Stinson 108 N647C accident near Grand Rapids, Minnesota

Probable cause

A loss of engine power after takeoff for undetermined reasons.

NTSB analysis

The pilot reported that he allowed the engine to warm-up for about 15 minutes before takeoff and used the carburetor heat. The takeoff was normal, but shortly after establishing climb power, he noticed a reduction in power although the engine was still running smoothly. He turned to a left downwind for landing; however, "several seconds" later, the engine "popped twice and quit completely." The propeller was windmilling. The pilot executed a forced landing and the airplane sustained substantial damage to the aft fuselage, left wing, left horizontal stabilizer, and right float.

Postaccident examination of the engine, including a test run, did not reveal any anomalies that would preclude normal operation. Although the weather conditions at the time of the accident were conducive to carburetor icing at glide power, the pilot reported that he used carburetor heat when the airplane was idling on the ground and that the airplane was operating at a high power setting when the engine lost power, both of which would have prevented the accumulation of carburetor ice. Thus, the reason for the loss of engine power could not be determined based on the available information and postaccident examination and testing.

Text from the NTSB. Open the NTSB docket for CEN19LA281 for the full record.