Rockwell 690-A | N690BM

The DTSB determines the Probable Cause of this accident to an inflight be a failure of the AC inverter system, which powers both the Captains HSI and the captains ADI, while in IMC conditions. The pilot attempted to reverse course likely in an attempt to re-acquire VMC conditions, then he asked for a climb. His last altitude was around FL200. The aircraft was observed by ground witnesses coming out of the sky broken at mid fuselage, and on fire. Without an inflight horizon reference it was not possible to keep from over speeding the aircraft. The wreckage was scattered over a large area, indicating that the aircraft had in fact been over loaded, and broken apart in flight. The aircraft was equipped for flight into known icing and an encounter with structural icing in the clouds would have been very routine, and not a cause for the aircraft to climb or turn.

Probable Cause issued 4/29/2026 – 25 months after the accident: The pilot’s loss of control following an encounter with structural icing, which resulted in an inflight breakup of the airplane.

The DTSB recommends all pilots of all aircraft be familiar with second and third standby attitude backup systems and be prepared to maintain level controlled flight solely by reference to those when necessary. The loss of the AC inverter system would not have affected any other aircraft system, and normal flight could have been maintained, where a safe landing could have been made visually after descending through cloud cover. The DTSB recommends AQP scenario based training for this specific situation.