NTSB Factual Report

HISTORY OF FLIGHT

On July 28, 1997, approximately 0937 central daylight time, a Beech F35 airplane, N3835B, owned and operated by the pilot as a Title 14 CFR Part 91 personal flight, was destroyed following an in-flight breakup near Richards, Missouri. The non instrument rated private pilot and his passenger were fatally injured. Instrument meteorological conditions prevailed at the time of the accident, and a flight plan was not filed for the cross country flight. The flight originated from the Sundance Airport, Oklahoma City, Oklahoma, about 0800, en route to Oshkosh, Wisconsin, with a planned fuel stop at Trenton, Missouri.

Weather radar data and radar ground track showed N3835B proceeding to the northeast, and was initially outside of precipitation and in visual meteorological conditions. About the time N3835B made an initial deviation towards the south, the radar data indicated that the airplane was in the vicinity of an area of convection. The airplane flew south until it was clear of the first shower/thunderstorm and then turned toward the northeast to resume course. The radar data indicated that shortly after resuming the northeast track, the airplane penetrated a VIP level three or four developing thunderstorm and remained in the cell until ground impact. The pilot had not been in radio contact with air traffic control, and there were no reported eye witnesses to the accident.

The pilot and passenger were to attend the annual Experimental Aircraft Association's (EAA) symposium and fly-in being held in Oshkosh. A four state aerial and telephone search was initiated when the aircraft failed to arrive. The Civil Air Patrol located the aircraft three days later near Richards, Missouri, with the use of the FAA National Track Analysis Program (NTAP) which provided a radar ground track of N3835B.

PERSONNEL INFORMATION

The non instrument rated private pilot purchased the aircraft on September 13, 1995. According to his pilot flight logbook, he completed a biennial flight review in the accident aircraft on September 22, 1995.

The pilot had a total flight time of 424.4 hours in all aircraft, with 389 hours as pilot-in-command. He logged a total flight time of 140 hours in the accident aircraft, with 15 hours in the last 90 day and 2 hours within the last 30 days. The pilot had a total of 1.9 hours of simulated instrument time (hood) prior to October 29, 1978. Hood time logged since 1978 was 0.3 hours on November 28,1994.

AIRCRAFT INFORMATION

The Beech Bonanza F35 is a four place, single engine airplane with retractable landing gear. The aircraft's empennage had the stabilizer leading edge cuff modification installed. A review of the airframe and engine records did not reveal evidence of any anomalies or uncorrected maintenance defects. The aircraft was not equipped with Weather Radar or a Storm Scope.

The aircraft had a total time since new of 4593.3 hours. The aircraft's last annual inspection was completed on September 13, 1996, and time flown since the inspection was approximately 96.8 hours.

The aircraft was loaded with camping equipment, two bicycles, lawn chairs, and personal luggage. The aircraft's maximum gross weight is 2,750 pounds, and an estimate of the weight of the aircraft at the time of the accident placed it within weight and balance limits.

METEOROLOGICAL INFORMATION

The Aviation Area Forecast (FA) for the North Central Area, issued by the Aviation Weather Center (AWC) at Kansas City, Missouri, and valid around the accident time, started in part:

FA issued July 28, at 0445, clouds/weather valid until 1700; Kansas, southeastern portion...above ground level clouds scattered to broken at 8,000 feet. At 0500-0900, above ground level clouds scattered to broken at 3,000 feet and broken at 8,000 feet. Widely scattered thunderstorms and moderate rain showers. Cumulonimbus cloud tops at flight level 45,000 feet.

Meteorological Impact Statements (MIS) issued by the Center Weather Service Unit at the Kansas City Air Route Traffic Control Center (ZKC), started in part:

ZKC MIS 01, valid July 28, 0730-1930; over eastern Kansas and western Missouri...area level 3-5 thunderstorms, over eastern Kansas moving from 270 degrees at 15-20 knots, tops above flight level 45,000 feet. Forecast to weaken over western Missouri. Over ZKC area after 1300...level 3-6 thunderstorms forming broken east-west lines. Tops above flight level 40,000 feet. St. Louis (Lambert International Airport) area...scattered level 3-5 thunderstorms in area after 1200. Kansas City (International Airport) area...area level 3-5 thunderstorms in area ending near 1100.

