Accident Overview
On November 13, 2022, about 0950 central standard time, a Cessna 152, registration N222UM, sustained substantial damage during a forced landing near Manchester, Michigan. The aircraft was operated as a 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor and student pilot were uninjured.
Sequence of Events
According to the flight instructor, the airplane was in cruise flight with the engine operating at about 2,400 rpm when he felt a power drop. The tachometer subsequently indicated about 1,300 rpm. The instructor took control from the student pilot, applied carburetor heat, and followed the checklist in an attempt to restore power. At one point, while varying throttle and mixture settings, the rpm briefly increased to about 1,500 for approximately 10 seconds before dropping back to 1,300. The instructor notified air traffic control of the power loss and diverted toward the nearest airport. When it became evident they could not reach the airport, he selected a field for a forced landing. During the landing, the nose wheel dug into soft soil, causing the airplane to nose over. The accident resulted in substantial damage to the vertical stabilizer and rudder.
The student pilot reported that after the engine rpm dropped to 1,300, the instructor applied carburetor heat, and the engine rpm decreased momentarily before increasing briefly.
Preflight and Preaccident Checks
Both pilots stated that the fuel tanks had been topped off the night before, and the airplane was stored in a hangar overnight. A preflight inspection, including sumping the fuel tanks, revealed no anomalies. After engine start and taxi, a run-up was performed with no issues noted.
Postaccident Examination
An examination of the wreckage confirmed control continuity from the cockpit to all flight and engine controls. Fuel drained from the carburetor and both fuel tanks contained no contaminants. The carburetor venturi showed no anomalies. The spark plugs were removed and found unremarkable. With the top spark plugs removed, thumb compression was noted on all cylinders when the propeller was rotated by hand. The magnetos were tested on the airframe, and sparking was observed on all leads in firing order.
Weather Conditions
The 0953 weather observation at Ann Arbor, Michigan, located 17 nautical miles from the accident site, recorded a temperature of 32°F and a dewpoint of 25°F. According to the FAA carburetor icing probability chart, these atmospheric conditions were conducive to the development of serious carburetor icing at glide and cruise power.
Probable Cause
None stated.