Incident Details
A commercial certificated pilot was conducting cruise flight at an altitude of about 800 feet above ground level in a float-equipped airplane. During the flight, the engine began to lose power.
Pilot Actions
The pilot reported that he switched the fuel tank selector from the right tank to the "BOTH" position. After this adjustment, the engine continued to run for approximately another two minutes. The pilot did not apply carburetor heat. Subsequently, the engine lost power again. The pilot selected a forced landing area on a small, marshy lake and successfully landed the airplane.
Post-Landing Inspection
Following the landing, the pilot noticed damage on the leading edge of the left horizontal stabilizer. He indicated that the damage appeared to result from striking a tree limb during the emergency landing. The pilot, who also holds a mechanic certificate, replaced the entire leading edge of the stabilizer. He reported that after the emergency landing, he did not find any obvious engine problem. Examination of the wing fuel tanks showed about 1.5 to 2 inches of fuel remaining. The fuel screens and fuel tank sumps were found to be clean.
Suspected Causes
The pilot stated that he suspected carburetor icing or water in the fuel as the cause of the engine power loss.