Accident Overview
On June 28, 2021, at approximately 1530 Alaska daylight time, a Piper J3C-65 airplane, registration N98109, sustained substantial damage during an accident near Sterling, Alaska. The pilot and one passenger were not injured. The aircraft was being operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Pilot Report
According to the pilot, he had filled the fuel tanks to capacity two days before the flight but had not flown the airplane since. During the preflight inspection on the day of the accident, he drained “minimal” water from the right-wing fuel tank. He added one quart of oil to the engine, bringing the total to seven quarts. All before-takeoff checks were normal.
While en route, the airplane climbed to an altitude of about 2,900 feet mean sea level as the pilot prepared to cross an ocean channel. He reported that the engine began to “cough, sputter and make popping noises with a loss of power.” He initiated troubleshooting, including turning the carburetor heat control to ON, and began searching for suitable landing sites. During the descent, the engine produced intermittent power only for brief periods.
The pilot notified air traffic control of the emergency and maneuvered the airplane for a landing on tundra. During the landing, the airplane nosed over and came to rest inverted. The empennage and right wing sustained substantial damage.
Engine Examination
An examination of the airframe and engine revealed no mechanical failures or malfunctions.
Weather Conditions
The nearest weather observation station, located about 25 miles from the accident site, reported a temperature of 59°F and a dew point of 46.4°F near the time of the accident. According to the Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35 carburetor icing probability chart, the flight was likely operating in conditions conducive to “serious icing in cruise power.”