Aviation Accident Summaries

Aviation Accident Summary CEN09LA536

Harrison, OH, USA

Aircraft #1

N14BB

BROWN STEEN SKYBOLT

Analysis

A witness reported that after the airplane lifted off, it proceeded “straight-and-level” down the runway about 50 feet above ground level (agl). When the airplane reached the end of the runway, it pitched up into a “very steep” climb angle of about 45-50 degrees. The climb continued to approximately 200 feet agl, when the airplane entered a left turn to an easterly heading. However, the airplane continued banking to the left until it became inverted. At that point, the nose of the airplane was “pointed almost straight down. The plane continued to spin to the left until it disappeared from sight behind the fence.” The airplane impacted terrain southeast of the departure end of the runway. A post accident examination did not reveal any anomalies associated with a pre impact failure or malfunction of the airframe or engine. Fractures of the pilot control stick and mating control rod were due to overstress separation resulting from the impact sequence.

Factual Information

HISTORY OF FLIGHT On August 21, 2009, about 2010 eastern daylight time, an amateur-built Brown Steen Skybolt, N14BB, piloted by a commercial pilot, was destroyed during an in-flight collision with terrain near Harrison, Ohio. The flight was being conducted under 14 Code of Federal Regulations Part 91 without a flight plan. Visual meteorological conditions prevailed. The pilot and passenger sustained fatal injuries. The local flight departed Cincinnati West Airport (I67), Harrison, Ohio, just prior to the accident. A witness stated that the flight departed runway 19 (2,803 feet by 60 feet, asphalt) at I67. He noted that the initial portion of the takeoff was out of his line of sight. However, when the airplane came into view it appeared to have just lifted off. He reported that it was flying “straight-and-level” over the runway about 50 feet above ground level (agl). When the airplane reached the departure end of the runway, it pitched up into a “very steep” climb angle of about 45 -50 degrees. The climb continued to approximately 200 feet agl, when the airplane entered a left turn to an easterly heading. However, the airplane continued banking to the left until it became inverted. At that point, the nose of the airplane was “pointed almost straight down. The plane continued to spin to the left until it disappeared from sight behind the fence.” The airplane impacted terrain about 0.15 mile southeast of the departure end of the runway. The site was located on an embankment near the perimeter fence surrounding a school bus parking lot. PERSONNEL INFORMATION The pilot, age 47, held a commercial pilot certificate with single and multi-engine land, and instrument airplane ratings. He held a current flight instructor certificate with airplane single and multi-engine, and instrument airplane ratings. The pilot was issued a second-class airman medical certificate with a restriction for near vision corrective lenses on August 14, 2008. The pilot’s flight time logbook was not available to the NTSB. At the time of the pilot’s most recent airman medical exam, about 1 year prior to the accident, he reported a total flight time of 3,800 hours. AIRCRAFT INFORMATION The accident airplane was an amateur-built Brown Steen Skybolt, serial number 101072. It was a two-place, bi-wing, aerobatic design, with a tail wheel landing gear configuration. The airplane was powered by a Lycoming O-360-A1G6, serial number L-16297-36A. It was a normally aspirated, 4-cylinder, reciprocating engine capable of developing 180-horsepower. The airplane was issued an amateur-built experimental airworthiness certificate on September 10, 1993. Aircraft maintenance records indicated that test flights were conducted between October 22, 1993, and December 8, 1993, and totaled 25.8 hours. The only additional entries in the airframe and engine logs were dated November 4, 1994, and indicated “First Annual Inspection.” No subsequent entries were observed in the logs. METEOROLOGICAL INFORMATION The Cincinnati/Northern Kentucky International Airport (CVG) Automated Surface Observing System (ASOS) was located approximately 14 miles south-southeast of I67. At 1952, the CVG ASOS recorded conditions as: Wind from 220 degrees at 3 knots, few clouds at 5,000 feet above ground level (agl), scattered clouds at 10,000 feet agl, temperature 23 degrees Celsius, dew point 16 degrees Celsius, and altimeter 29.83 inches of mercury. AIRPORT INFORMATION The West Cincinnati Airport, I67, was located about 2 miles east of Harrison, Ohio. It was served by runway 1-19, which was 2,803 feet long by 60 feet wide and constructed of asphalt. (The FAA Airport Facility Directory denoted the turf runway, 9-27, as closed indefinitely.) A single perpendicular taxiway provided access at the south end of the runway 1-19. Airplanes