On July 3, 2015, about 1308 Alaska daylight time, a Piper PA-18 airplane, N9189D, sustained substantial damage during a collision with terrain, following a loss of engine power during takeoff from Tidewater Airport near Wasilla, Alaska. The airplane was registered to, and operated by, the pilot as a visual flight rules (VFR) personal flight under the provisions of 14 Code of Federal Regulations Part 91. The pilot, who was the sole occupant, was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local area flight. According to the pilot, he was conducting test flights after having a rebuilt Lycoming O-320 engine installed, and completing an annual inspection. The first flight of the day he flew around the airport traffic pattern one time and landed uneventfully. During the second flight, he stated that the engine was showing signs of possible water contamination in the fuel. He landed and sumped the fuel tanks, which showed no indication of water in the fuel. Along with his mechanic, he did an engine run up, checking the magneto drop and carburetor heat application, and the engine ran smoothly. The pilot said that during the third takeoff, as the airplane climbed to about 300 to 500 feet above the ground (agl), the engine began sputtering and lost all power. The pilot stated that he switched fuel tanks, but was unable to restart the engine. During the subsequent forced landing, the airplane went through trees, coming to rest on its right side. The airplane sustained substantial damage to the wings and fuselage. On June 21, 2015, the NTSB IIC, along with another NTSB investigator performed a post-accident examination of the airframe and engine. Control cable continuity was established from the cockpit control to the engine for the throttle, mixture, and carburetor heat. The engine was manually rotated and continuity was confirmed throughout the drive train; thumb compression was obtained on all cylinders. All four cylinders were visually inspected by a lighted boroscope; the combustion chambers were free of foreign object damage, detonation and oil residue. The fuel strainer filter screen was free of visible contaminates. No anomalies, contamination, or evidence of malfunction was found in any of the engine accessories. The cylinders, pistons, valve train, crankshaft, and other internal components were all without evidence of anomaly or malfunction that would have precluded normal operation. After repeated attempts, the pilot did not submit an NTSB Pilot/Operator Aircraft Accident Report (NTSB Form 6120. 1).