Event Overview
On November 3, 2018, about 0940 Alaska daylight time, a Cessna 172 airplane, registration N2809L, sustained substantial damage during an emergency landing on runway 25 at Merrill Field (PAMR), Anchorage, Alaska. The airplane was operated by the private pilot under 14 Code of Federal Regulations Part 91 for a local visual flight. The pilot was uninjured. Visual meteorological conditions prevailed, and no flight plan was filed.
First Power Loss
According to the pilot, on a previous flight earlier that day at about 0900, when climbing through approximately 400 ft above ground level (AGL), the engine began losing power and ran extremely rough. In the traffic pattern, the engine was only able to produce about 1200 RPM. The pilot returned for an uneventful landing on runway 25.
Post-First-Event Actions
Following the first event, the pilot sumped both fuel tanks and the gascolator for contaminants, finding none. A run-up was completed with no anomalies, and the pilot taxied with carburetor heat on. After another anomaly-free run-up, the pilot departed for a traffic pattern flight.
Second Power Loss and Emergency Landing
Just after departure from runway 25, at about 300 ft AGL, the engine again lost power and ran extremely rough. An emergency was declared, and the pilot returned for landing. During landing, the left wing impacted the runway, resulting in substantial damage to the airplane.
Post-Accident Examination
The airplane was parked outside where temperatures remained below freezing. On November 4, the NTSB Investigator-in-Charge examined the airplane. The fuel caps were frozen in place due to a significant amount of water trapped in the recessed area. Upon cap removal, ice was found on the vent flap, and the filler neck was completely covered in corrosion. Corrosion particles were also present within the fuel tank. The gascolator was drained and tested for water; the fuel sample tested positive for water.
On November 12, due to cold temperatures, the carburetor was removed by Alaskan Aircraft Engines for inspection after thawing. The inspection report indicated a large amount of debris and water within the carburetor bowl.