HISTORY OF FLIGHTOn August 11, 2018, about 0855 mountain daylight time, an experimental amateur-built Hornet airplane, N218B, impacted terrain during takeoff from St. George Regional Airport, St. George, Utah. The pilot was fatally injured, and the airplane sustained substantial damage. The airplane was registered to the Western Sky Aviation Warbird Museum Inc. and was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. Video from a security camera at the airport showed the airplane taxiing toward the end of the runway, and then the airplane was no longer in the camera's view. Shortly thereafter, the airplane came back into the camera's view and was seen just above the runway surface in a nearly wings vertical, nose low attitude just before impact with the ground. The airplane's owner reported that, just before the accident, a gust of wind "came out of nowhere" that shook the building in which he was located. First responders reported that, when they arrived on scene about 10 minutes after the accident, the engine was still running. PERSONNEL INFORMATIONThe owner of the airplane reported that the pilot "was heavily involved" with the accident airplane, was "very meticulous" about maintenance and safety, and ensured that the airplane operated "as optimally as possible." The airplane owner also stated that the pilot had accumulated "thousands" of flight hours, some of which included light airplanes that were heavier than the accident airplane. The airplane owner estimated that the pilot had accumulated a total of about 5 flight hours in the accident airplane. Since the airplane was new, the pilot taxied the airplane around "quite a bit" and flew it only when the wind was calm to ensure that he could understand the airplane and its handling characteristics. AIRCRAFT INFORMATIONAccording to the airplane's owner, the airplane was built by its previous owner, who did not fly or certify the airplane. The previous owner subsequently donated the airplane to the Western Sky Aviation Warbird Museum, and the museum certified, operated, and maintained the airplane. At the time of the accident, the airplane had accumulated 17 hours total time. METEOROLOGICAL INFORMATIONAt the time of the accident, the wind direction was perpendicular to the departure runway with a reported wind speed of 8 knots. No gusts were recorded. The owner of the airplane mentioned that "random gusts of wind" similar to the gust just before the accident were relatively common at the airport due to the surrounding desert terrain. AIRPORT INFORMATIONAccording to the airplane's owner, the airplane was built by its previous owner, who did not fly or certify the airplane. The previous owner subsequently donated the airplane to the Western Sky Aviation Warbird Museum, and the museum certified, operated, and maintained the airplane. At the time of the accident, the airplane had accumulated 17 hours total time. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest in the dirt about 35 ft from the edge of the runway surface. The nosewheel was separated due to fracture, and the airplane came to rest in a nose-down attitude. The forward fuselage was bent toward the left. Both the left and right wings exhibited upward crush damage to the wingtips, and the tail was mostly undamaged. The cabin and fuselage structure were twisted, and its fabric was ripped in various locations. Flight control continuity was established throughout the airframe. Postaccident examination of the airframe revealed no anomalies that would have precluded normal operation. MEDICAL AND PATHOLOGICAL INFORMATIONThe Utah Department of Health, Office of the Medical Examiner, Taylorsville, Utah, performed an autopsy of the pilot. His cause of death was blunt force injuries. Toxicological testing performed by the Federal Aviation Administration Forensic Sciences Laboratory identified ibuprofen in the pilot's urine specimens; venlafaxine (and its active metabolite desmethylvenlafaxine), fexofenadine, and tamsulosin in the pilot's blood and liver specimens; and azacyclonol (a metabolite of fexofenadine) in the pilot's liver specimens. No ethanol or carbon monoxide were found in the pilot's specimens. Venlafaxine (commonly marketed as Effexor) is an antidepressant used to treat depression, anxiety, and panic disorders and has some off-label use for chronic pain management. Side effects can include dizziness and drowsiness, and cautions are specified about operating heavy machinery or performing other hazardous tasks while taking this medicine. Venlafaxine is a medically disqualifying medication for pilots. Fexofenadine (commonly marketed as Allegra) is an over the counter nonsedating antihistamine used to treat seasonal allergy symptoms. Tamsulosin (commonly marketed as Flomax) is a nonsedating medication used to treat an enlarged prostate. Ibuprofen is a nonsteroidal anti-inflammatory drug used to relieve pain and swelling.