NTSB Factual Report

HISTORY OF FLIGHT

On May 12, 2008, at 1105 eastern daylight time, a Beech V35 Bonanza, N7947M, operated by an instrument rated private pilot, was destroyed on impact following an in-flight breakup while in cruise flight near Bristol, Ohio. Instrument meteorological conditions existed at the airplane's assigned cruise altitude and marginal visual meteorological conditions prevailed at the surface. The personal flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 91 while on an instrument flight plan. The pilot and his passenger were fatally injured. The flight departed Tri-State/Ferguson Field (KHTS) in Huntington, West Virginia, at 1018 and was enroute to Greater Rochester International Airport (KROC), Rochester, New York.

At 0747, the pilot contacted the Washington Automated Flight Service Station to obtain a standard weather briefing and to file an instrument flight plan. The pilot initially stated that his planned cruise altitude would be 7,000 feet. The weather briefer informed the pilot that there was an active icing advisory for moderate icing between the freezing level and 20,000 feet. The briefer told the pilot that the freezing level at the departure and destination airports was approximately 6,000 feet and 5,000 feet, respectively, and that the cloud tops were approximately 15,000 feet. The briefer issued several pilot reports of icing conditions, consisting of light rime and light clear, that existed along the intended route of flight. The pilot was also told that instrument meteorological conditions, consisting of light precipitation and low ceilings, prevailed along his intended route of flight and that there was an active advisory for moderate turbulence below 15,000 feet. The pilot then filed a flight plan from KHTS to KROC with a cruise altitude of 5,000 feet.

According to Federal Aviation Administration (FAA) air traffic control data, at 1009 the pilot was issued an instrument flight rules (IFR) clearance from KHTS to KROC. At 1018, the flight departed KHTS on runway 30 and proceeded north-northeast enroute toward KROC. At 1023, the flight was cleared to the filed cruise altitude of 5,000 feet. At 1028, the pilot reported being near the cloud tops at 5,000 feet and requested a higher cruise altitude. The flight was subsequently cleared to 7,000 feet. During the climb, the pilot reported that the outside temperature at 5,000 feet was 0-degrees Celsius and that the cloud tops were at 5,700 feet.

At 1042:02 (hhmm:ss), the pilot established radio contact with Indianapolis Air Route Traffic Control Center's (ARTCC) Parkersburg Sector. The airplane continued north-northeast at 7,000 feet. At 1050:29, the pilot stated, "... can we try going up two or three hundred feet? I think we're right in the tops where we are." The air traffic controller subsequently cleared the pilot to climb to 9,000 feet. At 1055:27, aircraft radar track data showed the airplane level at 9,000 feet on a north-northeast course.

At 1055:49, the pilot was told to change to another Indianapolis ARTCC radio frequency. At 1056:46, the pilot established radio contact with Indianapolis ARTCC's Columbus Sector and was given the local altimeter setting. At 1056:55, the pilot acknowledged the local altimeter setting. There were no additional communications received from the accident pilot.

At 1102:00, the airplane made a 35-degree right turn to the east-northeast at 9,100 feet. At 1103:42, the airplane made a left turn to a north heading. The airplane then entered a right spiraling descent. During the next 40 seconds, the airplane descended from 9,100 to 7,800 feet. The calculated descent rate incrementally increased to approximately 4,200 feet per minute. At 1104:22, the airplane's altitude was last reported at 7,800 feet. At 1104:32, a final radar return was recorded without any altitude information.

PERSONNEL INFORMATION

According to FAA records, the pilot of N7947M, age 65, held a private pilot certificate with airplane single engine land, instrument airplane, and lighter-than-air balloon ratings. The instrument rating was issued on September 20, 2003. The pilot's last aviation medical examination was completed on May 18, 2007, when he was issued a third-class medical certificate with the limitation that he wear corrective lenses. A search of FAA records showed no accident, incident, enforcement, or disciplinary actions.

The pilot's most recent logbook entry was dated May 10, 2008. He had accumulated 1,012.9 hours total flight time, of which 968.1 hours were as pilot-in-command. He had accumulated 784.7 hours in single-engine airplanes, 228.2 hours in lighter-than-air balloons, 51.5 hours at night, 137.5 hours in actual instrument conditions, and 45.0 hours in simulated instrument conditions. He had accumulated 42.1 hours in a Beech V35 airplane.

The pilot had flown 156.5 hours during the past year, 27.1 hours during the prior 6 months, 14.7 hours during previous 90 days, and 8.1 hours during the prior 30 days. The pilot had not flown during the 24 hour period before the accident flight.

His last flight review was completed on September 27, 2007, in a Piper PA-28 airplane. His last instrument proficiency check (IPC) was completed on October 27, 2007. Subsequent to the IPC, he had logged 1 instrument approach and 2.9 hours of actual instrument time.

AIRCRAFT INFORMATION

The accident airplane was a 1966 Beech V35 Bonanza, serial number (s/n) D-8256. The Bonanza was a low wing, all-metal, single-engine, V-tailed, four-place monoplane. The airplane had a certified maximum takeoff weight of 3,400 lbs. The airplane was equipped for operation under instrument flight rules (IFR). The airplane was not equipped or certified for flight in icing conditions. A Teledyne Continental Motors model IO-520-B reciprocating engine, s/n 121048-6-B, powered the airplane. The 285-horsepower engine provided thrust through a Hartzell model PHC-C3YF-1RF, s/n EE5417B, constant speed, three-blade, metal propeller.

