NTSB Factual Report

HISTORY OF FLIGHT

On April 18, 2009, at 1633 central daylight time, an experimental amateur-built, Gladstone Kitfox, N191KF, registered to a private owner, operating as a Title 14 Code of Federal Regulations Part 91 personal flight, collided with the ground while maneuvering near Dubre, Kentucky. Visual meteorological conditions prevailed and no flight plan was filed. The airplane received substantial damage and the private pilot was killed. The flight originated from a private farm in Burkesville, Kentucky, at an undetermined time.

A witness stated he heard an airplane approaching his house. The airplane was about 200 feet above the trees. It made a left turn next to a creek and reversed its course, flying back towards Burkesville. The airplane reversed its course again, and was observed above the creek coming back towards the witness' home. The fuselage of the airplane was swaying from left to right and the airplane made a steep left turn. The left wing of the airplane was perpendicular to the ground and the ground speed of the airplane appeared to be slow. The airplane continued in the steep left turn, reversed its course again, and leveled out. The wings on the airplane were observed to wobble, and the nose of the airplane pitched down. The airplane collided with the ground in a nose down attitude, and came to rest upright. The witness reported no change in engine noise during the accident sequence.

PERSONNEL INFORMATION

The pilot, age 51, held a private pilot certificate issued on May 19, 2004, with ratings for airplane single-engine land and airplane multiengine land. The pilot's last flight review was conducted on April 7, 2008. He received a tailwheel proficiency check on June 7, 2008. The pilot was issued a third-class medical certificate on September 5, 2008, with the limitation, "must have available glasses for near vision." The pilot indicated on his last application for the third-class medical certificate that he had accumulated 525 total flight hours.

Review of the pilot's logbook revealed he had accumulated 507 total flight hours, of which 175.3 hours were in airplane multiengine land, 313.5 hours were in airplane single-engine land, 19.1 hours in helicopter rotorcraft, and 48.3 hours were in the Kitfox. The pilot had flown 3 hours in the last 90 days. These 3 hours were in the Kitfox.

AIRCRAFT INFORMATION

The Gladstone Kitfox is a two-place airplane with a fixed tail-wheel landing gear, serial number 1BS065, registered on November 5, 2008. The airplane was issued a Special Airworthiness Certificate and Operating Limitations on May 14, 1996. A Rotax 912, 80-horsepower engine powers the airplane. Review of the airplane logbooks revealed the last condition inspection was conducted on October 11, 2008, and the Hobbs meter indicated 427.1 hours. The Hobbs meter was destroyed during the accident and the total engine and airframe hours could not be determined.

METEOROLOGICAL INFORMATION

The nearest weather reporting facility is Bowling Green, Kentucky, located about 31 miles south of the accident site. The 1753 surface weather observation was: wind 210 degrees at 8 knots, visibility 10 miles, 10,000 broken, temperature 27 degrees Celsius, dew point temperature 4 degrees Celsius, and altimeter setting 30.07 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

Examination of the crash site revealed the airplane collided with the ground in a nose down, right wing low attitude, and came to rest upright on a heading of 178 degrees magnetic. The engine assembly was buried about 1 foot below the surface of the ground and remained attached to all engine mounts. Two composite propeller blades separated and one propeller blade remained attached to the propeller crankshaft flange. The spinner exhibited evidence of rotation. The engine cowling separated from the airframe.

The forward cabin area was crushed down and aft. The instrument panel was crushed down and onto the engine. The right wing remained attached to the airframe and was pushed aft. The leading edge of the right wing exhibited accordion crushing from the wing root, extending outboard to the wing tip. The right main fuel tank was ruptured, the fuel cap had a tight seal, and the fuel vent line was clear of obstructions. Browning of vegetation was present on the ground in front of the airplane. The left wing remained attached to the airframe and was accelerated forward. The leading edge of the left wing exhibited some accordion crushing, extending outboard from the wing root to the wing tip. The left main fuel tank was ruptured, the left main fuel cap had a tight seal, and the fuel vent line was unobstructed. Continuity of the flight controls was confirmed from the flight controls aft to all flight control surfaces. No anomalies were noted with the airframe.

The engine was partially disassembled. Two of the top spark plugs were removed. They had dark gray deposits and exhibited normal wear. The in-line fuel filters were examined and were clear of debris and water. The crankshaft was rotated by hand using the one main propeller blade. Valve and drive train continuity was confirmed by rotation of the crankshaft, and continuity was established with all accessory gears. Suction and compression was obtained on all cylinders. Test for spark could not be performed due to engine damage from collision with the ground.

MEDICAL AND PATHOLOGICAL INFORMATION

The State of Kentucky, Medical Examiner at Louisville, Kentucky, conducted a postmortem examination of the pilot, on April 19, 2009. The cause of death was “blunt force trauma." The Forensic Toxicology Research Section, Federal Aviation Administration, Oklahoma City, Oklahoma performed postmortem toxicology of specimens from the pilot. The results were negative for carbon monoxide, cyanide, and ethanol. Naproxen was detected in the blood and urine.

ADDITIONAL INFORMATION

Review of performance data in the Pilot's Operating Handbook states on page 5, Performance, the stall speed with a Rotax 912 engine power on, full flaps, solo is 34 mph, and dual is 42 mph. The stall speed power off, full flaps, solo is 37 mph, and dual is 45 mph. Additional performance data for the Kitfox revealed the airplane would stall at 39 mph power off.

NTSB Probable Cause

The pilot's failure to maintain airspeed while maneuvering at a low altitude, which resulted in an aerodynamic stall.