N602CFCzech Aircraft Works Spol Sro SPORTCRUISER · 2008

On July 21, 2008, about 1030 central daylight time, a Czech Aircraft Works Sport Cruiser, N602CF, sustained substantial damage when it impacted terrain near Cushing Field (0C8), Newark, Illinois. The sport pilot received fatal injuries. The airplane was registered as a Special - Light Sport Aircraft (S-LSA), and was operated as a rental airplane by Sport Pilot Chicago, located at 0C8. The 14 Code of Federal Regulations Part 91 personal flight departed 08C about 1030 on a local flight. There were no witnesses to the accident. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed.

A witness who was employed at the airport reported that he had returned to 0C8 about 1030. He observed the airplane takeoff from runway 36 (2831 feet by 80 feet, grass), but he did not continue to watch it. A pilot flying at the airport spotted the airplane in a bean field at 1300. The accident site was located within 0C8's traffic pattern about where the turn from a left downwind to a left base leg would be made. A small notepad was found in the cockpit that indicated that the airplane had departed with the Hobbs meter reading 76.5 hours. The Hobbs meter read 76.7 hours at the accident site.

The 77-year-old pilot held a Sport Pilot certificate with a single-engine land rating. The pilot was flying under Sport Pilot rules, and did not have (and was not required to have) an FAA medical certificate. The pilot’s logbook indicated that he received his Student Pilot certificate on June 27, 2006. He received his Sport Pilot certificate on February 23, 2007, and had flown about 50 flight hours in certificated airplanes. At the time of the accident, the pilot had flown about 104 hours in certificated airplanes and about 42 hours in ultra-light airplanes. He had about 19 hours in the make and model of the accident airplane.

An instructor pilot reported that the pilot had contacted him so that he could get re-familiarized with the Sport Cruiser, even though he was a certificated Sport Pilot and had flown the Sport Cruiser in the fall of 2007. On June 24, 2008, the instructor pilot flew with the accident pilot who demonstrated proficiency in basic flight maneuvers that included slow-flight, steep turns, stalls, and emergency procedures. The instructor pilot reported that the accident pilot demonstrated good “preparation, use of checklists, airplane control, attention to detail, demonstration of proficiency and safety.”

The airplane was a single-engine Czech Aircraft Works Sport Cruiser, serial number 08SC129, manufactured in 2008. It was equipped with a 100 horsepower Rotax 912 ULS engine. The two seat aluminum airplane had a maximum gross weight of 1,320 pounds. The last conditional inspection was conducted in May 2008. The airplane had a total of 76.7 flight hours at the time of the accident.

The airplane’s stall speed with the flaps in the extended position (Vso) is 37 mph. The stall speed at the maximum gross weight with wings level and the engine at idle is 39 mph.

At 1025, the surface weather observation at DeKalb Airport (DKB), located about 25 miles northwest, was: Wind calm, visibility 10 statute miles, clear, temperature 22 degrees Celsius (C), dew point 20 degrees C, altimeter 29.92 inches of Mercury.

At 0952, the surface weather observation at Aurora Airport (ARR), located about 16 miles north, was: Winds 140 degrees at 4 knots, visibility 9 miles, clouds broken 2,500 feet, overcast 15,000 feet, temperature 22 degrees C, dew point 21 degrees C, altimeter 29.88 inches of Mercury.

The airplane wreckage was located in a bean field and was 1.16 miles from 0C8 on a 211 degree bearing. The wreckage path from the initial impact point to the main wreckage was about 68 feet on a 168 degree heading. A shallow impact crater about 3 feet in diameter was located near the initial impact point. The nose landing gear was located near the impact crater. Pieces of the composite propeller blades and the composite main landing gear, which separated from the fuselage, were located in the debris field between the initial impact point and the main wreckage. Fuel blight was observed on the bean plants, but there was no post impact ground fire.

The airplane was found oriented on a westerly heading. Two propeller blades were broken at the propeller hub and the third blade was still attached to the hub, but it had impact damage. The engine was still attached to the engine firewall and exhibited minimal damage. The firewall was crushed aft at about a 30 degree angle. The cabin floor under the instrument panel was crushed aft and buckled on both the right and left side. The top of the pilot’s control stick was broken off. The pilot’s seat pan was found crushed downward. The pilot’s shoulder harness was found separated at the stitching where the shoulder harness webbing is stitched to the strap that was secured to an aft bulkhead.

The left wing exhibited more impact damage than the right wing. The left wing exhibited aft buckling at the wing root. The left wing’s outboard section was bent upward and aft, although the leading edge of the left wing was not crushed aft. The left wing fuel tank was compromised. The left flap and aileron were partially broken away from the wing, although both remained attached to the wing.

