Beechcraft F33 N3156W

The pilot departed on a visual flight rules cross-country flight in daylight marginal visual flight rules conditions. Flight track and weather radar data indicated that, about 15 minutes after departure, the airplane made a 360° decreasing radius left turn after encountering increasing rain showers and possible cloud layers. After the turn, the ground track became erratic as the airplane descended and its groundspeed varied between 150 and 34 knots, before it struck trees and impacted a field. All major components of the airplane were located in the vicinity of the main wreckage. Examination of the wreckage revealed no major malfunctions with the airplane that would have precluded normal operation prior to the accident. The pilot requested a preflight weather briefing along the intended route of flight for both the afternoon of the accident and the following day from flight service. The briefer stated that the forecast conditions for the following day included thunderstorms, rain showers, low ceilings, and reduced visibility; and that forecast conditions for the accident day included a convective SIGMET warning of instrument metrological conditions, heavy precipitation, and severe turbulence. The briefer advised that although reported observations indicated visual flight rules conditions at the surface, thunderstorms and rain showers were already present in the area, and visual flight rules flight was not recommended. The pilot stated that he would probably depart that afternoon because weather would be worse the following day and shared that his own review of weather showed “everything is VFR as we speak.” The briefer confirmed no instrument conditions at the surface existed but cautioned that cloud layers were “getting pretty close” and areas along the route may drop to instrument conditions due to precipitation. The pilot said he could avoid the precipitation unless he encountered a solid line of thunderstorms. He added, “If I’m going VFR I’m going this afternoon, unless I got clouds that are getting low enough that I can’t fly… and I haven’t heard anything to tell me that.” In response the briefer offered a recent weather observation from Mobile Alabama (about 25 miles west of the intended route of flight) showing visibility of 1.5 miles in heavy rain and mist, and advised the pilot that areas along the route of flight experiencing rain showers or thunderstorms may have visibility or ceilings reduced to instrument meteorological conditions, as it did in Mobile. The pilot and briefer then discussed where the precipitation was occurring, and the location covered by the convective SIGMETs before concluding the call. In the pilot’s conversation with the briefer, he expressed a sense of urgency to depart for the flight to a destination 267 nm away under less-than-optimal conditions because conditions were forecast to be worse the next day; and evidence indicates that the pilot had a meeting near the destination the day after the accident. As a noninstrument-rated pilot, his decision to conduct a flight into deteriorating weather conditions that included heavy rain showers and likely cloud layers, would have made him vulnerable to the development of spatial disorientation as he encountered areas of restricted visibility. Flight track data in the final moments show altitude and airspeed variations, an erratic flightpath, and a decreasing radius 360° turn, which are characteristic of the known effects of spatial disorientation.

Quoted verbatim from the NTSB record.