The accident airplane was issued a standard airworthiness certificate on August 9, 1966. The pilot purchased the airplane on September 27, 2007. The airframe and engine had a total service time of 2,616 hours. The engine had accumulated 1,301 hours since its last overhaul, which was completed on March 10, 1977. The propeller had accumulated 177 hours total time after being installed on March 10, 2006. The last annual inspection was completed on April 7, 2007, at 2,525 hours total service time. On March 22, 2007, tests on the static system, altimeter system, automatic pressure altitude reporting system, and transponder were completed.

The airplane was topped off with 29.8 gallons of 100 low-lead aviation fuel at the departure airport. The accident occurred during the first flight after being refueled. A post-accident inspection of the departure airport's fuel sources did not reveal any water or particulate contamination.

On May 10, 2008, the pilot requested the use of the departure airport's 28-volt ground power unit (GPU) because of a depleted aircraft battery. The aircraft was equipped with a single 12-volt Gill G-35 battery. According to several witnesses, the battery "exploded" as the pilot attempted to start the engine with external power attached. A local mechanic then replaced the damaged battery and repaired the airframe's battery box. No electrical system anomalies or malfunctions were noted after the completed repairs. The accident occurred during the first flight after the battery maintenance was performed.

A review of the maintenance records found no history of unresolved airworthiness issues.

METEOROLOGICAL INFORMATION

The nearest weather reporting station was located at Zanesville Municipal Airport (KZZV) about 18 miles north-northwest of the accident site. The airport was equipped with an Automated Surface Observing System (ASOS). At 1110, the following weather conditions were reported by the KZZV ASOS: wind 320 degrees at 9 knots; visibility 3 miles with light rain and mist; few clouds at 600 feet above ground level (agl), broken ceiling at 1,100 feet agl, sky overcast at 1,900 feet agl; temperature 11 degrees Celsius; dew point 9 degrees Celsius; altimeter setting 29.75 inches of mercury.

The accident location was within the boundaries of an instrument flight rules (IFR) advisory. Instrument meteorological conditions were possible within clouds between 2,000 and 10,000 feet. The accident location was about 18 miles northwest of the western edge of a moderate turbulence advisory area. Light to moderate turbulence was possible below 10,000 feet. The accident location was along the western edge of a moderate icing advisory area. There was a possibility of moderate structural icing from the freezing level to 20,000 feet. The local weather radar indicated weak radar echoes with cloud tops above 10,000 feet in the accident area.

An upper atmosphere model indicated that the freezing level was approximately 6,000 feet near the accident site. The outside temperature at 9,000 feet was approximately -3 degrees Celsius. Infrared satellite imagery indicated that the cloud tops were in excess of 9,700 feet near the accident site. According to an icing probability model, there was a 60-85 percent chance of encountering icing conditions in the eastern half of Ohio between 7,000 feet and 9,000 feet. The model further indicated that light-to-moderate icing was expected at 7,000 feet and moderate-to-heavy icing was expected between 8,000 and 9,000 feet.

FLIGHT RECORDERS

The accident airplane was not equipped, nor was it required to be equipped, with a cockpit voice recorder or flight data recorder.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located in a heavily wooded abandoned strip mine and reservoir. The wreckage debris path was orientated on a northeast heading and was approximately 1,730 feet in length. The overall wreckage distribution was consistent with an in-flight breakup. The right wing was found at the beginning of the debris path. The right and left stabilizers were found about 600 feet from the right wing. A majority of the fuselage and empennage were found between 800 and 1,000 feet from the right wing. The left wing was located about 950 feet from the right wing. The engine, propeller, and remnants of the cockpit and instrument panel were found submerged in a reservoir about 1,730 feet from the right wing.

All airframe structural components were located at the accident site. Flight control cable continuity could not be established due to multiple cable separations. All observed flight control cable separations were consistent with an overload failure. The right wing had separated from the fuselage with 7-inches of the center carry-through structure attached to the main spar. The right wing's aft spar had separated at the wing attach fitting. The right aileron and flap remained attached to their respective wing attachment points. The left wing had separated from the fuselage with 37-inches of the center carry-through structure attached to the main spar. The left wing's aft spar separated 13-inches outboard of the fuselage. The left aileron and flap remained attached to their respective wing attachment points. Both wing flaps were in a fully retracted position. The left and right main landing gear remained attached, and were found stowed in their respective wheel wells. The nose landing gear remained attached to the forward fuselage. The main cabin and cockpit were destroyed. The empennage's V-tail components were found in several pieces. The left elevator assembly was not recovered. The right and left stabilizers had separated from the empennage. Both elevator tip weights were recovered, but were separated from their respective elevators. The engine was found separated from the airframe. Engine crankshaft rotation was not possible due to impact damage. An internal engine inspection confirmed that all connecting rods remained attached to their respective pistons. All cylinders remained attached to the engine case. The propeller hub assembly was found separated from the crankshaft. All three blades remained attached to the propeller hub assembly. Two of the three propeller blades exhibited minor impact damage. One propeller blade exhibited multiple leading edge deformations.

The on-scene investigation revealed no pre-impact mechanical malfunctions or anomalies that would have prevented the normal operation of the airplane or its systems.

MEDICAL AND PATHOLOGICAL INFORMATION

On May 13, 2008, an autopsy was performed on the pilot at the Licking County Coroner's Office in Newark, Ohio. The pilot's cause of death was attributed to multiple blunt force injuries sustained during the accident.

The FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. No ethanol was detected in lung and muscle tissues. No drugs were detected in muscle tissue.

Toxicology tests were also performed on the passenger. No carbon monoxide, cyanide, or ethanol was detected in the passenger's blood samples.

NTSB Probable Cause

The loss of control during cruise flight in instrument conditions due to spatial disorientation.