The right wing was intact, but was found buckled forward at the wing root. The leading edge had some damage, but did not exhibit aft crushing. The outboard section of the right wing exhibited buckling. The fuel tank remained intact. The right flap was found disengaged from the flap actuation pin. The right aileron was intact.

The canopy was found in the open position by first responders at the accident site. The forward edge of the canopy bow was crushed aft. The canopy glass was intact with no cracks visible. The canopy frame exhibited impact damage on the left front side aft of the attachment point. The canopy lifting struts and the attachment hardware exhibited no impact damage. The left and right canopy latches were bent.

The empennage was found undamaged. The vertical and horizontal stabilizers had no impact marks. The elevator trim tab was found in a slight down (nose up) trim setting.

The flight controls exhibited continuity from the flight controls to the flight control surfaces. The engine was put on an engine test stand. It was started and it operated through the full range of RPM settings.

An autopsy of the pilot was conducted on July 22, 2008, in Crest Hill, Illinois. The “Cause of Death” was noted as “Multiple blunt force trauma sustained as the pilot of an airplane involved in an airplane mishap.” A Forensic Toxicology Fatal Accident Report was prepared by the Federal Aviation Administration (FAA) Civil Aeromedical Institute. The report indicated negative results for carbon monoxide, cyanide, and ethanol. Diltiazem and Irbesartan were detected in the blood and urine. Diltiazem and Irbesartan are commonly used to treat high blood pressure.

The pilot’s Lowrance AirMap 1000 global positioning system (GPS) was found in the airplane wreckage. The track data that was stored on the 32-megabite memory card was downloaded and plotted on a sectional chart. The Lowrance AirMap 1000 GPS only recorded latitude and longitude data, and did not contain time or altitude information. The last flight recorded indicated that the flight originated from Cushing Field and flew to Waukegan Airport, and then returned to Cushing Field. The time and date of the last recorded flight could not be determined by the GPS data. There was no track data recorded of the accident flight.

The pilot’s and co-pilot’s seat belt and shoulder harness assemblies were removed from the airplane and sent to the NTSB’s Materials Laboratory for examination. The pilot’s harness was in four pieces. The pilot’s seat belt portion of the harness had been cut in two locations during the on-site recovery. The co-pilot’s harness was intact.

The inspection of the pilot’s shoulder harness revealed that the single strap of the shoulder harness that attached the harness to the rear cabin bulkhead was separated from the shoulder harness yoke where it was stitched to the right and left shoulder straps. The stitching had failed at the attach point.

Two exemplar harness sets (labeled EX1 and EX2) were obtained for the purpose of examination and destructive testing. In order to determine the strength of the sewing pattern at the yoke (where the pilot’s harness failed) the exemplar harnesses EX1 and EX2 were subjected to tensile testing. For comparison, the sewing location at the rear fitting of the harness was also tested. The tensile test revealed that the EX1 harness yoke failure occurred at a load of 1,458 pounds, and the rear location failure occurred at a load of 3,384 pounds. The EX2 harness yoke failure occurred at a load of 1,456 pounds, and the rear location failure occurred at a load of 3,375 pounds.

The harness assemblies were manufactured by an Italian company “PIEMMESSE ITALIA,” previously known as, “ARCONSULTING.” The testing authority for the harness assemblies was the Union Technique de l’automobile du motocycle et du cycle (UTAC) based in Montlhery, France. The UTAC test report identified requirements for a dynamic test to be performed at 50 kilometer/hour (31 mph). The minimum breaking load for the webbing, under all circumstances, was 3,300 pounds. The UTAC report is referenced in a French Transport Ministry approval which approves the harness assemblies for installation on several automobiles.

The accident airplane was classified as a Light Sport Aircraft (LSA) and as such, was not certified by the FAA. LSA’s are described as “self certifying,” indicating that they are certified as airworthy by the manufacturer. The FAA has accepted the American Society of Testing and Materials (ASTM) International standards for LSA’s, which are published in ASTM F 2245, “Design and Performance of a Light Sport Airplane.” ASTM standard F 2245 requires that the harness and their attachments to the structure be designed for the maximum load factors corresponding to specified ground and flight conditions, and to specified emergency landing conditions. However, the current ASTM F 2245 standard does not specify any of the testing requirements, such as the tensile load testing, found in the UTAC report, although a tensile test to a minimum of 1,710 pounds is awaiting consensus.

In FAA certificated airplanes, restraint harnesses are manufactured in accordance with FAA Technical Standard Order (TSO) requirements. The TSO requirements for restraint systems for FAA certificated civil aircraft are found in Society of Automotive Engineering (SAE) Aerospace Standard AS8043, “Restraint Systems for Civil Aircraft.” The AS8043 requirement for the minimum breaking strength of the pelvic restraint (seat belt) webbing is 5,000 pounds, and 4,000 pounds for the torso restraint (shoulder harness) webbing.