History of Flight
On September 28, 2008, at approximately 1148 central daylight time, a Cessna 320, registration N4165T, sustained substantial damage when it impacted terrain while maneuvering to land at Airmen Acres Airport (OK93) near Collinsville, Oklahoma. The aircraft was registered to and operated by the private pilot. A witness, an FAA-certified mechanic who lived at the airport, observed the airplane conduct a high-speed taxi test, magneto check, and propeller cycling before a normal takeoff to the north at about 1140. The witness heard a normal approach without landing gear extended and took a photograph at 1147 showing both engines operating. The airplane then made a climbing left turn. The witness later observed the airplane on downwind with landing gear extended and heard engine rpm increase sharply, then return to normal. As the airplane turned left onto base leg, the witness looked away and when he looked back, the airplane was heading nearly straight down (about 85 degrees) with rolling wings. It disappeared behind trees and the witness knew it had crashed. Another witness saw the nose drop approximately 75 percent during the base leg turn, followed by a slight right turn before impact. Radar data showed ground speed decreasing toward stall speed on the second circuit.
Personnel Information
The commercial pilot held certificates for airplane single- and multi-engine land, instrument airplane, and flight instructor (single- and multi-engine). His last second-class FAA medical was issued June 10, 2008, at which time he reported 2,000 flight hours. The private pilot held certificates for airplane single- and multi-engine land and an FAA airframe and power plant certificate. His last third-class medical was June 28, 2007; his last application dated September 1, 2008, showed 215 flight hours.
Aircraft Information
The aircraft was a twin-engine Cessna 320. The logbooks were not located.
Meteorological Information
Weather at Tulsa International Airport (TUL), 9 miles south, at 1153 was wind calm, visibility 10 miles, clear skies, temperature 27°C, dewpoint 13°C, barometric pressure 30.16 inHg.
Wreckage and Impact Information
The airplane came to rest upright in an open field about one mile south-southwest of the airport, on a heading of 124 degrees, elevation 651 feet. All major components were present; no post-impact fire. Initial impact ground scars were about 1 foot to the right of the right wing and both engines. The right wing had extensive impact damage; the right tip tank was flattened and had separated, containing light blue fuel and an open-ended 1-1/8-inch wrench. A loose screwdriver was found near the tip tank transfer pump. The left wing had less damage; the tip tank was breached and empty, but the bladder cell was intact and wet with fuel. Fuel selector valves were in "main tank" position. Control cable continuity was established for all flight controls. Landing gear actuator was extended; flaps were fully retracted. The pilot's control wheel separated; the co-pilot's wheel broke in half. Shoulder harnesses were not installed. Both engines were examined: the right engine, a factory-rebuilt Teledyne Continental Motors unit, had impact damage; magnetos produced spark; fuel pump rotated; mixture control had debris and dark liquid; fuel manifold was empty. The left engine had no data plate; magnetos produced spark; fuel pump had bent coupling; mixture control had dark liquid. Both engines had valve continuity and compression, and spark plugs showed normal wear. The right propeller separated at the crankshaft flange; one blade bent aft with polishing, another bent aft, third straight. The left propeller remained attached; one blade separated from hub with forward bending and polishing, second bent forward, third straight.
Medical and Pathological Information
Both pilots were autopsied by the Office of the Chief Medical Examiner in Tulsa. Cause of death for both was blunt force trauma. The commercial pilot had fractures of both lower legs and ankles, right lower arm, near amputation of right thumb and index finger. The private pilot had multiple fractures of both legs and arms, and right hand fractures. FAA toxicology found fluoxetine, norfluoxetine, nortriptyline, and trazodone in the commercial pilot's blood; diphenhydramine in the private pilot's blood. The commercial pilot's personal medical records showed hip pain, post-traumatic stress disorder, and use of medications not reported on his medical application. The private pilot's wife reported occasional use of Benadryl, not noted on his medical application.
Tests and Research
Engine-driven fuel pumps and couplings from both engines were functionally tested by Teledyne Continental Motors; they operated properly through their full range.
Additional Information
The airplane was not insured and was released to a salvage company on October 30, 2008.