On October 26, 2004, about 1540 eastern daylight time, a homebuilt Zenith CH 601HDS, N166DK, was destroyed when it impacted a machine shop in Leominster, Massachusetts, shortly after takeoff from Fitchburg Municipal Airport (FIT), Fitchburg, Massachusetts. The certificated airline transport pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan had been filed for local flight test, conducted under 14 CFR Part 91. According to a Federal Aviation Administration (FAA) inspector, the accident occurred during the airplane's first flight. The inspector also reported that the pilot had previously flight tested many other homebuilt airplanes. According to the owner/builder of the airplane, both he and the pilot conducted a thorough preflight, and the pilot subsequently started the airplane per the start-up checklist, with the owner/builder looking over his shoulder. The owner then reminded the pilot to remove the Ballistic Recovery System (BRS) safety pin prior to takeoff, and to double check the trim indications. The pilot then taxied to runway 32, and announced over the radio that he'd hold in the run-up area to allow the engine to warm up. About that time, the owner/builder reminded the pilot again, via hand-held radio, to double check the trim indications and make sure the BRS safety pin was removed. The pilot then taxied the airplane onto runway 32, announced his intentions, and stated that it was the airplane's first flight. The owner/builder observed the first part of the takeoff roll to be "completely normal, and there was no side-to-side motion of the aircraft and a rapid acceleration as he brought in full power." The engine sounded "smooth with no misfires or strange noises." As soon as the airplane lifted off the runway, it climbed to approximately 40-50 feet, while simultaneously veering to the left. It appeared that the pilot was "fighting for control" as the airplane "veered slightly back towards the runway." There may have been a reduction of engine power, but the owner/builder was not sure. The airplane then veered back towards the left, toward a tree line. As it approached the tree line, the engine noise grew "noticeably louder," and the airplane went into a "very nose-high attitude." The airplane "appeared to hang on the prop as it was pulled up and over [the] trees;" however, no stall occurred, and the engine "appeared to be working without any issue." The owner/builder further noted that the airplane had remained "very low, well below the minimum for BRS deployment." In addition, "there were no external signs of what the problem was. Nothing departed the aircraft or appeared outside to be abnormal." The owner/builder also stated: "My overall perceptions are that he was having a control issue from the moment the aircraft left the ground. At no point in the flight did he appear to have complete control; with a steady flight path." According to another witness, a certificated flight instructor, he saw the accident airplane after it took off, and initially saw it 20-50 feet above the runway, near runway centerline, "but apparently experiencing what [he] believed was a stability or control problem." He saw the airplane "oscillating (porpoising?) in pitch, wings approximately level." The pilot then appeared to gain pitch control, and the airplane began a climbing left turn about 90 degrees from the runway heading, toward a tree line. The airplane then descended below and beyond the tree line, but subsequently came back up above it, and made another left turn back toward the airport. Then the airplane "banked steeply left, pitched down, and went into the trees in a steep nose-down and banked attitude (possibly stalled)." According to the FAA inspector, because the airplane was consumed in an "intense post-impact fire," a detailed examination of the wreckage could not be made. In an additional statement, the owner/builder discussed possible sources of instability, which included: - The Zenith was a "small, light aircraft", less than 1,057 pounds at the time of takeoff. High torque and P-factor would pull it to the left with the engine at takeoff rpm. - The airplane was equipped with small, almost flush MAC trim buttons on a MAC stick grip, that could inadvertently be activated without "feeling" it. The owner also reported that the "pilot's aggressive move to clear trees displayed both excellent piloting skills and a level of controllability in all axes, which further confuses finding a source of instability for me." The pilot held an airline transport pilot certificate for multi-engine airplanes. He also held a commercial pilot certificate for single engine land and sea airplanes, multi-engine sea airplanes, and gliders. According to his application for his latest FAA second class medical certificate, dated March 5, 2004, the pilot had accrued 5,250 hours of flight time. An autopsy was performed by the Commonwealth of Massachusetts, Office of the Chief Medical Examiner, Boston, Massachusetts. Toxicological testing was performed at the Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. Weather at Fitchburg Airport, recorded at 1552, included clear skies, winds from 310 degrees true, variable between 290 degrees and 010 degrees true, at 9 knots.