Aviation Accident Summaries

Aviation Accident Summary WPR17FA033

Santa Barbara, CA, USA

Aircraft #1

N188M

AIRBORNE WINDSPORTS PTY LTD EDGE XT-912-L

Analysis

The pilot of the weight-shift control aircraft uneventfully departed runway 15 and made a right turn to the crosswind leg of the traffic pattern. He then requested and was cleared for the downwind leg for the intersecting runway. While making the turn to the downwind leg, the aircraft entered a rapid descent and impacted the ground near an apartment complex. Postaccident examination of the airframe and engine revealed no anomalies that would have precluded normal operation. The crankshaft exhibited torsional twisting, consistent with the engine producing power at the time of impact. The pilot purchased the aircraft new and took delivery 4 days before the accident. Review of his logbook revealed 65 total hours of flight experience, with 12 hours in the accident aircraft make and model; however, his flight experience in the accident aircraft could not be determined. Toxicology testing on the pilot was positive for tetrahydrocannabinol (THC, the primary psychoactive component of marijuana) and tetrahydrocannabinol carboxylic acid (THC-COOH, an inactive metabolite); however, there is no established direct relationship between blood levels and impairment. Therefore, it could not be determined whether psychoactive effects from the pilot's use of marijuana contributed to the accident. Although the circumstances of the accident are consistent with a loss of control in the airport traffic pattern, the investigation was unable to determine the reason for the loss of control.

Factual Information

HISTORY OF FLIGHTOn December 6, 2016, about 1018 Pacific standard time, an Airborne Windsports PTY LTD Edge XT-912-L weight-shift control light sport aircraft, N188M, impacted terrain shortly after takeoff from Santa Barbara Municipal Airport (SBA), Santa Barbara, California. The pilot was fatally injured, and the aircraft sustained substantial damage. The aircraft was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed for the personal flight, which originated from SBA about 1016. Air traffic controllers working in the SBA tower observed the aircraft uneventfully depart runway 15 and make a right turn to the crosswind leg of the traffic pattern. The pilot then requested to enter the traffic pattern for runway 25, and the tower controller cleared the pilot to make right traffic for that runway. While turning onto the downwind leg for runway 25, the aircraft entered a rapid descent. The aircraft subsequently impacted the ground near an apartment complex. PERSONNEL INFORMATIONThe pilot, age 45, held a private pilot certificate with a rating for airplane single-engine land, issued March 14, 2013. The pilot received his endorsement for weight-shift control aircraft on June 24, 2016. The pilot's logbook indicated that he had 65 total hours of flight experience, 12 of which were in the accident aircraft make and model. He had no documented flight time in the accident aircraft. On July 27, 2015, the pilot was issued a third-class Federal Aviation Administration (FAA) airman medical certificate with no limitations. During the exam, he reported no medical conditions or use of medications; however, he had reported driving under the influence (DUI), and a conviction for marijuana cultivation more than 20 years earlier. The FAA initially denied the medical certificate because the pilot failed to show evidence of continued sobriety, but after providing the necessary evidence, the FAA issued the medical certificate. AIRCRAFT INFORMATIONThe aircraft was approved for a special airworthiness certificate on November 28, 2016. The pilot purchased the aircraft new and took delivery of it 4 days before the accident. AIRPORT INFORMATIONThe aircraft was approved for a special airworthiness certificate on November 28, 2016. The pilot purchased the aircraft new and took delivery of it 4 days before the accident. WRECKAGE AND IMPACT INFORMATIONThe aircraft impacted terrain in a residential area about 1 mile northwest of SBA. The first identified point of impact was the roof of a carport; beneath the carport were fragments of the fuselage and items from the cabin area. To the north of the carport was one fracture-separated propeller blade. Immediately adjacent and to the west of the carport was a small tree. A branch of the tree came to rest on an unoccupied parked car next to the carport; another tree branch was stuck in the aircraft's down tubes and control bar. Fragments of landing gear and roofing shingles were scattered until the main wreckage, which was about 30 ft west of the carport. The main wreckage came to rest against a vehicle, with the seat and engine of the aircraft on their right sides. The wing was bent in half and was resting above the engine and seat with the trailing edge toward the ground. The right side of the wing was bent downward and was draped across two unoccupied parked vehicles. During a postaccident examination, the propeller hub would not rotate freely when rotated by hand; therefore, the engine was completely disassembled. The intake manifolds, carburetors, ignition systems, and oil pump were removed and no anomalies were noted. The reduction drive gearbox was removed and undamaged; the magnetic plug was clear of debris. The valve covers were removed; the rocker arms and valve springs exhibited normal operating wear signatures. The cylinder heads, pistons, and hydraulic tappet lifters were removed and exhibited normal operating wear signatures. The crankcase was separated into its respective halves. The crankshaft would still not rotate by hand. The crankshaft's #3 piston web was not aligned with the #2 piston web, consistent with torsional damage. MEDICAL AND PATHOLOGICAL INFORMATIONThe Santa Barbara County Sheriff - Coroner, Santa Barbara, California, performed an autopsy of the pilot; the cause of death was multiple traumatic injuries. No significant natural disease was identified. The corner requested that NMS Laboratories perform toxicology testing, which identified caffeine, 3.1 ng/ml of tetrahydrocannabinol (THC, the primary psychoactive component of marijuana), and 6.5 ng/ml of tetrahydrocannabinol carboxylic acid (THC-COOH, an inactive metabolite) in subclavian blood. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing as well and identified 4.5 ng/ml of THC and 5.5 ng/ml of THC-COOH in cavity blood. THC-COOH was also identified in urine (67.9 ng/ml) and liver tissue (40.1 ng/gm).

Probable Cause and Findings

The pilot's failure to maintain aircraft control while maneuvering in the traffic pattern.

 

Source: NTSB Aviation Accident Database

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