CEN14LA320

The pilot reported that everything was normal when he conducted a preflight inspection and engine run-up of the single-engine, float-equipped airplane before takeoff from a lake. The airplane departed, and, as it began to climb, the engine started to lose power. The airplane then stalled, the left wing dropped and struck the water, and the airplane flipped inverted and eventually sank. Postaccident examination of the engine revealed that, when the propeller was rotated manually, all of the engine cylinders, except for the No. 3 cylinder, produced compression. The intake valve, exhaust valve, and rocker arm moved when the propeller was rotated. No further examination of the engine was conducted, and the reason for the No. 3 cylinder's failure to produce compression could not be determined. It is likely that, as the engine began to lose power, the pilot did not maintain the proper airspeed or angle-of-attack, which led to a stall and the subsequent impact with water.

On June 20, 2014, about 1600 central daylight time, a float-equipped Cessna 172, N758HP, sustained substantial damage shortly after take off from Pickerel Lake, near St. Cloud, Minnesota. The private pilot and the two passengers were not injured. The airplane was registered to and operated by the pilot as a 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. The pilot stated that he conducted a pre-flight inspection of the airplane and performed an engine run-up prior to takeoff and everything was normal. The pilot then departed the lake on a north westerly heading. As the airplane began to climb, the engine began to lose power. The airplane then stalled and the left wing struck the water. The airplane flipped over and sank inverted into the lake. All three occupants were able to exit the airplane on their own. The airplane sustained substantial damage to both wings and both floats were crushed. The propeller was also damaged. Postaccident examination of the engine revealed that when the engine was turned via manual rotation of the propeller, all but the No. 3 cylinder produced compression. Both the intake and exhaust valves and also the rocker arm moved as well. No further examination of the engine was conducted and the reason as to why the cylinder did not produce compression was not determined. Weather reported at St. Cloud Regional Airport (STC), St. Cloud, Minnesota, about 5 miles south of the accident, at 1553, was wind from 150 degrees at 7 knots, visibility 10 miles, broken clouds at 8,500 feet, temperature 28 degrees C, dew point 17 degrees C, and an altimeter setting of 29.88 inches of Hg.