NTSB Factual Report

HISTORY OF FLIGHT

On December 8, 2007, at 1516 eastern standard time, a Cessna T210N, N5431C, registered to a private individual and operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91, collided with the ground following an in-flight breakup in Bloomfield, Kentucky. Instrument meteorological conditions (IMC) prevailed and an instrument flight rules (IFR) flight plan was filed. The private instrument-rated pilot and passenger were killed, and the airplane sustained substantial damage. The personal flight originated from Charleston Executive Airport (JZI), Charleston, South Carolina at 1236, and was enroute to Clark Regional Airport (JVY), Jeffersonville, Indiana.

After takeoff, the flight proceeded towards the destination airport and air traffic control (ATC) communications with several facilities occurred. At 1509, while in contact with the Louisville terminal radar approach control (Louisville TRACON) and flying at 8,000 feet mean sea level (msl), the controller instructed the pilot to descend and maintain 6,000 feet msl, which he correctly read back. Radar and radio contact were then lost.

According to the National Transportation Safety Board Recorded Radar and Performance Study, the airplane was heading northwest towards the destination airport, descending through an altitude of 6,800 feet at a constant rate of about 650 feet-per-minute, when it began to make a subtle turn to the north. About 32 seconds later, the airplane continued to turn and descend at a constant rate, reaching a maximum bank angle of about 40 to 50 degrees and exceeding the structural cruise speed by 20 knots calibrated airspeed (13 knots less than never exceed speed). Trajectory calculations showed that the breakup of the airplane occurred about 5 seconds later. The debris field heading was in a southeasterly direction, located in close proximity to the last three radar returns.

Witnesses in the local area reported hearing an airplane and then a crash. The witnesses stated that the airplane's engine sounded very loud until the impact. Witnesses telephoned 911 and reported the accident.

PERSONAL INFORMATION

The pilot, age 78, held a private pilot certificate, with ratings for airplane single-engine land and instrument airplane. His certificate was issued June 27, 1998. He held a second-class medical certificate issued on September 22, 2006, with a restriction that he must wear corrective lenses. Review of the pilot's logbook revealed that he had accumulated 1,650 total flight hours, of which 500 hours were in the Cessna T210N. The pilot had also accumulated about 100 hours of actual instrument experience, and 150 hours of simulated instrument experience. The pilot's last flight review and instrument proficiency check were completed on April 20, 2007.

AIRCRAFT INFORMATION

The six-seat, high-wing, retractable-gear airplane was manufactured in 1979 by Cessna Aircraft Company. It was powered by a Continental TSIO-520-R, 300-horsepower engine and equipped with a McCauley constant-speed propeller. Review of maintenance logbook records showed that an annual inspection was completed on May 4, 2007, at 74 hours prior to the accident. The airframe total time at the time of the annual inspection was recorded at 4,264.7 hours.

METEOROLOGICAL INFORMATION

The 1456 surface weather observation at Louisville International Airport (SDF), Louisville, Kentucky, was wind 060 degrees at 6 knots, visibility 5 miles in haze, overcast ceiling at 1,200 feet, temperature 7 degrees Celsius, dew point temperature 4 degrees Celsius, and altimeter 30.28 inches of mercury.

A weather study was conducted by a Safety Board meteorologist. The study found that based on available weather data at the time of the accident, the airplane was likely in visual meteorological conditions until just prior to the accident. While there was no direct evidence that the airplane entered clouds just before the accident, cloud tops reached a height of about 13,000 feet msl.

WRECKAGE AND IMPACT INFORMATION

The aircraft impacted hilly forested terrain at an elevation of about 750 feet msl. The wreckage path was approximately 3,000 feet long on a heading of 145 degrees. Sections of the composite right wing tip and a section of skin from the right aileron marked the beginning of the wreckage path, followed within 100 feet by the top-half of the right wing tip, an inboard 2-foot section of the right aileron and the outboard 2 1/2-foot section of the right flap. Scattered throughout the middle portion of the wreckage path, on a heading of approximately 145 degrees, were the following larger sections in their approximate order: right elevator, elevator trim tab, right aileron section, outboard 3 feet of the left horizontal stabilizer, outboard 5 feet of the left wing, right elevator balance weight, right wing, right wing spar cap section, and right aileron outboard section with attached balance weights. The right wing and an outboard section of the right aileron containing the balance weights were recovered approximately 500 feet from the end of the wreckage path. The fuselage with the left wing, sectioned empennage, and engine still attached made up the main wreckage, which marked the end of the wreckage path.

Flight control cable continuity was established from the empennage surfaces to the cockpit controls. Aileron and flap control cable continuity was established from the individual surfaces through cable separation that bore signatures consistent with tension overload, to the cockpit controls and flap actuator. The right aileron bell crank displayed damage arising from repeated strikes to the stop bolts. The flap actuator measurement indicated retracted flaps. Precise Flight speed brakes had been installed. The engine remained attached to the airplane and the propeller remained attached to the engine. The landing gear was attached to the airframe. All of the fracture surfaces exhibited features consistent with static overload with no evidence of metal fatigue noted. There was no evidence of a postcrash fire in the area of the main wreckage site or at any of the secondary locations.

