On March 25, 2007, at 1058 central daylight time, a single-engine PZL-101A experimental airplane, N69NV, was substantially damaged during a forced landing following a reported loss of engine power during takeoff from the Spicewood Airport (88R), near Spicewood, Texas. The private pilot and his passenger were not injured. The Polish-built airplane was owned and operated by the pilot. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight was originating at the time of the accident. The 9,000-hour private pilot reported that following takeoff from runway 17, and while climbing out and passing through 500 feet above ground level, the 9-cylinder 285 horsepower radial engine lost power without warning. The pilot added that he continued to fly the airplane with partial power and elected to make a left-hand pattern for approach to runway 35 instead of landing on the south end of runway 17 due to the unsuitable terrain conditions. While executing the left hand pattern, the pilot reported that the engine lost additional power, and he began searching for a suitable landing area. Unable to find any suitable landing area at his disposal for the forced landing, the pilot elected to continue straight-ahead into a group of trees rather than into the houses to his left or the hangars to his right. The tailwheel-equipped airplane impacted the trees and came to rest in a nose-low attitude in the upright position. Both the pilot and his passenger were able to exit the airplane unassisted. The pilot reported that he confirmed there were 80 gallons of fuel aboard the 1969 vintage airplane prior to his departure. The Federal Aviation Administration (FAA) inspector that traveled to the accident site confirmed that the airframe sustained structural damage to the bottom side of the empennage, aft of the baggage compartment. The leading edges of both wings were also damaged, the empennage was buckled and twisted to the right, and the right horizontal stabilizer and right elevator were also structurally damaged. There was no post-impact fire. After the airplane wreckage was removed from the trees and recovered to the pilot's hangar, the pilot performed a detailed post-crash inspection of the engine and airframe. The pilot reported that he found the auxiliary fuel tank selector lever in the open position which he concluded must have been inadvertently moved with his left foot while assisting the passenger with the shoulder harness prior to the flight. The pilot explained that the auxiliary fuel tank lever is located on the floor outboard of the left rudder pedal. The pilot indicated that during pre-flight when he drained the fuel valve, the auxiliary tanks were closed. He further stated that he suspects there was water in the auxiliary fuel tanks that had entered the carburetor just after takeoff resulting in the loss of engine power. At 1053 CDT, a weather reporting station at Burnet, Texas, located 16 miles north of the accident site, reported wind from the south-southeast at 6 knots, 10 miles visibility, temperature of 66 degrees Fahrenheit, dew point of 61 degrees Fahrenheit, and a barometric pressure setting of 30.21 inches of Mercury.