Primary finding
Probable cause
A partial power loss of engine power during initial climb for undetermined reasons.
Investigator assessment
Analysis narrative
The pilot was departing from a fly-in event on a frozen lake. During the initial climb, at an altitude of about 150 feet, the engine suddenly lost power completely. The pilot attempted to turn the airplane away from trees that were ahead but hesitated to lower the airplane’s nose. The airplane subsequently encountered and aerodynamic stall and impacted the ice below, resulting in substantial damage to the right wing. A postaccident examination of the wreckage revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. Additionally, the temperature and dewpoint were not favorable to the formation of carburetor icing. Based on the available information, the reason for the loss of engine power could not be determined.
Source record
Factual narrative
On February 25, 2023, about 1245 eastern standard time, a Piper PA-12, N4433M, was substantially damaged when it was involved in an accident at Ebeemee Lake, Maine. The pilot and passenger received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, after attending a fly-in event on a frozen lake, he prepared the airplane for departure. After taxiing away from the parking area to warm up the engine and test the magnetos, the pilot initiated the takeoff. He described that the engine developed fuel power and he was able to rotate the airplane as normal. As the airplane reached between 100 and 150 feet, the engine “quit suddenly.” The pilot stated that he initially “hesitated to lower the nose to maintain airspeed” and banked to the right to avoid trees that were straight ahead. The airplane subsequently stalled and impacted the ice below, with the airplane’s right wing sustaining substantial damage during the impact. A postaccident examination of the wreckage by a Federal Aviation Administration inspector confirmed continuity of the engine’s valvetrain and powertrain, with compression observed on all of the cylinders when the crankshaft was rotated. No anomalies of the ignition system were observed. Fuel was present in the fuel strainer and in the fuel lines to the carburetor. An estimated ¼-tank of fuel remained within the fuel tanks. Overall, the examination revealed no evidence of any mechanical malfunctions or failures that would have precluded normal operation. The temperature and dewpoint reported at Millinocket Municipal Airport (MLT), about 18 nautical miles east of the accident site, were -10 degrees C and -17 degrees C, respectively. The calculated relative humidity at this temperature and dewpoint was 56%. Review of the icing probability chart contained within Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35 revealed the atmospheric conditions at the time of the accident were not conducive to carburetor icing.