History of Flight
On June 18, 2011, about 1306 eastern daylight time, a Cessna T210N, registration N210KW, departed from Westchester County Airport (HPN) in White Plains, New York, on a personal flight to Montauk Airport (MTP), New York. Shortly after takeoff from runway 34, the pilot reported to air traffic control that he needed to return and requested runway 16. When asked if he was declaring an emergency, the pilot affirmed but did not state the nature. He then reported he could not switch to tower frequency, and no further recognizable communication was received. Radar data showed the airplane reached a maximum altitude of about 1,400 feet mean sea level (about 1,000 feet above ground level) before radar contact was lost at 87 knots ground speed on a heading of 169 degrees, near the accident site.
A witness, a locally-based pilot, observed the accident pilot conduct about eight engine run-ups at the end of the runway before departure. The engine made a "chugga-chugga" sound during early run-ups but smoothed out later. The witness noted an unusually long takeoff roll and poorer-than-expected climb performance.
A summer intern at Panorama Flight Service observed the pilot start the engine on the ramp, noting a "clunky" idle and some exhaust smoke. The pilot then performed an engine run-up in the tie-down area, which the intern considered unusual. During the run-up, the nose gear strut appeared compressed, and the pilot cycled the propeller at least three times after advancing the throttle to high power for about one minute. The entire sequence lasted three to four minutes.
Aircraft and Pilot Information
The pilot held a commercial certificate with single-engine land, multi-engine land, and instrument airplane ratings, as well as flight and ground instructor certificates. According to his latest FAA medical certificate dated May 6, 2011, he reported 4,150 flight hours. His logbooks were not recovered.
The airplane was a single-engine, high-wing, retractable-gear Cessna T210N, serial number 21064181, powered by a Continental TSIO-520R9B engine rated at 310 horsepower. An annual inspection of the airframe and engine was performed on June 4, 2010, at a total aircraft time of 2,790.9 hours. The factory-rebuilt engine was installed on February 12, 2007. The last recorded engine maintenance was on February 11, 2011, at 74.2 hours since major overhaul, including an oil and filter change and replacement of the oil cooler vernatherm. Fueling records showed the pilot purchased 89 gallons of fuel between February 11, 2011, and May 28, 2011; there was no indication the airplane flew between May 29 and June 17, 2011.
Meteorological Information
The 1256 weather observation at HPN reported winds from 300 degrees at 10 knots, scattered clouds at 4,600 feet, a broken ceiling at 6,000 feet, visibility 10 miles, temperature 27°C, dew point 17°C, and an altimeter setting of 29.84 inches of mercury. Visual meteorological conditions prevailed.
Wreckage and Impact Information
The wreckage was located in a wooded area about one mile north-northeast of the approach end of runway 16. The wreckage path was oriented on a heading of about 153 degrees and was about 350 feet long. The first point of impact was the top of a mature maple tree about 60 feet tall, and the main wreckage came to rest near a tree with impact damage at about 40 feet. The cockpit and cabin sections were inverted and mostly consumed by a post-crash fire. Instruments were unreadable, and no components with non-volatile memory survived. Both wings and the empennage were found within the main wreckage area. Flight control continuity was established from control surfaces to cockpit controls. The landing gear and flaps were retracted. The propeller remained attached to the engine, which sustained minor impact and heat damage. The turbocharger rotated freely. The fuel gascolator was clean and free of fuel. The three-bladed constant-speed metal propeller blades exhibited impact-related bends and dents but no torsional twisting, leading edge gouges, or chordwise scratches. A smooth cut was observed on a tree trunk adjacent to one blade.
Medical and Pathological Information
A postmortem examination of the pilot performed by the Westchester County Medical Examiner on June 19, 2011, listed the cause of death as "PLANE CRASH" and noted chest blunt force trauma and heart lacerations. Forensic toxicology testing by the FAA Bioaeronautical Sciences Research Laboratory (CAMI) for the pilot showed negative results for cyanide, ethanol, and carbon monoxide; cetirizine was detected in urine but not blood; pseudoephedrine was detected in urine. Testing for the pilot's wife showed negative for cyanide and carbon monoxide; volatiles and drugs were not tested.
Tests and Research
Engine Examination
The engine was examined at Continental Motors in Mobile, Alabama, on July 18, 2011. The oil system contained fine aluminum particles, and the magnetic chip detector had larger metallic particles. The left magneto timing was 30 degrees before top dead center (BTDC), exceeding the manufacturer's specification of 22 degrees BTDC. The right magneto was broken due to impact; timing could not be determined. Both magnetos operated normally on a test bench. Spark plugs were normal except for the number 2 cylinder plugs, whose electrodes were fully imbedded with aluminum and appeared incapable of producing a spark. Disassembly revealed molten aluminum debris in the number 2 cylinder combustion chamber, on the intake and exhaust valve heads, and on the piston head, which exhibited thermal deterioration consistent with a pre-ignition or detonation event. The number 2 piston rings had mechanical damage. Other cylinders showed normal combustion deposits and operating signatures. The number 6 piston had less-than-normal combustion deposits and pitting. The throttle body, mixture metering unit, fuel pump, fuel manifold, fuel nozzle assemblies, and related components functioned properly when tested.
Sound Spectrum Study
A recording from airport noise abatement microphones was analyzed. The recording contained three regions: engine noise during takeoff climb, engine noise from the returning airplane, and a sound consistent with impact. The study indicated the engine produced significantly less sound pressure on the inbound leg compared to the outbound leg.