Mitsubishi MU-2B | N635TA

DTSB: The DTSB determines the Probable Cause of this accident to be Pilot Error, in that the accident pilot attempted to operate a very complex multi-engine turboprop aircraft as single pilot in IMC conditions, and lacked the necessary high workload IFR aircraft experience as well as avionics systems knowledge and experience, eventually losing speed awareness while maneuvering in IMC conditions. The accident pilot attempted an IFR GPS approach to runway 03 at airport 1B1, but was established on the course very late, remaining well west of the final approach course initially. ADS-b derived speed shown was both slow and variable, and altitude control was not consistent with a stabilized IFR approach. The pilot did declare a missed approach with ATC and turned 90 degrees to the right (to the southeast). The aircraft was likely on autopilot in both heading and altitude hold mode as it flew a perfect straight line, and constant altitude to the southeast. Upon turning back to the west, the aircraft was likely being hand flown as the altitude and speed decayed, and the pilot likely pulled up and to the right in order to re establish previous altitude lost. The subsequent high rate of descent crash occurred immediately after the turn back to the west, and was captured on witness video. The witness video clearly shows the accident aircraft all together, and no smoke or fire visible, but descending nearly vertical to the earth in an obvious full aerodynamic stall. The total elapsed time from the missed approach to the crash was approximately 3:00 minutes. For unknown reasons, the accident pilot did allow his indicated airspeed to decay rapidly while in a turn, entering flight well below DMMS, and the aircraft entered an aerodynamic full stall at an altitude from which recovery was not possible. The pilot was a well known neurosurgeon and neuroscientist. The aircraft had recently been updated to an all new Garmin avionics panel. The Probable Cause of this accident is Loss of Speed Awareness, and is related to a very typical aircraft accident scenario of “too much airplane, and not enough pilot.”

NTSB: NONE

DTSB: The DTSB recommends that all pilots of all aircraft avoid flight into IMC conditions in complex, challenging, high workload aircraft where experience and knowledge requirements are greater than those available.

NTSB: NONE