On August 19, 1998, about 1125 eastern daylight time, a homebuilt Kitfox IV 1200, N4038T, was destroyed when it struck trees while returning to land at a private airport in Granby, New York. The certificated commercial pilot, acting as pilot-in-command was fatally injured, while the certificated private pilot/owner received serious injuries. Visual meteorological conditions prevailed for the post maintenance evaluation flight. No flight plan had been filed for the flight that was conducted under 14 CFR Part 91. According to an inspector from the Federal Aviation Administration (FAA), the airplane had been modified with the addition of an elevator trim tab and cockpit adjusting system by the commercial pilot who also held mechanic's certificates for airframe and powerplant. The purpose of the flight was to test the installed system. Witnesses observed the airplane depart to north. One witness reported: "...The plane made a right turn after gaining altitude, made another right turn and headed south. The plane started losing power and altitude while southbound and it appeared that...[the pilot] was trying to get back to the runway. I saw the plane bank slightly to the right (west) and then pitched nose first into the trees just east of the runway...." Another witness reported: "...I saw them takeoff north, half way down the runway while the plane was in flight, I heard the engine drastically reduce power. After that occurred the plane turned east, then south [and] continued south it appeared they were going to turn to the west in an attempt to return to the runway. While in the turn to the west the plane took a sudden dive. The plane went straight down into the trees nose first...To my knowledge the engine never stopped until the plane crashed...." The airplane was examined by an inspector from the Federal Aviation Administration (FAA), and a New York State Police Officer. According to a report written by the New York State Police: "...The aircraft was observed to be facing in a northeast direction, with the tail section elevated and the nose in contact with the ground. The aircraft was equipped with a single propeller, having three blades attached. Two of the blades were completely broken at the nose section, with the third being split along the length of the blade. The left wing was observed to be supported by several tree limbs, which served as a support for the entire craft. The right wing was found to be in contact with the ground, and contact damage was noted to the extreme end of the wing. In addition, to the contact damage noted to the right wing, damage was observed to the left, pilot's side of the aircraft...Several part of the craft were noted to be dispersed in the general vicinity, including the right side tire and sections from the right wing. The sections of wing were located approximately 16 feet east of the nose of the aircraft. Also noted in the same area were three separate gouges to the ground with red paint transfer noted to some exposed rocks. Sections of the broken propeller blades were observed under the front of the aircraft.... According to the FAA Inspector who examined the airplane after the accident, the elevator trim tab was found in a trailing edge down position. The trim tab cable was found to loose where it attached to the actuating lever. It was possible to slip the cable where it attached to the actuating handle. In addition, the engine was started and ran after the accident. The FAA inspector reported that the owner/pilot was interviewed multiple times and had no memory of the accident or the events that preceded it. Examination of the Phase I Experimental Operation Limitations issued to the airplane revealed the following: "...Any major change to this aircraft, as defined by Section 21.93 invalidates the Special Airworthiness Certificate issued for this aircraft...." According to the FAA Inspector, the owner/pilot had not made application for a new Special Airworthiness Certificate, following the installation of the elevator trim tab. According to FAA records, the commercial pilot had in excess of 10,000 flight hours, and also held a mechanic's certificate for airframe and powerplant. The owner/pilot had a private pilot certificate with 110 hours, and a repairman's certificate for the accident airplane. The toxicological testing report from the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma, for the commercial pilot was negative for drugs and alcohol for the pilot.