ZKC MIS 02, valid July 28, 1000-2130; over southeastern Kansas and southwestern Missouri...cluster level 3-5 thunderstorms...tops above flight level 40,000 feet possible through 1300. Thunderstorms moving from 270 degrees at 15-20 knots.

Convective SIGMETs issued by the AWC and pertinent to the flight of N3835B, started in part:

Convective SIGMET 35C, issued July 28, 0755, valid until 0955 for Kansas; from 50 nautical miles south of Pawnee City, Nebraska, to 40 nautical miles west of Butler, Missouri, to 50 nautical miles west of Oswego, Kansas. A line of thunderstorms 30 nautical miles wide moving from 260 degrees at 20 knots. Tops above flight level 45,000 feet.

Convective Sigmet 40C, issued July 28, 0855, valid until 1055 for Kansas and Missouri; from 40 nautical miles west of Kansas City, Missouri, to Butler, Missouri, to 30 miles west of Oswego, Kansas. A line of thunderstorms 30 nautical miles wide moving from 270 degrees at 20 knots. Tops above flight level 45,000 feet.

Local residents near the accident site reported that there were thunderstorms and heavy rain in the area around the time of the accident.

According to FAA records, no weather briefings were provided to the pilot.

WRECKAGE IMPACT INFORMATION

The airplane wreckage was located northwest of Richards, Missouri, on July 31, 1997, about 1715, at latitude 37 degrees 55.32 minutes north and longitude 94 degrees 35.87 minutes west. The aircraft came to rest in a 10-foot-deep drainage ditch located within a tree line that runs north south along the east side of a soybean field. The aircraft impacted the ditch in a measured 40 degree nose down attitude, and rolled 100 degrees to the left. The aircraft's left wing was located 619 feet west of the main wreckage in the soybean field. The right stabilizer was located 381.2 feet southwest and the left stabilizer was located 491.8 feet southwest of the main wreckage in the soybean field. The left flap mid-section was found 1,057 feet south southeast of the main wreckage. See the enclosed wreckage diagram for detailed wreckage distribution.

Examination of the aircraft wreckage revealed that the fuselage was crushed aft, and the right wing, which remained attached to the fuselage, was crushed from the leading edge aft to the rear spar. The left wing had separated at the outboard ends of the wing attach fittings in an upward direction. There was a 45 degree spanwise wrinkle in the left wing's upper skin which ran from the leading edge at a position five feet inboard of the wing tip to the aft wing spar at the location of the outboard end of the wing flap. The left aileron's upper surface skin was swelled 2-inches upward along the length of the aileron. The left stabilizer had separated in an upward direction, while the right stabilizer had separated in a downward direction.

The engine and propeller were found buried in the east bank of the 20-foot-wide drainage ditch. The Continental E-225-8, 226 horse power, reciprocating carbureted engine had all of its accessories separated, and the crankcase halves forward of the number five cylinder attachment point were shattered. The crankshaft was bent 30 degrees at the number 6 crank pin and could not be rotated. The vacuum pump had sustained impact damage; however, the drive was intact and free to rotate. The unit was disassembled and no internal damage was noted.

The propeller was attached to the engine; however, one blade was separated from the propeller hub. The separated blade was found buried underneath the engine. One blade tip exhibited a 15 degree forward bend initiating at a position 8 inches from the tip. The other blade exhibited "S" bending and chordwise scratching.

Due to the extent of impact damage, flight control continuity could not be established though the cabin and cockpit area.

MEDICAL AND PATHOLOGICAL INFORMATION

The autopsy was performed by James Spindler, M.D., Office of the Medical Examiner, Springfield, Missouri. There was no evidence found of any preexisting disease that could have contributed to the accident.

Toxicology findings were positive for Diphenhydramine (Antihistamine) in the muscle and liver. The muscle contained 0.152 ug/ml of Diphenhydramine. Diphenhydramine is a sedating antihistamine. This medication was not approved by the Federal Aviation Administration for use while flying.

ADDITIONAL DATA

The aircraft wreckage was released to the owner's representative.

NTSB Probable Cause

The pilot's continued flight into adverse weather and the loss of aircraft control which resulted in the aircraft exceeding its design stress limits. Factors were the pilot's failure to obtain a weather briefing and the adverse weather.