On August 27, 1995, at 0820 central daylight time, an Isaacson, Kolb Twin Star MK II, homebuilt airplane, N141KE, impacted terrain following a loss of power after takeoff from Flying "L" Airpark near Mansfield, Texas. The student pilot and his passenger received serious injuries. The aircraft was substantially damaged. The experimental airplane, owned by the pilot, was being operated under Title 14 CFR Part 91. No flight plan was filed and visual meteorological conditions prevailed for the personal flight. The pilot reported that, after takeoff, and climbing through 300 feet above ground level, the "engine failed with no warning signs" while in a right turn. He further reported that, he attempted to "put the stick forward to get airspeed for landing, but did not have enough altitude." Subsequently, the airplane impacted the ground approximately "45 degrees" nose down. A witness observed the aircraft descend into a plowed field, and roll over after impact. The airplane came to rest inverted at the initial point of impact. Examination of the airplane at the site by a FAA inspector, revealed the following: The support structure tubing for the tail section was bent approximately 160 degrees backward, under the cabin section. Both support braces for the main landing gear exhibited upward bending, and the fuselage was deformed and bent. Additionally, the fuel tank was found to be approximately 3/4 full. The pilot purchased the airplane in March of 1994; however, no record was found that indicates aircraft registry in the pilot's name. Additionally, no record was found that indicates that the pilot had a solo endorsement on his student pilot certificate.