On September 20, 2009, at 1040 eastern daylight time, an experimental amateur-built Kolb Mark III Extra, N208NS, collided with the tops of trees while on final approach to Wychwood Field Airport (CT48), Mystic, Connecticut. The certificated sport pilot, who was the owner of the airplane, received minor injuries and the airplane sustained substantial damage. The flight was operated as a personal flight under the provisions of 14 Code of Federal Regulations (CFR) Part 91, and no flight plan was filed. Visual meteorological conditions prevailed at the time of the accident. According to the pilot, he was test flying the airplane in the traffic pattern. While on final approach, with a flap setting of 20 degrees, he increased the flaps to 40 degrees. At that time the airplane began to stall and he tried to increase engine power. He stated that when the airplane stalled, his airspeed was too slow and he was too low. The left wheel hit the top of some trees and then went down. According to a Federal Aviation Administration inspector, the airplane was observed about 100 feet into the woods in a nose low attitude. The left wing spar was snapped, the tail boom was broken into two pieces, and there was impact damage to the right wing. Damage to the engine consisted of the carburetors, exhaust and engine mounts. The airplane was certificated and issued a special airworthiness certificate on August 6, 2009. The pilot stated that he had about 4 hours in this airplane and that he was still test flying it. His total time in this make and model was approximately 9 hours and his total pilot time was about 60 hours.