departing from runway 19 were required to back taxi the length of the runway. Airplane parking and fixed base operator facilities were located at the south end of the airport. The airport was located north of West Road. Harrison High School was located east of the airport, and northwest of the West Road-Dry Fork Road intersection. The high school football field was located on the west side of the campus, about 0.16 mile east of the departure end of runway 19. A school bus parking lot was located directly across the street from the high school on the south side of West Road. WRECKAGE AND IMPACT INFORMATION The airplane impacted terrain about 0.15 mile southeast of the departure end of runway 19 at I67. The accident site was located near the perimeter fence surrounding a school bus parking lot. The airplane came to rest on a descending slope (embankment) adjacent to the fence. It was oriented on a southeasterly heading. The nose and forward fuselage structure was deformed and fragmented consistent with a direct, nose down impact. The cockpit area was compromised. Both the upper and lower wings were partially separated from the airframe. The wings exhibited leading edge deformation and crushing damage. The wing fabric presented diagonal wrinkles consistent with movement of the wingtips aft relative to the roots. The ailerons remained attached to the wings. Aileron control continuity was confirmed from the control surfaces to the cockpit area. The aft fuselage (beginning at a point near aft cockpit seat) and empennage appeared intact. The horizontal and vertical stabilizers appeared undamaged. The elevators and rudder remained attached to the stabilizers, and moved freely on their hinges when examined after the accident. Elevator and rudder control continuity was confirmed from the control surfaces to the cockpit area. The engine was dislocated from its normal position and the engine mount was deformed. The propeller remained secured to the propeller flange. However, the engine crankshaft was bent approximately 30 degrees at a point aft of the propeller flange where the crankshaft exits the crankcase. The crankshaft was fractured at this location. Internal engine continuity was confirmed via crankshaft rotation. (The crankshaft was rotated from the accessory section due to the damage to the forward end of the crankshaft.) Compression was obtained on all cylinders. The magnetos were fragmented which precluded functional testing. Teardown examination of the magnetos did not reveal any anomalies consistent with a pre impact failure. The spark plugs appeared intact and exhibited signatures consistent with normal operation. The propeller spinner was crushed. One propeller blade was bent forward about 10 degrees at a point outboard of mid span. The blade appeared otherwise intact. The second propeller blade was bent aft about 45 degrees at a point near the blade root. The blade exhibited chordwise scratching, leading edge gouges, and twisting. The recording hour (Hobbs) meter indicated 169.1 hours at the time of the post accident examination. The tachometer recording hour meter indicated 131.23 hours. No anomalies consistent with a pre impact failure of the airframe or engine were observed. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy of the pilot was performed at the Hamilton County Coroner’s Office, Cincinnati, Ohio, on August 22, 2009. The pilot’s death was attributed to multiple blunt force injuries as a result of the accident. FAA Civil Aerospace Medical Institute (CAMI) toxicology testing was negative for all substances in the screening profile. TESTS AND REASEARCH The mounting bracket supporting the pilot control stick and the mating control rod were separated. Specifically, the pilot control stick bracket was deformed and fractured through a weld joint along the periphery of the bracket. Metallurgical examination of the bracket revealed welded areas with inadequate weld penetration and lack of fusion. The fracture surfaces exhibited features consistent with overstress separation. The control rod was fractured on either side of the attachment hole for the control stick. The control tube was deformed adjacent to the attachment hole. The fracture surfaces exhibited features consistent with overstress separation as a result of bending. ADDITIONAL INFORMATION Airport records indicated two fuel purchases associated with the pilot about the time of the accident. On August 12, 2009, the accident pilot bought 15 gallons of 100 low lead aviation fuel. However, there was no aircraft registration number associated with this purchase. On August 16, 2009, the pilot bought 14.86 gallons of fuel. That record noted N14BB as the aircraft fueled.

Probable Cause and Findings

The pilot's failure to maintain adequate airspeed which resulted in an aerodynamic stall.

 

Source: NTSB Aviation Accident Database

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