NTSB Factual Report

On September 30, 2011, about 1303 central daylight time, an experimental, amateur-built, Heronimus Glasair III, N43KH, owned and operated by an individual, was substantially damaged after a loss of engine power and collision with a motel at Falls of Rough, Kentucky. The private pilot was fatally injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The flight departed the Rough River State Park Airport (2I3), Falls of Rough, Kentucky, at 1255.

According to witnesses, the airplane departed runway 20 at 2I3, circled, and returned to make a “fly-by.” As the airplane flew over the runway, witnesses reported that the engine sounded like it “over revved.” They also stated that they saw what appeared to be a puff of smoke emitting from the nose of the airplane. The pilot made a left banking turn, and then entered a left downwind for runway 02. The engine began to “rev” very high and then began to surge as the airplane descended. The engine went silent and the airplane turned towards the airport, but it did not have enough altitude to make it to the runway. The pilot appeared to level the wings and lower the landing gear before the airplane descended into trees. Shortly thereafter, an explosion was heard behind the tree line. First responders to the accident site found the airplane engulfed in flames behind a motel.

PERSONNEL INFORMATION

The pilot, age 61, held a private pilot certificate for airplane single-engine land privileges, issued November 29, 2010, and a third-class airman medical certificate issued November 3, 2010, with limitations for corrective lenses. The pilot reported 1,100 total flight hours at that time. The pilot's logbook was not recovered for examination.

AIRCRAFT INFORMATION

The two-seat, low-wing, retractable-gear airplane, serial number 3071, was manufactured in 2005. The airplane’s first flight was conducted on March 24, 2006. On October 26, 2010, an automobile engine conversion was completed. The originally-installed Lycoming IO-540 was replaced with a Chevrolet LS1 engine and equipped with a Vortech supercharger. The propeller was a Hartzell model HC-C2YK-1BF constant speed propeller. The propeller was attached to a propeller speed reduction unit (PSRU). A review of copies of the maintenance logbook records showed that on October 10, 2010, the airplane was inspected in accordance with Appendix D of 14 CFR Part 43. At the time of the inspection, the recorded tachometer reading was 1.4 hours. The tachometer was observed at the accident site; however, damage precluded determining a current reading. A review of the logbook records revealed that on March 3, 2011, the pilot/builder certified that the prescribed flight test hours were completed and that the aircraft was controllable throughout its normal range of speeds and throughout all maneuvers to be executed. The operating data that was demonstrated during the flight testing speeds were noted: Stall speed or minimum flight speed in landing configuration (Vso) 60 knots, speed that will allow for best angle of climb (Vx) 80 knots and speed that will allow for the best rate of climb (Vy) 170 knots.

METEOROLOGICAL INFORMATION

The reported weather at Godman Army Airfield, Fort Knox, Kentucky, which was located about 31 miles northeast of the accident site, at an elevation 755 feet, at 1255, was: wind 310 degrees at 11 knots gusting 17 knots, visibility 10 statute miles, clear skies, temperature 18 degrees Celsius (C), dew point 8 degrees C, and altimeter 29.97 inches of mercury.

WRECKAGE INFORMATION

The wreckage was located in the rear courtyard of a motel, approximately ¼ mile south of 2I3. A debris path originated at severed trees and continued approximately 50 feet on a 192-degree magnetic heading. The airplane collided with the rear motel wall before coming to rest. The post-crash fire consumed a majority of the fiberglass airframe.

The cockpit, cabin, and fuselage sections were completely burned by fire. The seat frames were present and in their respective positions. The control stick was identified and the push-pull tubes moved when the control stick was manipulated. The rudder pedals were melted and the rudder cables exhibited overstress fractures. The elevator control tubes could not be identified. The avionic instruments were fire damaged and no pertinent information could be obtained from them. Examination of the nose landing gear revealed that it was fire damaged and separated from the fuselage.

The left wing was fire damaged and separated from the fuselage. Further examination of the wing revealed that only cloth fibers remained. The left wing push-pull tubes were observed throughout the wing structure. The aileron moved correctly when the push pull tubes were manipulated. The fuel tank caps were not located. The left main landing gear was separated from the wing and located in the wreckage debris field.

The empennage and vertical stabilizer were fragmented and consumed by fire and only fiberglass cloth remained. The elevators and rudder were fragmented and consumed by fire. The flight control cables were located and were broken in multiple sections and exhibited overstress signatures.

The right wing was fragmented and consumed by fire. Fragments of the right wing push-pull tubes were observed throughout the wreckage debris field. The right wing tip was located on the wreckage path and was broken away from the rivet fasteners.

The engine assembly was located next to a concrete wall and was fire damaged. Visual examination of the engine confirmed that it was an automotive engine. The engine sustained impact damage and fire damage, which precluded rotation of the crankshaft by hand. The spark plugs were removed for examination and exhibited thermal damage on the ceramic insulator. The spark plug electrodes were covered with soot. The propeller remained attached to the PSRU, and the PSRU remained attached to the engine. Both propeller blades exhibited s-bending and chordwise scratching. The propeller blades were curled and melted near the tips.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot on October 1, 2011, by the Office of the Chief Medical Examiner, Urban Government Center, Louisville, Kentucky, as authorized by the Grayson County Coroner. The autopsy findings included “blunt force injuries” and the report listed the specific injuries.

Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no ethanol was detected in the liver or the muscle, and no drugs were detected in the liver.

TEST AND RESEACH

Examination of the PSRU by the NTSB Materials Laboratory revealed that the components had reportedly less than 50 hours of service on the drive train components. The PSRU system was designed with an automatic clutch and was tuned to remain disengaged at dead idle and become engaged with an increase in power. The components included the PSRU housing, propeller drive shaft, clutch hardware, propeller reduction unit gears, bearings, and additional hardware. The propeller drive shaft passed through the forward half of the propeller reduction unit housing and mated with a gear mounted on the aft half of the housing. The propeller drive shaft was fractured at its aft end where it mated with the internal splines on the gear. Approximately one-quarter of the forward fracture face exhibited rotational smearing. Rotational smearing was also observed on the aft face of the fracture, moving clockwise from the smeared area. Approximately one quarter of the forward fracture surface had a smooth appearance and exhibited curved crack arrest marks. The fatigue crack formed an approximate 45° angle with the longitudinal axis of the driveshaft. The remaining forward fracture surface had a rough appearance, consistent with an overstress fracture. Four cracks were observed in the gear that mated with the propeller drive shaft. The cracks were located at or near the internal splines that mated with the external splines on the propeller drive shaft.

NTSB Probable Cause

The failure of the propeller power speed reduction unit, which resulted in a loss of engine power at low altitude.