On June 14, 2003, about 0930 eastern daylight time, a Kolb MKIII homebuilt airplane, not registered with the Federal Aviation Administration, experienced an in-flight loss of control and crashed on the Flagler County Airport, Bunnell, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 maintenance test flight. The airplane was substantially damaged and the private-rated pilot, the sole occupant, sustained minor injuries. The flight was originating at the time of the occurrence. The pilot stated that prior to the flight, the horizontal stabilizers which had been folded up were extended. He attached the lower elevator flight control cables and performed a preflight inspection of the airplane; he did not have a preflight checklist. Following the preflight, he started the engine and taxied to runway 24, and after landing traffic cleared the runway, he taxied onto the runway and applied power to takeoff. The airplane became airborne and when the flight was approximately 15 to 20 feet above ground level, he heard a "boom" sound, and experienced an immediate loss of elevator control. The airplane began a right turn and pitched nosed down. He reduced throttle to idle, and the airplane impacted the ground between runways 24 and 27. He later stated the leading edge of the right horizontal stabilizer rotated up 90 degrees. Each horizontal stabilizer (stabilizer) is structurally attached to the boom tube at the front and rear of each stabilizer. Additionally, a flying wire attaches to the top and bottom of each stabilizer. The front of each stabilizer is secured to the boom tube by a clevis and a safety pin which secures through a u-shaped bracket on the boom tube and a mating fitting on the stabilizer. The rear of each stabilizer is secured to the boom tube by a 1/4-inch diameter bolt and self locking nut which goes through a hinge. According to the pilot, postaccident the forward clevis pin and safety pin of the right stabilizer was not located. The upper and lower flying wires of the right stabilizer were not failed, and the 1/4-inch diameter bolt of the aft attach point was installed.