Aviation Accident Summaries

Aviation Accident Summary DEN99FA109

CARPENTER, WY, USA

Aircraft #1

N801RB

Boeing Stearman A75

Analysis

While on a cross-country positioning flight, a flight of four aircraft was in cruise flight when the number four airplane entered a descending right hand turn and flew into the ground in an open field. The pilot received fatal injuries. Other pilots in the flight had been in communication with the accident pilot via radio within 2 minutes prior to the event. Investigation found no evidence of aircraft failures or malfunctions and a review of the pilot's medical history and autopsy findings provided no evidence of medical significance except for the presence of coronary artery disease.

Factual Information

HISTORY OF FLIGHT On June 29, 1999, at 1145 mountain daylight time, (all times are mountain daylight time unless otherwise specified) a Boeing Stearman A75, N801RB, was destroyed when it collided with terrain under unknown circumstances approximately one mile southeast of Carpenter, Wyoming. The commercial pilot received fatal injuries. The flight was a positioning flight to Saint Louis, Missouri, with a fuel stop in McCook, Nebraska, and was operating under Title 14 CFR Part 91. Visual meteorological conditions prevailed and no flight plan was filed. The flight departed Rock Springs, Wyoming, at 0915, where an overnight stop was made, and made a fuel stop at Cheyenne, Wyoming. The flight departed Cheyenne at 1135. The aircraft was number four in a flight of four Boeing Stearman A75's flying in a cruise formation. Approximately 2 minutes after other pilots in the flight had radio contact with the pilot involved in the accident, they discovered the accident aircraft was no longer in the formation. The remaining three aircraft backtracked along their route and discovered the accident aircraft in an open field. One of the aircraft landed on a nearby road and the pilot proceeded to the accident site. He had a farmer call 911 and report the accident. The other aircraft in the formation returned to Cheyenne. A ground witness, located on the south side of Carpenter, observed the formation fly over his house. As the formation proceeded away from him headed in a southeasterly direction, he said the airplane on the right side entered a right hand descending turn. After approximately 160 degree of turn, the airplane disappeared from his view behind some buildings on his property and he did not observe an impact and saw no smoke so he was unaware of the accident. He said the engine noise sounded normal. The accident site was located approximately 3 miles southeast of his residence. PERSONNEL INFORMATION The pilot was born in 1930 and held a commercial pilot certificate issued March 31, 1997, with ratings in single engine land airplanes, multiengine land airplanes, and an instrument rating in airplanes. In addition, he held a repairman - experimental aircraft builder certificate. A second class medical certificate was issued to the pilot on February 18, 1999, with no limitations. According to the operator, the pilot was experienced in the A-75 and according to available records had been through all their initial and recurrent training programs. According to company records, the pilot had 10,438 hours total flight time and 1,381 hours in the A75 aircraft. He had flown 21 hours in the preceding 90 days, 6 hours in the preceding 30 days, and 3 hours in the preceding 24 hours before the accident. AIRCRAFT INFORMATION The aircraft type was originally designated the PT17 and was built for the military as a primary trainer during World War II. Total airframe time was 11,195 hours and the last inspection was a 100-hour inspection conducted 65 hours prior to the accident. Primary hull and wing construction was wood with a fabric covering. This aircraft was powered by a Pratt & Whitney R-985-14B radial engine, which produced 450 shaft horsepower @ 2,300 rpm and 37.5 inches of Hg at sea level on a standard day. The engine had a total time of 11,507 hours since new, and 531 hours since overhaul. The last inspection was a 100-hour performed 65 hours prior to the accident. The propeller was a Hamilton Standard model 2D30-249 using two metal blades. Blade design was 6101A-12. The propeller had a total time of 2,195 hours and 656 hours since overhaul. The last inspection was performed on May 24, 1999. METEOROLOGICAL INFORMATION At 1156, the observed weather at the Cheyenne airport was clear skies, winds from 310 degrees magnetic heading at 17 knots with gusts to 24 knots, 10 miles visibility, temperature 73 degrees Fahrenheit, dew point 34 degrees Fahrenheit, and an altimeter setting of 29.99 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The field where the aircraft impacted was hard, flat, and had a grass covered surface. The initial impact witness marks, oriented on a base course of 285 degrees magnetic heading, consisted of two parallel drag type marks approximately 30 feet in length. The northern most drag mark contained portions of the right wing tip. At the end of these marks was a crater approximately 18 inches in depth that contained one propeller blade and part of the engine sump. A portion of the trailing edge of the propeller blade was broken out and found in the crater with the blade and the blade exhibited twisting toward low pitch and chordwise scarring. The field was devoid of marks from the crater for about 130 feet. At that point the main wreckage consisting of wings, fuselage, and one main landing gear were located and remained as a grouping connected by cables and wires. Parts of the fuselage and wings were scattered from the initial impact point to the main wreckage in a fan-like scatter pattern. The engine, with the remaining propeller blade and propeller hub attached, was located approximately 65 feet beyond the main wreckage. The furthest item from the initial impact point was the right main landing gear, which was located approximately 302 feet down the scatter pattern. All of the aircraft was accounted for at the accident scene. MEDICAL AND PATHOLOGICAL INFORMATION The Wyoming State Crime Laboratory performed an autopsy on the pilot on June 29, 1999. The medical examiner listed the cause of death as "massive blunt deceleration injuries." In his summary, the medical examiner noted there was significant coronary artery disease. The FAA Aeromedical Laboratory in Oklahoma City, Oklahoma City performed a forensic toxicology screening. The results of the screening are attached and are discussed in the attached NTSB Medical Officer's report. The NTSB Medical Officer conducted a review of the autopsy report, FAA medical records, and the pilot's personal medical records during the investigation. No disqualifying conditions were found to exist. For details of the pilot's medical history see the NTSB Medical Officer's report. TEST AND RESEARCH An interview was conducted with the director of training for the operator and the operator's records were reviewed regarding training, proficiency, and pilot experience. No evidence was found during the course of the investigation to indicate the pilot was improperly or incompletely trained or lacked proficiency or experience in the accident aircraft make and model. A review of the aircraft maintenance records provided no evidence of improper or incomplete maintenance. An interview was conducted with the pilot's spouse. No evidence was developed as a result of the information provided to suggest any psychological or physiological condition, which could be related to the accident. ADDITIONAL INFORMATION Parties to the investigation were the FAA and the operator of the aircraft. The wreckage was released to the operators insurance company on July 1, 1999, following the completion of the on-scene investigation. No aircraft parts were retained.

Probable Cause and Findings

Pilot incapacitation for unknown reasons.

 

Source: NTSB Aviation Accident Database

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