carburetor heat during the flight and thought the throttle lever probably remained at a cruise power setting after the engine lost power. After one restart attempt, he focused on maintaining proper glide speed and searching for a forced landing area. He identified a suitable area and executed a forced landing into a field, during which the airplane nosed over and the right wing was damaged.
Post-Accident Examination
Examination at the accident site revealed the carburetor heat control was in the off position. The engine was started and ran normally at various power settings, with no anomalies noted in the engine or fuel system. Recorded temperature and dew point data from a nearby weather station, plotted on a carburetor icing chart, showed that the weather was conducive to moderate icing at cruise power and serious icing at descent power around the time of the engine power loss.
Carburetor Icing Information
According to the Pilot's Handbook of Aeronautical Knowledge, when conditions are conducive to carburetor icing during flight, periodic checks should be made to detect its presence. If detected, full carburetor heat should be applied immediately and left on until certain all ice has been removed. Applying partial heat or insufficient time may aggravate the situation. In extreme cases, full carburetor heat should be used even after ice removal to prevent further formation. A carburetor temperature gauge, if installed, is useful for determining when to use carburetor heat.