A section of the left wing at the aileron to flap junction, outboard of the wing box structure, had separated in-flight. The aileron remained attached to the outboard wing section. The remainder of the wing remained attached to the fuselage. The flap remained attached to the inboard section of the wing. Separation signatures were consistent with a downward separation of the outboard wing section. A cable cut, created by the aileron balance return cable, extended across the entire width of the cabin roof, just aft of the top of the windshield. It continued along the leading edge of the inboard section of the wing, from the root of the wing to the outboard rib of the wing box structure, just inboard of the wing separation. The Precise Flight speed brake remained partially extended. The speed brake blades were distorted and interference between the two blades prevented their complete retraction. They appeared to be in the approximate mid-travel position.

All of the right wing main spar plates, spar caps, spar reinforcements, and spar web separated from the main wing spar fitting assembly at the outboard end of the assemblies. The outboard 2 inches of the lower aft spar fitting assembly, and all attaching lower wing spar structures, were bent aft approximately 5 degrees. The lower forward spar fitting assembly was not displaced or bent. The upper spar fitting assemblies were not displaced or bent. The front spar attachment displayed signatures consistent with an aft bending of the right wing. The Precise Flight speed brake was observed in the retracted position. The right wing tip, aileron, and inboard 4 feet of the flap were not attached. The inboard 4 feet of the right wing, aft of the main spar, was fragmented and not attached to the remaining wing structure. The outboard 4 feet of the flap remained attached to the wing structure. The wing was bent down approximately 10 degrees at the mid-span. The main spar caps and four spar plates were fractured in this mid-span area. The lower main spar cap and the four spar plates separated from the remaining wing structure. All mid-span separation surfaces displayed signatures consistent with bending in a downward direction. The main spar web and the bottom skin of the wing displayed compression wrinkles. All of the fracture surfaces examined exhibited features consistent with static overload with no evidence of metal fatigue.

The outboard one-half of the left horizontal stabilizer separated in-flight from the empennage. The remainder of the empennage assembly, including the vertical stabilizer, the right horizontal stabilizer and the inboard section of the left was located at the main wreckage site. The right horizontal stabilizer was twisted up and aft about the root, fracturing the front spar about 2 inches outboard of the side of body. The left horizontal stabilizer was twisted aft and down about the root, fracturing the front and rear spars 3 feet outboard of the side of body at the middle elevator hinge point. The vertical stabilizer was bent 90 degrees to the right, fracturing the forward and rear spar caps about 4 inches above the as designed aftward change in the angle, or sweep, of the spars. All of the fracture surfaces examined exhibited features consistent with static overload with no evidence of metal fatigue.

Examination of the engine found that it remained attached to the fuselage by damaged engine mount members, control cable, electrical wires and fuel lines. The magnetos were removed from the engine, and rotated freely with impulse coupling engagement and produced spark on all leads. The upper spark plugs displayed a worn out normal signature in accordance with the Champion AV-27 chart. The spark plug electrodes displayed light gray deposits. The propeller was removed and the crankshaft rotated by hand. Compression and valve continuity were established for each cylinder. Valve train continuity was established for the accessory gears, forward camshaft drive gear and starter drive. The turbocharger separated from the engine. The compressor/turbine shaft rotated freely. The waste gate assembly remained attached to the exhaust tube. The gate was in the open position. The waste gate control valve moved freely under pressure. No preimpact anomalies were noted to the engine.

The airplane was equipped with two vacuum pumps; one engine driven vacuum pump, and one electrically driven back-up vacuum pump. The engine driven pump mounting flange was separated in the impact sequence. The drive coupling was intact, but the pump could not be rotated by hand. The rotor was fragmented into three major pieces, which displayed rotational scoring. The electric motor driven back-up vacuum pump drive coupling was intact and the pump was rotated freely by hand.

The propeller remained attached to the engine crankshaft. Three sections of tree branches impacted by the propeller and engine were located at the impact site. Each piece was approximately 16 inches long and 2 inches in diameter. Each displayed propeller cut signatures at each end. Blade "A" was observed loose in the propeller hub. The blade was bent forward approximately 90 degrees in a large radius bend starting at the propeller hub. The outboard 1-inch section of the tip of the blade was bent in the opposite direction, or aft approximately 45 degrees. The leading edge displayed light impact damage. Blade "B" was tight in the propeller hub and bent slightly aft, less than 5 degrees at the blade shank, otherwise the blade was unremarkable. Blade "C" remained tight in the propeller hub. It was bent aft approximately 45 degrees in a large radius bend starting at mid-span. The blade tip was twisted beyond 0-degree pitch to a near feathered position. The leading edge displayed impact damage and chordwise polishing.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot on December 9, 2007 by the Office of the Chief Medical Examiner, Louisville, Kentucky. The autopsy findings reported the cause of death as massive blunt trauma with multiple injuries.

Forensic toxicology was performed on specimens from the pilot by the Federal Aviation Administration (FAA), Aeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated that Carbon Monoxide and Cyanide tests were not performed and that there was no Ethanol detected in urine. However, there was Cimetidine and Terazosin detected in blood and urine, 113.3 (ug/ml, ug/g) Acetaminophen detected in urine, and Ephedrine detected in urine and lever and pseudoephedrine was present in urine and liver.

TESTS AND RESEARCH

The left and right speed brakes were examined at the manufacturer's facility on April 2, 2008, under the supervision of a Safety Board investigator. No anomalies were found during the examination. All of the fracture surfaces examined exhibited features consistent with static overload with no evidence of metal fatigue.

NTSB Probable Cause

the pilot exceeded the design stress limits of the airplane, which resulted in the in-flight break up. Contributing to the accident was the pilot's loss of control in-flight due to spatial disorientation.