Columbia Aircraft Mfg LC41 N2536T accident near Woburn, Massachusetts

Probable cause

The pilots' loss of control during an instrument approach in instrument meteorological conditions as a result of spatial disorientation.

NTSB analysis

The instrument-rated pilot and one passenger were approaching the destination airport following an instrument flight rules cross-country flight in instrument meteorological conditions; the reported weather at the destination included ceilings between 400 and 600 ft above ground level and visibility of 2 miles in mist. The controller cleared the airplane for the instrument landing system (ILS) approach; the pilot intercepted the localizer and immediately descended below the minimum altitude he was required to maintain prior to crossing the final approach fix (FAF). The controller issued a low altitude alert as the airplane was crossing the FAF about 700 ft below the minimum altitude. The pilot responded that he was climbing; he did not report any problems or issues with his airplane to the controller. The airplane then drifted right of the localizer course and the controller advised the pilot of such, but there was no response. The airplane subsequently proceeded left of the localizer course, after which the controller issued another low altitude alert and asked the pilot if he was still on the approach. The pilot responded that he was not on the approach and that he was "pulling." During the final minute of the flight, the airplane was observed in rapid, turning climbs and descents until radar contact was lost.

The airplane impacted terrain about 4.2 miles east-southeast of the airport. Accident site evidence and impact damage to the airplane were indicative of a high-velocity impact. Examination of the wreckage revealed no evidence of any preimpact mechanical anomalies, and analysis of a video doorbell that captured audio of the airplane in flight revealed an engine speed consistent with high power.

The reduced visibility conditions present at the time of the accident and the high workload associated with the instrument approach were conducive to the onset of pilot spatial disorientation, and the airplane's erratic maneuvering and the high-energy impact are both consistent with the known effects of spatial disorientation. Therefore, it is likely that the pilot became spatially disoriented during the instrument approach, which resulted in a loss of airplane control.

Text from the NTSB. Open the NTSB docket for ERA18FA251 for the full record.